E-MTB Drive Gear with Spur Gears "Directdrive"

Nowind · November 22, 2016, 6:25pm

Thanks Lox,

peel of what comes of then use “BrakeCleaner” and a towel. The trick is not to use to long the same place on the towel, change it often and aply breakcleaner. One Motor one Minute this way

@whitepony I thought alot about your last comments. I still think that a further reducing of the reduction is maybe problematic with the available Motors. Dont forget that on 12S even the 149kv Turnigys will give you over 50kmh Vmax.

BUT: Actually it would be even with the 1:5 Gearing possible to be inside of the wheels. The axledistance is 60mm and Motor radius is about 32, so by 200mm Wheels you are INSIDE. I really thought about if the small round braces could be as good as the known horizontal braces. And in fact they cant be, if we maybe completely go without them the mount will get more compact. There would be no need anymore to be bigger then the motors. As you said (-;

Maybe another way for additional motorprotection could be to adapt something from the underside of Truck where the Springplate is attached … something like a brushguard as mentioned by @mmaner

I would like to ask @trampa : Is it possible that the trucks are not machined out of one zero point? So if you wanna have the best alignment to the Steelaxle you have to seperate both sides?! Thanks for your help Frank.

trampa · November 22, 2016, 8:08pm

Hi Jens, the hangers are forged and polished, then heat treated, then painted, then CNCed. Problem: How on earth do you clamp that raw hanger in a super precise way, when it is still raw, without any holes etc. Its not that easy. I think you should accept the fact that 100% precision is hard to guarantee on a forged, heat treated and polished hanger. We will try to get a better alignment in future, maybe designing a new Hanger. BTW.: If you interconnect your rods, use six of them, as seen on our drives, its a very sturdy casing you get

Motor KV: We have the 118 and 136KV motors. We measured@1Nm so the values are a bit more realistic for board speed and efficiency assumptions. No load KV is roughly 125 and 145KV. These would be perfect for your drive. 40km/h is in my eyes fast enough. Torque is what you want, going off road.

You should really test your drive, set up as a single drive. Singles are under more strain! Hope the gears last… What about noise?

Cheers, Frank

Nowind · November 23, 2016, 6:12am

Thanks for fast reply. Yeah i will accept (-; just want to be sure about before i break my neck by trying to align both sides together.

Your Hexa Design of Motorcase is nice, but i got not enough space between truck and motor for it.

I thought about your Motors, anyday i have to test them for sure. Actually for the Spur setup the motorshaft is to long, its about 38mm i cant get it in the housing. And to cut it would be very nasty, always wishes the last years for longer Motorshaft (-; but in this case not needet.

Never thought about a Single Drive Test with the Spurs… yes you are right stress will be bigger for sure. Time will tell how good they last… noise is not that bad, belt is nicer for sure. But also the drag is higher by the Belt, the Spur is really good by free coasting.

Thanks again. Cheers Jenso

trampa · November 23, 2016, 9:16am

Hi Jenso,

its easy to make a replacement shaft. We use double keyway (Pulley and Motor Can). I would not cut our hardened shaft, agreed… Usually the Belt is 98% efficient and schould not create drag if the belt tension is adjusted adequately. Using Spurs, I can see the advantage in having smaller Drive Train and improoved gearing. No system is without advantages and disadvantages. You gain this, you loose that. In the end its a matter of durability and personal prference. Very good skills BTW, keep up the hard work! If you like, feel free to ring my Mobile.

Frank

Nowind · November 23, 2016, 5:27pm

Yes this is a good thought to go with a shorter replacement shaft. As you said each drivetrain has it pros and cons, at least a choice of personal preference. Thank you, always trying to develope new/other/better stuff. This E-MTB stuff is so freaking awesome, i get a little addicted (-; I give you a call. Cheers

Nowind · November 23, 2016, 6:44pm

Some video stuff from the last runs. First part with 200KV, ungreased. Second Part 149KV greased. Really impressed so far from the Drivetrain. Unfortunally the days are so short at the moment, can only go out for half an hour before it gets dark. Anyway, half hour full of ADRENALIN

Hang Loose

DavidC · November 23, 2016, 7:03pm

And what about 200kv greased?

Nowind · November 23, 2016, 7:25pm

Yeah why not Its really speedy and makes tons of fun, but to be honest this Topspeed i will not bottom out! I´m sure you can if you go with stiffer dampas and more pre-compression on the springs.

