vanilla ice
1 MW
I've seen chopppers that use the sprocket as the disc trick. I've always wondered how the chain lube dont screw up the friction. I guess it doesn't really matter since its the rear wheel.
The E-cumbent - A project by Matt Shumaker
- Thread starter Storm
- Start date
recumpence
1 GW
Belt skip cured!
Alright! I finally cured the belt skip and belt shredding problem.
Here's what I did;
The belt I was using was 9mm wide 5mm pitch. I decided to go with a 15mm wide belt. You can see the difference in belt width between the first setup, and the new setup.
That did two things for me;
#1 No more skip.
#2 I was able to eliminate the belt wrap idler. You will notice in the pictures, the idler is still used. However, I removed it and still have no belt skip, yet the motor runs cooler with better efficiency (much better efficiency). However, I did not want to pull the side plate off to take another picture without the idler. But, I am thrilled to say, no idler is needed anymore and it runs great!
One issue I was having as well (related to the belt skip) is motor shaft flex. So, I bored a 1/2 inch hole in the motor pulley and pressed a 1/4 inch by 1/2 inch bearing into that hole. Then I fabricated a support plate form 3/16 thick carbon fiber plate I got surplus from Boeing a few years back into a shaft brace. This CF is tough as nails! I have been saving it for just the right application.
The CF plate is adjustable with the motor for belt tension adjustment. You can see the steel standoff in the end of the CF plate. That standoff goes into the bearing at the end of the motor pulley. This CF plate and bearing setup eliminates motor shaft flex and prevents the motor from moving back and loostening the belt under heavy load.
There is one final issue that I cannot easily cure, though. The AXI motor I am using has a strange trait. It tends to confuse the controller (the back EMF going to the controller) under certain load at certain RPM. It only happens once in a while under just the right circumstances. But, when it does, the motor makes sort of a singing sound and does not want to speed up any further untill I reduce throttle a touch and get back on it. This is part of what was aggrivating my belt skip. I spoke with the manufacturer of the controller. He explained it to me. It is not the controller, but this particular motor. He has seen it before in RC planes. It is no big deal. But, eventually, I will go to a different brand motor to cure this. I almost hate to bring it up, because it is so minor. But, the bike is running so perfectly, this one issue really stands out.
Tomorrow I will be back a the shop modifying the clutch. I am removing the fiber friction pads and installing tough, dried leather friction pads. The pads I am running now are wearing down. the leather pads have roughly the same surface friction properties without the tendency of wearing down to dust like the fiber pads. I will post pics of the clutch update soon.
More updates to come!
Matt
Alright! I finally cured the belt skip and belt shredding problem.
Here's what I did;
The belt I was using was 9mm wide 5mm pitch. I decided to go with a 15mm wide belt. You can see the difference in belt width between the first setup, and the new setup.
That did two things for me;
#1 No more skip.
#2 I was able to eliminate the belt wrap idler. You will notice in the pictures, the idler is still used. However, I removed it and still have no belt skip, yet the motor runs cooler with better efficiency (much better efficiency). However, I did not want to pull the side plate off to take another picture without the idler. But, I am thrilled to say, no idler is needed anymore and it runs great!
One issue I was having as well (related to the belt skip) is motor shaft flex. So, I bored a 1/2 inch hole in the motor pulley and pressed a 1/4 inch by 1/2 inch bearing into that hole. Then I fabricated a support plate form 3/16 thick carbon fiber plate I got surplus from Boeing a few years back into a shaft brace. This CF is tough as nails! I have been saving it for just the right application.
The CF plate is adjustable with the motor for belt tension adjustment. You can see the steel standoff in the end of the CF plate. That standoff goes into the bearing at the end of the motor pulley. This CF plate and bearing setup eliminates motor shaft flex and prevents the motor from moving back and loostening the belt under heavy load.
There is one final issue that I cannot easily cure, though. The AXI motor I am using has a strange trait. It tends to confuse the controller (the back EMF going to the controller) under certain load at certain RPM. It only happens once in a while under just the right circumstances. But, when it does, the motor makes sort of a singing sound and does not want to speed up any further untill I reduce throttle a touch and get back on it. This is part of what was aggrivating my belt skip. I spoke with the manufacturer of the controller. He explained it to me. It is not the controller, but this particular motor. He has seen it before in RC planes. It is no big deal. But, eventually, I will go to a different brand motor to cure this. I almost hate to bring it up, because it is so minor. But, the bike is running so perfectly, this one issue really stands out.
