1/10 4WD build

95PGTTech

Well-Known Member
Messages
338
Wife has COVID, which leaves care of all 3 kids (3.5, 4 months, 4 months) to me, so if I get an hour during the middle day nap to play that's a lot. It's okay, I've been mostly waiting on parts.

Traxxas 6878 slipper, front and rear diff housings 6880 and 6881. My HOPES were that the slipper would be a direct-ish swap - not much as far as dimensions available but what was, measured pretty close to what I had in the ECX slipper. Not even close. Won't even begin to drop into the ECX space provided for the slipper, let alone get the bearings to line up the ring gear. Looking at other options, mostly Team Associated, or swapping the motor mount/slipper mount assembly in its entirety.

Diff housings were equally a miss. I was hoping that the bottom would line up mount wise with the ECX chassis then it would just be up to me to figure out mating to the driveshaft and bumper mounts (the shock tower is easy, just swap to Slash towers). One thing I didn't figure is that on the ECX the lower control arms mount to the differential assembly via the pin braces. The Slash, they mount to the bulkhead. Slash bulkheads (and LCG lower center of gravity) are impossibly different than ECX, I can't just swap to them.

This thing is going to hit the shelf for awhile. I found a replacement slipper....$53 but whatever. I found an old thread back in 2014 where people were already having problems with this slipper holding power (and ring gears seperating from the diff cup, which I haven't experienced). I need to work on the 2wd, and think about this guy. Right now, the most likely scenario is return it to the nice driver it was on 3S power and move onto a slash chassis at a later date.
 

Attachments

  • A38BCBCC-AB10-4499-973C-5F0A5192B6D1.jpeg
    A38BCBCC-AB10-4499-973C-5F0A5192B6D1.jpeg
    156.3 KB · Views: 2
  • 2681795A-0106-4FE0-8665-016631F26644.jpeg
    2681795A-0106-4FE0-8665-016631F26644.jpeg
    152.6 KB · Views: 2
  • 80E6AEF9-F154-4DA5-8256-46A7F53A3B7A.jpeg
    80E6AEF9-F154-4DA5-8256-46A7F53A3B7A.jpeg
    200.7 KB · Views: 2
Last edited:

slick2500

Well-Known Member
Messages
423
Location
Rapid City SD
Wife has COVID, which leaves care of all 3 kids (3.5, 4 months, 4 months) to me, so if I get an hour during the middle day nap to play that's a lot. It's okay, I've been mostly waiting on parts.

Traxxas 6878 slipper, front and rear diff housings 6880 and 6881. My HOPES were that the slipper would be a direct-ish swap - not much as far as dimensions available but what was, measured pretty close to what I had in the ECX slipper. Not even close. Won't even begin to drop into the ECX space provided for the slipper, let alone get the bearings to line up the ring gear. Looking at other options, mostly Team Associated, or swapping the motor mount/slipper mount assembly in its entirety.

Diff housings were equally a miss. I was hoping that the bottom would line up mount wise with the ECX chassis then it would just be up to me to figure out mating to the driveshaft and bumper mounts (the shock tower is easy, just swap to Slash towers). One thing I didn't figure is that on the ECX the lower control arms mount to the differential assembly via the pin braces. The Slash, they mount to the bulkhead. Slash bulkheads (and LCG lower center of gravity) are impossibly different than ECX, I can't just swap to them.

This thing is going to hit the shelf for awhile. I found a replacement slipper....$53 but whatever. I found an old thread back in 2014 where people were already having problems with this slipper holding power (and ring gears seperating from the diff cup, which I haven't experienced). I need to work on the 2wd, and think about this guy. Right now, the most likely scenario is return it to the nice driver it was on 3S power and move onto a slash chassis at a later date.

I've been wanting to make a MT based on the Rival MT10 with a Pro4 SC10 chassis or a Pro4 SC10 with MT tires and the nerf bars removed.
 

95PGTTech

Well-Known Member
Messages
338
I've been wanting to make a MT based on the Rival MT10 with a Pro4 SC10 chassis or a Pro4 SC10 with MT tires and the nerf bars removed.

I actually started looking through parts diagrams/owners manuals for 1/8 4x4s, since that's basically the power I'm trying to hold up to at this point. I was able to find a few different models that are potential candidates, so I have a bunch of diff housings on the way to me now to measure since no one seems to list any sort of dimensions online (even of aftermarket aluminum $$$ pieces). The one I am most hopeful for is the AARMA Kraton 6S EXB/Outcast 6S EXB stuff, but I've learned to not get my hopes up too high. What I showed in pics of the process of ordering and returning parts to get the axles/suspension sorted out like I did is literally probably 1/10 of the actual parts I had on hand to try. I'm basically using Amazon Prime as the old school LHS that would carry everything and we could just go to the parts racks and start mocking stuff up. Too bad none of them exist anywhere near here anymore, the overhead on carrying the kind of inventory I'm talking about (I have five different manufacturers parts on the way) is astronomical and would put a brick and mortar out of business
 

