Oops bought myself a DT03

[BackITG 34]

A month ago I got back into RC and now I have a newly built TT-01e, a NIB TT-02R and a DT-03 (used) will be delivered this week   Now need to slow down here as continuing with on this pace will end up in 20projects before the end of the year  

I'm using the TT-01e as a parkinglot basher, geared it up and alu driveshaft, oil suspension and ball bearings. As it felt limited in where I can drive I bought a DT-03 yesterday with the intention to drive it onto short grass and on the beach. It comes with some upgrades like ball bearings and adjustable wishbones and steering rods. It has the torque tuned motor, and that's pretty much it. The body is new, so I will go nuts on the painting. I might add some parts to make the chassis bulletproof, with a metal cover or something like that. For the suspension, i'll just go with the standards until it cracks. 

I want it to get a little faster, so gearing up is a starting point. With sand and grass as main surface, what do I need to take in consideration? I have brushless set on the shelf but it's 3665-3600kv so not sure if it would fit? 

 

[BuggyDad 6021]

42 minutes ago, BackITG said:

I want it to get a little faster, so gearing up is a starting point. With sand and grass as main surface, what do I need to take in consideration? I have brushless set on the shelf but it's 3665-3600kv so not sure if it would fit? 

The DT-03 is a fun car. Tough enough (mostly), drives OK, great value. My son and I have one each and they get most of our running. 

On gearing you've only got the two pinion size options available (0.8 mod, 17 and 19 tooth). I haven't found the 19t trouble with any motor I've tried on buggy wheels. If you fit truck wheels, personally I think the 17t can suit well but I haven't had overheating problems there either myself on 19. We like truck wheels for grass.

Do make sure you get a good quality pinion, either steel or hardened aluminium.

On motors, we are running 10.5 turn sensored brushless in ours. I think that's broadly akin to your 3600 kv. In my opinion that's a little hot for the car as stock but it's not outlandish and you can always turn town the dual rate on your transmitter. 

Sensorless, personally I'm not a fan of but others are happy.

3665 is the can size? Sorry, can't help on that. 

Ours are quite heavily modified, but that's mostly for toughness rather than performance. 

Tyres are a thing to consider. Fronts anyway. If running buggy wheels, we dislike the kit fronts for essentially anywhere, prefering a soft compound spike for more grip because of its tendency to understeer. 

Also suspension. I think stiffer rear springs are a necessity. On the front I've gone much softer than stock but I'm not sure everyone would - mine is good on really rough ground and a fun drive but pretty poor in real performance terms on anything grippier/smoother. Anyway, whatever you do with springs you'll probably need to mess with damping to match. 

If you get further down the rabbit hole, I think the biggest performance improvement I made was to introduce rear toe in, to improve driveability at this power level. But that required 3d printed rear uprights. Some diff stiffening is nice too - my jerry-rigged solution has loosened up over time and I'm now seeing again the disadvantage of a free diff (it lifts a wheel and diffs out on grass). 

Oh and resilience - your mileage may vary but we snapped a tonne of front shock towers and the noses on two chassis. As a result we modified ours to brace the front shock tops back to the chassis which solves both issues but isn't very pretty. Most people have not felt the need to do such a thing, but ours get crashed around by kids, ripped along the beach and all sorts of other abuse. 

[BackITG 34]

1 hour ago, BuggyDad said:

On gearing you've only got the two pinion size options available (0.8 mod, 17 and 19 tooth). I haven't found the 19t trouble with any motor I've tried on buggy wheels. If you fit truck wheels, personally I think the 17t can suit well but I haven't had overheating problems there either myself on 19. We like truck wheels for grass.

1 hour ago, BuggyDad said:

Tyres are a thing to consider. Fronts anyway. If running buggy wheels, we dislike the kit fronts for essentially anywhere, prefering a soft compound spike for more grip because of its tendency to understeer

Thanks - I will go with 19t steel to start with and will use the wheels they come with initially and see how it turns out grip wise. I have to experience for myself what works and what not. It's my first buggy anyway 

 

1 hour ago, BuggyDad said:

On motors, we are running 10.5 turn sensored brushless in ours. I think that's broadly akin to your 3600 kv. In my opinion that's a little hot for the car as stock but it's not outlandish and you can always turn town the dual rate on your transmitter. 

Sensorless, personally I'm not a fan of but others are happy.

3665 is the can size? Sorry, can't help on that. 

It turns out the 3665 is 15mm longer than a standard 540 can. Alternatively I want to see if I can make this one fit in the TT02R as their seems some room on the chassis. Either way I'll end up one day buying a suitable brushless, wether for the DT-03 or the TT02R. When it comes to the turns /per motor I'm clueless and have zero knowledge on what to do to be honest  but that's for another day  

 

[alvinlwh 7254]

4 hours ago, BackITG said:

3665-3600kv so not sure if it would fit? 

