# Polar Lights TOS Enterprise Warp Engine Fan Motorss



## Alien (Sep 5, 2001)

Hi Guys,

I have finally stumped up the cash and ordered a Classic Enterprise.
They are expensive to get here to New Zealand. Postage is a killer!!

Any how, I have seen many YouTube videos of completed and in progress models and the one thing that bothers me is the Lighting Kit.
The LED lights are OK but the noise that the supplied geared motors make spinning the 'fans' in the warp engines seems very loud and annoying.

I have opted not to buy the lighting kit and to do it myself. (Yes I know I will have to construct a few bits and pieces.)

I plan to use stepper motors to spin the fan blades. Stepper motors can connect to the blades directly and do not use noisy gears. Yeah! 

I have purchased a few mini stepper motors and built a small bit of electronics to spin them... All good so far! And yes, one of them is spinning silently on my workbench as I type.:thumbsup:

But how fast do they spin?? I guess I could watch the series on DVD and calculate it but I thought that I would ask the question here. (And I am lazy.)

How fast do the Polar Lights motors spin the fans?
Does this speed look OK to the critical Star Trek eye? (Especially on the completed model.)

Anyone else used stepper motors in this way?? Any traps, ideas, suggestions??

Alien


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## Mark2000 (Oct 13, 2013)

My solution was to connect the motors to a potentiometer and an external knob. That way I can change the speed (and in my case the noise level) any time. The show's fans changed speed and direction from scene to scene so there is no one way. If you have the pot you can just eye it.


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## RossW (Jan 12, 2000)

I'm also doing my own lighting solution for the kit but I've yet to find motors that are quiet enough. The Saumya's are cheap and less noisy than PL's, but still too loud. Based on a suggestion on another board I've bought some more expensive swiss ones but haven't done a decibel comparison yet.

You should check out Trekriffic's build as he moved the motors back into the nacelle and wrapped them in pipe insulation. He connected the motor to the spinning half dome with a typical RC configuration (I believe).

As for speed, I'm also building in speed control but via PWM which is supposed to be better for controlling DC motors than a potentiometer (which changes the voltage delivered to the motor) since it provides constant voltage but turns it off/on very quickly to achieve the desired duty cycle. You can see my prototype board here:






I'm very interested in your approach with stepper motors. Do you think you can achieve smooth rotation? Please keep us updated with your progress.


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## steve123 (Feb 9, 2009)

(The internet can raise a big ruckus) The motors do make noise. I described it to the two clients I built them for as the sound an HO slot car makes going slowly. Life isn't perfect. The light kit needs some tweaking when you install it, but it's still easier than making your own. This is a big wonderful kit.

Steve


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## steve123 (Feb 9, 2009)

I forgot to add that when you run small electric motors at very slow speeds you can get carbon build up in the brushes. Try to make the motors servicable if you are going to step them down...


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## Fozzie (May 25, 2009)

I thought about using stepper motors myself because they can be virtually silent. If I were to build a 2nd one (doubtful!), I would definitely look into using stepper motors.


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## Alien (Sep 5, 2001)

Nice work RossW,

You can't beat a slab of breadboard and some PIC micro controllers. :thumbsup:
And yes, PWM is certainly the way to go for controlling DC motors. 
Do the motors that you are using have a gearbox or are you connecting the domes directly to the shafts?? No gearboxes would certainly mean less noise as long as you can get a slow enough rotational speed with the PWM control.

I think your prototype looks very good. The warp engines look excellent.

I am also using a PIC to drive my stepper motors (With a L293D motor driver chip. Probably what you are using too?)
I am micro-stepping the steppers so the rotation is pretty smooth.
I just have to do some mechanical work on the motors. They came with a cog wheel attached to the shaft. I have to remove that and make up an extension shaft to fit on it. Luckily I have a little lathe.

Good tip about the motor brushes Steve. Serviceability is the key with anything mechanical, especially motors. That is also one of the reasons I am looking at stepper motors. No brushes!

Alien


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## RossW (Jan 12, 2000)

Thanks Alien! I'm using a SN754410 motor driver and it seems to work great. The nice thing about this setup is I can switch the direction of the port engine without having to change any connections (one input for each motor controls the direction; then the PWM value is flipped to (255 - x)).

My motors have metal gears built-in; they're hidden within the housing. But I plan on connecting the motor shaft to the spinning dome in a similar way as Trekriffic did on his.

What stepper motors are you using? I'd like to experiment to see the difference.

EDIT: Steve123 - I agree about both the PL model and their lighting kit. They are excellent and extremely well thought out. I just want more control and additional features, plus I love doing my own lighting stuff.


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## Alien (Sep 5, 2001)

RossW, the SN754410 is pin for pin identical to the L293D that I am using. (Just made by a different manufacturer.)