95PGTTech

Well-Known Member
Messages
338
slash slipper "in" ecx ruckus
28E5DE3B-5DD0-4E07-BD32-71FDFD639C12.jpeg


long story short, but I took one of the old rear diff outputs that I had snapped off, ground some bevels in it and welded it to the back of the slipper. I test fit it a million times in the chassis between tacking it to try and make sure I was getting my lengths correct and keep it spinning true. This is the final product after welding, grinding, and balancing it. This means I *should* never have to replace a broken rear diff input cup again, because there isn't one, it's direct drive. I didn't really take great pictures of it, but I disabled the lockout by removing the 4 nuts/bolts through the slipper. I added that extra washer you see and upgraded the slipper to a triple disk with some slight machining. I'm back to using the gasket material pads (x3) roughed up with 150 grit, superglued, and I put a 36 grit finish on all the clutch plates. Slipper set to full tight backed off 1/4 turn and red loctite. Hopefully this can hold up to 3S power and the traction we are making.
61B99CFD-9F2E-4047-AE70-33D3F543C66A.jpeg D4F3410E-C66D-4B40-BD27-BB6CE852BD1A.jpeg



the obvious downside to doing this is that in order to get the slipper out of the car, you'd need to pull the top of the rear diff housing off to get the pinion out too. honestly, this stupid car design you can't get the slipper out (or even tighten it!!!) without taking the entire spine/upper chassis out. once that is out, getting to the diff is removing the rear bumper/wheelie bar (4 bolts) and then there are two bolts left to seperate the rear diff upper housing and the rear suspension.

the obvious upside is now there is no more joint to break and the rear suspension and rear pinion are supported by 4 bearings (instead of two each). hopefully this also eliminates the deflection issue of the rear pinion cup (diff input cup) that caused the nose of the other rear diff housing to break off. again, this is all experience and best guess theory at this point - I could also hit the throttle once and this become a claymore mine. this is not an optimal solution in my book, as I've certainly made a completely one-off prototype custom part (downsides of that discussed at length before), but I was really out of alternatives.
7EAA6EE0-0D74-43EA-B72C-632D289D19EF.jpeg


rear diff, rear suspension, motor, replacement ESC installed
31C90D25-1922-4C48-9B8F-77BE882B1AD7.jpeg


trimmed away some from ECX231010 kick plate (the piece that supports the entire front assembly) to clear the new steering idler arm while I had it off
1A20991A-ECEA-436F-BEA6-81951058030A.jpeg


that temporary shock I used check out the lower aftermarket chineseium alloy HobbyPark lower ball end. I don't even jump this thing lol
80DF2698-EE06-4104-8FB0-FF526DAC1FD3.jpeg


starting point for the front end
59FE2968-FACF-480D-8A18-AAB6AAAF64AB.jpeg


finally got around to trying to cut the new tungsten carbide 3mm stock I got for hinge pins...oh my is this stuff hard. cutting then grinding to exact length was time consuming...and I got a reminder in metallurgy when I went to gently put a piece in a vicegrip to hold it (so I could stop freehand holding it to grind it) and it immediately shattered. The harder a metal is, the more brittle it tends to be, so this is going to be an awful choice for a hinge pin. I went back and ordered some high strength grade 5 titanium 56B9D2E1-731C-4559-AF29-FB7AC8A3318E.jpeg
 

Attachments

  • 5C6A8493-22E2-420E-94DC-8655AD91C0FC.jpeg
    5C6A8493-22E2-420E-94DC-8655AD91C0FC.jpeg
    200.4 KB · Views: 1
Last edited:

95PGTTech

Well-Known Member
Messages
338
Got around to the front end, I had a to do list from a long time ago for the next time I tore it apart (plus fixing the damage from that big hit it took against the raised garden bed 4x4). Finally got the H-R hinge pins out of there. I think the only piece of their trash I still have on this thing is the steering brace.
A532C3A5-1E0D-48A6-BACF-B26D2F5850A1.jpeg EDE565CD-33D1-4D6B-8335-57C6AA25C307.jpeg 44E827DC-FA23-4C19-994D-27B75050F7CA.jpeg




I always thought it was weird that where the camber arms and the tie rods for the front there is some gap/free play (verified slash correct part numbers). I just put washers in each side to tighten it up (I'd later solve and fix this in the next post.

