Slawek's angle grinder drive

slawek

10 mW
Joined
Apr 5, 2011
Messages
22
Location
New York City
This is my first post so I would like to say Hi to everyone on this forum. I came from Poland, and last six years I have been living in New York.
English is my second language so please forgive me my mistakes. I would like to say, you guys are really people who have passion to create really amazing things.
You are my inspiration, thank you all of You.
I have been reading this forum for few months, and I decided join to you guys, because I think, I can finally contribute something. Hopefully some of you might find this helpful.
I would like to share with you my experience from my e-bike build (I started experiments january2010).
My first goal was build city commute e-bike (work-home, and a little around), with relatively light weight drive. Top speed about 20-22MPH, and 20 miles range.
For my project I took my 700cc wheel bike with Shimano Alfine SGS500 Disc brake 8-spd Internal Hub

GiantTranSendEX-1.jpg


I picked motor Hacker A60-18L 150kV due to low gear ratio needs, and I planned to run this on 6S LiPo 22.2V because I try to stay close to legal requirements with is 750W and 20MPH. I estimated if Hacker rated this motor with 45A constant current it shouldn’t develop more than 1000W at 22.2V. Minus energy lost about 10-15% on gearbox and minus another 10-20% on chain, it stay about 810 – 680 W delivered to rear wheel. (But later turn out my estimation was so wrong). With this I decided go to angle grinder gear box Bosch rated as 2HP. So I ordered new set: Gear crown and pinion. Next fabricate gearbox at my work. Small pinion was placed directly on motor shaft. Everything works in oil bath.

Gearbox1.jpg


I used ESC CC Mamba Monster form my RC car E-max.
Speed was regulated by Turnigy servo tester, battery also from my RC car 10Ah 6S LiPo
Than I did quick assembly, and had first test run.

Bikeasembly1.jpg


Bikeasembly2.jpg


First; max. speed turn out to be 24MPH, (for calculation I used nominal 3.7V per cell, but fresh charged is ~4,2V)
Second; power close to 2000W during acceleration :shock: (whooooaaaaa!!!)

100A current just amazed me, I thought that, impedance at half of max voltage should not let reach so high current. What else interesting is, even though motor is rated for 65A max. @15 seconds current, at 100Amps (during very often acceleration on NYC streets) never got hotter than 65°C - this just make me happy.
So I was wondering what is going to break first. After 80 miles of run, motor shaft snap, and small pinion was worn out about 30-40%. There was no sense to fix this.

Brokengearbox1.jpg


P1000409.jpg


During these 80 miles I realized that, I need stronger breaks at the front wheel, so switching from 160mm to 203mm was necessary.
One more thing, it might be big rain of criticism on my head, but I realize that active safety wasn’t on right level. My e-bike was to slow to flow with traffic, an especially on switching lines for left turns. Thereafter I kept in mind to build 7S Battery when that time will come.
I decided to make new stronger gear box. I calculate torque and this Time Dewalt grinder rated 5,3HP was able to handle that. I mount small pinion on bearings independently from motor shaft, and like previously gearbox filled with oil for long life. Total ratio is 10,5:1.

Newgearbox1.jpg


Newgearbox2.jpg


Right after I build new battery pack using LiMnNi Rechargeable 26650 Cell: 3.7V 4Ah, rated – 10A continuous max. Discharging current. I pick cylinder shaped battery because are more resistant to vibration and unfortunately my bike have no rear suspension. I build 7S10P pack, over 1KWh. This gave me about 30 - 35 miles range @27MPH (NYC a lot accelerations and stops). And of course I had to buy new ESC capable handle higher voltage – CC Phoenix Ice 100. Now top speed and acceleration is very satisfying.
Some pics of my battery pack:

Bat1.jpg


Bat2.jpg


Bat3.jpg


Bat4.jpg


Bat5.jpg


On new gearbox and new battery so far I have done over 600 miles and I realize that chain must be replaced with belt because:
1. Noise
2. Nonstop dirty pence or leg and bike
3. No effective breaks on rear wheel after every chain lubrication
I bought small pulley POLY CHAIN TIMING PULLEY 8MX-22S-12 and fabricate rear pulley 50 toth.

Rearpulley1.jpg


Rearpulley2.jpg


Newbelt1.jpg


O new belt I have done 35 miles so far and looks like going to works fine.
If I do some modifications, or error come out I will write about this.

Sławek
 
Excellent first post, Welcome Slawek! One of the reasons that keep bringing me back to ES are the unique builds people come up with. I like your compact setup. Do you have any videos, what is the noise like as well? Thanks for posting!
 
Hillhater said:
Very impressive ! :eek:
Well thought out and engineered too, resulting in a neat compact drive package.
do you have throttle control or just the servo tester ?

