New Savage Center Diff ideas...... -
10.14.2011, 07:08 PM
Well I tore the truck down and sold the Kershaw tranny and 1717 motor. I picked up a 1520 and HB D8T center diff instead.
I have 3 different concepts in my head that I want to try. I'm close to finishing the first one in Solidworks so I thought I would post some pics. I just need to add the shelf for the RX and ESC. Possibly do some weight reduction.
- What I don't like about this idea is the center of gravity is very high.
- What I do like is the center diff drops out the bottom while the motor and housing stays in place.
I can drop the center diff out the bottom of my truck and it is a big plus. If you move the motor to the side you will able to get it a lot lower and fit something beside it to help counter balance. My motor still sits a bit across the center line.
Ya the spur gear does hang lower than I like. It was either that or the motor sits higher. I intentionally designed it using a 50T spur gear so I can always use a smaller one. Plan B was to take one of my RPM skids and see if I can heat it up and form it around the spur. (Or just cut a slot and deal with it)
The second concept is going to move the spur gear higher and hang out the side of the chassis so the motor sits lower and off to the side like _DV's layout.
Nice build _dV. I just went through the whole thing. Very clean and solid. I like how you can fit 4s and 6s inside of the tvp's. The slipperential looks a lot smaller than I thought it was.
I was originally concerned about having a cutout in the skid plate for the spur. After countless runs on various terrain though I can safely say it's not a problem. I haven't had a single issue with small rocks being jammed or the spur being damaged(metal spur). I do have a large cutout though due to the slipper being a larger diameter than a normal diff.
One thing that I did notice though is that your diff is an enclosed area. If small rocks get in there the only way they could get out would be through the cutout in the bottom, or if the truck turns upside down.
I think RCM has a universal diff mount that can be integrated. Once I settle on a design I like, I plan on making 5 or 10 of them. It tends to be cheaper that way when you have them machined.
1. Opened pocket around diff per _dV's suggestions.
2. Slotted hole for motor shaft and reduce diameter to keep dirt out.
3. Added shelf for electronics.
4. Chamfered some sharp edges.
5. Added slots on 2 sides for motor wire routing to ESC.