the beginnings of weapon X-updates 2/21/2011

[treehugger]

If reversing the motor becomes desired here is a cheap option. It’s fairly long, but it looks like there might be space there. These motors are strong and last forever too. Looks like an awesome project.

http://cgi.ebay.com/Traxxas-Titan-550-Reverse-Rotation-Motor-E-MAXX-E-REVO-/360178280477?cmd=ViewItem&pt=Radio_Control_Parts_Accessories&hash=item53dc4c681d

so roughly how many turns do you think it is
Paul

[Toasted Coastie]

I'm going to guess 21t...

regular: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXF54&P=V

reverse: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXVDT4&P=FR

[jwscab]

I hope to put a brushless system in it, but we will see.

[jwscab]

Got some time to assemble some things to check wheelbase, and drive system, width, and a potential body for this thing. I'll snap some pics later tongiht, but this thing has practically fallen together.

the losi and traxxas sliders work together, I never knew they were the same spline!

wheel base on my shot in the dark chassis drawing is practically dead on. I'm shooting for a nominal 10.8" wheelbase, with adjustment to 10.7" and 10.9" by moving some shims.

the traxxas belt even fits, albeit kinda tight. I think the belts stretch, so this is probably a good thing.

the great and not so great part, is that a losi jr body fits on the car like a glove, but now I am going to have to find one. the body matches the contour of the chassis almost perfectly!

is anyone repro'ing the jr body? is the pro or something like it very similar? the jrx2 body has an extra radius in it behind the front wheels where the jr body is a straight line more or less, and I think the pro does also.

does the xx or xxx body do the same thing? ie, can the xx body fit on a jr chassis?

[jwscab]

some pics:

[shane]

How is this project comming along, jwscab?

[Mr. ED]

I have been looking for this thread; couldn't remember the title
It downed on me that swapping the moter over to the other side doesn't serve any purpose if you do it by putting in a reverse-rotation motor.

The dynamics stay exactly the same so you don't get the advantage a 4 'th gear gives you

[jwscab]

august and september have been realllllllly busy....so the last pic is as far as I got.....but on a good note, I got my lathe finally up and running so now I can make fancy cool parts....of course, when I get time.

the next step will be to cut out the chassis and start bolting stuff together, then mocking up the rear shock tower. I hope to forge ahead on the car as early as 2 weeks from now.....

yes Mr Ed, in order to get that benefit, the motor has to stay the same rotation, and the only way to do that is to add that 4th gear interface.

edit: that is a lie. I did do some other things.......I changed my mind on the yellow wheels so now I'm going to use jconcepts rulux wheels all around. I love 'em, and with a combined tower order coupon, free shipping, etc, the wheels were pretty much free.....

[Mr. ED]

4th gear or change to a belt and pulley configuration instead of pinion and spur

[jwscab]

the creation of the 'low-buck' thread coincided nicely with some spare time I managed to get due to snow days, and extra time here and there.

my lathe is also up and running so making spacers and other items is super easy for me now.

first we'll start with a sheet of yellow G10 fiberglass.

some holes drilled, some for actual use, some to make it easier to cut out the shapes.

after some cutting, filing, drilling, and we get some test fit with temporary hardware:

cutting out 'X' brace:

[jwscab]

some final test fits, I need to trim the 'X' brace a little, countersink the bottom screws, and put everything together for a final fit.

couple problems I have.....rookie mistake, I put some holes very close to the edge in a couple places, so there is a possibility of having some weak holes once countersunk, but I don't think it's that big a deal.

I need to make threaded spacers for the top brace, the ones on there now are through-mounted, leading to some really long hardware. just makes assembly easier with hardware mounted top and bottom.

I may need to raise the whole rear bulkhead by one chassis thickness(making a small plate to fit underneath) to allow for more motor adjustment. The 4tec had a huge hole in the chassis to allow the motor to drop down flush with the bottom of the chassis. I'd rather raise it up, since it would weaken the chassis how I have it laid out.

otherwise, the final build will be the following:

custom chassis and brace, rear shock tower, based on jrx2 tower
mix of B2/B3 front suspension
custom spacers
B4 Rulux wheels
traxxas E-4tec rear bulkheads and top shaft
traxxas Nitro 4tec gear diff and eccentrics
losi xx4 rear arms, VLA rear hubs, axles, cross-shafts and standard losi inner slider
traxxas truck outer sliders, output yokes and cross-shafts
associated ball cups and some kind of turnbuckles
B4 cell carriers
B4 blue shocks
losi xx body
custom hinge pins for rear of car, xx4 pins would also work, but I can make them.

[Charlie don't surf]

[Toasted Coastie]

rolling right along man, looks great!

[Mr. ED]

I'm partial on the design of the brace: the shape doesn't help much torsion-wise. For now I'd certainy advise you to add a stand-off along the middle line; in front of the batteries and maybe one more further aft.

[jwscab]

it is stiff as he$$. the x brace works both longitudinally and torsionally, probably the best way to connect 4 points, engineering wise. for me, it was just the easiest way to implement it, and ties nicely into the 'x' theme. if you notice, the arms have 'x' type members as well.

if you think about it, trying to push the front right to the rear left the loading is along a full single beam, and vice-versa, they just happen to be joined in the middle.

I do think a standoff mounted in the center is a good idea. I may put the holes in, and see if it's needed.