I used Turnigy servo tester. I removed original 10Kohm potentiometer and connected directly Magura E Bike Electric Scooter Twist Throttle 0-5K Ohms, and so far works god.


AussieJester said:
Very nice love the belt drive whats the noise like from the grinder box?

KiM

P.S and thats one mighty first post....welcome to the forum mate ;)

Yes it's kind of... But sound is very soft (due to rpm are ~ 6 times smaller than original tool rpm.) It’s used to be worse with chain, but now with belt is kind of nice and quiet.

kfong said:
Excellent first post, Welcome Slawek! One of the reasons that keep bringing me back to ES are the unique builds people come up with. I like your compact setup. Do you have any videos, what is the noise like as well? Thanks for posting!

I will make one soon.


PS. Thank You for kind comments.
 
VIDEOS or BAN!

Just kidding, welcome to ES. cool idea.
 
Welcome to ES. Great innovative angle reduction build and solution to chain dirt and noise.
We look forward to the video.
Thanks
 
Yes! Nice build, I have two of those boxes awaiting playing with! I am thinking of using one on my wifes bike after I finish my build!
 
Whoawa-wee-woo..... tech.

You seem to indicate you made these parts yourself. Are you a fitter and turner machinist by profession? Or have you learnt as a hobby in a well equipped workshop?
 
i like the way you have made up your battery packs, very neat, sturdy and basically foolproof.
wonder if this would take 36v instead of 29v would be pretty fast
 
Hi Slawek and welcome to ES,
What a cracking first post.. love the right angle drive please can I ask how did you attach the pinion sprocket to the the motor shaft on the second gearbox? and do you have any pics please. You have inspired me :wink:
 
You mentioned excessive wear on the right-angle drive pinion, what type of lube were you using in the gear-box?

I really like how you attached the belt-pulley to the rear brake disk, very clever and helpful...
 
boostjuice said:
Whoawa-wee-woo..... tech.

You seem to indicate you made these parts yourself. Are you a fitter and turner machinist by profession? Or have you learnt as a hobby in a well equipped workshop?

I am metal worker. I make custom furniture from brass, stanley steel, aluminum ect.
The thing is I make them from blueprints to final product, so I have to be everything: milling machine operator, turner, TIG welder.

darkone040 said:
i like the way you have made up your battery packs, very neat, sturdy and basically foolproof.
wonder if this would take 36v instead of 29v would be pretty fast

36V yes I wish, but bicycle without full suspension at speed over 30mph just scares me.

Wheazel said:
I like your work alot!
Did you encounter any difficulties when changing to beltdrive or was it very straight forward?

Like you noticed I did this the same way like chain and belt is just 12mm wide. I bought the smallest available pulley – 22 tooth (the closest to old free wheel) the closest belt length to the chain and calculate what maximum pulley I can fit on rear. Unfortunately this change my ratio by 10% down, and I thought bike will be faster, but is not, and this also affect my total range from 30-35 to 25-30 miles. Before I had stabile 27mph on flat road after full charging, now sometimes is 25 sometimes is 29 – conclusion: motor is over loaded. Now I am getting ready to make custom pulley 21 tooth even though Gates do not recommend that for their belts, and new one 51 toot for rear to have exactly ratio I use to have.

gwhy! said:
Hi Slawek and welcome to ES,
What a cracking first post.. love the right angle drive please can I ask how did you attach the pinion sprocket to the the motor shaft on the second gearbox? and do you have any pics please. You have inspired me :wink:

I used hardened screw for shaft

Shaft1.jpg


motorconection2.jpg


and few more

Insidegearbox2.jpg


Insidegearbox1.jpg

this rectangle no the bottom gearbox it's magnet to attract unwanted particles.

spinningmagnets said:
You mentioned excessive wear on the right-angle drive pinion, what type of lube were you using in the gear-box?

I really like how you attached the belt-pulley to the rear brake disk, very clever and helpful...

I do not know :oops: , I got this oil from someone, i grab from my shelf and feel up gear box. I thought oil is oil this bike is not a rocket... it wont fly to the moon ... :lol: :lol:
But for my second gearbox I did my homework an now I am using: Mobil SHC 634 (ISO VG 460)
This one is for low rpm and high loaded gears.

Sławek
 
That battery pack assembling looks very professional. I don't think I've seen a neater solution.
I may steal that idea one day.

Well done.
 
slawek said:
this rectangle no the bottom gearbox it's magnet to attract unwanted particles.
That's genius...I dunno how many gearboxes in various equipment I've seen trashed just because some little bit of metal ground or flaked off a gear, then began chewing up another gear, then all those pieces chewed some more.... :( That magnet might've saved them (assuming an oil bath for the bits to float downward in, isntead of jelly-like grease).
 
I love it and welcome to ES!
 
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