E7437449-0466-4E03-9A3C-758406136BAA.jpeg



Even hinge pins that don't seem bent, are when rolled on a flat surface or compared to a known good one. I replaced both front pins with 3mm titanium grade 5 high strength. It was very interesting cutting them, they throw off insanely bright white (not yellow-orange) sparks. I'll do the rear next time something breaks and I have it apart. I did replace the front RPM a-arm whose hole got just a little slotted on that big impact (left).
4E557D1E-7727-4E4E-B1B2-837A9AB101D2.jpeg


Tore apart the diff and did it to match the second version I did the rear one in. 30k fluid up front, two large washers outside the spiders, one inside, added the Traxxas t-bone, glued the ring gear bolts
4EBE9919-3B1F-4039-B588-EA1D753F0496.jpeg
9CEA5EF1-E7AB-4398-BA77-693EFD0A5914.jpeg
495EF561-A714-4518-846C-B84B0DAC9E02.jpeg
2CE47900-FE5B-4C8D-9106-357F68B5CBBC.jpeg
 

Attachments

  • 6D23DF1A-00DB-4EF0-B7EB-15EDF9FCC206.jpeg
    6D23DF1A-00DB-4EF0-B7EB-15EDF9FCC206.jpeg
    106.5 KB · Views: 0
Last edited:

95PGTTech

Well-Known Member
Messages
338
And more
 

Attachments

  • 113ABDA7-5ECC-4D49-8AB8-0D2964632A31.jpeg
    113ABDA7-5ECC-4D49-8AB8-0D2964632A31.jpeg
    237.1 KB · Views: 0
  • F50A35C3-47D2-439B-B480-F06242A7D423.jpeg
    F50A35C3-47D2-439B-B480-F06242A7D423.jpeg
    164 KB · Views: 0
  • 5C20B4B7-3380-4B69-8E05-2C962AFB6FBE.jpeg
    5C20B4B7-3380-4B69-8E05-2C962AFB6FBE.jpeg
    152.2 KB · Views: 0
  • 0126FFD0-155F-4C16-BE0C-B5EB16A48AAA.jpeg
    0126FFD0-155F-4C16-BE0C-B5EB16A48AAA.jpeg
    145.3 KB · Views: 0
  • 1A7760F2-9CF0-4098-961B-60B955E2CEA9.jpeg
    1A7760F2-9CF0-4098-961B-60B955E2CEA9.jpeg
    111.7 KB · Views: 0
  • C9682E4C-BE52-4744-A634-16B102595FE0.jpeg
    C9682E4C-BE52-4744-A634-16B102595FE0.jpeg
    241 KB · Views: 0
  • 77B19C4F-C02C-41D4-A999-99415E68A6AC.jpeg
    77B19C4F-C02C-41D4-A999-99415E68A6AC.jpeg
    158 KB · Views: 0
  • B1EDE86F-6E5C-43E6-81B1-C3132065A03E.jpeg
    B1EDE86F-6E5C-43E6-81B1-C3132065A03E.jpeg
    162.4 KB · Views: 0
  • BD5FC977-EBDE-40F4-92CE-A3AAE330CE14.jpeg
    BD5FC977-EBDE-40F4-92CE-A3AAE330CE14.jpeg
    192.1 KB · Views: 0

95PGTTech

Well-Known Member
Messages
338
Got a couple minutes in today. Got another 3S 100c so I don’t have to keep swapping back and forth all the time. I’m a big fan of my hard case Zeee’s but they don’t offer a xt90. Hobbywing tech and I had a conversation and long story short it’s all I will be using unless a XT150 is called for. The graphene 4S I have seems to do well, so I bought their 3S offering.

I checked the weight balance and it needs to go fully forward so we hacked up another of James foam bricks
B46E3313-BE46-467B-847F-57E97CFAA522.jpeg



Still don’t like how it sits in the battery tray (particularly the things the wires need to get near as it exits the hold down), so I just got rid of the stock stuff, ground down the hump in the chassis that kept it from going even farther forward, and machined slots for a Velcro strap. I need one a little longer.
I should have room for the GNSS behind it, but I may need to grind off the matching rear wall. So three of the very few stock parts on this thing are now gone 🤣

C9B52C25-EC87-4D7F-BEBF-4DD78A560572.jpeg

BC299B41-9EB9-4B9A-956A-804C9D1BD72C.jpeg E393F3E3-5837-4E40-B8E2-C072CB9CB6F8.jpeg
832ED6D2-CFF2-449A-A293-4DF7ACF6D606.jpeg


Traxxas 3643x arrived and installed. Remember when I was wondering why there was so much more width in the front caster block, then I found some exploded diagrams that listed these (I want to say Slash ultimate). Beefy AF, impressed 7mm adjusters (from 5mm). They say TRX on them, I know Traxxas aluminum caster blocks say it too maybe it’s a whole lineup. The included card gave me the numbers for the tie rods and rear camber rods.
A73FEB23-91D5-4069-A284-C97CD90BFBD3.jpeg


Threw some wheels I had sitting around on and used the old camber rods as makeshift front shocks (remember I broke that GTR shock…the rebuild kit I ordered…based off the paperwork included with those shocks was wrong. I was able to find the right stuff and it’s on its way later this week
F6C7DC49-E43A-4ED0-9D19-1174E1A7D477.jpeg



I took it outside and ran it for a few minutes. It has some…interesting geartrain noise. Hard to describe, definitely different pitch than before and increases in speed, but not in a way that’s terribly concerning. I didn’t get anywhere near full throttle (being that my front suspension is more or less a solid pipe from the shock tower to the LCA), but it went and turned and stopped without anything exploding or some failure that abruptly ended the drive. Progress. Went digging through my parts boxes and found the original battery wire clip. Actually added a stock part back on this heap 🤣
04B59FE3-1BBD-443E-B66B-1D56C3686177.jpeg
 