I searched around for quite sometime for mini steppers: 

There are lots of BIG ones: Too big and heavy. (Warp engine droop!)
Teeny tiny micro ones: Used in cameras to drive the zoom lens, but would blow away if you sneezed on them. 
Ones designed for Arduino micro controller users: But the shaft is offset from the middle of the motor (Because of internal gearing I guess.) and that I didn't think it would fit in the nacelle.

But I managed to find:
Jtron Mini 15mm Two-Phase Four-Wire Stepper Motors
US$5.73 for five of them. 
Here is the link: 
http://www.dx.com/p/jtron-mini-15mm-two-phase-four-wire-stepper-motor-sliver-5-pcs-269595#.U0BcnaiSx_Q

They seem to be more than powerful enough to spin the dome with the fan blades.
I couldn't find a voltage rating for them but they do run on 5 volts but get a bit warm. I currently have a 33 ohm resistor in series with each coil and they still have plenty of torque and now run cool.
I will revise that resistor value when I get the real domes to spin when my Enterprise kit arrives. (Not at warp speed.)

And I am definitely with you, I too like to do my own lighting. Nothing wrong with lighting kits on the market but I get as much satisfaction soldering up some LED's and controllers as I do gluing, sanding, painting and decaling a kit.

And you do have to give a round of applause to Polar Lights/Round 2 for creating an entire lighting unit (With motors!) that anyone can fit without having to a be a solder monkey.:thumbsup:

Alien


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## RossW (Jan 12, 2000)

Those are out-of-stock at the moment, but I'll keep checking back.

I found these at Pololu but they're very pricey: http://www.pololu.com/product/2294

EDIT: I found yours at AliExpress (http://www.aliexpress.com/snapshot/6057328993.html). Ordered a set of 5 for $6.


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## Alien (Sep 5, 2001)

My other favorite website, aliexpress.com, also has them. 
http://www.aliexpress.com/store/product/Jtron-Mini-15mm-Two-Phase-Four-Wire-Stepper-Motor-Silver-5-PCS/1038287_1623922507.html
US$6 for 5 units. Won't break the bank!

Alien


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## RossW (Jan 12, 2000)

Alien - I've only ever programmed DC gear motors with PICs. For stepper motors, how do I control the speed of rotation? If the L293D is identical to my SN755410, do I also control the motor direction in a similar manner? Also, if you have a circuit diagram with your L293DI'd appreciate seeing that.


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## Alien (Sep 5, 2001)

Ross,

Here is an image of the driver circuit that I am using with the L293D. 
You can just use your SN754410 instead.









As you can see, the driver chip that can normally drive two DC motors is used to drive the two coils in a single bipolar stepper motor.

I have added the two 33 ohm resistors, that I am currently using, to the circuit diagram. (They may get replaced later when I get my Enterprise kit and connect the real domes that it will be spinning.) Why did I use 33ohms? I just found some in my resistor stash and they did the job. Nothing scientific.

And there is also a 100mfd capacitor as the load from motor on the power supply interfered with the PIC operation.

I have labeled the inputs to the motor driver chip to correspond to the GPIO ports on a PIC. 
Note: If you are using the smaller PICs then GP3 is always an input so you will have to use another IO pin connect to the driver chip.

Once you are all connected up, you need the PIC to drive its output pins in a certain sequence in order to get the motor to spin.

Here is some Assembler.
You would also need a DELAY subroutine to call. A delay of 100ms is a good place to start. The longer the delay, the slower the motor will rotate, and vice versa.
The code below assumes the motor driver is connected to GP0,1,2,3 as in the circuit diagram.


Start
movlw	b'000001'
movwf GPIO
CALL	DELAY 
movlw	b'000101'
movwf GPIO
CALL	DELAY
movlw	b'000100'
movwf GPIO
CALL	DELAY
movlw	b'000110'
movwf GPIO
CALL	DELAY
movlw	b'000010'
movwf GPIO
CALL	DELAY
movlw	b'001010'
movwf GPIO
CALL	DELAY 
movlw	b'001000'
movwf GPIO
CALL	DELAY 
movlw	b'001001'
movwf GPIO
CALL	DELAY 
Goto Start

This code will half step the Stepper motor. (I mistakenly wrote micro stepping in my previous post.. Sorry.)

To reverse the rotation you just energize the outputs in the reverse order than in my program.

Have a look at this webpage, it contains a lot of good Stepper information.
http://www.nmbtc.com/step-motors/engineering/full-half-and-microstepping.html

Hope all this helps.

Alien


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## b26354 (Apr 11, 2007)

I cheated and bought one of these:

http://www.ebay.com/itm/New-Stepper-Motor-Driver-Controller-Board-Speed-Adjustable-with-Remote-Control-/271266051637

and a bunch of 8mm diameter stepper motors. 

They get kind of hot but some current limiting resistors in series with the coils should sort that out.

Alien, where in NZ are you BTW?


