Upgrade to Brushless Motor for Dark Impact Advice Wanted

[Hullstorage]

Hi all,

I am new to this building models so please go easy on me? lol

I am looking to make my car faster (hopefully) by upgrading the motor to a brushless system.

What would I need to do and what would be a suitable budget motor for it.

Would I also need to upgrade other parts of the gear build??

Thanks

Simon

[Gruntfuggly]

I had an ezRun combo (8.5T I think) in mine which worked a treat.

[mike_o]

Hello Simon,

welcome to the forum! You don't tell us what motor and battery is currently in your car, so that makes the question a bit more difficult to answer. I'll assume that the current motor is the stock silver can (Mabuchi/Johnson RS-540SH).

What to do: You need to buy a suitable BL (brush less) motor and a corresponding BL ESC (preferably with a power connector that fits your battery - otherwise, you need to get one separately and solder it to the ESC). Unless you are racing at a track, a sensorless system will do and save you some money over a sensored system.

Concerning your need for speed: You don't have to hope for more - It will come almost automatically with a BL set-up :-) The question is how much more power you want; If you choose a 8.5T BL, your battery may not be up to the job. Furthermore, the high RPMs of a 8.5T motor would also require a new pinion gear to avoid overheating the motor. Finally, the transmission of the DF-03 (Dark Impact) doesn't have best reputation when it comes to high power.

The increased speed of a 8.5T motor could also lead to more and more serious crashes, increasing repair costs.

You may want to choose a more moderate power increase, like 10.5T or 13.5T and you could just get by with your existing battery and pinion. The gear ratio of the Dark Impact is 9,17:1 (the motor turns 9.17 times for every time the wheel turns) with the stock 26T pinion gear. LRP recommends around 9:1 for their 10.5T (4100) Eraser motor and 8:1 for their 13.5T (3100kV) motor in off-road application. So the calculation would go 26T x 9,17/8,00= 29,8 meaning that a 30T pinion would be a better match for a 13.5T motor.

Depending on your driving style, a 13.5T would require a slightly less expensive ESC than a 8.5 or 10.5T motor, as the current draw would be lower (also incresing the run time). I you want a substantial power increase, then go for a 10.5T (or 3900-4100kV) motor.

[Percymon]

The simplest upgrade from the kit box silver can motor is a sport tuned, or for a bit extra a Super Stock TZ/RZ motor. All of these can utilise the existing ESC (speed controller) and are a simple swap over of motor.

Brushless set-ups will require a new motor and ESC, and may need better batteries to cope witht he current draw of a fast motor

You should also swap any plastic bushings for proper ball bearings if you have any fitted - www.rcbearings.co.uk is a good source of bearings at good prices. I'd recommend the rubber shielded (option when adding to basket) for use at the wheels where they wil be exposed to moisture and dirt.

[vycalais]

Hi guys, first post here also.

I thought the DI was already ball-raced? I wanted to know the exact same thing as the OP and was looking at the EZRUN 9T.

Any thought would be appreciated. Have the recently purchased DI in box and my first RC since Blazing star when I was in my 20s lol.

[Percymon]

Hi guys, first post here also.

I thought the DI was already ball-raced? I wanted to know the exact same thing as the OP and was looking at the EZRUN 9T.

Any thought would be appreciated. Have the recently purchased DI in box and my first RC since Blazing star when I was in my 20s lol.

If you've bought a used car, you never know what the previous owner has done !

Appreciate the thread is titled brushless but there is more than one way to get more speed, and all depends upon budgets.

[vycalais]

Thanks for that percy, but I have heard a couple of times now the BNIB kit has bearings included. I am yet to open mine and have a look.

Although new to the forum, I am not new to RC or Tamiya. I might still be wrong about the bearings, or perhaps it was an Australia thing? Not really sure. Getting off topic a bit.

So apart from the motor Percy, what would you recommend upgarding on the DI? Is the DF03 generally considered a good chassis?

[Percymon]

The DI kit does come originally with bearings, but as i said you never know what people throw in there !

[vycalais]

Cheers Percy.

