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3D printed RC12E project

Posted: Wed Jan 18, 2017 8:27 pm
by makoman1860
Hello,
First off forgive any stupid questions as I have never had, nor worked on a pan car of any kind (except motors). A friend of mine at work had toyed with building an R/C car using 3D printed parts and all, just for fun. When I saw the RC12E that Chris had drawn up I thought it would be a perfect project. Question I have is on the rear axle, from what I gather the 12E's used a solid axle and later on the ball diff was added. For tearing around the office conference room is a Diff going to make that big of a difference or would you stick to the simple solid axle? Also where is a good place to get tire foams? We are going to print off the wheels ourselves. Any advantage to moving the steering servo to the chassis and running a direct steering setup? Like I said, totally green to pan cars. Thanks!!

Re: 3D printed RC12E project

Posted: Wed Jan 18, 2017 11:36 pm
by rraeford
As far as the diff goes, I installed one on my first 12E in 1982 (long before I could drive worth a flip) and I noticed a tremendous difference. Basically, without it you turn quickly in one direction and push badly in the other. So I would make that change. I have the steering servo mounted on my 12E chassis -- like in a 12i. I don't know if there is an advantage other than lowering the center of gravity.

Re: 3D printed RC12E project

Posted: Mon Jan 30, 2017 12:21 pm
by makoman1860
Got the first of some of the 12E parts back from the printer. My co-worker/friend used to work in the full size racing industry....and so couldnt help but modify the designs a bit. He drew up his own wheels as well, BBS style. Ill toss some pictures up if anyone is interested.

Re: 3D printed RC12E project

Posted: Mon Jan 30, 2017 2:59 pm
by GoMachV
Yes please 8)

Re: 3D printed RC12E project

Posted: Mon Jan 30, 2017 4:03 pm
by Mr. ED
We all love pics

Re: 3D printed RC12E project

Posted: Mon Jan 30, 2017 7:11 pm
by makoman1860
Pics it is.......any thoughts?
Image
Image

Re: 3D printed RC12E project

Posted: Mon Jan 30, 2017 9:46 pm
by ChisaiKuso
rraeford wrote: Wed Jan 18, 2017 11:36 pm As far as the diff goes, I installed one on my first 12E in 1982 (long before I could drive worth a flip) and I noticed a tremendous difference. Basically, without it you turn quickly in one direction and push badly in the other. So I would make that change.
A lack of a differential will not make a car turn quickly in one direction and push badly in the other. A car doing that is unbalanced (i.e. "tweaked").

Re: 3D printed RC12E project

Posted: Mon Jan 30, 2017 9:48 pm
by ChisaiKuso
makoman1860 wrote: Mon Jan 30, 2017 7:11 pm Pics it is.......any thoughts?
I would be skeptical about the strength of those parts, but they look awesome! 8)

Re: 3D printed RC12E project

Posted: Mon Jan 30, 2017 9:59 pm
by makoman1860
Strength wise, its not bad once vacuum impregnated with structural epoxy, about the same as nylon 6/6. Im interested to see how well they hold up. As a back up Im printing the original design as well.

Re: 3D printed RC12E project

Posted: Tue Jan 31, 2017 12:24 am
by Mr. ED
makoman1860 wrote: Mon Jan 30, 2017 9:59 pm Strength wise, its not bad once vacuum impregnated with structural epoxy, about the same as nylon 6/6. Im interested to see how well they hold up. As a back up Im printing the original design as well.
Is that impregnation commonly available ? Sounds interesting.
And a pretty design too.

Re: 3D printed RC12E project

Posted: Tue Jan 31, 2017 10:09 am
by makoman1860
Mr. ED wrote: Tue Jan 31, 2017 12:24 am
makoman1860 wrote: Mon Jan 30, 2017 9:59 pm Strength wise, its not bad once vacuum impregnated with structural epoxy, about the same as nylon 6/6. Im interested to see how well they hold up. As a back up Im printing the original design as well.
Is that impregnation commonly available ? Sounds interesting.
And a pretty design too.
It seems pretty common in industry if you are dealing with laser sintered nylon. We have done parts in laser sintered nylon that has carbon fiber strands in it as well, however the material cost is about 6x that of standard SLS. The fun here has been to see how low the cost can be kept by making all our own parts. Looks like at this point, the only parts that need to be bought are a spur gear, diff balls and thrust rings, ball bearings and steering linkage, plus screws. The rolling chassis minus body should cost about $30. Add a brushed ESC, stock can motor, cheap servo and cheap radio and we are looking at maybe $120 RTR with a NiMh battey pack. Might be a fun little spec type racer for an office league.....

Re: 3D printed RC12E project

Posted: Tue Jan 31, 2017 11:02 pm
by rraeford
Those wheels look bada$$! Do you plan to make the stock ones as well? Hard to find those in good shape.

Re: 3D printed RC12E project

Posted: Tue Jan 31, 2017 11:22 pm
by makoman1860
I dont see why not? As soon as I get the other printed parts they can all get dyed.....havent decided on a color yet though.