I think a 3665 can fit. I have a 550 in my DT-02 and it is OK. 

EDIT: I think 3665 has a 5mm motor shaft, on my 3660 it is. Make sure you get the right pinion to go with it. 

[BackITG 34]

So I got the DT-03 delivered right before the weekend and found some time to check the state it is in. It came with a new body but it already had some dents and scratches and the former owner tried to cut it out (which didn't work, clearly ) but that's ok for me. I have used the shell now as a test one to practice my painting skills. It will anyway get beaten up.. 

The highlights/lows:

- front bearings are missing (?) incl wheel hex and wheel mounts (front and back) so need to order
- it came with new tires and rims so that's a plus. Need to glue them 
- CVA oil shocks, to keep or not to keep
- Servo included a well as an Tamiya ESC and Torque tuned motor. I search on this forum on DT02/DT03 I get a lot of hits on "overheating brushed motor etc" so  I'll try to install the brushless combo. If that doesn't work I stick to the Torque tuned I guess 
 

I think I'll start running it as it came in and take it from there Will finish the body tonight - and will upload some pictures of course 

[alvinlwh 7254]

18 minutes ago, BackITG said:

front bearings are missing (?) incl wheel hex and wheel mounts (front and back) so need to order

Don't think DT has hex on the front? 

[BackITG 34]

Well - they are available on the market so I assumed they should have been there.. 

[BackITG 34]

@alvinlwh you're right! i checked the manual and it doesn't show the hex on the front. It does show the bearings and wheelmounts I both miss. 

[alvinlwh 7254]

3 hours ago, BackITG said:

@alvinlwh you're right! i checked the manual and it doesn't show the hex on the front. It does show the bearings and wheelmounts I both miss. 

What do you mean by wheels mounts? The whole steering arms BA15/6 are missing? If not, all you need to do is just slap some 1150 bearings on and away you go. 

[BackITG 34]

No I meant the lock nuts, sorry I literally translated in my head from dutch to english  anyway I ordered those + some bearings, should be delivered tomorrow

[Juls1 1718]

The 3665 should be fine, the gearbox itself is plenty tough to take the power although the suspension arm mounts can be ripped off if you do too many high speed cartwheels resulting in needing new gearbox casing.  As a sand or grass machine with the right tires it’ll use that power nicely, forget about low traction surfaces or slippery tires though with that much power. I would get a steel pinion gear before you do anything the stock aluminium ones will kill themselves and also the whole gearbox. A steel pinion gear fixes that. Tamiya sells 54628 and 54629 as a fix, but if you have a 5mm shaft motor you’ll need a aftermarket pinion.
 

cva’s can be fine as long as the shock shafts are not bent. There is some simple mods you can do that makes them alot better (replacing pistons/shafts and seals) the tt02b/df03 alloy set add a heap more ground clearance and superior performance if you can make the budget stretch they are worth it, if not then stick to the cva’s everything in between is just burnt money. 
 

The dt03 makes a great sand rail, adding some paddle tires on the back its a great beach basher as long as you’ve got plenty of power on tap. 

[BackITG 34]

6 hours ago, Juls1 said:

The 3665 should be fine, the gearbox itself is plenty tough to take the power although the suspension arm mounts can be ripped off if you do too many high speed cartwheels resulting in needing new gearbox casing.  As a sand or grass machine with the right tires it’ll use that power nicely, forget about low traction surfaces or slippery tires though with that much power. I would get a steel pinion gear before you do anything the stock aluminium ones will kill themselves and also the whole gearbox. A steel pinion gear fixes that. Tamiya sells 54628 and 54629 as a fix, but if you have a 5mm shaft motor you’ll need a aftermarket pinion.
 

cva’s can be fine as long as the shock shafts are not bent. There is some simple mods you can do that makes them alot better (replacing pistons/shafts and seals) the tt02b/df03 alloy set add a heap more ground clearance and superior performance if you can make the budget stretch they are worth it, if not then stick to the cva’s everything in between is just burnt money. 
 

The dt03 makes a great sand rail, adding some paddle tires on the back its a great beach basher as long as you’ve got plenty of power on tap. 

Yep steel pinion was ordered on the weekend! Bit of a hassle to find 5mm shaft versions, but i managed to find them on a german webshop. 
 

on the springs, i dont know.. From what i see now is that they are extremely soft and do not bounce back. Like there is not enough oil in them. Need to check that. 
 

I screwed up the paintjob by the way… Its my very first dual color body and I screwed up the masking. As mentioned wadloper, it’s a bashing body anyway due being not in good condition to start with, but it will do for now. Lessons learned! 
 

Sorry for the dark picture, I haven’t seen the colors yet in daylight but will share later on. 

