95PGTTech 1/10 2WD ECX Ruckus build

We have all seen that you have put a significant amount of time into this truck.
I personaly think it would be cool if and when you get to a point that you think you got it as good as you can get, and it is fairly plug and play.
It would be cool to see a build sheet that others could use.
I mean it may never get to that point, but you never know.

other than the rear motor mount/wing mount/wheelie bar mount, someone could pull off our build (or close to it) with more or less off the shelf aftermarket parts, and the rear mount can be done with just the ax10 trans as many others have. we are in a position where both the new chassis is not ready to run yet and where we'd like to see where the ceiling of this one is - I think it's north of 60. I'll keep a build sheet in mind. Ruckus will eventually be retired to a much more mild setup for yard bashing, probably 4s/max10/3674 again.

There is a guy on the speed group who claims to have done 58mph with a 2wd Slash but the video and GPS don't really meet requirements - I have no doubt he actually did it, we have been helping him out for months with setup. Running a number bigger than that would
 
Installed some brass standoffs to help get wiring where I want it, and cut down and put a new connector on the ESC wiring to clean it up. What to do with the antenna, we seem to be good at breaking loose ones?

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Ready to rock - 18/44 (because I was an idiot and lost the 17). We finally found a better spot, a large park with a non-restricted soccer area (around here all really nice groomed fields are off limits without permit).

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And in a familiar heartbreak, it was on the best hit of its life, James had actually been able to go full throttle with it, when it suddenly wheelied at 46mph and caught a slight divot, sending it cartwheeling and large pieces flying off. All told, it actually wasn't that bad - the front axle pulled through the wheel bearings, leaving the races in the front hub, and what was seen flying off was the complete assembly wheel/axle/hex/nut which we recovered. Considering all, it's incredible it suffered that little damage. I have a set of axles back at the shop, it was due for front wheel bearings anyway. Excited to have a better venue though (and it has a killer playground to boot)!

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race ready weights minus body 2566g front 3120g rear (with a 350g removable ballast front)
previously 2112g front 3646g rear

so reduced roughly 70g from the old setup, 420g in an apples to apples comparison (almost 10%)
bias went from 36.6% front to 45.1% front is what should make a huge difference
 
Got the front back together, only to take it outside to run it and find the right rear super wobbly and needed a set of bearings...literally the only ones I don't have on hand. A wrong shipment by Amazon, and the truck is down for 3 really nice days. Boooo.

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I wanted to experiment with getting the wheelie bars even lower, so I drilled another hole and ran a m4 bolt through with some zip ties for now. If this helps, I'll relocate the upper mount.

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The big mod1 44T spur/slipper is REALLY close to the driveshaft. I'm afraid any wear of that front input shaft bearing is going to mean metal on metal. Putting together a new clutch setup to try. Modified another 272R input shaft to accept a modified DR10 gear, then a Revo 3.3 clutch assembly with the upgraded slipper pads. I have 42T and 34T spurs that will fit this setup, and I can buy any in between. When I pull the trans out the next time to slot the motor mount holes to make the motor actually adjustable position I'll put this in the trans. This eliminates the 2.5mm cross pin I had to drill out for the big slipper...already learned the lesson once of what happens to input shafts when I drill them oversize. The Revo clutch uses a 2mm that this 272R shaft accepts without modfication.

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I had it out today doing some shakedown runs, did a 42mph without breaking a sweat and looking really neat and tidy doing it (I was limited by the amount of space). I had a shutdown due to loss of power but I think I've diagnosed it as a faulty ESC on/off switch, so we will get that sorted (I have one on hand, or I can just bypass it), and be back at it. Still on the hunt for that real high quality space to run this in, that seems to be the real limiting factor right now.
 
Well...bypassing the switch by connecting the two reds powered up the ESC. Replaced the switch with all 4 wires connected as they should be, and the ESC/fans/receiver powered on.

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Connected the motor wires to the ESC, powered it back up, and turned the radio on, and instantly the ESC sparked and caught fire.