This has probably been asked before but will the standard DI gearbox(es) handle a 9T or even a 5.5T EZRun?

[TA-Mark]

Cheers Percy.

This has probably been asked before but will the standard DI gearbox(es) handle a 9T or even a 5.5T EZRun?

The gearbox will handle it fine. They just won't last long with high powered motors fitted. The aluminium gear on the mainshaft wears almost as quick as an aluminium pinion will. There is an upgrade available from Five Stars that have a hardened steel gear. Part number FS7038 for the standard mainshaft and FS7039 for the slipper mainshaft. These make the gearbox last well with high powered brushless in them.

The Tamiya 0.5 module pinions for the DF03 are all steel, so these are not a problem. Instead, they put the aluminium 'wear out quick so we make money from lots of spares' gear on the mainshaft. Once the mainshaft aluminium gear wears out it usually takes out the idler gear that runs from it and also the rear ball diff gear too. If you let the mainshaft wear that far it's 3 parts bags needed to repair, slipper set, bevel gear set, diff gear set. Not a cheap fix to say the least.

There are pinion and spur combinations from Tamiya for the DF03 that allow fitting of even the hottest motors and still keep the gear ratio right.

[vycalais]

The gearbox will handle it fine. They just won't last long with high powered motors fitted. The aluminium gear on the mainshaft wears almost as quick as an aluminium pinion will. There is an upgrade available from Five Stars that have a hardened steel gear. Part number FS7038 for the standard mainshaft and FS7039 for the slipper mainshaft. These make the gearbox last well with high powered brushless in them.

The Tamiya 0.5 module pinions for the DF03 are all steel, so these are not a problem. Instead, they put the aluminium 'wear out quick so we make money from lots of spares' gear on the mainshaft. Once the mainshaft aluminium gear wears out it usually takes out the idler gear that runs from it and also the rear ball diff gear too. If you let the mainshaft wear that far it's 3 parts bags needed to repair, slipper set, bevel gear set, diff gear set. Not a cheap fix to say the least.

There are pinion and spur combinations from Tamiya for the DF03 that allow fitting of even the hottest motors and still keep the gear ratio right.

Thanks mate, so the 'slipper' is an add-on as well?

Might invest in those box upgrades pronto.

Could you PM any links to Tamiya, five star or eBay (or post if allowed) to steer me in the right direction? Would rather genuine parts but if 'five star' are okay I will have a look.

Sorry been out of the RC game for a while..

Thanks once again for the prompt reply

[TA-Mark]

A slipper is a slipper clutch. It replaces the standard spur gear and mainshaft. Highly recommended for powerful motors or if jumping the buggy. Tamiya Part #53925

The Five Stars parts are a bit harder to find. Usually only in Japanese hobby shops. The FS7038 replaces the kit supplied mainshaft, and FS7039 is for use with the #53925 slipper clutch set.

Search eBay (and possibly google) for the part numbers. RC Champ (Tamiya Club sponser) did have the Five Stars shafts a few months ago.

[vycalais]

A slipper is a slipper clutch. It replaces the standard spur gear and mainshaft. Highly recommended for powerful motors or if jumping the buggy. Tamiya Part #53925

The Five Stars parts are a bit harder to find. Usually only in Japanese hobby shops. The FS7038 replaces the kit supplied mainshaft, and FS7039 is for use with the #53925 slipper clutch set.

Search eBay (and possibly google) for the part numbers. RC Champ (Tamiya Club sponser) did have the Five Stars shafts a few months ago.

Thanks, yes just been browsing TamiyaShop downunder for some parts. Seems slipper is a must and the hardened shaft as well hey? Anything else to recommend? Obviously I'd rather avoid expensive repairs and heatache and build this thing right.

Today I stripped the spur gear in my Blazing Star and its not the price, its finding the standard replacement!!

Thanks heaps for your help

[TA-Mark]

The DF03 is well built. It's only real weakness is that aluminium gear on the mainshaft. There's no mods that it needs apart from that. The rest is all personal choice and bling.

The DF01 on the other hand needs a few parts replaced to make it reliable, but we'll cover that in the other thread.