95PGTTech

Well-Known Member
Messages
338
Put some shocks in that I have sitting around. Parts for GTR will be here Thursday and I’ll align it. Confirmed camber arms do need to be on backside of shock tower to clear shocks


Clipped some together. Seems to be holding up so far. Hobbywing warrantied my Max 10 SCT (at cost) despite being out of the warranty period. “m” from tech spent a long time troubleshooting with me and prompt email responses…like minutes. We did a full diagnostic and decided it was my fault I drew too much current through it (4000kv on 4S 100c). They will be all we ever run for ESCs and I will run their motors when possible. It’s rare I run stickers on anything (free advertising), but they definitely earned their spot. They also said stop running deans on anything. XT90 for 4S and below, XT150 for anything above

Leaves a little soft, but I have the ESC set to punch 1 (lowest). I may bump it up a little, and putting it’s proper rear tires on will help (Proline Badlands). Overall it drives really easily and handles the terrain we run well, temps were good. I have spent a lot of time researching and ordering new differential housings from other 1/10 and 1/8 models (as well as motor/slipper/center diff mounts) and the unfortunate truth is just nothing fits. I could make it fit, but I mean in terms of relatively bolt on. I think we have reached the horsepower limit of the stock chassis. For now.
 

Attachments

  • 981C1725-005B-4873-85C9-1FA5A9319E8E.jpeg
    981C1725-005B-4873-85C9-1FA5A9319E8E.jpeg
    168.5 KB · Views: 0
  • 8883AC96-68C3-4C58-ADF5-3D8C4326538B.jpeg
    8883AC96-68C3-4C58-ADF5-3D8C4326538B.jpeg
    209.7 KB · Views: 0
Last edited:

95PGTTech

Well-Known Member
Messages
338
Finally got the correct parts for the GTR shock that we broke. I included the pic of the correct stuff I needed to get. What's super annoying is in the shock kit (the original package) there is a parts diagram breakdown with part numbers. That's what I ordered the parts off the first time that were wrong. They look to be for a standard GTR shock, these are the XXL ones. I was able to find a listing for the XXL piston online, and then went backwards and found what models that was compatible with and ordered the other parts based off that. Got it in, they seem all good. I put it back on the same side I crashed it on (L) and marked it so I know in the future if we have a problem it just might need to be totally replaced.
D5C06EAA-DAA1-464B-A559-88A53BDAFF1B.jpeg BC70A8C1-0586-43F9-A1C1-BD0996F99030.jpeg B8C26BA8-8FF5-467D-9AF9-C1A6AD7B1803.jpeg 9D1189D7-A63F-4A69-B522-34B58B6A0B97.jpeg




Found replacement just tires for the Traxxas wheelie bars. superglued on now
0D953275-BCE3-42B3-8655-75F06E1F12E7.jpeg


Proline front wheel centers finally came in. They are narrower offset than the "narrow" plastic options. Will have to see if the decreased track width affects anything (the switch from the big tires and the big offset to the narrower tires and narrower offset actually helped)
3AF9EB24-7750-4915-8B4C-36F27FB25E5B.jpeg
0343BB95-AAB7-46B6-981C-2A66D556E80F.jpeg


Put ESC back to punch 3 (middle setting)
29C315BD-47DC-4947-A1BB-DF6C5A336668.jpeg


I'm not used to "to do" lists looking so close to done
72D4B708-B5AB-41F1-A0DF-79B06A389E4A.jpeg


Excited to run it, but been heat warnings every day lately. Even 8pm at night with the sun down it's still 90+ with 90% humidity
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
One of the other settings I changed was to reduce the braking force and reduce the drag brake. I would get hard on the brake at the end of runs and it would damn near front flip. Unfortunately, I underestimated that change on my first hard pass where I actually used the brake and put the right front tire into a 4x4 pressure treated raised garden bed at about 20mph.
A0108826-E13C-4F95-A533-E07D7F2EA5B6.jpeg D8EDA5E8-7062-43AC-9EE7-B70901910B39.jpeg B44162F9-6EC5-4D15-8AC1-9B91190169D2.jpeg C6953AB3-0F8B-4278-B828-9671E389C89D.jpeg 44135E83-BC2A-46D1-B16A-C055C8BFDF92.jpeg 15B3F026-D09F-4D51-8940-133B680903C6.jpeg


It could have been much worse. I replaced the control arm with the slotted hole since I had an extra one on hand anyway (from the last hit), cut a new set of pins, had a replacement tie rod, replaced the upper shock bolt. I must have forgotten to take a picture, but the inserts that the pins go into on each end...the front one got knocked completely out (I assume when the pin bent) and the rear one got slotted. Again, had the stuff on hand. 2 hours give or take - a 3 year old slows stuff down a little, lol.