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I was able to cut the black lead coming off the ESC to kill power and put out the flames with a wet cloth. I guess something was internally wrong with the ESC and frying the switch was just the first round of problems. This is a pretty old 1st generation max8 that I got used and already replaced a cap in, so not terribly surprising. Glad I got it out without anything else being lost (I'm going to get a replacement receiver just in case).

Sigh, losing really good weather days while we look for one/get it shipped.

EDIT: Ordered a WP-MAX8-RTR off aliexpress, used a coupon and my Paypal for protection. Nothing used on eBay available, no equivalents on Jenny's so it was that or $150 direct from Hobbywing. I guess I'll get the clutch/input shaft and motor mount done while we wait and go through this thing nut and bolt. I can toss a max10 and a 3674 in it for now if I really need to.
 
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ESC ETA keeps fluctuating between May 13-18. Ordered up another set of belted Badlands (the skinny ones) and aluminum narrow offset wheel centers, should be here before then to run them at all 4 corners and see if there is any difference with less drag and internally belted tires (not my fishing line wraps) and high speed stability. Always trying to get faster trying new things.

I have lost 3 of these receivers now due to broken wires, either in accidents or them coming loose from where I've had them tied up and getting caught in stuff. As we get faster, I hope this pushes our range out a little further too (the antenna).

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Got the rear seperated, that modification I did to unbolt it from the shock tower now instead of that tiny plastic bracket makes it SO much faster. Got the trans apart to swap over the input shaft and the new clutch, doesn't look very happy in there. Found that the bolts for the differential had come out (I'm assuming backed out, despite red Loctite). One was completely gone, I'm assuming turned to dust. One was bent badly and in the hole but not really threaded in, and one had about one thread left. They had left significant engravings along the inside of the case as they backed out, but after cleaning everything up seemingly lucky that no holes were made and the bearing areas are all intact so it's just cosmetic. I guess all I can do is replace the bolts and try again. I'm not really sure what can cause this type of failure. I test fit the shaft and clutch, I need new bolts for the trans case to allow more clearance, but overall looks like it will work fine. I'm going to start modifying the motor plate tomorrow.

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Bunch of rainy days, so I can’t avoid doing the work of modifying the motor plate any longer. I was able to re use most of the lower screw slot by just opening it to m4 but the center shaft slot had to be mostly redone and the upper one entirely, and the old stuff welded shut. Copper back plate makes the job not terrible, just a lot of time with various grinders and files.

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I changed the hardware for the trans over to button head for more clearance to the back of the clutch/spur plate

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Still not enough, had to grind off the cooling fins off the back of the plate

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Still not enough clearance, so ended up countersinking the holes and using recessed hardware. Even still, there is probably less than 2mm clearance between the clutch backing plate and the motor plate. I guess if the input shaft bearings go again I’ll know quick.

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25/43 is the smallest pinion I can run and still get the mesh I want (the motor itself hits the transmission case). With 29 on, there is still an air gap between the teeth so 32-33 is probably the maximum. If I need to go shorter ratio for some reason, I’ll have to change the spur. I have a 43 and they make a bunch of options between 38-43 (and I think higher too).


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Not pictured, I modified the input shaft again by adding back material where I had to grind flats in it to fit the dr10 gear. This allows it to fit tighter into the bearing race and takes the tiny bit of runout the shaft had. M2x6 are on order for the diff gear/outputs. Maybe I should just weld it on 🤣
 
New bolts arrived, somehow had enough clean threads left to tighten down well. Used stud lock this time, no intention to ever take this apart.
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That color red grease is a lot better than the silver metallic I had when I opened this thing up. You can actually see what I was talking about with the input shaft in this pic.

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Everything back together, batteries charged up, just need the ESC to go back to battle. May 12 estimate right now.

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Shock rebuilding. Have some stock ones off the 4wd mind as well while I’m at it. Took a screenshot of the Tazer ESC parameters just in case I think about bumping up the motor again. I did end up ordering that fan. Old transmission out, new Axial one in. Fairly bolt in affair. Refined my wheelie bar mount just a little again.

