I also want to have a nitro stampede, but one time after watching a ton of vids on youtube, I decided to get a stampede 4×4 vxl. I have few experience on electrics, so I watch many videos and read many books to learn about electrics.
I have the following in the mail to me now:
- 2 x 7200mah 2S 50C Gens Ace lipo battery
- RPM front carriers/c-hubs
- RPM rear carriers
- 4 new stock slider axles
- 4 new chevron style tread stampede 3.8 4×4 (non-vxl) wheels/tires (I like the tread pattern on my other MT’s)
- 14T pinion (probably unnecessary now)
- 4 12mm alloy wheel hex’s
- new fast eddy bearings for the diffs, all 4 hubs, steering and center shaft
From what I’ve read (and what I see on the truck), the stock sliders won’t hold up very well. I’m hoping the new ones hold up a while.
Spent $300 shipped on the truck and $130 on parts. Buying new locally with tax would have been near $520, so I’m $90 short of that. I totally should have just bought new.
As it sits now.
Slayer tires rub here:
That I do. Nothing like a good day burning through a few thousand cc’s of fuel. Those days are few and far between for me now that I run alone. When there was a group of us, I could tear through half a gallon in a day. Now I’m lucky if I burn through 2 gallons a year. Lol
Here it is now:
Rpm front carriers/spindles
Fast Eddy bearings everywhere but steering and rear. Steering bearings seemed ok and I’m still waiting for RPM rear carriers to put new bearings in.
12mm alloy wheel hex’s
New stock slider axles
Gens Ace 7200mah 90C 2S lipo(s)
I also pulled the diffs apart apart, cleaned, shimmed and loaded with 50K diff oil. I didn’t have any 30K around. Used new bearings on both. Replaced X-ring o-rings in the diffs with some I found on McMaster-Carr. Hoping the hold up a while. The x-rings in it were all torn to shreds and there was almost no grease or oil in either diff.
Also, the drag link in the steering had a ridiculous amount of play. I ran it today with all the new stuff and it was like driving a drunk snake when on concrete. When on hard power, it would torque steer really badly. I’m not 100% sure, but the slipper may be slipping a bit much. Is hard to tell, the traxxas motor is really notchy and it’s hard to hear much over the noise it makes with the drive train. Wheelied whenever I wanted, top speed could be a hair faster, but I don’t want to over gear the motor/esc. May look around to see if I can find something with a few more RPM’s, or at least wait until it warms up to get proper temp readings.
Anyway, replaced the drag link with a piece of 3mm threaded rod and a couple ball cups. Had to bend the rod and grind the the tops of the cups and where the ball ends mounted in the drag link holes for clearance on full lock and to avoid rubbing on the center axle. Not sure how long that will hold up.
It’s hard to see, I should have taken a photo when I had it apart.
Trying to at least find some 3x5mm bronze bushings or something instead of the shoulder bolts so the bushing will wear instead of the drag link.
I didn’t have much time to run it today, but I ran it pretty hard for 15 minutes straight. I wanted to see how it did so I could get whatever sorted for the weekend vs rushing through whatever this weekend then going out to bash. After 15 minutes, the motor was a bit warm to the touch and it was 40F outside. The esc barely felt warm.
I rebalanced the Gens Ace 7200mah pack and it took 3000mah on the dot. So it seems, I should be able to get 35-45 minutes out of a pack. Since I have 2, I can easily run hard for an hour with this, then another 1.5 hours with my ERBE before my packs are all dead.
Well, after regearing to a 13T pinion, I took it out to the parking lot after logging off from work the other day to try it out. It was drizzling rain a bit so the ground was wet and it was a bit cool, 40F or so. So, grip was minimal at best. After 5 minutes of buzzing WOT up and down my parking lot, I stopped in the middle and tried to get a wheelie… all 4 tires spun, then one side grabbed and it slammed WOT into a drain pipe. Blew apart a shock and snapped one of my new RPM rear carriers in half.