I changed the length of the fronts from 54.5mm to 54.00mm. They are still grade 5 titanium 3mm.
731D5D22-2134-454D-89CC-73AF03A7A8E5.jpeg FACB0314-BA54-4285-8D31-F1C3E9871D8E.jpeg B2439D56-3885-4007-B496-0803513934F0.jpeg
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
Got a chance to run it again, managed to not hit anything, but five minutes in heard a pop then an increasing grinding noise with each pass. The metal on metal gear grinding sound that you just pray is the pinion came loose or the motor mount came loose and it spread the pinion/spur mesh apart.

Wrong.
864E3C06-881C-47DF-90EF-59A178730276.jpeg


In the rear I did the complete pinion tooth delete mod. The ring looks not terrible, there's one tiny chip out of one tooth and all the teeth are pretty sharp so it's really just a matter of time
EFE2F250-A012-4896-A9E9-19FFEB56D3C3.jpeg 5DB07A28-203C-44EF-8500-9FF3BBF3EB51.jpeg


Somehow I managed to get the front too, albeit less (probably since less power actually gets put to the ground, most of it goes to wheelspin). The pinion looks okay-ish and isn't missing teeth but there's clearly an abnormal wear pattern and the teeth are razor sharp.
BF9D9088-13B8-46EE-B7B5-7D21C5003F0D.jpeg


It's brutally obvious looking inside the diff grease that there are tiny metal shavings everywhere. this was red and tacky when installed (the diffs were cleaned spotlessly prior to putting it in).
D9412225-468D-4DC9-ACCD-732B6D4CB2B5.jpeg 04DFA92B-CF37-4A6D-B66B-4B7C6F8FD052.jpeg




I'm out of pinions at this point, so it's back to a shelf queen. ECX232022 is what I need. Ordering a complete diff (even if you could get one) only gives you the ring gear. Nothing on amazon, jenny, or ebay. Clicked every single link that comes up on google for all six pages of results. If there is one out there, they aren't advertising it in a way I can find it. Which is a really moot point anyway, because even if I could find one we're proving pretty clearly that these can't handle 3S power. I am never going to be happy on 2S with this after seeing what 3S and 4S can deliver (even for a short while). Pretty bummed, all this work to have the same result just for a different part failure/unavailability. I'm going to let it sit and we will play with the 2wd for awhile and think.

Solutions that come to mind (that aren't sell it):
1. Loosen the slipper back up, Punch 1 to minimize drivetrain shock, shorter can 36 motor (all methods to decrease torque applied from a standstill)
2. Put crappy tires on it like the stock ones to increase wheelspin
3. find another ring and pinion and cryo/rem polish to strengthen the gears
4. continue searching for another diff unit I can drop into the ECX housing
5. continue searching for an entire housing swap

1 and 2 I absolutely hate because they mean trying to get reliability by killing performance. 3 I have done before (for 1:1 anyway) but isn't a guarantee to work if the base metal is crappy to begin with and doesn't solve the availability issue. 5 has been really fruitless so far and 4 I haven't put much effort in because I thought 5 would be easier/more practical

Super bummed. I really, really liked how it drove on 3S prior to grenading these. Great balance of acceleration, speed, handling. Other than drivetrain, this thing has been really reliable too (outside of user error driving it into stationary objects at speed). I even like the way it looks, lol.
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
I managed to scoop up a new old stock chassis for a steal, which makes a lot of this mock up a lot easier (when it was running, I'd need to take off the entire front end or rear end to test fit a diff housing).
96A3D8FD-6A13-4D0D-8074-0E46EF6EA7CF.jpeg


Been doing a lot of research into a differential housing transplant. I think I've looked at the exploded parts diagram of every 1/8 and 1/10 4WD rc made decently available in the last ten years. I need one with a 4 bolt rectangular attachment flange, LCA pins on the diff housings, input centered on the housing (some Losi type racing ones are offset). Here are some of the ones that looked close enough from pictures it was worth ordering to try. It would be even better if they would post attachment dimensions online, but hey. Slash 4x4, Associated Rival MT10, Redcat Dokuno (1/10), Redcat Kaiju, Arrma 6S, Associated MT8 (which turns out to be the same as the Kaiju). None of these are going to be a direct bolt on. I have about a 3 page MS Word doc of notes I've taken, most diagrams I looked at you could see weren't even close enough to bother ordering. Of all of these, I think the Arrma 6S is probably the closest.
66DC0135-2291-44C9-925C-9B68F0EF1776.jpeg