[vycalais]

The only weakness I have found with my DF 01 is the spur and yes, best for another thread as Ive already hijacked this one.

So will P/N #53925 do the trick to run a 5.5T reliably on a jumping DI runner or do I need more bits?

For some reason I like eBay for stuff like this rather than online shops with little accountability and no viewable reputation to worry about.

[TA-Mark]

Both the kit supplied mainshaft, and the mainshaft in the #53925 set have the same soft aluminium gear pressed onto the shaft. This gear is the weakness.

It's not the spur gear in the DF01 that is the problem, it's the aluminium gear that's running on it. Go read the other thread.

My DF03MS.

[vycalais]

Both the kit supplied mainshaft, and the mainshaft in the #53925 set have the same soft aluminium gear pressed onto the shaft. This gear is the weakness.

It's not the spur gear in the DF01 that is the problem, it's the aluminium gear that's running on it. Go read the other thread.

My DF03MS.

Thanks Mark, just noticed we are both in Oz. can you recommend anybody local that has a good rep and fast post for this stuff? I'm out west.

[TA-Mark]

Don't know anyone in Australia with the Five Stars shafts. I got mine from Japan. Part supply for Tamiya in Australia isn't very good either due to ToyTraders (Aussie official importer). Most hobby shops refuse to deal with them.

As for wait times on shipping. Items I buy from Japan or Hong Kong get to me before items I buy mailorder from local sellers or hobby shops (and the postage cost is cheaper....). Everything I buy is mailorder being central sourthern QLD and no hobby shops for a very long drive.

[kontemax]

Where can we get the Five Stars FS7039 please?

Max

[TA-Mark]

RC Champ (Tamiya Club sponser) did have the Five Stars shafts a few months ago.

[Wooders28]

I too have been out of the RC game for a while (20 yrs!! ),so may ask what some of you will think to be daft questions.

I have the Dark Impact,DF03,and my brushed motor (10t double) went fizz and also took out the elec speed controller,so its seems only right to go brushless.

I found this thread while looking for hints on gearbox strenghtening,which has been perfect so thank you.

A few other questions though:-

I see quite a few cooling fins available,Do brushless motors require extra cooling fins? Or does that just depend on where the motor is situated in the chassis and if using what all the time,gear ratio etc? I do have the 'heat sink bar Tam-53924',will that be sufficient?

I see brushless are available in can size (380,540's etc),Turns and KV's.Back in the day,i used as a rule that single motor windings where for 2WD and had low torque but high RPM while the double and triples had more torque,suitable for the heavier 4WD,which meant better exit from hairpins etc.Do brushless have similar properties? Or do you just low gear a high RPM motor?

Power supplies - I have a couple of 6 cell NiMH batteries raging from 1800 to 3800mAh and a suitable 12/240v peak charger.Is going to a 2 cell lipo setup justified? I know they offer a big increase in Amp hours and 0.2volt ,but they do look expensive as i will need charger,battery and explosion charge bag?!?

Any input will be appreciated.

[sosidge]

I see quite a few cooling fins available,Do brushless motors require extra cooling fins? Or does that just depend on where the motor is situated in the chassis and if using what all the time,gear ratio etc? I do have the 'heat sink bar Tam-53924',will that be sufficient?

Brushless motors will tend to run cooler, optional heatsinks rarely do much to cool down a seriously overheating motor.

I see brushless are available in can size (380,540's etc),Turns and KV's.Back in the day,i used as a rule that single motor windings where for 2WD and had low torque but high RPM while the double and triples had more torque,suitable for the heavier 4WD,which meant better exit from hairpins etc.Do brushless have similar properties? Or do you just low gear a high RPM motor?

You'll need a 540 size motor for the Dark Impact. Turns and KV only make sense when compared to motors of a similar design. You won't (generally) find the equivalent of single and double winds in brushless.

Power supplies - I have a couple of 6 cell NiMH batteries raging from 1800 to 3800mAh and a suitable 12/240v peak charger.Is going to a 2 cell lipo setup justified? I know they offer a big increase in Amp hours and 0.2volt ,but they do look expensive as i will need charger,battery and explosion charge bag?!?