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## Alien (Sep 5, 2001)

b26354,
Another Kiwi on the boards!! Great to see.:thumbsup:

Those controller boards look fantastic. Great price! 
I certainly don't think that you are cheating!
It has an Atmel chip doing all the work. It is a similar micro controller to the PIC chips that RossW and I are using, just a different brand.
If you add the current limiting resistors to the stepper motor coils you could probably drive two motors off the one controller.

I live in Wellington city. Where William, Kate and baby George are suffering very rainy weather on their royal visit.

Where abouts are you??
Also, have you brought the Polar Lights Enterprise kit??
If so where did you get it and how much was it??
My local hobby shop could only get it for about $340. I managed to order one from fishpond.co.nz for $223 and that is shipping direct from the US. Freight charges are the real killer on this for us in godzone. (And obviously the local distributor mark up.)

Alien


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## RossW (Jan 12, 2000)

Thanks Alien! So if I need to drive two motors (opposite rotation), I need 2xSN755410's? And 8 output pins?

BTW, I've driven through Wellington but spent most of my time in NZ in Christchurch (plus Auckland & Milford Sound). One of my favourite places on Earth.


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## Alien (Sep 5, 2001)

Ross,

That would be the best way to do it.
I plan to use a PIC and a motor driver chip in each of the warp nacelles. I then only have to run two wires for power up the pylons to each nacelle.
The PIC can also blink the LEDs as well as spin the motor.

You have been to New Zealand, cool!
Yes, many people just drive through Wellington on their way on and off the inter-island ferries.
You probably will not recognize Christchurch after the February 2011 earthquake. Lots of vacant sites in the CBD where buildings have been demolished.

I have been to your home town, Toronto, too. Had a great couple of weeks, even though I was there for work. The Ontario Science Center was a real highlight as was an ice hockey game. (Indoor activities were good as it was cold outside!)

Alien


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## RossW (Jan 12, 2000)

I just realized - I probably won't be able to go the stepper motor route as I only have 4 wires going to my nacelles (2 for the lights, 2 for the DC motor). I would need 6 if using a stepper motor, unless I buried my motor controller/PIC in the nacelles which I'm reluctant to do (as I won't be able to control speed/direction).

Funny, I did have 9 ribbon wires running up the pylons (which are glued together) since I was planning on having all the light/motor logic in the base. I've decided instead to do use SMD PICs on my custom nacelle discs which is why I cut down the wires to 4.

I was devastated when the Christchurch earthquake happened. One of my favourite cities - I spent a very happy 3 months there in 1987/88.


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## RossW (Jan 12, 2000)

Here's a shot of my custom nacelle discs (this is an older version, prior to changing them to put the SMD PIC onboard). I got the dimensions of the placement of the LEDs from Gary Kerr and it fits in the nacelles perfectly.


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## KUROK (Feb 2, 2004)

RossW, very cool!
Is your custom setup designed to flash such that the motors/fans are not needed to simulate the effect?


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## RossW (Jan 12, 2000)

KUROK said:


> RossW, very cool!
> Is your custom setup designed to flash such that the motors/fans are not needed to simulate the effect?


My board is similar to PL's in that there are 5 steady-on 3mm amber LEDs and 5 flashing ones of varying colours (1.8mm). The difference is that (a) the 5 flashing LEDs all have different on/off times with built-in randomization which means between the two nacelles the flashes won't be in sync, and (b) with separate wires for the motors the LEDs won't be affected by their current draw, which means they start working as soon as power is on.

I am using motors, though. I've done a solid-state approach before (I developed the Waddell Warp Board for DLM) but in my opinion you really can't replicate the strobing effect of the blades with just LEDs.


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## RossW (Jan 12, 2000)

Alien said:


> Here is some Assembler.
> You would also need a DELAY subroutine to call. A delay of 100ms is a good place to start. The longer the delay, the slower the motor will rotate, and vice versa.
> The code below assumes the motor driver is connected to GP0,1,2,3 as in the circuit diagram.
> 
> ...


I code in BASIC (actually, PicBASIC Pro) but I'm comfortable with C as well. Not so much in assembly. Any chance you have this code in some other form?

Also, I haven't been able to find technical specifications for the Jtron motor. Don't we need to know the current draw and resolution (angular rotation per pulse)?


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## J_Indy (Jan 28, 2013)

This looks like a really great idea to still have spinning motors - but can anyone confirm that the noise level is greatly reduced using these stepper motors in a state of constant spin? I've looked for vis on YouTube but they are mostly guys showing how to rotate the motor on turn, then reverse it. I haven't found one (with sound) that just shows them spinning continually in one direction.


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## RossW (Jan 12, 2000)

J_Indy said:


> This looks like a really great idea to still have spinning motors - but can anyone confirm that the noise level is greatly reduced using these stepper motors in a state of constant spin? I've looked for vis on YouTube but they are mostly guys showing how to rotate the motor on turn, then reverse it. I haven't found one (with sound) that just shows them spinning continually in one direction.


