DT-03 Spur Gear and Brushless Power

[BBB Spread 6]

So I am running a Castle 5700 on 2s in my DT-03 and it only lasts a few minutes before my spur gear turns to dust. I've never even gotten to full throttle. I've seen videos of this set-up working successfully on 3S even. I'm running the standard 17t pinion on 2.2 pro-line dirt hawgs. 

Is there a modification I am missing here, or is there a better gear grease I could be using to reduce friction?

[Wooders28 4723]

Is it a hardened pinion with the correct pitch?  

I've run the castle 5700kv with a 19t pinion on 5s for speed runs and the spur is still fine.

[BBB Spread 6]

It's the stock 17t pinion for the DT-03t. I decided after I posted to take a look at the bearings within the spur gear, and the one on the outside looks like it failed. I lossed my fast eddy bearing (sealed) and used some other one I had from a HK seller on ebay. Looks like that bit me in the end.

that 5S...is that a soft case lipo? For the 03T model, I can't seem to get more than a 2S hard case in there.

[Wooders28 4723]

1 hour ago, BBB Spread said:

take a look at the bearings within the spur gear, and the one on the outside looks like it failed.

That would do it! 🖒

 

1 hour ago, BBB Spread said:

that 5S...is that a soft case lipo? For the 03T model, I can't seem to get more than a 2S hard case in there.

3s Orion rocketsport in the normal battery position and a 2s Orion on the nose wired in series 😁

https://www.tamiyaclub.com/forum/index.php?/topic/80775-tamiya-club-official-top-10-fastest-rcers-list/&page=47&tab=comments#comment-675516

[Juls1 1661]

Doesn’t matter what spur/slipper arrangement you have on any car, if the bearing supporting the shaft holding the spur packs it in then it’s unlikely the spur gear will survive, could also make a mess of many other things.

i have to say I’ve never had a bearing go that far south on a RC car (seen it plenty of times on farm machinery in 1:1.) you must have been using it for quite some time with the bearing slowly self destructing till there was enough slop to blow out the spur gear. 

[BBB Spread 6]

So for an update, I replaced the spur and the bearings and did a speed run with a 2S 75C lipo  w 16t pinion and got to about 46mph. It wheelies quite easily even when moving at a good speed. Checked the spur gear after the run and it was perfectly fine.

I just got my compact 3S lipo in the mail, so I can't wait to see what that does.

BTW If you've never tried Hobbystar batteries I would give them a shot. Great power, run times, and prices.

[Wooders28 4723]

Glad the 16t fits, bought one a while back, to fit in for beach bashing 🖒

[BBB Spread 6]

The 16t fits well, but not perfect. It was needed to counter the cogging issue and help on the starts.

 

[Wooders28 4723]

4 hours ago, BBB Spread said:

It was needed to counter the cogging issue

Cogging issue?

I had no issues what so ever with the (sensorless) castle 5700,what esc are you running?

[BBB Spread 6]

It's the sidewinder SV3. The cogging wasn't terrible, but was noticeable. Going down a tooth didn't hurt top speed to bad, but cured what cogging there was. 

It's probably my esc settings. I'm new to the product, and am learning the ropes. What settings do you run? Do you use castlelink?

[Wooders28 4723]

I'm running the mamba max pro, yes I've the castlelink, can't remember settings off hand, but only cogging was with a 2.5t 

[BBB Spread 6]

since you're running this kind of power, you've probably noticed that a wheelie bar would be quite helpful. Have you found a wheelie bar that actually works, or fits on the chassis with little modification?

[LeftyAl 164]

Pretty sure the wheelie bar in my boy's DT-03 is off a Lunch Box. All I did was drill one of the the gear box screws with a 3mm drill and use a longer 3mm bolt with nut to secure it. I did take the single wheel off and used a longer axle to mount an R/C aeroplane  wheel each side of the bar.

[BBB Spread 6]

That would work on a stock motor housing, but I modified mine for better cooling. Motor temps were in the 220 range before, but now they are at around 150 after a full 3s battery. I basically cut away the rear portion and added a full heatsink.

I was hoping someone tried the Traxxas Rustler wheelie bar as the appearance of the bolt pattern looks like I could mount it under the gearbox.