[BackITG 34]

Now in daylight. As you can see not the best paintingwork ever ! Especially the striping on the back going over the roof… I’ll add some decals here and there to give it a more finished look. 
 

the majority of the parts I needed just came in, So I can do a testdrive shortly. The steel pinions will arrive later this week hopefully.
 

 

[BackITG 34]

So, after doing some testruns it seems to work all OK - however I find it rather slow. Since there's no room to play around with the gearing  I'll try to make the brushless combo I have on hand fit, the wiring is going to be tight challenge...

Alternatively I would consider cheap *** brushless set (eg Hobbyking with a hobbyking ESC120) that should do what I want it to do. Some extra speed and power on a budget! As from what I read on this forum is that brushed motors will run hot on the DT-03 so that doesn't seem to be the option.  

Last option, that pops my mind while writing this, is to change to lipo. That does require some investment on a suitable (and safe!!) charger but can make all my cars go faster just on the same solution. 

[alvinlwh 7254]

47 minutes ago, BackITG said:

Hobbyking with a hobbyking ESC120

Get them, they had been out of stock like forever. I see that they are now finally back in stock.

[BackITG 34]

Yeah just ordered it! I ordered also a Turnigy XK-3650 5400KV brushless. this should set me up for a while and have some fun 

[alvinlwh 7254]

14 minutes ago, BackITG said:

5400KV

Wow! You are brave.

[BackITG 34]

8 minutes ago, alvinlwh said:

Wow! You are brave.

Or stupid.. It's a thin line . Now let's hope that this 25$ spent here doesn't result in a $200+ bill for the damage I make.. 

[alvinlwh 7254]

10 minutes ago, BackITG said:

Or stupid.. It's a thin line . Now let's hope that this 25$ spent here doesn't result in a $200+ bill for the damage I make.. 

Good luck! This is what a 3300kv did to one of my car over the weekend, and it was "just" on 2S only. 50% more power and speed if I had it on 3S.

It had a metal chassis, if not I think it will not be a bent screw but complete smashed chassis. 

[BackITG 34]

Oops.. I have single metal in this DT-03  probably need to find some parts to improve the strength but i'll try out first..  

[Wooders28 4936]

On 9/3/2024 at 9:21 AM, BackITG said:

I want it to get a little faster, so gearing up is a starting point.

For grass and beach running, unless you've got a powerful motor, it may run slower, with the extra drag.

 

On 9/3/2024 at 9:57 AM, BuggyDad said:

only got the two pinion size options available (0.8 mod, 17 and 19 tooth)

Yeah but no but...

32dp = 0.7938 mod , so although not strictly correct, a 32dp works fine (what I run in mine).

A 16t kind of fits, but probably wouldn't run it with a high powered motor- 

 

 

A 20t does work with high powered motors (this ran 5700kv / 5s ), but you need to leave a motor bolt out, so probably advisable to check it's still tight periodically...

 

 

 

On 9/3/2024 at 11:07 AM, BackITG said:

When it comes to the turns /per motor I'm clueless and have zero knowledge on what to do to be honest

This is a kind of rough guide.

KV of a sensorless is kind of set in stone, but the kv of a sensored (usually measure in Turns) isn't, as you can add timing via the esc (think Vtec ) and it'll rev higher (a 13.5t will run around 5000kv, with a bucket of timing)

 

 

 

 

[BackITG 34]

Thanks @Wooders28

The brushless set arrived earlier this week, not realizing I would have to get connectors separately and solder the whole bunch to get the ESC wired to the battery and the motor.  I'm not prepared for that nor have I ever done this before. 

Can I get around the soldering with just the right connectors etc? 
 

[Kowalski86 4317]

5 hours ago, BackITG said:

Thanks @Wooders28

The brushless set arrived earlier this week, not realizing I would have to get connectors separately and solder the whole bunch to get the ESC wired to the battery and the motor.  I'm not prepared for that nor have I ever done this before. 

Can I get around the soldering with just the right connectors etc? 

For the motor to esc, solder on plugs from the motor to the esc, and of course your battery plug of choice to the esc.

With most brushless combos you'll need to solder at least a few parts, even some of the expensive Hobbywing setups.

[alvinlwh 7254]

6 hours ago, BackITG said:

Can I get around the soldering with just the right connectors etc?

Simple answer is no. You still need to get the wires to "stick" to the connectors and, again no, electrical tape will not work. 

[Wooders28 4936]

7 hours ago, BackITG said:

Can I get around the soldering with just the right connectors etc? 

Naa, 

Tbh, it's kind of a given you're going to have to solder, on the faster stuff, as connections are a weak point.

I've got motor bullet connections on my Castle ESC, and a deans for the battery, as it going between my DF03 and DT03 (it's a 6s esc, so use it for speed runs), it really does not look neat...

 

 

 

My KF2se on the other hand, has its dedicated esc, wires cut to length ,and soldered directly onto the motor.