New build, BHT mid-drive "direct", custom frame

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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DanGT86   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by DanGT86 » Mar 31 2018 10:19pm

Cool project! I'm a big fan of frames with lots of steel tube fabrication. Hope the rest of the frame looks like the swingarm so far.

You could add a plate on the other side of the thin slotted motor mount area. Drill holes the same as your motor mount bolt pattern and use set-screws to set the chain tension by jacking the plate forward against the swingarm mount. This would also help to gusset the thin area you are concerned with by locking the whole motor mount flange together. Something like this:
plate.png
plate.png (12.73 KiB) Viewed 2572 times

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madin88   100 MW

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Re: New build, BHT mid-drive "direct", custom frame

Post by madin88 » Apr 01 2018 4:38am

Overclocker wrote:
Mar 31 2018 10:21am
the motor can slide forward/back to adjust chain tension. i probably have to torque those bolts really hard though to keep the motor from "creeping"
Did you do calculations for the maximum pulling force on the motor?

The controller phase amps multiplied with kT will give you max motor torque.
From the torque and sprocket radi you get the force.
On a similar setup i got 1500N on the chain but with a larger sprocket. On your setup i would guess up to 2000N, or 200kg of load.

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Apr 02 2018 10:47pm

DanGT86 wrote:
Mar 31 2018 10:19pm
Cool project! I'm a big fan of frames with lots of steel tube fabrication. Hope the rest of the frame looks like the swingarm so far.

You could add a plate on the other side of the thin slotted motor mount area. Drill holes the same as your motor mount bolt pattern and use set-screws to set the chain tension by jacking the plate forward against the swingarm mount. This would also help to gusset the thin area you are concerned with by locking the whole motor mount flange together. Something like this:
plate.png
yes will definitely do something like that at the first sign of motor "creep". but i was thinking of of welding on a piece of bar that's tapped. the set screw simply pushes on the "legs" of the motor

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Apr 02 2018 10:48pm

madin88 wrote:
Apr 01 2018 4:38am
Overclocker wrote:
Mar 31 2018 10:21am
the motor can slide forward/back to adjust chain tension. i probably have to torque those bolts really hard though to keep the motor from "creeping"
Did you do calculations for the maximum pulling force on the motor?

The controller phase amps multiplied with kT will give you max motor torque.
From the torque and sprocket radi you get the force.
On a similar setup i got 1500N on the chain but with a larger sprocket. On your setup i would guess up to 2000N, or 200kg of load.

zero calculations made w/ this build (except for RPM calculations) :lol: it's all based on intuition :roll:

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madin88   100 MW

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Re: New build, BHT mid-drive "direct", custom frame

Post by madin88 » Apr 03 2018 2:04am

Overclocker wrote:
Apr 02 2018 10:48pm
zero calculations made w/ this build (except for RPM calculations) :lol: it's all based on intuition :roll:
Yeah i do it the same way most of the time, but sometimes it's deeply interesting to know some values :)

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Apr 03 2018 9:33am

madin88 wrote:
Apr 03 2018 2:04am
Overclocker wrote:
Apr 02 2018 10:48pm
zero calculations made w/ this build (except for RPM calculations) :lol: it's all based on intuition :roll:
Yeah i do it the same way most of the time, but sometimes it's deeply interesting to know some values :)
yeah it would be great to be able to do finite element analysis and such. instead of the good old throwing stuff at the wall and see what sticks :lol:

btw this is also my 1st "serious" welding project so i do have the feeling that i'm biting off more than i could chew :mrgreen:

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The Stig   100 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by The Stig » Apr 03 2018 5:15pm

Hi Overclocker,

I just wanted to confirm: which website did you buy the BHT motor from?

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Apr 04 2018 9:26am

The Stig wrote:
Apr 03 2018 5:15pm
Hi Overclocker,

I just wanted to confirm: which website did you buy the BHT motor from?
https://www.e-bike-diffusion.com

but i'm not sure if it's still available

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madin88   100 MW

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Re: New build, BHT mid-drive "direct", custom frame

Post by madin88 » Apr 04 2018 9:34am

The Lightningrods "big block" motor, Denzel D4500 or the motor LMX have should have identical performance. Check them out.
From what i know the LMX motor is the most powerful one because it has a 60mm long stator :wink:

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The Stig   100 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by The Stig » Apr 04 2018 9:55am

Great! thanks all. I was actually trying to confirm y'all are buying from https://www.e-bike-diffusion.com/ since i want to want to buy something from there but couldnt find any reviews about buying from that website.


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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Apr 28 2018 3:11am



Image
Last edited by Overclocker on Apr 28 2018 6:17am, edited 1 time in total.