If I'm going through all that work, I'm also putting a better motor mount and center diff mount in it (getting away from the slipper). I would have to find a way to make the stock stuff deliver power to the two differentials anyway. This is the stock Arrma 6S setup. The 4wd Ruckus stock wheelbase is 333mm. The Arrma 6S Outcast is 328mm. Kraton 377mm. Notorious 328mm. Talion 378mm. These are the Arrma 1/8 scales that use the differential housing I liked best and that motor mount/center diff setup so I know the driveshafts will be compatible it's just a matter of picking the right length ones. The other Arrma 1/8 in their lineup use a completely different diff housing where the chassis is actually the lower half.
9ABCCB0A-50E3-41F5-A44D-C6A1BC9A1379.jpeg
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
Hitting more walls. The Arrma 6S diff case that was my first choice the bolt holes line up front to back, and are pretty close side to side they'd need to be slotted 1-2mm each give or take. In the pic there are actually 2 bolts installed it's not just sitting there. I thought it looked really, really close (this is a 1/8 diff case on a 1/10 chassis) to the steering so I stole the steering bellcrank and, sure enough, not happening. the bellcrank extends into where the hinge pin braces need to be to hold the lower control arms and it actually even extends into some of the area of the lower control arms themselves. It already sits on the very, very end of the chassis so I can't push it out that way any further. This is the smallest of the 1/8 diffs I have that fit my criteria of close enough in pics to purchase to try, so basically all 1/8 diffs are out. Everything in the Arrma 1/10 lineup incorportates the differential housing as a molded part of the main chassis (you just attach a top half clamshell after you drop the diff in), so they are all out.

F0DB31BD-0AA7-45E6-84C3-32DE06BE955F.jpeg 32270339-1071-4F69-B23F-F030E66F8D0C.jpeg 0BA1AF7E-4280-45E3-933F-FFCE4814FE08.jpeg


Team Associated MT10 is the next closest in terms of size, it fits on the pad decently, but none of the 4 bolt holes line up. Two are too far apart, and two are too close together. If I ignored where all the bolt holes were and line the end of the diff case up with the end of the chassis and just redrill holes, it looks like the steering will clear. The hinge pin that I'd have to attach to the diff housing I have on hand doesn't seem like it will be a problem.

Untitled.jpg
657CE0FF-7C84-45BE-8C6A-E07118A2BA43.jpeg


The other 1/10 diff case I have on hand is a redcat 06045 (Dokuno according to my notes). The bolt hole spacing is actually physically wider than the front/rear chassis section. The bolts would attach to (literally) thin air. My notes do say that Redcat uses a variety of chassis and diff housings and I didn't do a deep dive into all of them, so maybe I need to look harder there.

5117662F-526E-415B-98A0-3778E3A7DFA6.jpeg


I've also looked into Tekno, Traxxas, HPI, Losi, and Kyosho and striking out left and right. Most don't even meet the basic requirements of flat bottom chassis 4 bolt attachment and LCAs that attach to the diff housing. If I drop the 4 bolt attachment requirement and just stay with centered outdrive and flat bottom chassis and LCA mounts and just accept that I'm going to have to redrill the mounting points maybe I can go back and it opens options up I'll check my notes.

I also had a thought on the toilet - the XO-1 is unique to the Traxxas lineup in that it is a flat bottomed chassis, but they bolt mostly slash parts to it. I showed earlier in this thread why slash housings wouldn't work (wrong bolt pattern, no LCA attachment), and why you couldn't just bolt on entire slash bulkheads. The XO-1 uses a special adapter piece that bolts the slash differentials to the flat bottom chassis, and gives it LCA attachment points. I ordered up the front and rear, I don't want to get my hopes too high but it's worth a shot. A huge bonus of those over other 1/10 differentials is the upgrades available for them that are already documented to hold big power. The XO-1 wheelbase is 404mm (1/7 scale). Ruckus may be on life support, but he's not dead yet.
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
Redcat BS213-010a arrived today (Blackout models). I knew it didn't have LCA mounts on it but it looked like I may be able to make it work. Same problem as other Redcat diff housing I had before - bolt holes are wider than the piece I have to bolt it to.
8FBC96F2-6BA0-4EDB-B94C-6F211207AAA3.jpeg
6D0D5AC4-CF4F-4614-A71A-13E996B1A293.jpeg




A little hope...XO-1 front bulkhead arrived today. Two holes match up perfectly and I started screws through them for the pictures. Obviously some clearancing of the ECX front plate will need to be done to get it to sit down tighter. It places the differential in a decent location front to rear, and those big plastic poles are the stubs for the XO-1 steering assembly...directly above where the ECX assembly would mount, so we know steering geometry should be in the ballpark of correct. The other two bolt holes are in areas where I could drill the ECX plate. There are two extras I could even drill if I want to. The rear bulkhead is on the way, so before I go nuts modifying this front plate I want to try that (on both front and rear, I possibly could just run two rears).
271716C6-FA52-4520-8AEF-06C1602F39BD.jpeg 1F1A730B-B8A5-40EF-A0BB-F79919D77444.jpeg 59AAD8C4-6AF9-48A3-AC48-53478713ECE1.jpeg

It puts the driveshaft a tad higher than I would really like having a bulkhead under the diff case, but it doesn't seem to be an issue on the XO-1. Based on where the control arm is, I'm going to be giving up some ride height/ground clearance for sure


EDIT:
This is LOSB3104 - front and rear gearbox for a Losi 10-T. It only comes as a pack of two. One is offset to the side, but what I think it the rear one is center output. It's the right general size and the bolt spacing is the same front to back, but not side to side. Not optimal at all, but close enough to hang onto for right now.