I plan on using a decibel meter to measure the various DC motors as well as this stepper to see which is quieter. The only advantage to using a stepper motor (that I can see) is if it is significantly quieter; otherwise, coding for a DC motor is fairly easy and I only need 4 wires going up the pylons (2 for the LED board, 2 for the motor).


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## MartyS (Mar 11, 2014)

I've wondered how slow you could get one of the little brushless intrunner motors used in RC helis to run? It would probably have to be a custom controller, I doubt any standard speed controller would be adjustable to a speed as slow as would be needed for the model.

I've got a few similar to this, only slightly larger diameter than the stock motors:


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## RossW (Jan 12, 2000)

Are those regular DC motors or steppers?


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## MartyS (Mar 11, 2014)

RossW said:


> Are those regular DC motors or steppers?


It's not DC, but not a stepper, it's more like a tiny 3 phase AC motor.


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## Alien (Sep 5, 2001)

Ross

Had a bit of a look at the PICBasicPro reference guide.
My assembler used instructions to turn on and off GPIO pins all in one go.
I think that in PICBasicPro you have to use the HIGH and LOW commands to turn on and off individual pins. (I could be wrong!)
But anyway:..
All we are interested in controlling are Pins 3,2,1 and 0 and lets assume we are using PORTA on the PIC.
movlw b'000001'
movwf GPIO
CALL DELAY​This sets output pins 7-1 to LOW and pin 0 to High and then calls a pause subroutine. In PICBasicPro your would use something like this:
LOW PORTA.3 'Set pin 3 to low
LOW PORTA.2 'Set pin 2 to low
LOW PORTA.1 'Set pin 1 to low
HIGH PORTA.0 'Set pin 0 to high
PAUSE 100 '100mS delay​
Then for the next half step:
LOW PORTA.3 'Set pin 3 to low
HIGH PORTA.2 'Set pin 2 to high
LOW PORTA.1 'Set pin 1 to low
HIGH PORTA.0 'Set pin 0 to high
PAUSE 100 '100mS delay​
And keep going, following the bit patterns in my assembler code.

Obviously if a pin is not changing state you don't have to use HIGH or LOW on it again but I just just wrote the above code to be a bit more obvious. (I Think!)

I love your PCB. Looks fantastic.
Where did you get that made? I am wanting to get some PCB's made for another project and am looking for recommendations of manufacturers.


I could not find any real technical info on the JTRON steppers either.
They were cheap so I just fired them up to see what happens.
You certainly want to know the step angle if you are using them to precisely move some mechanical mechanism but as we are just constantly rotating them so it doesn't matter as long as they don't jitter to much when rotating.
And you can easily control the speed of rotation by just altering the 'PAUSE' time between the steps.

And just another thought. If you mounted the PIC's and motor driver IC's in the nacelles to spin the motors and flash the LED's you could just use three wires to them. Two wires for power and another wire that has an analog voltage (Maybe supplied by a pot in the models base.) fed to an ADC input on the PICs and that is used to alter the PAUSE time to control the speed of the steppers.


J_Indy... The little stepper motors are REALLY silent. I cannot hear it when I am inches away from it. I have to pick it up, so I can feel its slight vibration, to see if it is actually spinning. 

MartyS... I would be surprised if you could get those little brushless motors spinning slow enough, as they are designed for speed. It maybe possible to slow them down with a PWM (Pulse Width Modulation) controller but you would have to do some experimenting. I reckon the reason Polar Lights went with geared motors is because they couldn't get DC motors to reliably run slow enough.

Alien


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## MartyS (Mar 11, 2014)

Alien said:


> MartyS... I would be surprised if you could get those little brushless motors spinning slow enough, as they are designed for speed. It maybe possible to slow them down with a PWM (Pulse Width Modulation) controller but you would have to do some experimenting. I reckon the reason Polar Lights went with geared motors is because they couldn't get DC motors to reliably run slow enough.


They are made to run at really high speed with enough torque to spin a fairly large rotor, but this application requires practically no torque, so the proper wave forms on the 3 leads might spin the motor that slow. I wonder if a stepper motor controller would work? When you turn the motor by hand you can barely feel the "steps", the larger versions I have you can really feel the steps.


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## b26354 (Apr 11, 2007)

I'm in Wellington too. I bought the kit from culttvman - it was US$183 including shipping which sounds about the same as yours. I thought The Hobby Stop in Kilbirnie had one but looks like it sold. They have the refit though and it's not a bad price.

I'm debating buying the new Galactica kits from the US or waiting to see what they're priced like here.

I feel bad for not supporting the local guys - but pretty much everything I buy (aside from paints) ends up being a special order - last week I tried to get 2 Revell C17 kits figuring that modern military jets might be easier to find on the shelves - but I ended up getting 1 from Auckland and 1 from Tauranga.