Not my original idea, here’s the link for credit:

It’s a locker trans. For what we do, that’s a plus not a minus. I’m building a spare stock trans with heavy diff gear fluid to try and get as close to a LSD as possible as a backup. I need to fabricate a wheelie bar to trans mount and a trans to shock tower mount (I will not be doing what he did in the video).

The unit is awesome (on the bench anyway) for the price. Here’s a video:

How did you go about securing the top of the new trans case to aboid flex?
 
I see it, this is a great build thread! Just ordered the same transmission for my ECX MT hoping to have all the parts i ordered on by this weekend

I did break it as you can see in this thread a couple times, but once I found the right guts for it, it has been pretty good to me. certainly better than anything the ECX trans could have taken
 
I did break it as you can see in this thread a couple times, but once I found the right guts for it, it has been pretty good to me. certainly better than anything the ECX trans could have taken
Which guts did you end up using for it? Im only going to be using 3s lipo but i just got the mew trans in and did notice the spur gear was plastic. I have a hot racing metal spur coming in that i was going to use for the ecx trans but i dont think it would work with this new trans
 
Which guts did you end up using for it? Im only going to be using 3s lipo but i just got the mew trans in and did notice the spur gear was plastic. I have a hot racing metal spur coming in that i was going to use for the ecx trans but i dont think it would work with this new trans

I've been through a few different kinds, but the robinson racing stuff should do you just fine. I think I broke the amazon one piece locker diff gear the first time out.

currently I have a incision hardened gearset, supershafty 8mm outputs, mip x duty axles, custom input shaft made from a traxxas 272r hardened input shaft and a dr10 hardened input gear, revo 3.3 clutch set with the upgraded pads and ring, 38T mod1 gear. but I'm putting 6S through this.
 
WP-Max8-RTR arrived almost a week early. It really is identical except for the stickers, even the instruction manual is the same (minus the Hobbywing branding)

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Got the wiring how I like it, and trimmed back the front shock tower just a bit more to give a hair of clearance, I didn't want any rubbing

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Ready to go...I would really like to cut down the xt90s off the ESC a little bit more to clean the wiring up even more, but I simply am not confident enough in my soldering ability on that large a gauge wire to do a clean job of it.

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Gave it a tiny bit of throttle on the bench, fearful I was going to have another fire, no issues spotted. Only for me to take it outside, and not even a minute into its maiden run it to cut out. Not the over-amperage or over-temp shutdowns where the ESC is still on it just doesn't deliver power to the motor, completely off. No fans, no receiver. Power it back up, same thing. Any throttle input = cuts out. Checked all my connections. Picked up the back of the rig to get the wheels in the air, even does it with no load on it.

Brought it inside to take pics and a video for the seller to get reimbursed, and instead of the cutout problem happening, caught the switch letting the smoke out.

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To the sellers credit, immediately refunded my money including the shipping. Now that I own it, I cut the switch off and bypassed it by putting the two red wires together. Which immediately caused a huge plume out of the motor itself. Exactly like the last one did after replacing the switch. I now have 2 ESCs that failed in identical ways - I could write the first one off as previously owned, had some crash damage, I replaced a capacitor in it, but now I know something is up.

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I purchased a battery tester that can do internal resistance and got 10, 2, 11 and 10, 2, 14 on both batteries. With a DVOM they measure 12.38v DC each, and the polarity measures correct. There is no swelling or signs of impact. The wires and connectors show no signs of issue. I wanted to try and power this back up with the motor disconnected to isolate that as a cause, but the ESC is clearly shorted internally at this point, connect the batteries even with the switch off and it sparks and smokes. I tried to eliminate a backfeeding receiver or servo (as some on the groups suggested) by putting in the old max10sct and 3674. Same servo, same receiver, same radio. No issues. Even used both of these batteries to try and eliminate them too.