7F51FFBC-183B-44BC-9682-B97A741A5FAE.jpeg


I have a few other outliers that I haven't tried, specifically from Losi and Tekno, but I can't order them anywhere with no obligation returns, and we're talking $30ish per guess. I'll wait to see what pans out with the XO-1 stuff first.
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
Dang bro, I have like 4 extra Arrma gearboxes laying around that I could have sent you.

I was really fantasizing about that working...Arrma 6s boxes are identical front and rear, so are ECX, so if I could get one to mount in stock location-ish I could get the other, then use Arrma center diff and motor mount, and since Outlaw and Ruckus wheelbase is the same, that probably means the driveshafts would work too. Basically an Outlaw 6S bolted to a ECX plastic underbelly. But they are just too big to work without redesigning a whole chassis, unfortunately.

XO-1 rear should be here Saturday according to USPS before 8pm. I've done a ton more digging deeper into brands like Redcat that I only skimmed the surface of before and even went to like WLToys and Hosim manuals but their base stuff is like plastic diff gears and metal ones are an "upgrade" no way they would hold the power I want to make.
 

95PGTTech

Well-Known Member
Messages
338
The ECX nose/skid plate holes are pretty close to the XO-1 front subframe holes, just need to be slotted just a little. Note that the front set of holes on the ECX skid plate is for the bumper, so we are aligning to the second set of holes as the Traxxas diff housings and the ECX original diff housings are for all intents and purposes the same size. I have a countersinking bit I used after slotting the ECX holes 1mm each.
BFD5B6A4-C3B4-4DBC-87FE-F653C06325BC.jpeg



I had to knock off two bolt hole bosses on the front of the ECX chassis that used to bolt the nose/skid plate to the front of the chassis in order for the XO-1 front subframe to sit tight. No other mods to the subframe were needed. With the two bolts installed and the subframe where I wanted to I used some blue tape, outlined the subframe with sharpie, centerpunched the holes and drilled them to 4mm and countersunk them. Old 2 holes in center, new 2 holes are the tiny 2mm pilot bit shown here.

C55E8D83-13CE-4830-8046-775B42DC94C0.jpeg 7691E2AA-8D01-43C1-B298-6B5F1E82CEE3.jpeg


I think we nailed it. The two screws that effectively got deleted are replaced now by larger ones. I was going to mill down some of the XO-1 rear part of the subframe to get the control arm mounting points to sit a bit more level, but looking from the side profile the steering pivots are almost perfectly vertical which makes me think Traxxas wanted this upsweep built into the control arm angle. The same occurs in the rear, just reversed. Here is what it looks like with some pins and spare Slash 4x4 arms I had from RPM.

37DD7CC8-F9EB-4769-832B-BA90DE395209.jpeg B74E1D7B-E065-460E-9EB6-2F63854ADB92.jpeg B3BCC206-2E48-45E9-A97F-71E19A42D13D.jpeg



Rear diff housing (they are different, and cannot be swapped, nor can the two clamshell sections be interchanged, I tried) mounted to rear XO-1 bulkhead.
62369099-91CE-48DF-8B68-F6DADFBFB912.jpeg


Before deciding to go ahead and modify/mount the front subframe I did try this rear housing/bulkhead on the front of the Ruckus. It could be made to work, but I didn't like it as much as I liked the front on the front. The upside of the rear is it uses a bigger bearing on the differential input (pinion). See the bottom two holes to the bottom front of the bulkhead, this is the kind of slotting I meant. Soooo close. There may be 2 or 3 of these chassis left and this guy is cutting up a brand new one lol. B3BC77A6-736A-49BA-8A5C-14A81E32B21A.jpeg


The rear Traxxas bulkhead I did modify, there were two bosses on the front bolt holes that I knocked down to get the smooth/level surface you see here.
F8F4FD38-78B1-4329-B53A-0C06B9CF3184.jpeg
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
I also knocked the boss off of the factory ECX rear of the chassis that helps locate the ECX diff housing
CB8A0E34-60DC-4173-B33C-9850C2FF8549.jpeg


Same process, got the first two that are close done, then the other two need to be completely custom drilled. The factory XO-1 says the diff housing bolts for the rear are m3 x 12 (m4 x 12 front), but I'm not sure how comfortable I am with this by the time I needed to slot and then countersink.
2604C966-0E14-4C86-A3AF-BABF9B71840D.jpeg F8AD7CC6-E474-4AD3-818F-4020E3B79116.jpeg


I ended up drilling the Traxxas rear bulkhead holes oversize to 3.3mm and then tapping m4x0.7 and using m4 hardware like the front. I'm much more comfortable with this.
05C89C9C-CAFA-4DB3-A0D3-0E76971C2608.jpeg 870D18E0-D606-4412-8FE6-4F4FBF5E196A.jpeg