Tomorrow I will be back a the shop modifying the clutch. I am removing the fiber friction pads and installing tough, dried leather friction pads. The pads I am running now are wearing down. the leather pads have roughly the same surface friction properties without the tendency of wearing down to dust like the fiber pads. I will post pics of the clutch update soon.
More updates to come!
Matt
Attachments
EMF
100 kW
*Drool* Dude, you got something now. I really did not think that little motor could haul you around town, but I stand corrected! 8)
For the past 2 days I have been researching a way to use one of these new Cyclone kits, that both Ypedal and GGoodrum have ordered, but I want to make it a belt drive. I hope I can figure aout a way to do it. I have already seen both Sturmey Archer and Nexus 3 speed hubs on bikes that have a belt drive. Where there is a will there is a way. :wink:
For the past 2 days I have been researching a way to use one of these new Cyclone kits, that both Ypedal and GGoodrum have ordered, but I want to make it a belt drive. I hope I can figure aout a way to do it. I have already seen both Sturmey Archer and Nexus 3 speed hubs on bikes that have a belt drive. Where there is a will there is a way. :wink:
Well done, Matt.
The belt should last a bit longer without the aggressive back-bend, too. You might want to leave the idlers on there as "snubbers", though - that way they won't affect the efficiency but will increase the slippage threshold.
The belt should last a bit longer without the aggressive back-bend, too. You might want to leave the idlers on there as "snubbers", though - that way they won't affect the efficiency but will increase the slippage threshold.
safe
1 GW
- Joined
- Dec 22, 2006
- Messages
- 5,681
I like the larger (closer) pictures of what you've done. That's some incredible machine work. It definitely is going to make a lot of people here really question what they have when they compare it to what you have.
Excellent... my guess is the future will look something like this... (at least on the high end bikes)
Excellent... my guess is the future will look something like this... (at least on the high end bikes)What an awesome build. The simplicity and strength of your drive is astounding and yet it is complicated at the same time. The design is in an amazingly small package. I could see mass producing the same basic design with various different types of mounts for mounting on a standard MTB. Actually I still like the idea of gears and think the Cyclone style addition to the drive train would be a fun way to go but I digress... I love how you got the whole package under the seat. I wonder if you really need the torque rod from the rear wheel but I suppose it is better to have that than to twist the frame.
Have you seen this motor? http://tinyurl.com/46jzps I can't help but to dream of incorporating your design into my own off road MTB with this motor.
I have been lurking and enjoying watching. It is obvious that the RC motors are far more sophisticated than the over priced hub motors. Are there any motors as nice as the one you use that produce ~20HP?
Thank you for publishing your build so that we can all look and learn. Amazing work... Please keep updating your web page or this thread as you create and do more to your ride.
Have you seen this motor? http://tinyurl.com/46jzps I can't help but to dream of incorporating your design into my own off road MTB with this motor.
I have been lurking and enjoying watching. It is obvious that the RC motors are far more sophisticated than the over priced hub motors. Are there any motors as nice as the one you use that produce ~20HP?
Thank you for publishing your build so that we can all look and learn. Amazing work... Please keep updating your web page or this thread as you create and do more to your ride.
recumpence
1 GW
Hmm, 20hp is alot. I know of a 12,000 watt RC motor. Finding a controller to drive it is another story.
I will keep you guys posted on the progress. This thing is not the perfect setup (too complicated). But, it has far exceeded my expectations in power and accelleration.
Oh, speaking of which, our building where my shop is located, is 150 feet long. My bike winds out at over 35mph from one end of the building to the other. 0 to 35 in 150 feet, I am thrilled with that!
I just hope the police don't hassle me with this thing.
Matt
I will keep you guys posted on the progress. This thing is not the perfect setup (too complicated). But, it has far exceeded my expectations in power and accelleration.
Oh, speaking of which, our building where my shop is located, is 150 feet long. My bike winds out at over 35mph from one end of the building to the other. 0 to 35 in 150 feet, I am thrilled with that!
I just hope the police don't hassle me with this thing.
Matt
lawsonuw
1 kW
Good to see that nearly all the bugs have been worked out of this! I just have some suggestions for future builds. First, I was considering rolling my own e-bike drive like you have before I bought my BD-36. Specifically This United Hobbies Motor was my preferred motor. It has a few things going for it. First it's cheap so no worries If I killed it. Second it has a 10mm output shaft. Most of the rest of the motor's I've seen this size have an 8mm shaft. The extra 2mm should almost double the stiffness of the shaft. Also, when combined with the short rotor this larger shaft should allow this motor to spin happily at higher rpm. My other suggestion is to move the belt line closer to the motor's face. This will reduce the bending loads on the motor shaft a lot, preventing it from flexing.