Alien said:


> b26354,
> Another Kiwi on the boards!! Great to see.:thumbsup:
> 
> Those controller boards look fantastic. Great price!
> ...


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## Alien (Sep 5, 2001)

b26354, 
Another Middle Earth Wellingtonian. Great.
Yes, I like to support my local hobby shops too. But sometimes you are forced to go elsewhere.
Just a heads-up for the Moebius kits. Keep an eye out on mightyape.co.nz as they often have Moebius kits at really good prices compared to the hobby shops.
They have the new original MK1 Viper in stock for NZ$39.99 http://www.mightyape.co.nz/product/Battlestar-Galactica-Original-Mark-I-Viper-Model-Kit-132-Scale-by-Moebius/21513105

Alien


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## RossW (Jan 12, 2000)

Alien said:


> Ross
> 
> Had a bit of a look at the PICBasicPro reference guide.
> My assembler used instructions to turn on and off GPIO pins all in one go.
> ...


Thanks Alien! I'm impressed you went and read up on PBP to help me out! As for turning on/off pins, you could do it with the HIGH/LOW command (only works on a specific pin) or something like this:

PORTA = %00000001 ' or PORTA = 1
PAUSE 100
PORTA = %00000101 ' or PORTA = 5
PAUSE 100

etc.

For PCBs I use Seeed Studio (yes, there are 3 e's) exclusively. I used to get some done through SparkFun's BatchPCB but it's changed and I don't think it's much cheaper. You can get a 5 or 10 quantity of a double-sided PCB for $9.60 USD (+ shipping, which is around $8 USD to Canada). It's a fairly simple process - just upload your Gerber files (I use Eagle Cadsoft for schematic design and board layout; there's a plug-in to produce the 7 required Gerber files which you then just zip up), choose some options and submit. Takes around 3 weeks to arrive from China.

http://www.seeedstudio.com/service/index.php?r=site/pcbService&gclid=CPvboPGP1r0CFYeUfgodLCQARg

I'll have to now look elsewhere for the JTRON motors - AliExpress just cancelled my order as the seller failed to ship the item by the specified date.

EDIT: Found these on ebay (http://www.ebay.com/itm/2X-New-Mini...409?pt=LH_DefaultDomain_0&hash=item1e898d8251). At 20mm they're bigger than the JTRONs but might still fit.

BTW, how are you planning to link the gear on the motor to the spinning half-dome?

And you're absolutely right about using a 3rd wire for a trim pot to control speed. I wouldn't be able to us a rotary encoder like I am now (which also has a built-in button that is used for toggling the port motor spin direction and also to reset everything to factory defaults) as that has 5 leads, but it's got me thinking ....


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## J_Indy (Jan 28, 2013)

Thanks for the info Alien - that sounds like an ideal solution then to have traditional motors but keep the noise level down.

I was wondering the same thing as RossW about attaching the inner dome to the shaft - can the gear on the shaft be removed without damaging the motor so that only the bare shaft can be mated to an extender that goes into the inner dome cylinder?


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## MartyS (Mar 11, 2014)

J_Indy said:


> I was wondering the same thing as RossW about attaching the inner dome to the shaft - can the gear on the shaft be removed without damaging the motor so that only the bare shaft can be mated to an extender that goes into the inner dome cylinder?


It can be hard, I used to do it pretty often on micro heli motors, you'll need one of these or something similar to do it without damaging the bearings in the motor:


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## Alien (Sep 5, 2001)

Ross,
I knew that there must have been a command to turn on and off multiple pins in one go. I couldn't see as it was probably right in front of my face and I am often told my eyes are just painted on!
And thanks for the PCB information. I had been looking at Seeed Studio so it is nice to hear a positive comment about them. 

Marty
That is a great set of tools. 

I managed to get the gears off my motor shafts with some kiwi-ingenuity.
I cut a slot in some thick aluminium (AKA aluminum in the US, and we pronounce it differently too.) that was wide enough to slide the motor shaft into. I suspended this, with the motor hanging by its gear, over an open bench vice. 
As my smallest punch was the exact same diameter of the motor shaft I was forced to file down a small nail and use that to punch out the shaft from the gear. (Very high tech!)
Got the gears off all five of my motors pretty easily. Only bent three nails and the aluminium is now a bit bent and mangled, but it worked and caused no damage to the motors. 
I do need a set of those punch tools Marty!

I am lucky enough to have a small modelers lathe so I will just use some K&S bass rod and drill a hole big enough to fit over the motors shaft.
I will probably just glue my rod onto the motor shaft with CA glue.

Note: You could just use tube instead of drilling out a rod. The K&S brass tube that I have does fit over the motor shaft but it is of slightly bigger diameter so you would have to be very precise in gluing it on otherwise there is going to be wobble. But you may find other tube that would fit better.