Here is the two of them together. Now that these are mounted and I've "chosen" this route over other diff housing options, I put an order of XO-1 stuff in from Jenny's. steering setup, braces, links, strut towers, etc. Bonus to this route is a lot of the slash 4x4 from the old chassis will be able to be swapped right over to this, most of it is interchangeable (versus if I went with the Arrma or the MT10 setups, I would have had to order entirely new front and rear suspension kits to fit them).
C8F7FAEB-CBB7-4120-A2D1-280B4ECBE6B7.jpeg 6E16DF73-DD22-48CE-A207-5ADD16C679F2.jpeg

As best I can measure it, axle centerline to axle centerline at the housing is equal each side, the cross diagonals are equal so these are square to the chassis. Axle to axle is approximately 5mm greater than the old build (not to be confused with wheelbase, which is measured at the hub, but they roughly correspond). I had intended to just mock these in and then figure out other mounting and kinda put it all in at once, but there really isn't much choice on where to put these front to rear. I'd rather not be as close to existing holes as it is.

Next I need to get the front and rear suspensions on so it's a roller again, and figure out the driveline. I haven't decided between the Arrma 6S setup or the XO-1 setup yet, but it will probably be determined by what's available as far as dogbone lengths out there. Yes, I'm obviously going to have to cut the poop out of that center tunnel. The upper chassis spine is a complete no go because it mounted to the differentials, for starters. I will be making a tower to tower brace and tower to chassis bracing. I ordered the XO-1 brace, it will be far too long but I may be able to use it as a starting point.
 
Last edited:

95PGTTech

Well-Known Member
Messages
338
Decided to move along with the Arrma 6S motor mount setup. The XO-1 would be nice, but then I'm limited to a slipper clutch and I don't have the best relationship with them. Not to mention I already have a lot of the Arrma pieces and a center diff on the way, whereas the XO-1 I'm going to get nickled and dimed to death. Both are probably the most impressive 1/8 scale setups I came across - I needed something that mounted to a flat plate bottom chassis and I wanted an integrated motor and diff mount. Both have aluminum aftermarket alternatives and dual motor options. The big appeal of the XO-1 was that it would be continuity of parts to use all XO-1 driveline, but because of the wheelbase difference that just isn't possible at minimum the center driveshaft is going to need to be custom.

Stuff should be here tomorrow to get it back to a roller status, and differentials are on the way. I'm hoping to be able to get the drive cups on the differentials and the center diff and then measure for driveshaft lengths and be able to find two from other RCs that are sufficient. In a dream world, I'd be able to mount the motor perfectly centered F/R in the chassis and run equal length driveshafts.

I'm still curious to see how much the higher LCA pin point affects overall ride height. Comparing it to the old chassis, the LCA pin is 20mm higher give or take. If this setup ends up working out well, maybe it will be worth exploring 3d printing new, smaller profile bulkheads to mate chassis to diff (and make the holes line up without having to redrill!). Overall, I'm happier. My brain has moved on from is this thing going to be able to be saved? to its just a matter of time and finding the right parts to save it. No one said going fast on this platform was easy.
 

95PGTTech

Well-Known Member
Messages
338
Parts from JennysRC arrived. Great first experience dealing with him. Fixed a last minute change order, fast shipping, excellent packing and organization.
A9C206E2-786E-4EEC-9EB6-05D46C6216C0.jpeg


Comparison of the tower-tower braces shows how much more wheelbase the XO-1 has - and therefore why I can’t just bolt the entire XO-1 drivetrain in. I’ll keep the brace though, I may just section it and weld it back together.
CA995104-6B6C-42B2-A2CD-E3D27991E2CE.jpeg
35DF5EFD-5CB4-49FC-B3B1-BF5C8087E6D5.jpeg


Arrma 6S center diff mounted
CF2E65F8-0814-4620-A97D-F3C00D1B1ABE.jpeg


XO-1 rear shock tower. I’m not too keen on these standoffs after seeing them in person I’m going to get a slash tower built for bashing
29BF64BE-B55A-4416-9C22-8A7A8DA28FD3.jpeg


Slash ultimate diff. It’s just what he had on hand, this will get XO-1 diffs and aluminum housings and what not, I’m just trying to get stuff mocked together. RPM arms, XO-1 pins
16D86E29-ED6C-4696-9FE0-85283C11A489.jpeg


Started stealing parts from the old donor rear - GTR xxl shocks, VG racing springs, eBay hardened steel axles, slash camber rods, XO-1 hubs, brass 8mm hexes.
66FCC166-DF0F-48C2-B719-A9732A7D0EFE.jpeg
F9E1B201-BBDF-4632-8E4A-4EDC7EFF4F78.jpeg


All together on the “new” chassis
FF1B169B-3C94-4F0F-8D67-F3F5616376B3.jpeg


Another issue…nothing captures the rear of the hinge pins they can just slide out. On the XO-1 it’s actually part of the rear diffuser. On a slash it seems to be part of the rear bumper, which mounts to the top of the diff so it should work. I’ve heard the RPM bumpers are good, and I’d like to run. wheelie bar again. Time to do some digging.
 
Last edited:

Latest posts

Members online

No members online now.
Top