New Savage Center Diff ideas...... - Page 2 - RC-Monster Forums

roost · 10.17.2011, 08:51 PM

Looking good! hopefully Mr. Mike allows a few extras to be exchanged

are you making up custom dogbone(s) too?

RC-NUT · 10.17.2011, 09:19 PM

This setup uses the aftermarket flux center driveshafts.

http://www3.towerhobbies.com/cgi-bin...2&I=LXGPE9&P=K

http://www3.towerhobbies.com/cgi-bin...?&I=LXGPE8&P=M

I haven't ordered them yet or I would have drawn them in there.

Gdot · 09:03 AM

hey those are the same as a stock replacement so dont you still need longer ones? hpi measures pin to pin and those are measured pin to cup pin so they arent actually any longer than stock flux. i though they were also and ordered one a while ago to try on a flat chassis project i wanted to make, but it was the same as the 78 with the stock drive cup.
your chassis pics look good. must be a low kv motor you have

Gdot · 10.22.2011, 09:02 AM

i just figured out you maybe made the chassis plates shorter to make up for the more small center diff. is that right?

RC-NUT · 10.22.2011, 05:55 PM

Im using 2 of the rear drive shafts. When I started the project I centered the diff between the front and the rear and then measured the distance. I determined that 93mm was my sweet spot so I searched online for all available dog bones and universals of that size. It turned out the HPI drive shafts worked.

They arrived last night so I need to model them in solidworks and see how they fit.

Quote:

must be a low kv motor you have

The motor is a 1600kv

mothman · 11.05.2011, 02:58 PM

Is this the front or the rear? Do you have the other measurement as well?

RC-NUT · 11.05.2011, 11:58 PM

That was for both. I have the diff centered in the chassis.

mothman · 11.06.2011, 09:50 AM

Quote:

Originally Posted by RC-NUT

That was for both. I have the diff centered in the chassis.

No what I meant was the measurement for front or rear of LST2 CVD.. Or do they have same CVD for front and rear?

roost · 11.06.2011, 01:02 PM

Is this set up for stock length or xl?

RC-NUT · 11.27.2011, 10:08 PM

The LST2 shafts are the same length for the front and rear. It would have been sweet if they fit.

This is going to be a standard length build.

Design #2 is under way. I've flipped the motor 180 deg so it's now in the front of the truck. I think that will be better for weight distribution. I'm also working on a new bracket layout. The heavy duty Flux CVD will be in the rear and a 110mm dogbone will be in the front.

RC-NUT · 02.14.2012, 11:34 PM

It's been a while since I updated this post so I thought I would share my progress.

I'm working on the second concept now that is a lot stronger and probably over-kill but that's what makes it fun. My Kershaw tranny would constantly bend hardware from the weight of the motor & tranny.

I changed the hardware from 4-40 to 6-32 screws and all parts are machined from 1/4" 6061-T6 stock. It won't be light but hopefully less than my last 14.8pound Flux. The motor mount changed from vertical slots to a pivot. Easier to mesh and less chance of slipping.

Did I mention the motor also flipped 180 deg and is now in the front of the truck above the servo? The shorter universal will be in the rear where most of the torque is applied. More weight balance to help with traction as well.

RC-NUT · 02.14.2012, 11:36 PM

More pics......

Also an alternate motor plate with heat sink fins. I'm worried about strentgh though. To get as much surface area as I can the actual meat left to hold the motor is only .100" thick.

RC-NUT · 02.14.2012, 11:37 PM

With heat sink plate.

rcs2022 · 02.15.2012, 01:21 PM

I'm really liking the project, myself am still in the middle of something similar.
If you don't like wheelies and want more planted stance, definitely go with motor in front flipped backwards, thats what i did, and it drives really great! still need to update a video in my build.
What esc are you planning on using?
If you are going for mechanical brakes, the motor heatsink you modeled can be thicker to clear the brakes, then you won't be worrying about strength.
planning on machining it yourself or getting it done in a machine / cnc shop?

RC-NUT · 02.15.2012, 05:31 PM

Thanks man. I'm not planning on using mechanical brakes. My last Savage build had a problem with the brakes being too strong on the 1717. If I tapped the brakes the truck would do a violent front flip. I had to program it out on the MMM. I will use the same ESC again with the 1520.

I plan on machining some it it myself and farming the rest out. I have a bridgeport at work but I'm not the greatest.

I hope with this design, and some programming, I can get on it and the truck just takes off. Before, anything over 1/2 throttle and I was on my lid.