I will have to wait until the Enterprise kit arrives (Early May so I am told.) before I make the shafts for the motors. In the meantime, I will emulate Ross and make some LED's flash with a micro controller.

Alien


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## RossW (Jan 12, 2000)

MartyS said:


> It can be hard, I used to do it pretty often on micro heli motors, you'll need one of these or something similar to do it without damaging the bearings in the motor:


Marty - where do you find such a kit?


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## MartyS (Mar 11, 2014)

RossW said:


> Marty - where do you find such a kit?


I forgot to mention the picture is a link to Amazon.

That is the same kit I've got, made by Walkera, so only a few places in the US sell it.

Search for "walkera pinion puller" for that particular one.

Great planes makes one that doesn't do 1mm but does do 2mm, search for "great planes pinion gear puller".


With a few drops of tri-flow in the gearboxes the stock motors are nearly silent when out of the model, and pretty quiet when in the collectors and still off the model, but when attached the vibration throughout the model is what is creating most of the sound. 

This might be an issue with stepper motors, while the motor itself is silent, the vibration from the steps might create sound coming from the model if you don't isolate the motor somehow.


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## RossW (Jan 12, 2000)

Which is a perfect segue to this: Trekkrific's solution for isolating the motor to reduce vibration and hence noise.

I've gone through his postings to the *1/350 TOS Enterprise Building Tips and Tricks* sticky as well as his own build journal (*My 1/350 TOS Enterprise Build --Why not? WIP*) to pull out these relevant items:

http://www.hobbytalk.com/bbs1/showthread.php?p=4512272&highlight=Tips#post4512272

http://www.hobbytalk.com/bbs1/showthread.php?p=4512281&highlight=Tips#post4512281

http://www.hobbytalk.com/bbs1/showthread.php?p=4512806&highlight=Tips#post4512806

http://www.hobbytalk.com/bbs1/showthread.php?p=4512812&highlight=Tips#post4512812

http://www.hobbytalk.com/bbs1/showthread.php?p=4573084&highlight=Tips#post4573084

http://www.hobbytalk.com/bbs1/showpost.php?p=4555580&postcount=229

http://www.hobbytalk.com/bbs1/showpost.php?p=4522026&postcount=6

http://www.hobbytalk.com/bbs1/showpost.php?p=4553995&postcount=223

(That's a lot of info, I know, but I wanted to be complete).

I'd be very interested to hear what you and Alien think. I've no background with motors - this is the first application in a model for me, not to mention controlling them with a PIC.

EDIT: I should've given props to JHauser for coming up with this solution that Trekkrific detailed for his build.


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## Trekkriffic (Mar 20, 2007)

RossW said:


> Which is a perfect segue to this: Trekkrific's solution for isolating the motor to reduce vibration and hence noise.
> 
> I've gone through his postings to the *1/350 TOS Enterprise Building Tips and Tricks* sticky as well as his own build journal (*My 1/350 TOS Enterprise Build --Why not? WIP*) to pull out these relevant items:
> 
> ...


For those who are interested in trying this approach (JHauser came up with it by the way so I can't claim credit for it) there are a couple of things I discovered later that were not mentioned in the postings Ross linked to above ...

When I first powered up the motor inside the foam sleeving with the completed bussard spinner shaft and silicon tubing in place inside the nacelle I found out that there is just enough torque to turn the motor instead of the shaft inside of the sleeve. Obviously, not a good thing. I fixed that issue by wrapping the motor with double sided scotch tape. The tape really sticks to the foam and prevented it from turning. 

Squirt some 3-in-1 household oil inside of the tunnel to give the bearings some lubrication. The oil will help prevent the bearings from squeaking which I had a small problem with. I already had the bearings in place with plastic washers glued to the front and back of the bussard housing to prevent them from falling out so I ended up drilling a small hole thru the wall of the shaft tunnel between the bearings. Then I squirted the oil into the tunnel and flipped the nacelle back and forth so it ran to either end and lubed the bearings. I've had no issues with squeaky bearings since then. 

Also, it's important to make sure the motor shaft and spinner shaft are perfectly aligned. You don't want any bend in the silicon tubing.


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## Alien (Sep 5, 2001)

Great links thanks.

On the stepper motor front...... As I haven't received my Enterprise kit I can comment on how loud the stepper motors will be when installed in the nacelles but........

I programmed my PIC micro controller to spin the motors at about the right speed. (That ended up being a 25mS pause between steps for those playing along at home.)

I then made a noise amplifier. Sounds high tech but just look at the photo and please don't judge me.









Yes it is just a large paper tea/coffee cup with a hole cut in the bottom and the motor double sided sticky taped on.

I feel a bit like the HMV logo with the dog looking down the gramophone.:drunk:

Anyhow, the cup amplified the sound of the motor HUGELY. But saying that it was still really quiet and I had to listen very quite hard to hear it a few meters a away. 
When it is installed in the nacelle, and not an open ended cup, it should be even quieter. A bit of foam will also help if needed.