Marty
Marty
lawsonuw said:
Good points, Marty.
The Astro Flight motor (above) has a 3/8" shaft as standard and is available with up to 12mm - it's not cheap, though. Apart from the price, it's almost the perfect motor for us: SmCo magnets, so no worries about frying them, and it's an inrunner so it can be kept cool without venting it.
The 55mm class Scorpion motors, when they become available later this year, will be a cheaper alternative - they use N50 NdFeB magnets which are rated to 200 deg C. apparently.....
recumpence
1 GW
Those components look familiar, Miles.
Hmm, lets see, HV ESC, Dimention Engineering BEC, Eagle Tree Micro Logger with power panel, etc.
Nice! :wink:
Matt
Hmm, lets see, HV ESC, Dimention Engineering BEC, Eagle Tree Micro Logger with power panel, etc.
Nice! :wink:
Matt
recumpence
1 GW
Hmm, it looks a touch shorter than my HV110, but I cannot tell from this angle.
I would guess the HV85?
Matt
I would guess the HV85?
Matt
recumpence
1 GW
Do I get a gold star? 
Matt
Matt
recumpence
1 GW
With the belt issue worked out, I decided to fucuss some attention on the clutch.
The fiber pads I was using worked well, but were wearing down. So, I replaced them with leather pads. These pads are very tough, dried leather.
You can see the carbon fiber plates that mate with the leather pads. The carbon fiber plates are bonded to the aluminum with medium CA glue. The leather pads are bonded to with the same medium CA glue.
Now, the clutch works much more consistantly with precious little dust created. It also heats up less than with the fiber pads.
I also replaced the clutch center slave bearing (not shown in these pictures). I went with a larger shielded bearing to replace the smaller open bearing that was making some noise.
After the clutch was done, I did some torture testing of the bike (in 88 degree weather). I did a series of hard launches and panic stocps to test the clutch, drive system, and brakes. I found out the bike is not a dragster. It launches fine and accellerates hard, but if done repeatedly (5 or 6 times in succession) heat shows its face. The motor reached 140 degrees, the clutch was very warm (about 125 degrees), the belt got hot, and even the wires going to the motor got warm. But, what would you expect pulling 4000 watts accelerating repeatedly?
I also found out this belt system is sensitive to belt tension. The belt likes to be run with just the right amount of tension otherwise the efficiency goes down. It is not hard to set the tension, though. Also, once set, it holdd tension without needing readjustment.
At this point, I will focus on finding the ideal ratio and reducing heating under repeated hard launches. But, admittedly, this is a 50 pound bicycle, not a drag racing motorcycle.
Matt
The fiber pads I was using worked well, but were wearing down. So, I replaced them with leather pads. These pads are very tough, dried leather.
You can see the carbon fiber plates that mate with the leather pads. The carbon fiber plates are bonded to the aluminum with medium CA glue. The leather pads are bonded to with the same medium CA glue.
Now, the clutch works much more consistantly with precious little dust created. It also heats up less than with the fiber pads.
I also replaced the clutch center slave bearing (not shown in these pictures). I went with a larger shielded bearing to replace the smaller open bearing that was making some noise.
After the clutch was done, I did some torture testing of the bike (in 88 degree weather). I did a series of hard launches and panic stocps to test the clutch, drive system, and brakes. I found out the bike is not a dragster. It launches fine and accellerates hard, but if done repeatedly (5 or 6 times in succession) heat shows its face. The motor reached 140 degrees, the clutch was very warm (about 125 degrees), the belt got hot, and even the wires going to the motor got warm. But, what would you expect pulling 4000 watts accelerating repeatedly?
I also found out this belt system is sensitive to belt tension. The belt likes to be run with just the right amount of tension otherwise the efficiency goes down. It is not hard to set the tension, though. Also, once set, it holdd tension without needing readjustment.
At this point, I will focus on finding the ideal ratio and reducing heating under repeated hard launches. But, admittedly, this is a 50 pound bicycle, not a drag racing motorcycle.