Replacement ESC is on the way, and since it cost actually less than the same motor, got a 4292 1030kv monster on the way. For the cost of what this receiver and servo cost, I may just replace them for the hell of it. One guy suggested that possibly the switch mount using longer screws could have shorted out something in the ESC, but I checked it only goes into the heatsink. Regardless, for first fit I will use the ESC exactly as it comes out of the box no switch mount or shortening the wires. I'll probably start it off on one of my known good 4s too. Verified in the manual this combo was okay for 6s (after somebody suggested the max6 is needed for 6s). Motor and ESC due here sometime early June. Dangit. I just couldn't bring myself to drop 250 on the gen2 max8 combo stateside to get it here in a few days when we're building a new chassis. Some bling bling did arrive, birthday gift from James to me (for his truck LOL) belted truggy Badlands and aluminum short offset wheel centers. I already have a set of these we ran on the front for awhile, we're going to try and run them at all 4 corners and see what happens.

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Finally a good update! I did find one burnt prong on one of the battery connectors (and its matching one on the ESC), but there isn't a corresponding mark on the first ESC. I think this happened when I was connecting it again and again trying to diagnose stuff after clearly the second one had already shorted out, so I cleaned it up and let it be. On suggestion from another member of the RC FB groups, I did check the screws for that plate to hold the esc switch. They are longer for both the switch and the area that holds the fan down so I checked and make sure they aren't going through too far and into something and shorting it out...nope, unfortunately. Witness marks on the ESC heatsink show it's not going through that, and on the switch side it's only going into plastic. I'll run the new one without the plate at first just to elimiate another variable. New battery tester showed internal resistances of both batteries well within normal, I have no reason to suspect they are the cause. I'm going to replace ESC, motor and servo/receiver. More than one person mentioned having a backfeeding servo or receiver killing setups in their past. I can't see any defects or burns in either and both test fine with a DVOM, but they're both so cheap it's stupid of me to not try to replace them too (versus the cost of the ESC/motor anyway). I'm also not going to modify the servo wiring or the ESC wiring at first to eliminate that variable.

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4292 1030kv is finally here. This thing is massive

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27 is the smallest pinion that fits a good gear mesh with the 34 spur. Limiting factor is the motor physically hitting the trans case, so if I want to shorten the ratio I have to go up in spur. I do have a 42T around, and I think they may even go bigger for revo 3.3

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You can see in the last pic I have the short offset aluminum centered belted skinny Badlands on. At full droop, wheel contacts the lower shock spring cup, and is super close to the camber rod/rear knuckle. Nowhere else in the articulation, just at full droop, where it almost never is, so I think I'll just run it and see. A witness mark will be very obvious.

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Replacement ESC is here. Not modifying the wires (now), but I am gluing them the same way I did the last one to keep them away from the shock tower. Not a ton of clearance there. I don't have time to do more of an update right now, but long story short, these came in a few days ago, we ran it around the yard and it did fine, we took it to the park for some shakedowns and it did fine. It's a long way from our previous best or the current 2wd record (58mph), but it's running well and didn't light on fire. So something we changed worked.

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Looks...odd with the narrow Badlands and the small offsets.

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Changed out the steering servo and the receiver, ended up changing the servo arm too because it got stuck on the old one. Have plenty sitting around, not worth the time right now to cut the old one off I'll get to it eventually.

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Modified my battery hold down/GPS holder again in order to help the motor wiring fit a little better. Not totally thrilled with having all this servo/ESC wire looped around everything, but like I said running it "out of the box stock" at first to eliminate variables.

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Set a quick alignment, programmed the ESC, set the controller endpoints, set up the new servo. Took it out in the yard, everything went fine. Nothing exploded. Didn't crash it. I have zero room to make speed, especially with the kind of real estate a 2wd needs to brake. 35 is pretty much the fastest anything has been on the amount of space I have. Motor did get a little warm, but it's also 92F ambient out. Definetely did well enough to warrant going to the park and giving it a hit.

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Charged up the batteries again, did some touch ups to the body, and out to the park we went. A little sketchy at full throttle, but doesn't seem to be rubbing the shocks or anywhere else, I think it's the reduction in rear track width, so a lot of aborted runs, but got a few decent pulls in. Other than it being really disappointingly slow (42mph), everything went great. Motor eventually got hot, cool batteries, cool wires, cool ESC. Nothing broke, we didn't crash it. So I'll say a good day.

