Wide CRT .5 A-Arm Renderings
 

Well, I went ahead and drew up some wide CRT .5 A-Arms. These are renderings of the front arms. I'm still working on the rear ones. If machined out of 6061, predictions are 34g. I'm sure a lot more material could be removed without sacrificing weight, but in the current form, I think these are going to be EXTREMELY durable.

http://img262.imageshack.us/img262/5...ont1vl0.th.gif

http://img252.imageshack.us/img252/1...ont4tb3.th.gif

http://img262.imageshack.us/img262/9...ont3vy6.th.gif


For the rears I was planing to incorporate a 5-10mm extension (frog leg) into it, much like the Revo setback arms. I was also thinking of incorporating a way to adjust the amount of extension (though the adjustment range would have to be small or else the dogbone would bind or fall out at the max settings in each respective direction). However, the biggest downside is that it would mean that two separate CVD lengths would have to be made (one for front, one for rear), and for this reason I am going to ditch the idea and not have any set-back.

They would be impossible to machine with the sharp angles. you need to make rounder shapes on it in order to work with a mill; you could just make it more round, but that way the entire design goes to waste. (and it will be adding weight as well)

Nice! Maybe I could test a set, Like I did the chassis....

Bye:mdr:

Yea - I actually made new renderings with a more machine-friendly design. I'll post em up in a bit.

Wire EDM or better yet water jet could handle those tight radii.

yep, but his standard machinist doesn't have this stuff! (Mike.. :) )

And the pockets still need to be machined, so it would become a more expensive arm this way.

Can you wire EDM aluminum? How small of a mill bit does he need to size the part for (.100?.125?)

I increased the radii of the corners. If Mike has a 1mm bit, then he can machine it fine, if not, well, I'll have to make a few more changes! :yes:

Serum is absolutely right about the standard machinist part. :mdr:

Here are some new renderings...

http://img118.imageshack.us/img118/5...0008uc3.th.gif

http://img408.imageshack.us/img408/3...6794iy1.th.gif

http://img131.imageshack.us/img131/3...8065yi3.th.gif

http://img122.imageshack.us/img122/8...2997ay8.th.gif

Estimated weight is 30g, so I saved about 4g over the last version :yipi:

Let me know what ya guys think (and Serum can let me know if its machinable).

well the first set looks cooler... the X's that it makes throughout the arm is cool to me.

but i dont think it will matter once its on the truck! as long as it is durable i dont think it matters.

How much are these arms extended? Also the second version looks a little weak IMO, but they would be aluminum so maybe I'm underestimating them. Put me down for a set too. (if you talk to mike about them, mention about me wanting a set, if you do not mind.)

Bye:mdr:

The extension is 15mm. Its a little much now I think of it (30mm total when both sides are accounted for). I think it'd be better if it was 20mm total... I think I'll revise them.

The arms are 7mm thick (height) and the main sections of the arms are about the same in width, so its a 7x7 bar for the main sections of the arm. Thats pretty darn strong if ya ask me.

To be honest, I just designed these up out of pure fun, but they should bolt right up, so if you want a set, I could send the designs to Mike. Not to mention, he could throw these up on the store (once a few members test them to make sure they are indeed durable) and it would save him some time - maybe I can even get a free set out of it lol... (hey, one can always dream).

I'll draw up the rears and fix the fronts (shorten them) tonight and post more renderings.

What Program did you use to make em? if you have Solidworks did you do a cosmos on it?

I'm using emachineshop...I wish I had solidworks...but at 100 bucks for the student edition (which lasts just a year), its not something I can readily dish out money for...

Oh I didn't know Mike was making them. I guess I missed that. I really don't know when Mike finds time to sleep.

You can if the machine is equipped for it. Back on topic.

One of my co-workers recent quotes, "Well you better put on your eye patch."

Ok, here we go. Final renderings. I'll probably double check all measurements, but they should be good to go...

Fronts:

http://img209.imageshack.us/img209/6...ont1zr4.th.gif

http://img209.imageshack.us/img209/201/front2ll9.th.gif

http://img220.imageshack.us/img220/4...ont3ir1.th.gif


Rears:


http://img208.imageshack.us/img208/2039/rear1li4.th.gif

http://img208.imageshack.us/img208/7039/rear2hl7.th.gif

http://img138.imageshack.us/img138/9235/rear3zp9.th.gif

Let me know what ya guys think.

Again, specs are 10mm extension (so 20mm total width increase). I also added more shock mounting positions. One on each side of the current 2, for a total of 4. They can be used on the right or left side (universal). Weight is ~30g per arm.

Nice! now what about driveshafts?

Bye:mdr:

These ones (post #16) look excellent, it looked like there were a few scissor points in the last ones you posted. It looks like you may have a bit of a sheer problem with the front a-arm on these. I circled a thin piece at the top right of the shock mount from the first photo that I think could sheer under a hard forward impact (and seperate from all of your otherwise excellent triangulation) :)
http://i217.photobucket.com/albums/c...ont1zr4_th.jpg
Sorry I coudn't make the circle red, but for some reason I couldn't get it out of grey scale....

Ok, I thickened up that section a bit. Its about 70% thicker now. Should be fine.

Good work BP-Revo, nice job on the arms.

What kind of files are they? if there something common, go on and send the file to me, ill run it threw Solidworks Cosmos for a analysis if ya want

BP

Are these going to be real? Any price estimate on them?

I talked to Mike(rc-monster) and he has plans for 3/8'' extended arms. He told me to wait for them to come out.....

Bye:mdr:

Nice!

Thanks for the info

What about making wheel hub extenders like they do for 1/8 buggies and trucks?
http://www.amainhobbies.com/product_...ducts_id/12748
It seems this would be an easy fix and would eliminate needing longer driveshafts and arms, but I don't know how easy it would be to machine.

That is a valid idea, although it's not always so practical - by pushing the wheel out further, it effectively allows the force from the wheel to have more leverage against the bearings. This causes premature bearing wear, and then extra replacement bearings. But by keeping the wheel in the same spot relative to the bearings and a wider arm, the result is a wider truck without any abnormal bearing wear.