Alien


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## MartyS (Mar 11, 2014)

Love the amplifier. :thumbsup:

That should give you some idea, maybe try a plastic cup, something more stiff than paper would be closer to the model.


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## Alien (Sep 5, 2001)

My Enterprise kit arrived yesterday.
I am one happy Alien. 

Now I just need to find some time to build it. 

But I had a crack at the warp nacelles in relation to fitting the little stepper motors.
I am lucky enough to have a wee lathe so I used it to bore out the end caps so the stepper motors would fit snugly in. There was just enough plastic to do this.








The slot is there so the connections of the motor can fit in.

I then turned up a little extension shaft out of brass and attached that to the motor shaft.









And the clear kit part fits perfectly.









All spins very well when it is all assembled..

Onwards and upwards..

Alien


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## RossW (Jan 12, 2000)

Great start, Alien. Since there are screws in the face plate of the stepper motor, I don't think you really need to worry about the PL motor support channel (the one you cut the slot for the wires), do you? Also, are you going to put some kind of rubber or silicone between the motor and the plastic? That might help to keep the noise down.

Once assembled, it would be great to see a video so we can hear the motor noise level.


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## Alien (Sep 5, 2001)

Hi Ross,

I could mount the motors from the rear of the part (#41) but then I would have to cut away the tubular section and be very very careful in mounting the motor at the exact center. Probably would of had to make a styrene disc to glue in and mount the motor to that.

As the motor is perfectly round, and there was enough plastic around part #47, this seemed a bit easier and more accurate.

I have not connected up a motor mounted in a nacelle as yet so I can't comment on the noise level. That is my next task.
The motor that I have connected to my test circuit will have to be reconnected so its wires so it will fit through part #41. Didn't have time to do that. (I was too busy basking in my motor/rotor/nacelle cap fitting glory.)

But like The Terminator, I'll be back.

Alien


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## RossW (Jan 12, 2000)

I'll be waiting with bated breath!


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## Alien (Sep 5, 2001)

Well, I trimmed up a nacelle so I could tape it together with the stepper motor mounted inside to see what the noise level was like.
It is incredibly quiet, especially when the front engine dome is in place.

I tried to record the actual noise, but try as I might my phone just recorded background noise and the actual motor noise was inaudible, no matter how loud I turned up the recording on my PCs big speakers.

So yes it is very quiet. It is certainly audible when you get close but I reckon when the nacelles holes are all sealed up with the appropriate parts it will be even quieter.

One thing that I found was I had to replace the 33 ohm resistors with 12 ohm ones in series with the Jtron motor coils. The motor did not quite have enough torque to spin my brass shaft, with the spinner attached, reliably.
It has been running for an hour and everything nice and cool.

Onwards and upwards... Warp factor 7.

Alien


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## Alien (Sep 5, 2001)

I came across an interesting device that may be of interest to those people considering using stepper motors for the Enterprise engines, or other projects.

Take a look at:http://www.pololu.com/product/1182
These little modules will allow you to control a stepper motor (Rather than using a L293D or SN754410 motor driver chip.) and they give you the ability to micro step the stepper motor for extremely smooth rotation.
These modules are designed for use in 3D printers that require very precise fine movements.

You still need something to send pulses to this module, to step the motor, but that could be a micro controller or even just a simple 555 timer circuit.

You can even find a better price on sites like: http://www.aliexpress.com searching on 'A4988' 

This seems to be quite a good cost effective solution and if you want to micro step your stepper motor as it would be much easier than programming up a micro controller to do it.

I have not tried these modules, but I intend to order up a couple and see what they are like.

Alien


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## teslabe (Oct 20, 2007)

Alien said:


> I came across an interesting device that may be of interest to those people considering using stepper motors for the Enterprise engines, or other projects.
> 
> Take a look at:http://www.pololu.com/product/1182
> These little modules will allow you to control a stepper motor (Rather than using a L293D or SN754410 motor driver chip.) and they give you the ability to micro step the stepper motor for extremely smooth rotation.
> ...


Very good suggestion, I use them in all my builds that have stepper motors in them. 
Here is a photo of two stacked ontop of an Arduino Pro-mini controller and here is a short video of them running the two motors for my JJ-Prise.


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## RossW (Jan 12, 2000)

Alien - thanks for the info! I've ordered some from AliExpress. I'm assuming that if you use this stepper motor driver you don't need to worry about the resistors as long as you know the motor's operating voltage and you determine the current limiting setting on the driver? BTW, I found this link on Pololu's forum to get people started on the A4988:

http://forum.pololu.com/viewtopic.php?f=15&t=3428

teslabe - could you share your Arduino sketch for controlling motors? I'm going to try using stepper motors as well but I want to:


Counter-rotate the 2 motors (port & starboard)
Control the speed via a quad encoder (or even a trim pot)
Ramp up the speed of the motors to the set value when power is turned on
These are all things I can do currently with my DC motors but the noise level is unacceptable.