Matt
Attachments
safe
1 GW
- Joined
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- 5,681
I just can't get over how cool this stuff looks. It reminds me of when I used to hang out at the racetrack on the professional road racer race day and get into the pits to look at the works machines. Everything was made with machining equipment and completely built from scratch. In the old days people could wander through the pits and look at the bikes up close and even listen to their conversations.
Again... excellent work and the future of ebikes in my opinion.
Again... excellent work and the future of ebikes in my opinion.
It won't be long and you will be contemplating water cooling... you're going down the same logic process I've been down. All the roads converge.recumpence said:
Matt,
I've been drooling over your setup - wonderful! My Bionx-equipped Swissbike LX is getting the job done for now, but I've got my sights on a Surly Big Dummy with a rig using a number of your ideas.
Since your machining skills are beyond my skill set, I'm considering something like the Staton 18.75 to 1 reduction box (http://www.staton-inc.com/Details.asp?ProductID=2362) - $239 + $20 for heat-treated gears, life-time warranty, and when I contacted Dave Staton and asked about adapting this to an RC motor with an 8mm or 10mm shaft, he indicated that a local machine shop would be able to handle that no problem. From there, going to 100 rpm or so at the bottom bracket or some other form of in-line chain drive (a la http://www.cyclone-usa.com/, http://epacpower.com.au/, http://www.bike-elektro-antrieb.ch/startseite.htm, http://ecospeed.net/, or http://www.electric-bikes.com/betterbikes/e-4.html) should be a cinch.
The throttle/limiter you've mentioned would probably be pretty important, and I'd be in line to buy one!
Any feedback or input? Is this a dumb idea, or is it worth pursuing?
cheers,
waldemar
I've been drooling over your setup - wonderful! My Bionx-equipped Swissbike LX is getting the job done for now, but I've got my sights on a Surly Big Dummy with a rig using a number of your ideas.
Since your machining skills are beyond my skill set, I'm considering something like the Staton 18.75 to 1 reduction box (http://www.staton-inc.com/Details.asp?ProductID=2362) - $239 + $20 for heat-treated gears, life-time warranty, and when I contacted Dave Staton and asked about adapting this to an RC motor with an 8mm or 10mm shaft, he indicated that a local machine shop would be able to handle that no problem. From there, going to 100 rpm or so at the bottom bracket or some other form of in-line chain drive (a la http://www.cyclone-usa.com/, http://epacpower.com.au/, http://www.bike-elektro-antrieb.ch/startseite.htm, http://ecospeed.net/, or http://www.electric-bikes.com/betterbikes/e-4.html) should be a cinch.
The throttle/limiter you've mentioned would probably be pretty important, and I'd be in line to buy one!
Any feedback or input? Is this a dumb idea, or is it worth pursuing?
cheers,
waldemar
JEB
100 W
Hi Waldemar-
I have a friend that has been using the Staton 18 to 1 gear boxes with gas engine , his major complaint it that they get noisy after a while, they use grease (moly type it looks like) the latest one he purchaced, after about 6 hours run time has been getting more and more gear noise- he was thinking of sealing the case and running it in a oil bath.
I have gone to a planetary 9 to 1 box that is smaller and lighter- then to a 2 to 1 chain reducer- then to a jack shaft, bmx X 2 ( like the cyclone system) -but useing a 1.6 hp gas engine.
The same 9 to 1 planetary box (from a wire rope hoist) to a powerpack motor with the "D" shaft output will fit on the box with a adapter plate, it has much larger gears in it then the one that cyclone uses, the pp motor will give one X 2 or more power than the cyclone 500w. going to try a kelly brushless controller with this motor.
jeb
I have a friend that has been using the Staton 18 to 1 gear boxes with gas engine , his major complaint it that they get noisy after a while, they use grease (moly type it looks like) the latest one he purchaced, after about 6 hours run time has been getting more and more gear noise- he was thinking of sealing the case and running it in a oil bath.
I have gone to a planetary 9 to 1 box that is smaller and lighter- then to a 2 to 1 chain reducer- then to a jack shaft, bmx X 2 ( like the cyclone system) -but useing a 1.6 hp gas engine.
The same 9 to 1 planetary box (from a wire rope hoist) to a powerpack motor with the "D" shaft output will fit on the box with a adapter plate, it has much larger gears in it then the one that cyclone uses, the pp motor will give one X 2 or more power than the cyclone 500w. going to try a kelly brushless controller with this motor.
jeb
lawsonuw
1 kW
waldemar said:
Nice gearbox find. I would expect it to get noisy as the above person posted. Sealing it and running an oil bath would help with the noise. Also shaving down the case so it's lighter would also reduce it's ability to emit sound. (i.e. a more complex shape is less likely to resonate and radiate sound) Using helical gears or a timing belt for the first stage reduction would be a way to reduce noise if I was building my own.
