# tjet controllers



## hartracerman (Jan 9, 2005)

I have just ordered 4 120 ohm resistors from Bob Marketos, but started thinking why there are not more high resistor controllers available for stock tjets? Is it a UL problem? There seems to be plenty of market for tjets, so why not better controllers ready made to go with them? If this is posted in the wrong area forgive me and put it in it's proper place. This inquiring mind wants to know.


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## vaBcHRog (Feb 19, 2003)

Parama just started making a 90 ohm and BRP has several different high ohm controllers.

http://blake.prohosting.com/horacer/brp/nitro.html

However Jerry who makes these for BRP is in the NAVY and currently deployed but will be back this fall.

Roger Corrie


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## Mike(^RacerX^) (Mar 15, 2003)

Sorry I can't answer your question.But I can tell you that I picked up a pair of the BRP 120's a few months ago,and they made racing my pancake motor cars 1000 times more fun.

WHat a difference!!!!!

Mike


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## tjd241 (Jan 25, 2004)

*Happy with 120 ohm resistors.*

I popped 2 of the 120's into my pair of Parma econo-controllers and it does make a noticeable difference (for the better). Now the cars seem to not act so abrupt. Its not such an "on-off switch" feeling with the trigger anymore. I have no clue if a higher ohm would be beneficial though?? tjd


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## buzzinhornet (Jan 20, 2000)

vaBcHRog said:


> Parama just started making a 90 ohm
> 
> Roger Corrie


Does anyone know who's selling the new 90 ohm Parma controllers? Any reviews on this item? 

GP


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## AfxToo (Aug 29, 2003)

> Is it a UL problem? There seems to be plenty of market for tjets, so why not better controllers ready made to go with them?


The UL has nothing to do with it. They don't plug into wall outlets. 

There are plenty of high resistance controllers available now. The BRP ones seem to be the "smartest" design, but this should not come as any surprise considering the source.

The bottom line with standard controllers is that no single fixed resistance controller fits the bill for all of the combinations of cars and tracks that you use. Unless you only have one type of car and one type of track you'll be needing (or at least wanting) more than one controller. Having lots of controllers adds up cost wise and takes up a lot of room in your pit box. At some point, having a single adjustable controller (sometimes called an "electronic controller") makes more sense all the way around. Most hard core TJet racers use adjustable controllers.

There's still a lot of people running AFX cars and magnet cars. Most of these run pretty well with 45 ohm or even lower controllers.


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## car guy (Nov 22, 2003)

OK, here's one for 'ya A2, my track (someday, lol) will be at the longest point (i'm hoping)...5-6 ft.X 3 or 4 ft. max. (wide). Now I plan on running just about all the different cars, i've got PLENTY of JL, both Mag. & Non, Tyco 440's, LL, Super G+'s & Turbo's...get the jist? Now what (in your honest, humble) opinion would be the best ALL "ROUND controller?

P.S. They're all stock, at least for now. lol


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## roadrner (Jul 21, 1999)

buzzinhornet said:


> Does anyone know who's selling the new 90 ohm Parma controllers? Any reviews on this item?
> 
> GP


 
I just orderer four from [email protected] at his eBay







store, $23. per unit. Figured I get something that would give better control running the stock T-Jets, AFXes and the likes. Based on earlier posts, these seemed to be a good middle of the road controller for these type of cars. Will let you know in a week or so after I give them a go.  rr


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## AfxToo (Aug 29, 2003)

Judging from the results of the more recent Fray races the hot ticket adjustable controller for TJets is the Trek Lawler Electronic controller. Send an email to the builder and ask specific questions about the controller models for the types of cars you'll be running. 

email: [email protected]

The Professor Motor controllers with adjustable sensitivity SHOULD work fine for TJets but I haven't tried them personally. I believe that Slott V has one and he may chime in with his hands-on evaluation. I would consider a dual polarity model just to make sure you won't have any problems running on tracks that aren't wired for positive polarity. The models that sound good on paper are: PMTR2050, PMTR2052, and PMTR2056. (The 2052 is the best and most expensive one.) Again, email the builder and ask specific questions about the controller models for the types of cars you'll be running. He has lower cost models ($50-$60 range) if you are okay with positive polarity only and a less sophisticated sensitivity arrangement. 

email: [email protected]

The other compromise is again the BRP Nitro 95. The bottom line is that ANY car including stock magnet cars can be run with a high resistance controller. The problem is that cars that need more juice will barely move until the trigger is pulled nearly all of the way. It's the exact opposite effect of using a too low resistance with a JLTO - which move too fast with too little trigger pull. The BRP resistors (reostats if you prefer to call them) have a non-linear wind. They have more windings on the lower end of the throttle pull to give you slower take off and finer control. They have fewer windings on the high end of the throttle pull to get you to top speed with less trigger pull. What this means for the magnet cars is that you won't have to pull the trigger 3/4ths of the way before the car starts moving. It will start moving sooner. 

I use a Parma 25 for racing magnet cars (G3s, P3s, and Storms) and some stock magnet cars, a Parma 45 for AFX, XT, stock geared TJets, and stock magnet cars, and a Parma 60 for JLTOs, TycoPros, and LL Pro Tracker SS cars. I'm actively looking into getting a single adjustable controller so I can lighten my pit box and outfit my home track with 4 variable controllers instead of 12 or more fixed ones.


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## okracer (Mar 11, 2002)

what do you guys think of this controlerhttp://www.inlandempirehoraceway.itgo.com/custom.html


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## AfxToo (Aug 29, 2003)

The design of variable resistance controllers has been around for many decades because it applies the most fundamental of electrical properties. If you go to the Siberia racing site (http://home.att.net/~medanic/Tech-Parma.htm) you'll find a schematic for building your own variable controller using parallel resistors (fixed and/or variable) to change the effective resistance of the controller. The problem with using parallel resistors is that you can never increase the effective resistance of your controller above its base value. This technique works well if you have a high resistance controller, say a 120 ohm, and also want to be able to adjust it for cars that run better with say a 60 ohm or 35 ohm controller.

If you want to increase the effective resistance of your controller, say from a 60 ohm to a 100 ohm, you must add resistance in series. That's what the controller with the potentiometer (listed in the previous post) does. The problem with using series resistance is that it permanently limits the current through the controller because the resistance is always in the circuit, even at full trigger pull. It's like placing a block of wood under your car's gas pedal so you can't floor it. What most people do to work around this limitation is to add a relay or mechanical bypass that senses when the trigger is pulled all of the way so the series resistor is bypassed. The full pull bypass effectively yanks the block of wood out from under the gas pedal when you floor it. This can of course cause a bit of a surge at the end of the trigger pull. 

Another thing to consider with the series approach is that the series resistor must be able to handle the full current, so it's typically a larger component with a higher power rating. Parallel resistors only handle a portion of the current so they tend to be smaller and lower power rated.

Coming up with the electrical design of resistor based variable controllers with series and/or parallel resistors or variable resistors, bypasses, variable brakes, etc., is a very simple and straightforward process. The physical construction and getting the right parts put together that are durable and properly rated is the much harder part. The controllers shown on http://slotcar.itgo.com/custom.html do seem to be very well constructed. With this type of controller you are really paying for the skill of the fabricator, not the electrical design and engineering that goes into the controller. 

With true electronic controllers, you are also paying for the electrical design and engineering that goes into making it work.


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## ParkRNDL (Mar 20, 2002)

As usual, AfxToo, your description is excellent. I've struggled with the concept of variable resistance controllers for a while, but the analogy with the block of wood drove that home for me. Thanks.

--rick


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## buzzinhornet (Jan 20, 2000)

*?*

Has anyone tried this controller "powerhouse box"? 

http://www.coastcd.com/powerhouse.html 

GP


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## okracer (Mar 11, 2002)

i have seen it but the price i think was like 179 bucks 
i have 80 in four parma contollers and i still have the hundred bucks lol


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## tbolt (Jan 6, 2005)

T.S.S. Hobbies , www.tsshobbies.com


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## roadrner (Jul 21, 1999)

Rec'd the 90 ohm Parmas and added clips last night for a couple of laps around the track. Can say I am definitely glad for the upgrade (from stock Aurora Russkit style). Was really surprised with the difference in control. Like others stated, not like an on/off switch. Gradually increases as you apply the the trigger, more realistic to accellerating. Again, this is the first time I've switched from stock controllers so I was easily impressed. Definitely gave me more control, especially with the pancake cars, regardless of manufacturer or version. Ran stock (w/silicones) Tjets, AFXes, TYCOs, LLs, JLs around for a couple of hours and it was a blast. Had to learn how to run some of these cars a new way with these controllers. Would have to say for my set up (50' course) and the "stock" cars I run this was a good investment. :thumbsup: :thumbsup: rr


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