I'd also appreciate any info you can share re: stepper motor selection and how you connected the motor to the PE vanes. Also, is your video indicative of the noise the motors make? Seems pretty quiet to me.


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## Alien (Sep 5, 2001)

Ross,

I think that you are right about not needing the resistors as the module can be adjusted to the current requirements of the motors that you would use.
We will see when the modules arrive.. I ordered mine yesterday.

Testlabe may be able to shed some light on adjusting the modules for individual motors.

And Teslabe, I too would love to know what type of motors that you are using in your JJ-Prise warp nacelles. (Love your video, looks great.)

My current plan is to use a PIC 16F505 micro controller in each warp nacelle.
It has plenty of i/o pins to individually flash the five colored LEDs as well as output the pulses to the stepper motor module.
If you wanted the spin direction to be changeable under program control then one pin of the PIC could also be connected to the stepper modules DIR pin.

I would also like to create some sort of 'power up' sequence for the warp engines. 
Maybe something like:

Orange LED's fade up slowly
Fans start spinning up slowly
Multicolored LEDs start to flash
Fans now spin at full speed

Well, it is a work in progress.. 

Alien


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## RossW (Jan 12, 2000)

That's the same sequence I'm trying to do! But now that I've moved my blinking multicoloured LED logic to a PCB in each nacelle, I don't know if I can include the fade in of the amber LEDs (they're just hooked up to the +5V supply line as I need all the output pins of the 12F683 to do the 5 blinking multicoloured LEDs).


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## J_Indy (Jan 28, 2013)

Excellent. I liked that scene of the Defiant (CGI, I know) firing up in "Enterprise".


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## Alien (Sep 5, 2001)

Ross,
Google up 'charlieplexing' (I am not joking, its a real thing.)

You can control 6 LEDs using only 3 I/O pins.
Unfortunately, with charleplexing, only one LED can be illuminated at once, so you have to turn individual LEDs on and off very fast (multiplexing) to give the impression of multiple illuminated LEDs.

Alien


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## RossW (Jan 12, 2000)

I've seen that before, thanks Alien. My goal was to replicate the 1960's Christmas tree blinking lights that were used in the 11' studio model.

Also, I want to be able to set the speed via a quad encoder and switch the port engine's direction with a button. That tells me the board should be in the base with the controls and have 4 wires up to each nacelle.


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## Alien (Sep 5, 2001)

Ross,

That's the reason I am using a bigger PIC chip.
The 16F505 doesn't have a lot of program memory (I don't need much anyway.) but it has 12 i/o pins.

In fact the mailman just delivered me 10 16F505s an hour ago... Thanks aliexpress.com!

I have already written a program to blink the 5 colored LEDs at ever so slightly different blink rates to simulate the Christmas lights random-ish blinking pattern. 
The original lamps would have blinked with bi-metallic strip switches in the bulbs themselves. 

Reminds me of my childhood and the blinking lights on our Christmas tree. The model makers may have used the exact same bulbs as we had.. No LEDs back then.

Alien


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## RossW (Jan 12, 2000)

I ordered these small bipolar stepper motors off eBay but they came without leads. Unfortunately, I can't seem to solder wires to them - even after sanding, the posts won't accept solder.



Any ideas?


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## Alien (Sep 5, 2001)

Ross,

That is really weird that you can't get solder to stick. These motors are typically designed to be soldered into flexible printed circuit board so solder should stick.

Looking at my ones (That seem to be very similar to yours, but with only one screw mounting hole,) the motors coil wires are just wrapped around the metal posts and soldered on to them. I can't quite tell if that is the same as your motors. Need a bigger image.
If the coil wires can be soldered on to the posts the you 'should' be able to solder on your fly leads. (But you knew that anyway!)

The posts could have a lacquer coating on them (Can't think why.) and you may need to scrape that away with the edge of a hobby knife. (Maybe the sanding that you undertook did not quite get rid of the lacquer???) However if there is lacquer insulation on the posts you also not should get a resistance reading on a multi-meter when you probe the coils.

Using separately applied flux, rather than whats embedded in the solder, can help. I use it a lot if there is a bit of corrosion on what I am soldering. It can work like magic!

If solder will still not stick.... Mmmmmmmm Thinking thinking.......
You could get some wire wrapping wire and wrap that around the posts. And maybe secure it with some epoxy.

That's the end of my knowledge. Boy that came quick.

Lets know how you go.

Alien


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## RossW (Jan 12, 2000)

Judging by the wear-and-tear on them, they're definitely used. I can see the copper coil wire around each post but no matter how much sanding/filing I can't get solder to stick. The posts seem to move around a bit when I apply my soldering iron (electronically controlled, set to 675) so I don't want to linger.


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