New Approach to 4500W Mid Drive
- Thread starter cozy35
- Start date
Grantmac
10 kW
I REALLY like that! I've thought about using T-bolt clamps plus some sort of backing material in a similar way.
cozy35
10 W
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Here is the in-frame mount setup. Using the same Webbing strap system or T-Bolt setup. This method of mounting does not require BB bracket mounting, simplifying installation. It simply wedges between the seat stay and the down tube.
Now, in order to make the Planetary Box End Plates interchangeable between the in frame and bottom bracket mounting, I need to re-look at the BB bracket plates done in 2mm Carbon Fiber plates.
Now, in order to make the Planetary Box End Plates interchangeable between the in frame and bottom bracket mounting, I need to re-look at the BB bracket plates done in 2mm Carbon Fiber plates.
Grantmac
10 kW
You may need a webbing with less elasticity than polyester. Maybe something like HMPE?
I'd want some sort of backing so the t-bolt strapping doesn't ride directly on the frame. Both a longer mount on the bottom and some sort of conforming top piece.
I'd want some sort of backing so the t-bolt strapping doesn't ride directly on the frame. Both a longer mount on the bottom and some sort of conforming top piece.
cozy35
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Grantmac said:
Polyester Webbing is stronger than Polypropylene ad Nylon, and it also is great at repelling water.
I have incorporated my own T-Bolt design and the strapping rides on the frame and as I stated a 0.5MM poly-carbonate clear sheet can be used. Poly-carbonate is tough stuff. For that matter many clear thin sheet polymers can be used what ever is easily obtained.
Grantmac
10 kW
It's strong but it creeps so you'll need to retension it multiple times most likely. It's used for running rigging (which controls the sails) on sailboats but not used for the standing rigging (which supports the mast) for that reason. Likewise it's not used for bowstrings (another hobby of mine).
HMPE has basically the same elasticity as steel. I like non-metallic options when possible since they have less chance for galvanic corrosion.
HMPE has basically the same elasticity as steel. I like non-metallic options when possible since they have less chance for galvanic corrosion.
Grantmac
10 kW
I wouldn't touch kevlar, it doesn't have the working envelope you want. Specifically almost no resistance to abrasion and it doesn't work well around bends.
HMPE is commonly called by it's trademark name of "Dyneema" and you can buy webbing for climbing or sailmaking. It's brilliant stuff, a single .021" strand will easily hold +100lbs with almost zero stretch.
HMPE is commonly called by it's trademark name of "Dyneema" and you can buy webbing for climbing or sailmaking. It's brilliant stuff, a single .021" strand will easily hold +100lbs with almost zero stretch.
cozy35
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Grantmac said:
I read up some more about the HMPE webbing and I stand corrected that this is Polypropylene? I was incorrectly under the impression that Polyester webbing is superior to Polypropylene. Googling HMPE did not really produce any results, unlike "Dyneema"!
I actually have loads of this stuff in 1" wide pieces of 1.2M each that I used to secure 105AH AGM batteries in trolley cabinets. This webbing is very dense and measures just a tad under 1MM thick.
Grantmac
10 kW
It's nothing alike unfortunately.
HMPE= High Modulus Polyethylene
Polypropylene by comparison might as well be an elastic band.
HMPE= High Modulus Polyethylene
Polypropylene by comparison might as well be an elastic band.
cozy35
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Tomorrow the laser and water jet cutting order will be placed. I am sure I am close to the stage of conclusion of the initial version 1.0 design. (not that it ever ends)
The mount design are done and I will post some pics later. The real challenge now is to make these universal for all the different widths of bottom brackets and chain-ring off-sets. There are a myriad of widths.
I have the following widths in MM:
68
73
83
92
100
104
107
120
121
107
120
121
124
132
141
144
So now for some ingenious designing.
The mount design are done and I will post some pics later. The real challenge now is to make these universal for all the different widths of bottom brackets and chain-ring off-sets. There are a myriad of widths.
I have the following widths in MM:
68
73
83
92
100
104
107
120
121
107
120
121
124
132
141
144
So now for some ingenious designing.
cozy35
10 W
- Joined
- Oct 23, 2013
- Messages
- 71
I think I am done now with the version 1.0 of the 4500W Mid Drive System.
Specifications:
4500W Alien Power Systems APS 8050 Out Runner (50KV)
Two Stage Planetary Reduction Drive.
- Stage one is 4:1
- Stage two is 3:1 (Optional can be 4:1) for a 16: reduction
- Total of 12:1 on the output freewheel sprocket
- Output max output torque with this motor/box combination should be 112NM.
- 12 Cell 50V @ 65A
- Cadence of 120 RPM
- Maximum Speed - 55 - 60 Km/H
The cads are off to the laser/water jet cutters and I should have them back in a week or two.
I have one concern that is mingling in my mind - The pinion gear that is available off shelf has a bore of 8MM and the APS motor shaft is 10MM with a 3MM keyway. There is just no way that a bore of 10MM can be had on a 4:1 Input Pinion Gear together with a 3MM keyway. So if I use this ratio, I will have to have the gear bored out as a shrink/press fit. If I swap the stages around, then I can have the 3:1 as an input pinion gear and this can be broached for a 3MM keyway. I just think it is more efficient to have the higher ratio is an first stage. (My logic)
Any thoughts on this?
Specifications:
4500W Alien Power Systems APS 8050 Out Runner (50KV)
Two Stage Planetary Reduction Drive.
- Stage one is 4:1
- Stage two is 3:1 (Optional can be 4:1) for a 16: reduction
- Total of 12:1 on the output freewheel sprocket
- Output max output torque with this motor/box combination should be 112NM.
- 12 Cell 50V @ 65A
- Cadence of 120 RPM
- Maximum Speed - 55 - 60 Km/H
The cads are off to the laser/water jet cutters and I should have them back in a week or two.
I have one concern that is mingling in my mind - The pinion gear that is available off shelf has a bore of 8MM and the APS motor shaft is 10MM with a 3MM keyway. There is just no way that a bore of 10MM can be had on a 4:1 Input Pinion Gear together with a 3MM keyway. So if I use this ratio, I will have to have the gear bored out as a shrink/press fit. If I swap the stages around, then I can have the 3:1 as an input pinion gear and this can be broached for a 3MM keyway. I just think it is more efficient to have the higher ratio is an first stage. (My logic)
Any thoughts on this?
Animalector
10 kW
any updates?
cozy35
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Animalector said:
I have been very busy lately with increased business demands and I also purchased and assembled my own 3D printer to alleviate my dependency on others for concept pre-cnc parts. My printer is up and running and the first test print proved comparable with many other commercially available printers. It an elcheapo Anet A8. (open source with many followers and contributors.)
Lithium_Bob
1 µW
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Hi cozy35. Have you had any progress with this project?
cozy35
10 W
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Lithium_Bob said:
Yes, after quite a long busy work schedule. I have just last week received the cnc machined parts and also the VESC 100A controller. I have now been waiting 6 weeks for the APS8055 Motors. It is taking so long because of the reworked shaft to suit my needs.
Once I get the Motors in hand I can assemble and then figure out the proper size and shape of the BB mount plates.
I still need to order a heavy duty freewheel crank.
Funding is slow.
I'll post some pics from my phone of current progress here.
cozy35
10 W
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OK, so I am waiting for admin to reset my password and change user e-mail. Somehow I cannot login from my phone to post pics. I will be out of town until Saturday. Taking a road trip to Hakskeen Pan where the current tests are underway of the Bloodhound for next years land speed record. This is the reason I want to post from my phone.
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