37 replies to this topic

[Mark Onofri]

Anyone know what grade of spring steel is/was used for chassiss? When the first primiter style came out, my friend Gordy Root had some made. Only problems are
1) I don't remember what grade he used
2) I don't remember what method was used.
What I do remember is there was a issue of degrading the temper as a result of whatever method he used.
Also,is hydrocutting a viable option to EDM? I'll bet money that Dave Crevie
or, Mike Swiss knows.
As luck would have it, there's a metal fabrication shop right down the street from mine. They have hydrocutting capabilities. I just don't want to waist the time and money if it's (hydrocutting) not a suitable method.

[Tex]

not a terribly relevant comment, but I believe the VERY first spring steel center sections were cut from saw blades.....

[MSwiss]

1095 is the most common steel used.

[Jaeger Team]

not a terribly relevant comment, but I believe the VERY first spring steel center sections were cut from saw
blades.....

...with a dremel tool

[Dave Crevie]

Yes, 1095 high carbon steel is what I would use. Pre-tempered. A water jet will cut it, as will a laser. Water jetting might be better, less heat developed. Laser will be much faster, but might create some small amount of distortion in some areas. That, of course, depends on the design of the chassis. Use the largest radii you can in all inside corners. 

[Phil Hackett]

Yes, 1095 high carbon steel is what I would use. Pre-tempered. A water jet will cut it, as will a laser. Water jetting might be better, less heat developed. Laser will be much faster, but might create some small amount of distortion in some areas. That, of course, depends on the design of the chassis. Use the largest radii you can in all inside corners. 

 

With modern cutting tools it can be milled too. It's best on a CNC mill where the cut can be fine-tuned. I have done it several times but not for slot car chassis.

 

I have become very good with .032" endmills.

[Dave Crevie]

Milling creates more heat than water jetting. It's been too long since I used a 1/32nd inch dia. endmill, but the feed rate and chip loading has to be extremely small. But if anyone was to try it, I'd say you should be the one, Phil. I would use TiAlN coated cutters.

 

Traveling wire EDM has the advantage in that you can stack blanks and cut several chassis at the same time. Saves time, and EDM cutting is charged out by time of cut. The downside is that you can't start a hole without a starter hole to pass the wire through. You can cut in from the nearest edge, and that works in most instances. 

 

Many years ago I tried making a wing car chassis from a composite material. It showed promise, but needed a lot of sorting out. The big advantage is that it wont bend in a wreck. Cahoza made one, but it was designed all wrong. I would still like to see someone continue with that direction.   

 

[dc-65x]

Here's an example of what my "laser dude" could could do with his CNC laser cutter...........before it took a dump.  

 

I'd supply the CAD file and he'd do the cutting:
 
 

I know "parts is parts" but these are special. Fresh from the Laser dude we have the first test pieces for the Diamond In Steel chassis:
 

 
Here's how they fit together:
 

 
A closeup of how the bumper, center section and guide tongue interlock:
 

 
The motor box area awaiting its array of piano wire braces:
 

 
Me like :mrgreen: This may not be the final version. I'll have to start building to see if "the project can come together".
 
Onward

That's "blue tempered spring steel" from McMaster Carr and hobby shop brass.

[Phil Hackett]

The way modern cutting tools work is there's very little heat induced into the work and if you use coolant it's even better. A large percentage of the heat of cutting is transferred into the chip. CNC grinding of endmills has enabled profiles and geometries that promote this heat transfer.

 

There's an entire metal cutting subject called "hard turning" or "hard milling" where cutting tool steels of RC60+ are common. The machined pieces are precise and the surface finishes challenge ground finishes.

[Mark Onofri]

Text,I heard that also.I had mentioned it to Billnh,he had suggested hand saw blades.
Dave, Mike, I knew you guys would know!!

[Bill from NH]

Scraper blades used in woodworking & some drywall knifes will work too. Both come in different sizes & thicknesses.

[Phil Smith]

Remember the '80s Koford wing car spring steel chassis that were acid etched?

[Mark Onofri]

Although a carborundum blade, milling machine, and Lazer cutting are all viable option, there not convenient. Like I said, this shop is right down the street from mine. If I had a Rockwell or Britnell (?) Hardness tester I could get (almost) exact before and after statics. Maybe they do.
As far as the carbon fiber chassis, I had discussed this with Scott at PCH . His opinion was that mounting of the motor, uprights,etc. would present a problem. I'm not convinced of that. The reason for this inquiry was, I have a friend who's family owns a titanium and carbon fiber factory in China. It's a unique opportunity and,if I could make it financially viable, it would be a once in a lifetime chance. Only so many hours in the day.

[Mark Onofri]

Dc65-x,
There should be a award for your patience, time and, prowess in this hobby.

[Bill from NH]

Mark, there were carbon fiber wing chassis at the '97 USRA Nats. I don't think any of them made it into the final. I had a chance to talk with Rudy Garriga, owner of Slick 7, at length about carbon fiber wing chassis. This was after he had built & tested several. Today's technology is more advanced than back then.

[JerseyJohn]

anyone know which kind of laser can cut up tp .040 brass ?

[NSwanberg]

Lapham-Hickey Steel.

 

1095 oil quenched, blue tempered.

[Jaeger Team]

Today's technology is more advanced than back then.

That's for sure. See, for instance, NANOALLOY by Toray

[Dave Crevie]

As far as the carbon fiber chassis, I had discussed this with Scott at PCH . His opinion was that mounting of the motor, uprights,etc. would present a problem. I'm not convinced of that. 

 

Not a problem at all. The motor mount and rear axle uprights were a separate spring steel unit bonded and riveted to the composite main structure. 

[Mark Onofri]

Jersey John, I might be wrong but, if I remember correctly, cutting brass with a Lazer is restricted do to the reflectivity.
PS: I aquired one of your chassis, nice!
Dave, I didn't think it would be a problem. I don't know enough about G-27,G-7 cars to make a qualified statement or, comment.

[Mark Onofri]

I'm not opposed to circle saw blades but, the hole makes it tough. I'm pretty sure hand saw blades are to thin. The minimum thickness is.45 from what I've read.
Anyone?

[Bill from NH]

How thick to you want it? Circular saw blade might be good steel but not necessarily spring steel. I think CMT blades were Italian.

[Mark Onofri]

LMFAO, I resemble that remark!

[Dave Crevie]

Too simple. From McMaster-Carr. 1095 spring steel ready to use;

 

 

The prices might seem high, but how much is a hand saw. Generally speaking, a circular saw blade will not work since they are thicker near the O.D. than in close to the center. They are "hollow ground". 

 

There are other suppliers for steel, but I have been happiest with the service and quality of their materials. They have brass sheet as well. 

 

If you carefully lay out your designs on the steel, (it comes blued so takes a line scribed with a scratch awl or scriber very well) you will find that you can get more frames out of a piece of steel. If you are having the cutting done by laser, water jet or travelling wire, the operator can help you with that.

 

The main problem I see with milling the chassis is it is slow compared to laser or water jet. Plus the kurf is wider, which shouldn't affect anything unless you have some very narrow slits to add.   

[dc-65x]

Here's another example of what Dave is talking about.

This Tonyp style chassis was laser cut form McMaster Carr 1095 blue tempered spring steel.

 

Guys that cut this stuff with a Dremel have my total admiration.

 

 

You can buy a 1 foot length 8-10 inches wide for under $40: