37 replies to this topic

[Mark Onofri]

Thanks guys,is the last list also from McMaster? I didn't get a list as detailed as those when I went to their site.

[Bill from NH]

Any thick enough?

[dc-65x]

It's a McMaster Carr list Mark. I refined my search to lengths of 1 foot.

[Dave Crevie]

How thick do you need? I can't imagine a spring steel chassis made with anything thicker than .062. (1/16th)

 

I included the longer lengths in the price list because if you are doing multiple chassis, the cuts can be layed out to save material when the lengths are matched to the number of parts.

 

Many people will measure the width of the part, and double it if they are making two of the same part. They will most likely layout their cuts like this;

 

 

 

But to reduce waste, (remember RoHS you guys across the big pond), you are better to try laying out as many parts as you can on graph paper, and order the size of sheet you need to cut out those parts. You may end up with the cut lines layed out like this;

 

 

The yellow areas would most likely be thrown out. But with a little more fussing, you might be able to fit some of the other detail parts, like uprights and guide tongues, into the small spaces, reducing waste even more.

 

 

 

 

 

 

 

 

[Bill from NH]

Dave, my thickness comments were an inside joke to Mark.  I never saw a spring steel center section that was 1/16" thick. The sheet steel I got from Tony P. & Camen in the '70s was in the .035-.045 range. No circular saw plate is that thin. 

[Mark Onofri]

Lol, I forgot that Billnh is the only one in on that joke.
Somewhere I have to a article with the world championship cars of the 80's. I remember that.045 was a little thin, maybe just for that track. I'll see if I can find the article.

[Bill from NH]

Mark, if you're going to cut more than one, make it easy on yourself & build a table saw-like device with a sliding table. Power it with a Dremel & carbide cutting disc, use ball bearing drawer guides to slide the table. It might be easier to use than holding the steel in one hand while you hold a Dremel in the other.

[Dave Crevie]

OK. I missed it. But you are correct on the thicknesses normally used for wing car and eurosport chassis. While I was working I had the good fortune to have SolidWorks 3d solid modelling at my disposure. I would sometimes run a chassis center section or perimeter frame through the stress analysis. It would give me a pretty good idea of how that chassis was going to act on the track. 

 

Using a Dremel by hand with an abrasive cut-off wheel can be dangerous. Any twisting of the wheel in the cut can cause it to break and scatter little pieces of the wheel in every direction.

[Mark Onofri]

Billnh, you missed it, I'm planning on having some hydro cut.
Dave, Billnh was nice enough to provide me with copies of the originals from four (4) manufactures. It's going to make it far easier to do the layout. If I'm not mistaken, I believe the fab-shop provides this service. As far as chassis deflection,have you ever seen a GM photo of how they tested for chassis deflection? (In response to Nadar)It was based on how much it takes to deflect it 1° . I'm not sure if I can post it but, I will post the reference shortly. If I can find it.

[Mark Onofri]

I just went back to dc65-x's post. In the TonyP (rip) chassis blueprint, there is a reference to a winning one being cut from .040.

[dc-65x]

Mark, here's what Tonyp said about the steel thickness for the chassis styles in my thread:
 

Rick, I used both styles.
 
The two rails were made from .040" steel and were stiffer, we used them mostly for flat tracks like Elmsford and glue. The three rail was made from thinner steel and had more flex. These we used for spray and or limited glue races.
 
The two rails we ran with no bar under the rear axle as this gave it more bite...
 
Not sure on the year. The illustrations seem to contain both Bob Emott's and my handwritting so I believe they were from either Bob's two issue newspaper he tried to start or Somebody's Got To Eat It.
 
Years I do not remember. The two rail came first, than the three rail... The drawing says that Ernie did use this style to win at Clementon. I am sure it was used after the Iso that you already did a build on that also won there. So we know it was between then and the Elmsford World Champs that Paul Pfeiffer won as I had quit building by then and just built a couple of cars for Ernie for his last race.

Here's a link to the original thread:
 

Tony P's steel cars

[Dave Crevie]

GM actually made a video of their testing of designs for both full frame and uni-body cars. They developed their own software. This had to be 40 years ago, when 8-node brick 3-D modelling was just coming around. I went into Computer Aided Design kicking and screaming all the way. I felt, as did all of us "board guys", that it was going to put us out of our jobs. But once I got on board, I found it to be the biggest boon to manufacturing since the bronze age.  

[Mark Onofri]

The reference I'm referring to looks like a Vincent Price wet dream. They've (GM) got a bizillion dial indicators in every conceivable position measuring a chassis that looks as if it's tied to a rack in a Spanish inquisition!