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I had an order that was supposed to ship a couple days ago, one of the items hasn't been printed yet

My order was supposed to ship today. Instead I get an email stating that it'll probably be another week. The good news is that yesterday I met a guy at the track who has his own 3D printer. He can't print at the quality level that I want but he can print good enough that I can get prototypes made within a week. That was I can see if the designs work or not. If they do, the files will get loaded directly to Shapeways. That should save weeks in the process.

Good idea

Dave.

That sounds good Fred. I'm actually thinking about buying a 3d printer too, maybe this spring some time. Will definately speed up development time

My Shapeways order with the McAllister lowering kit and other prototype parts for a project shipped today. That's weird because the wide rear arm order was placed a few days earlier out of the same material and in a smaller total quantity. Oh well. At least I'll know if the lowering kit is correct or not. Still waiting on the arms...

I know that you can print Nylon and other materials, but does the layered printing process still have the same durability as injection molded Nylon? Looks interesting. I'd like to see a car with the longer stock looking arms on it to see how much it changes the stance of the car.

From a dimensional standpoint I'd say no. The arms flex more than the stock ones do. However, an arm that is designed with their material in mind can easily be as stiff and strong but it won't have the same profile. I've been prototyping new arms for my Invencer dirt oval car update and the arms I have made for it are very rigid and strong. I have no problem running 3D printed parts but if ultimate performance is the goal then they need to be designed around the material chosen.

How about from a non-dimensional standpoint though? If you were to 3D print a stock a-arm (not any longer) replica, would the structural strength and rigidity be the same? I'm just wondering if the 3D printing process of Nylon makes the part any weaker given the same dimensions. If they are similar and can handle high jumps and hard packed clay/track border impacts, then that is awesome!

No it would not be the same. It would be more flexible. The longer arms are the same profile and shape, just stretched. To make them more rigid they'd need to be thicker.

Hey Fred, what do you think about machining delrin to make parts vs. nylon?

I've got access to some delrin sheet (1/4" and 3/8" thick) and could get my hands on similarly sized nylon...

Thoughts?

Byrdman

Delrin is softer. For machined rc parts I prefer Nylatron GS which is a grade of Nylon filled with Molybdenum Disulphide. It's what all of the old Bullet Racing Products parts were machined from. It's also dark grey to black in color.

fredswain wrote:No it would not be the same. It would be more flexible. The longer arms are the same profile and shape, just stretched. To make them more rigid they'd need to be thicker.

Sorry, Fred. I just re-read my post and I didn't type what I meant. If you 3D printed a stock arm (not stretched), would it be comparable in strength to a stock injection molded arm do you think? I'm just wondering how much abuse a 3D printed arm can take vs a stock one or if they would be more for show.

They will definitely be a little more flexible. I don't know if that translates to weaker or not but running 3D printed parts doesn't scare me. Some people can and will break practically anything. I'm currently designing an entire car with the intention of the parts being 3D printed with no injection molded parts.

People have been sucessfully running the NIX cars with most every part being 3D printed. I only know of one arm failure so far, and that was before the redesigned beefed up arms were available.

My arms finally shipped! The next few days will be torture.