# Scratchbuilding Tutorial #1: Flat-Nose Riggen



## K.L. VanAtta (Mar 23, 2009)

Hello Racers and Hobbyists,

It is time to get started building the flat-nose Riggen Can Car from the 1971 ( thereabouts ) Michigan HOPRA season. The photograph is of all the necessary raw material needed to construct/modify the Riggen chassis. Needless to say, you’ll not need all the material shown in the photo or described in the text to build the chassis; the motor would have a difficult time dragging all that mass around the track. That being said, NO ONE ever makes a perfect bend, cut or fold and EVERYONE has to remake parts from time to time because we make mistakes. Unless you have lots of time and money to invest in dies and jigs to make these parts identical then no two chassis’ will ever be exactly the same. So, that extra metal may come in handy.

That is some of the fun of scratchbuilding; I can show you a plan and method of building a type of car, but, you are building it. You are giving it it’s own unique qualities and is a “one of a kind” work. Be proud of it and always try to improve your skills. On to the parts list.










From the top of the photo down.

A Riggen Chassis, from RiggenHO.
0.032” x 1” brass strip
0.063 piano wire
0.055 piano wire
0.047 piano wire
0.032 piano wire
0.016” x 1/4” brass strip
0.047” ( 3/64” ) solid brass rod
0.032” ( 1/32” ) solid square brass rod, K & S, S-1
0.093” ( 3/32” ) square brass tubing
0.063” ( 1/16” ) square brass tubing
0.093” ( 3/32” ) brass tubing
0.063” ( 1/16” ) brass tubing
0.010” brass sheet
0.008” tin sheet
0.005” brass sheet

All of the raw material I obtained from my local hobby shops or hardware store and is all made by K & S. I have a really good old time hardware store close by with a bunch of bins to look through and find neat things in. Anyway the most difficult piece will be the 0.032” square solid brass rod, it is K & S stock number “S-1”.

Next, a measurement and straightness test.

Be good,
Keith


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## K.L. VanAtta (Mar 23, 2009)

Hello,

Please look at the following photograph as it quantifies a flaw in the Riggen chassis from day one, it is too narrow! This example is a bit narrower at the rear than at the front. Where does the Riggen get close to 1.25” width? At the shaker plate! Wrong place to solve a width problem with mass up in the air. We will make this right.










In 1971 the maximum width of a HO slot car under Michigan HOPRA rules was 1 & 9/32”, 1.281”, we will use this width as our maximum. Even today I use this width as my starting point for tuning cars and employ a stepped scale of wider and narrower overall wheel widths. This is not so important in magnet cars but, non-magnet racing will put an emphasis on the “squareness” of the “pushing” of the rear tires to the guide.

Much of this “theoretical” talk about chassis setup and design will be more relevant after the chassis is completed. Brass cars like controlled slides; fishtailing is bad.

Be good,

Keith


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## K.L. VanAtta (Mar 23, 2009)

Hello Again,

“A picture is worth a thousand words.”










If I’m putting together a car for a showcase as an example of a Riggen or, to race with my friends when we get together, then this is okay. I’m building a race car that I want to be as fast as it can be, and make it through as much as 60 minutes of racing and be consistent and reliable. This chassis is not there yet.

As you can see the axle upright is at an angle and the rear of the chassis is bowed up about 0.016”. With a bit of work we can cut the misalignment in half, with patience, even better. I would like to achieve a fit like the machinist’s square base to the aluminum block on the left. We’ll see.

Be good,

Keith


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## Hornet (Dec 1, 2005)

I read the calipers at almost 1.283,when i went to school that's wider then 1.281 :thumbsup:
Am i missing something


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## K.L. VanAtta (Mar 23, 2009)

Hornet,

Please take a second look at the photograph and take note of the following:

-All numerals are to the left of the mark on the scale which indicates its position.
-As the dial indicator rotates through the 0.100” range the indicator on the numerical scale first passes the mark indicating the tenth digit of the reading as in 1.1XX”. As the numerical scale indicator approaches the 1.200” reading the “2” will be visible on the scale before the reading is 1.200” because the positioning of the “2” is to the left of the indicating mark.

I hope this explanation helps. 

For the record the reading is 1.183” ( to me it looks like an 8 in the ten thousandth place; 1.1828…” ).

Be good,

Keith


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## slotcar58 (Jun 21, 2007)

Great work, as always! I will get the how-to in either the Oct. or Jan. issue of HORCTC.

Leo


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## Hornet (Dec 1, 2005)

My mistake Keith,i should of blown the pic up more,and looked closer,blind in one eye and can't see out the other.:thumbsup:


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## joegri (Feb 13, 2008)

thanx for getting the scratchbuild started. i guess i,ll break down an existing riggen and use that 1 for the flatnose. just a silly question but what does a flatnose riggen look like? k van if you can could you post a pic of what 1 would look like. thanx. my project van is almost finished and yard work is comming to an end. also i believe i have almost all of the materials needed give or take a few. as you said no chassis are the same. thanx


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## slotking (May 27, 2008)

> -All numerals are to the left of the mark on the scale which indicates its position.
> -As the dial indicator rotates through the 0.100” range the indicator on the numerical scale first passes the mark indicating the tenth digit of the reading as in 1.1XX”. As the numerical scale indicator approaches the 1.200” reading the “2” will be visible on the scale before the reading is 1.200” because the positioning of the “2” is to the left of the indicating mark.


that why i do not do clocks or calipers with hands!!!!!!!!!!!!!

give me digital:tongue::wave::thumbsup:


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## Bill Hall (Jan 6, 2007)

Lemee see if I got this straight...

....if Mickey's big hand points to the "one"... and his 'lil hand points to the "one"...

....then it's eleven o'clock....right?


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## K.L. VanAtta (Mar 23, 2009)

Except...if its binary.

I don't own a "digital" measuring device. The closest I have is the "digital" analog micrometer in the photograph in the tools section and it is nearly 40 years old. I remember an old Art Deco desk clock my parents had that had numerical wheels that rotated to display the time; I thought it was really cool so I never took it apart.

Mike ( SlotKing ) feel free to repost this on your site as per your request or, do you want me to become a member of the site?

Be good,

Keith


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