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Pretty decent conditions for speed. Just no speed, LOL. But hey, nothing caught fire!!!



Being that the motor was so hot but nothing else was, the first stab I tried to take was gearing. Normally on the 4S and 3674 (or dual 4S and dual 3674) I'd gear it so damn tall it couldn't even take off without me pushing it with my foot and it STILL would be luke warm motor at best. I guess what I was hoping was that 34/27 was so tall, it didn't have enough acceleration to get up to speed and was just bogging down and heating up. I went to a 42 spur and a 19 pinion (the smallest pinion I could get a good mesh with once picking that spur). Huge change, 1.26:1 to 2.21:1. Helped the temps a lot, didn't help the speed. 37mph if I remember right, I can go back and look at the logs. Also mounted the on/off switch back to that bracket - there was a question raised were the screws to the switch or to the fan going too far into something so I ran it first "box stock" and no problems, now put the bracket back in. No issues, so those two variables eliminated.

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Checked the slipper clutch, not hot, no burn marks, no reason to suspect it's slipping at full power and that's the source of lost speed. Being what effect the gearing change had, I'm thinking the change that's needed is the motor kv. We went from 4S 2250kv to 6s 1030kv. The 1030 chart says it's good for 100A up to 42v. This is a 150A ESC, and the highest kv 4292 offered (1780kv) can do 150A @ 28v. So I'll try that one. In the mean time, capacitors look okay, ESC LEDs light up correctly indicating it sees full throttle. Maybe add a cheap cap pack? I can't wait to get into big boy stuff that does datalogging so I can see how many amps it's pulling at any given time and really troubleshoot. For now, I have another 3S battery I'm going to swap in, one at a time, and rule that out. On the bench, both of these charge and discharge at the same rate and measure fine with the tester and internal resistance, but maybe it's losing something under load through that burnt tab. Trial and error I guess.
 
Went to aluminum wheel centers wide offset on the rear. Side by side shot of narrow offset and wide offset. Going to wide offset in the rear made the track width roughly 30mm wider and also eliminated any concern about shock or hub/upright clearance. It made a dramatic difference on speed runs at the park, a ton less aborted runs due to it trying to get sideways when rolling into the power. Still not laser straight just mash the throttle and hold it by any means, but a lot more consistent and a lot less letting out of it afraid of wadding it up. Maybe I'll do the wide Badlands (the monster truck style ones that I belted myself) and these narrow Badlands with wide offset back to back and see if there's any further improvement or if it's just carrying more rolling resistance around.

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It's costly, Badlands are costly to begin with, but the modular wheel system itself is a massive upgrade. Round off a hex? Swap out a wheel center ($9 for 4) instead of buying a wheel (or usually, buy a pair of wheels and tires). The Proline glue is great and you'll never have to touch it. If you do go to the aluminum wheel centers, put a good nut on it and red loctite and I've never once had a wheel/hex/nut issue since. I'm putting 6S (25.2v) through a 12mm hex, I don't think plastic anything is surviving long.

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Babies are getting really close to walking, Mike saw the opportunity to steal Ruckus and use it as a walker

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Got to the park to try and eliminate a bad battery as a variable (the one with the connector that looks a little crispy. I have an older zeee 3s that I subbed in for it. Not in love with Deans connectors, but it's just for five minutes. Nope, no change. 38mph. Since I was there anyway, I then ran the Zeee with the other one, no change. 40mph. I did some calculators when I got home, I think I just put some numbers in wrong when I was picking the motor for the first time. I'm just not turning this thing enough rpm on 6S (26000 rpm). The 1780kv should be 45000ish (on a max rating of 50k). Keeping everything else the same, the speed calculator said 73% more speed. One small issue of left rear axle broke the outer pin (or the set screw came loose). I got super lucky and the ejected shaft was recovered. Cleaned up the LCA and rebuilt the axle. Removed the old motor, new one should be here next couple of days.

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Happy Fathers Day guys. Me, my dad, and my 3 boys on the swingset/playground we built in Covid
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