LiPo is a definite improvement in performance and durability compared to NiMH (assuming correct use). Charge bag is not necessary unless you are nervous, but you must never use a NiMH charger with LiPo. You wouldn't regret the upgrade. You can still use your NiMHs with a brushless setup though.

Any input will be appreciated.

The Dark Impact probably wouldn't appreciate anything faster than a mild modified brushless, I would say an 8.5 as the limit, maybe even a 10.5 or milder. As a racer, I prefer sensored but a lot of bashers are happy with the sensorless systems. Hobbywing EZRUN's seem to be the best sensorless setup, there is a long list of good quality sensored race systems, but Hobbywing's XERUN is probably the best value. Just watch out for the fakes on that well known auction site.

[Wooders28]

Thanks for input,i will try and stay off auction sites and support local modelshops.I am not planning on getting back into racing anytime soon,but never say never as they say! Had a quick look at sensored motors and think i will go with the sensorless.As far as i can gather sensored motors alter the timing (like setting the degree on the old brushed motors) to get the max performanc at any RPM?.Not really needed unless racing i feel.I will upgrade to lipo once the charger or batteries give up the ghost.I might have to sell some cars to fund the upgrade as it is!!!

[TA-Mark]

As far as i can gather sensored motors alter the timing (like setting the degree on the old brushed motors) to get the max performanc at any RPM

Both sensored and sensorless motors operate their 'timing' in a similar manner. The timing of when each phase will 'fire' can be controlled by the ESC (and adjusted in the ESC setup), as opposed to turning the endbell on a brushed motor.

The difference is that a sensored motor has a separate sensor unit that relays the position of the rotor to the ESC so the right phase can be sent to the motor at all times. Sensorless systems use the back EMF from the disused phase to determine the position of the rotor. The sensorless motors have some trouble in determining the rotor position if the rotor is stationary (no back EMF) or the motor is rotating the wrong direction (incorrect back EMF). The result of the ESC interpreting the incorrect or no back EMF is that the motor will jerk (or cog). Sensorless systems run cooler, have fewer internal components in the motor that can fail, and less wiring to the ESC. The best systems use a sensored system to start the motor, then they switch to a sensorless mode when the motor is rotating (the best of both worlds).

Note that all batteries are dangerous. Tracks will require you to use a Li-Po sack to charge your packs at the track. It's a good idea if not using a Li-Po sack to charge them away from flammable surfaces/objects, or put them in something that can contain the fire if something does go wrong. Li-Po batteries when damaged or mistreated are a fire risk (hot burning plastic that bursts from the pack). Ni-MH and Ni-Cd are the ones that explode if the cell vents become clogged. They go off like a hand grenade when they do go bang. I've had Ni-MH explode on me before (burns and cuts to my face and arm). Have had no issues with Li-Po in the years I've used them. Only use hard case Li-Po packs in vehicles, soft packs are for planes and may be damaged easily in a vehicle from flying debris (sticks/rocks) or vibration. If you notice a Li-Po pack swell, stop using it and replace.

The covered in location of the motor in the DF03 naturally leads to a hotter than normal motor when running. There's very little air that can pass over the motor. The heatsink bars, if fitted as directed, are still in a covered location and get little to no air flow over them, thus are not much better than not using them at all. Turning them around and fitting them on backwards puts them out where air can pass over them and they actually do something. (See image for how I mounted them).

[sosidge]

Thanks for input,i will try and stay off auction sites and support local modelshops.I am not planning on getting back into racing anytime soon,but never say never as they say! Had a quick look at sensored motors and think i will go with the sensorless.As far as i can gather sensored motors alter the timing (like setting the degree on the old brushed motors) to get the max performanc at any RPM?.Not really needed unless racing i feel.I will upgrade to lipo once the charger or batteries give up the ghost.I might have to sell some cars to fund the upgrade as it is!!!

I wouldn't worry about the timing advance properties of sensored... sensored is simply smoother at the bottom end and has a feel much closer to brushed.