Its up to you Bro (-:

darkkevind · November 30, 2016, 12:08pm

Christ! That’s quick!

stylr · November 30, 2016, 12:49pm

@Nowind

Now that you’ve made and tested all various different drive trains, I was wondering if you had any thoughts on the advantages/disadvantages of each? (Chain, Belt, Direct)

Nowind · November 30, 2016, 9:12pm

Hey.

Chain ISO-05 (similar/stronger then #25)

light and cheap, easy to change gearing, resitant against any kind of dirt

not strong enough for high powersetups IMO, if it breaks it blocks the wheel… could be dangerous

Belt HTD5-25mm wide, Roller/Support Bearing

smooth and silent, extrem strong

higher drag then chain/spur IMO , if not sealed you get problems with mud/grass

Direct Drive MOD2

super direct feeling, free coasting, ultra compact

need machining on axle, you get some noise by rough terain and if wheels slip (IMO its the backlash of the spurs what will create some knocking sound) No longtime expierence of how long the spur will last !

DavidC · November 30, 2016, 9:52pm

Hi Jens! Are you thinking of making a sealed belt drive-train?

kovjanos · November 30, 2016, 10:21pm

…or just a shield attached to the motor mount frame?

R, J.

Rob.Endless · November 30, 2016, 11:09pm

I’m still waiting for my Trampa e-toxx belt drive sk3 6374 192kv 12s7p build. once I get it, I will take some videos for sure. I need to find a bmx track around here.

Nowind · December 1, 2016, 5:50am

Both would be possible! If its only supposed to hold dirt away it could be a thin shield or printed cover. If it should be also a protective part for the drivetrain it has to be more massive, for that a reduced gear ratio is needet otherwise the inteference contur gets to big.

I[quote=“Rob.Endless, post:94, topic:9586, full:true”] I’m still waiting for my Trampa e-toxx belt drive sk3 6374 192kv 12s7p build. once I get it, I will take some videos for sure. I need to find a bmx track around here. [/quote]

Yeah looking forward to some action videos, hard packed clay bmx tracks are a blast to ride!

Some pics of inside the Spurgears after about 70-90km, not easy in winter to get alot miles … gets dark to early… or i work to long

… the white grease is still white you dont see any debris inside

I cant see any kind of wear on the gears, but of course its only running for a short time

In general its running really good, free coasting is very good. On nice roads its not loud but as i mentioned above on rough terrain you got some knocking of the gears. Its hear and noticable, this is the backlash of the spurs i guess.

Worked on the next mounts : Removed all connection points of the last version for the round braces, also reduced unneedet material around the motors, you are now completely INSIDE of the tires !

Improoved the truck connection, increased the clamping area by nearly double the wide :

Not sure if this will really needet, but it cant be a disadvantage

But i have to say its of course more work, the both Parts need to machined together, and they are fixed also with two “matching pins” know what i mean ? Its pinned not sure if its the right term … But this way the both parts are not able to move anymore in no way (-;

Cheers

whitepony · December 1, 2016, 6:12am

awesome, love that its even more compact now! interesting that you basically had no wear so far. the white grease color check is very smart

Nowind · December 1, 2016, 6:22am

Yeah its very good to see, but actually i will change the lubricant to a better one, unfortunely its not white

The white grease was something i just have in stock but i regocnice that caused due the high RPM not much grease stucks to the gears. Now got some stuff which is supposed to this use case. Whats really important is to choose something without acids, it must be compatible with the POM.

kovjanos · December 1, 2016, 8:04am

Yep, only against dirt and small stones. 3D printed cover is good idea!

R, J.

Nowind · December 1, 2016, 10:09am

Yes i think you should try with 3D print. Would nice to share your result. Let me know if i can help you. Cheers

Nowind · December 4, 2016, 7:56am

Some pictures of the sealment part out of POM :

Parts as it comes as rawmaterial with 625 gramms :

Ready machined with 88 gramms :

This is where the gramms go :

This is a machine rate of 85 % … but this piece is strong as hell … can stand on it :

Milling the greasing point :

With metal thread insert :

This is “Helicoil” thread inserts, very nice stuff. Very usefull also for repair stripped threads on Motors !

Batch of 4 Sets for first Beta Testers :

Hang Loose Jenso