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skeetab5780   10 MW

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Re: New build, BHT mid-drive "direct", custom frame

Post by skeetab5780 » Apr 28 2018 6:05am

Looks and sounds great! now onto the rest of the bike?? Nice swing design

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Apr 30 2018 3:12am

thanks. gotta get to work on the rest of the frame. this seems useful

http://cq.cx/tubejoin.pl

Image

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madin88   100 MW

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Re: New build, BHT mid-drive "direct", custom frame

Post by madin88 » Apr 30 2018 5:13am

Swingarm looking strong and solid. I also like the design.

How is the drag (or cogging) of the drive compared to a hubmotor?
Do you plan to use regen?

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » May 02 2018 11:02am

madin88 wrote:
Apr 30 2018 5:13am
Swingarm looking strong and solid. I also like the design.

How is the drag (or cogging) of the drive compared to a hubmotor?
Do you plan to use regen?

tbh i haven't even ridden a hub motor :lol: so i have no idea

yes i'm planning to get something w/ regen even just to save the brake pads. that's another reason why i wanted a drivetrain w/ no chain slack i.e. to prevent any chain issues when using regen.

ideally something w/ variable regen controlled by a hall-type throttle. any recommendations? although i probably won't be able to use very strong regen as my cells (samsung 26f) have low charge rate capability...

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trazor   100 W

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Re: New build, BHT mid-drive "direct", custom frame

Post by trazor » May 02 2018 12:28pm

This build is looking really good!

I would like to try a motorcycle rear hub for my OpenEmoto project. ( https://endless-sphere.com/forums/viewt ... =openemoto ). Yours look very lightweight but strong. Do you know where to get it online? Or a model number? Or which motorcycles it is designed for?

Also, what do you think is the minimal distance between dropouts to fit that hub?

Subscribed, please keep posting.

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » May 02 2018 10:52pm

trazor wrote:
May 02 2018 12:28pm
This build is looking really good!

I would like to try a motorcycle rear hub for my OpenEmoto project. ( https://endless-sphere.com/forums/viewt ... =openemoto ). Yours look very lightweight but strong. Do you know where to get it online? Or a model number? Or which motorcycles it is designed for?

Also, what do you think is the minimal distance between dropouts to fit that hub?

Subscribed, please keep posting.

you have a very nice build! and our builds have lots of similarities too :lol:

here in southeast asia the 110 to 150cc motorcycles are all over the place. what i'm using is an aftermarket hub for a Suzuki Raider 150cc. but i had it lathed in some places to save some weight.

spacing between "dropouts" is exactly 160mm

Image

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Sep 26 2018 9:23am

Image

Image

Image


finalizing the geometry...

machined the head tube...

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skeetab5780   10 MW

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Re: New build, BHT mid-drive "direct", custom frame

Post by skeetab5780 » Sep 26 2018 9:39am

Nice i have almost that exact same piece of tubing, its the first step to the thought of building my own frame. You started on a swing first which is a pretty good idea. I would likely get the front done then the back wouldn't adapt

nice progress! watching closely

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Oct 31 2018 10:43am

skeetab5780 wrote:
Sep 26 2018 9:39am
Nice i have almost that exact same piece of tubing, its the first step to the thought of building my own frame. You started on a swing first which is a pretty good idea. I would likely get the front done then the back wouldn't adapt

nice progress! watching closely

Image

it's a piece of water pipe which is almost the exact size needed to fit the cups. the machinist only had to remove a small amount. it has a seam i hope it doesn't split :lol:

Image

Image

Image

just for fun i traced it against the sur-ron
Last edited by Overclocker on Nov 01 2018 8:12am, edited 1 time in total.

SlowCo   100 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by SlowCo » Oct 31 2018 1:39pm

Overclocker wrote:
Oct 31 2018 10:43am
it's a piece of water pipe which is almost the exact size needed to fit the cups. the machinist only had to remove a small amount. it has a seam i hope it doesn't split :lol:
Make sure the seam is facing to the rear so it will be closed in by the frame tubes that will be welded to it. And join those tubes left and right together with small plates.
Great build. Keep going and updating this thread 8)

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Nov 04 2018 11:12pm

SlowCo wrote:
Oct 31 2018 1:39pm

Make sure the seam is facing to the rear so it will be closed in by the frame tubes that will be welded to it. And join those tubes left and right together with small plates.
Great build. Keep going and updating this thread 8)

yes that was the plan. we don't want it to split in front and lose the fork :lol:

just got proper front tires. specialized butcher DH, 2ply downhill casing. mounted on super-wide jetset downz (40mm outer width). now building a really ghetto frame jig...

Image

Image

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Overclocker   10 kW

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Re: New build, BHT mid-drive "direct", custom frame

Post by Overclocker » Dec 23 2018 3:23am

Image

Image

http://cq.cx/tubejoin.pl

finally the holidays, i think i'll have some time to work on this


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