YR-4 custom buggy conversion

[AllenB.5979]

So... I said before I wasn't happy with the steering set up. The tiny ball cups are too flimsy, there's too much play in them and the travel is limited. I gave it some thought and this is what I came up with.

Nothing fancy here. Just some calipers, a pencil, a straight edge and some paper.



Some aluminum bar stock for the plate.



A pair of RC12L front wheel bearings for pivots. Had to offset them 1mm from center to clear the bulkhead. The drawing had them centered.





First test fit. Here you can see why the offset was needed. Works great so far. Great travel and super smooth action.





Now to make clearance for the diff pulley.





So now all I have to do is trim up and shape the ends of the plate, drill holes for and mount the ball ends and clean up the finish. Should be able to wrap this up this evening.

[AllenB.5979]

Came out just perfect. Steering issues solved. Nice tough ball ends, great travel, nice and smooth... Couldn't ask for better. A bit different than the original plan but I'm very happy.





I'll post another pic when the car is all back together with links in place.

[Lonestar]

Btw... Love your thumbnail! Have you got any little Lunch Boxes running around yet?

The VLB's on this pic were mine and a buddies and one day as we were goofing around they got stuck like that, and that was a kodak moment

I sold mine, it was modded like hell with a third shock mod, chassis braces, the works... and my buddy Roop moved to another country. Good ol' times, this was 10yrs ago

Have fun with your build! And post vids when it runs. here's my VLB in action as posted on a friends website (not sure how to embed...)

http://overrc.com/techniques/reglages/tamiyalunchbox/vlblonestar/PICT0019.MOV

Paul

[jwscab]

pumpkinfish made these arms 3d printed to work with JC racing wheels, which I believe are based on 91/93 wheel offsets.
https://www.shapeways.com/product/VWZHV2JS6/yokomo-yz10-870c-long-rear-arms?optionId=57783062

this might get you the width you need at a better price than original 91/93 arms. suppose you still need a front arm solution to match the 91/93 front c-hubs.

this thread has good axle/bone information, just FYR.
http://www.rc10talk.com/viewtopic.php?f=29&t=19786

[AllenB.5979]

Btw... Love your thumbnail! Have you got any little Lunch Boxes running around yet?

The VLB's on this pic were mine and a buddies and one day as we were goofing around they got stuck like that, and that was a kodak moment

I sold mine, it was modded like hell with a third shock mod, chassis braces, the works... and my buddy Roop moved to another country. Good ol' times, this was 10yrs ago

Have fun with your build! And post vids when it runs. here's my VLB in action as posted on a friends website (not sure how to embed...)

http://overrc.com/techniques/reglages/tamiyalunchbox/vlblonestar/PICT0019.MOV

Paul

Ahh... Looks like true love if only for a fleeting moment.

[AllenB.5979]

pumpkinfish made these arms 3d printed to work with JC racing wheels, which I believe are based on 91/93 wheel offsets.
https://www.shapeways.com/product/VWZHV2JS6/yokomo-yz10-870c-long-rear-arms?optionId=57783062

this might get you the width you need at a better price than original 91/93 arms. suppose you still need a front arm solution to match the 91/93 front c-hubs.

this thread has good axle/bone information, just FYR.
http://www.rc10talk.com/viewtopic.php?f=29&t=19786

Yes. Thank you. I actually had come across that set somewhere in my searching. I thought the same thing. Nothing for the front. Can't win em' all. Plus, let's agree that they are the ugliest dam arms ever to grace a yok. They are functioning though and that's what's important. If I can come up with something similar for the front perhaps I'll give them a try. Appreciate the help friend!

[Mr. ED]

I took my laptop home and will try modeling up a set. Do you want something that could be machined easily, or more fancy: 3d printable only?

[AllenB.5979]

I took my laptop home and will try modeling up a set. Do you want something that could be machined easily, or more fancy: 3d printable only?

That's a tough one. What manufacturing process do you think would cost more? I know a milled / machined piece would be a lot stronger. That's probably the way to go. I priced table top mills a while back and that to me seems a more useful investment than a 3d printer. Home quality prints just aren't there yet unless you spend a fortune on the printer. As far as having a 3rd party print or machine it, I have no idea what the cost associated with either is. I've just never looked into it.

Another thing to think about is material. What would you want to make them out of? I know milling / machining offers much more flexibility. I mean a milled arm could even ( theoretically ) be made from solid carbon fiber. Then you have aluminum and nylon. I know I posed more questions than answers. It seems though my argument is stronger for a milled / machined piece.

[Mr. ED]

The printed version for the front arm could look like this. Bottom and top are symmetrical so they'd fit both left and right.

[jwscab]

Machined nylon plate ala dynotech style would be strongest. Printed stuff will not be as strong but can be made to look original where the machined stuff will not, dollar for dollar.

[Mr. ED]

Orb design uses printed parts for his FWD buggy, and the guys here for the ten-4, and the replica of the masami prototype too... I think.

Ideally you 'd have glass-fibre reinforced nylon.

Anyway, This is the design for machining: in Delrin or nylon or whatever you can get.

A 3 axis machine would be enough and you'd only have to change the part orientation once since there's no machining from the bottom side.
(Slight disadvantage: left and right are mirrored = not symmetrical, which means 2 different milling programs and possibly higher charges than 2 identical parts)
I recommend a 12mm bit to do the outline and pockets quickly, and 4mm to finish the smaller radii. The holes for the shockmounts and hinges are 2.5mm. You can manually tap them for M3 and ream them for the 3mm hinges.

What kind of file would you need? I can do a step (stp) export, stl (good for printing I think), or a 2D drawing in dwg format for a laser cutter or waterjet cutter, or plain pdf with dimensions: for the folks who have no data exchange.

Both versions are available for free: send me a pm with your email and tell me what you need.
(But maybe wait a bit till I've got the rear ones finished also.)

[rccars4sal]

Hi MrEd, can you do a .dxf file? Ive been toying with making arms on a manual mill, but would like to try sing my cnc. The material i have is too thick, so I would likely add a rough cut process to the mix, or possibly mirror the process on each side to produce symmetrical arms.

[Mr. ED]

Sure I can do dxf. That's just a variant of the dwg format.

Here's the printed version for the rear:

And all 4:

And the machined version for the rear:

I've added 2° of toe-in at the wheel hinge.
That'll make it harder for the machined version, I know. But it made a world of difference on my YR4.

[AllenB.5979]

Wow Mr. Ed! I am thoroughly impressed. I better get my act together and buy that mill! You exceeded anything I'm capable of in 5 minutes. Let me see if I can catch up.

[Mr. ED]

It took me quite a bit more than 5 minutes to do this . But it went pretty smooth. I'm glad you like them.
They are easy enough to modify, so maybe some day I'll make some slightly shorter ones to use with cvds and hex wheels with more neutral offset.