I don’t have any support parts really for this other than what I’ve taken off and the spare bits/pieces the guy included. I have an integy motor fan somewhere, but can’t find it. Have a feeling I tossed it… anyway, I lost the bladder out of the shock, so I couldn’t rebuild it to run it this weekend. In my many drawers of parts, I remembered that I had bought a slayer at some point, so thought maybe I still had the springs for it and maybe I could cobble something up with a spare set of revo shocks. After finding they are a bit short for the rear and too fat for the front, I dug in my savage spare parts… back in the day, I had 8 OFNA 9.5 buggy shocks on my savage. I still had the shocks along with a full set of front/rear shocks from the OFNA ultra buggy I sold recently as I had put new ONFA 9.5 front/rear shocks on it. Unfortunately, the 9.5 rear shocks were way too long. I did fit them, but didn’t take any photo’s. I ran it for a bit, but it was very tippy since it stood so tall in the rear.
Then I decided to re-seal and oil the OFNA Ultra front shocks, since I had spare o-rings and whatnot. They fit on the rear pretty nice and the springs feel almost the same weight as the stampede springs:
With that done, I could run it tomorrow if it warms up a bit out. The shocks fit pretty good, but are too long for the front, so not sure what would fit there that would be 1/8th buggy tough. With OFNA shut down, replacing shafts and whatnot would be a pain, but I was just trying to get it together to perhaps run through a couple packs when it warms up Sunday.
I just ordered a full set of stampede shocks/springs to replace mine along with alloy shock caps as that seems to be the weak spot noted on many threads at the traxxas forum. I also got a center diff. Figured maybe I could eek a bit more life out of the stock axles before dropping $100 on MIP’s. With the 3 or 4 outings I’ve had so far, the ears on the new axles I installed are getting a bit of slop already. Still, adding a center diff should help the front/rear diff life as well without fighting with the slipper that’s annoying to adjust. Time will tell.
Got another upgrade, MIP X-Duty CVD’s. Got them with $ my father in law gave me for my b-day. As a 40yo guy… it’s weird getting cash for your b-day, but it’s a nice gesture none-the-less. He knew it was going to somehow end up being for RC parts.
Unfortunately, the rear ones didn’t come with the little grub screws with nubs to lock the hubs onto the diff outputs, so I found a couple HPI standard pins to use for the time being. Also had issues with the rear bearings binding when I tightened down the wheel nuts. These hubs are the slotted axles without hub pins, so the hub slides until it can’t when you tighten the wheel nut. They come with a 2mm and 1mm shim, one for the back side (not sure what that’s for) and one to go between the bearings. In my case, I needed 2.5mm between the bearings, especially with the RPM arm on one side. I added a couple .25mm shims between the bearings with the 2mm shim they include and was able to tighten the wheel nuts properly without any binding. The fronts seemed to not have an issue.
Of course, I took today off for my b-day and the temps outside are a high of 26F. Supposed to get to 32F Sunday, so perhaps I’ll give them a go at the skate park then. See how much rotational mass these add.
I also used a wax based lube vs grease on the joints and slider part. That seemed to do well on my bones/cvd’s on my savage-x, so guessing it will work well here at not collecting dirt while still lubricating.
I also had to grind out the hub area on the front c-hubs. Guessing the RPM hubs have a bit more material than stock. Without grinding, they fit, but fit tight and bound pretty bad. The larger sanding drum for a dremel was the perfect size to take out about 1mm and now they spin nice and smooth without binding.
Also installed the alloy spur bearing hub vs the stock plastic one. Can’t see it, but it’s in there. Guess the next logical upgrade would be to get the diff cups that use the x-bar and x-pin retainers… may worry about that if I decide I need to go with a larger motor and 3S to avoid overheating.
I have to say, this rig has been a total blast at the skate park. Electric is a ton of fun so far!