Marty
recumpence
1 GW
waldemar said:
Looks like a decent idea.
I actually disagree that hogging material off the casing will quiet it down. You will gain more sound by thinning the walls of a gear case (generally) than you will quiet it by breaking up the flat surfaces (I have built alot of gearboxes and various drives). But, it would save weight hogging it down!
Matt
recumpence
1 GW
I did some refining work on the bike today.
First I reduced belt tension a bit. That quieted the drive down to its lowest point ever. It runs really quiet now! I also gained back much of the efficiency I lost going to the wider belt.
Next I mounted the speedometer magnet and pickup. You can see I mounted it to the chain idler. I did htat for two reasons;
#1 This speedometer is designed for RC cars and, as such, it is adjustable to a maximum of 20 inches of roll out per magnet revolution. That is not long enough for normal bicycle use (my rear wheel is 78 inches circumfrence, not 20 inches). It also achieves s neat added benefit;
With the magnet on my idler, I was able to achieve the 20 inches roll out (maximum) the speedometer is looking for, and that also gave me much better resolution. A typical bike speedometer relies on one read per wheel revolution. It looks at the last few revolutions an averages them to give a reading. So, a typical speedometer refreshes the display slowly and looks jumpy as it skips from one speed to another every few seconds. With this arrangement gives me 3 to 4 magnet readings per wheel revolution (depending if it is used on a 20 inch or 26 inch wheeled bike). Now I get 3 to 4 times the resolution and the speed changes on the display in a very smooth linear manor with reater accuracey in speed measurement. It also means at slow speed, the system is more accurate than a typical bike speedometer.
I also fabricated a mount for my old trusty Burley trailer. I machined an aluminum mount and threaded two holes into the rear dropout. Now I can pull my trailer.
Anyway, that is it for now. I will update again when I do more work on the bike.
Oh, also, here is a pic of the drive from the bottom.
Matt
First I reduced belt tension a bit. That quieted the drive down to its lowest point ever. It runs really quiet now! I also gained back much of the efficiency I lost going to the wider belt.
Next I mounted the speedometer magnet and pickup. You can see I mounted it to the chain idler. I did htat for two reasons;
#1 This speedometer is designed for RC cars and, as such, it is adjustable to a maximum of 20 inches of roll out per magnet revolution. That is not long enough for normal bicycle use (my rear wheel is 78 inches circumfrence, not 20 inches). It also achieves s neat added benefit;
With the magnet on my idler, I was able to achieve the 20 inches roll out (maximum) the speedometer is looking for, and that also gave me much better resolution. A typical bike speedometer relies on one read per wheel revolution. It looks at the last few revolutions an averages them to give a reading. So, a typical speedometer refreshes the display slowly and looks jumpy as it skips from one speed to another every few seconds. With this arrangement gives me 3 to 4 magnet readings per wheel revolution (depending if it is used on a 20 inch or 26 inch wheeled bike). Now I get 3 to 4 times the resolution and the speed changes on the display in a very smooth linear manor with reater accuracey in speed measurement. It also means at slow speed, the system is more accurate than a typical bike speedometer.
I also fabricated a mount for my old trusty Burley trailer. I machined an aluminum mount and threaded two holes into the rear dropout. Now I can pull my trailer.
Anyway, that is it for now. I will update again when I do more work on the bike.
Oh, also, here is a pic of the drive from the bottom.
Matt
Attachments
lawsonuw
1 kW
recumpence said:I actually disagree that hogging material off the casing will quiet it down. You will gain more sound by thinning the walls of a gear case (generally) than you will quiet it by breaking up the flat surfaces (I have built alot of gearboxes and various drives). But, it would save weight hogging it down!
Matt
Huh, I yield to the guy with more experience then. While I've built lots of gear boxes, I've never cared about how loud they were before
I was basing the above statement off of second hand info of how noisy steppers are when screwed to sheet metal vs. die cast parts. Anywho, something else to look at. Silent Chain Is used in high speed and power drive trains. The "SC" ASME standard stuff comes in 3/16in pitch, small enough for us. Seems that most applications for silent chain have an oil bath of some sort.
Marty
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