recumpence
1 GW
As far as I know, if it is a 3 wire sensoreless motor, yes.
Matt
Matt
The E-cumbent - A project by Matt Shumaker
- Thread starter Storm
- Start date
lazarus2405
10 kW
Don't they have problems starting, though? My 200w plane motors twitch or spin backwards for a couple of seconds if the rotor is stationary.
This is because the sensorless controllers decide which coil to energize by inferring rotor position from the inductance in the unpowered coils. When it starts from stall, it has to "guess", by just picking a coil and running with it until it can gather enough information to get the timing right. Since it has a low chance of getting it really right, it will twitch or stall or turn backwards for the first moment until it finds the right rhythm.
On a bike, such a behavior can be very, very dangerous, especially on a high power setup. This is why "sensorless" ebike controllers are called "pedal-first" controllers, since for safety they will not energize without being able to detect rotor pole positions. Our experiences with them argue that the convenience of a sensored motor and controller outweighs any simplicity or efficiency gains from
I think the efficiency gains you mention between sensored and sensorless setups is purely coincidence. RC motors were developed to higher efficiency, and sensors were not required. Less advanced small EV motors are less efficient either because of poor quality, engineering, winding, or manufacturing, but are sensored for unrelated but very practical reasons.
This is because the sensorless controllers decide which coil to energize by inferring rotor position from the inductance in the unpowered coils. When it starts from stall, it has to "guess", by just picking a coil and running with it until it can gather enough information to get the timing right. Since it has a low chance of getting it really right, it will twitch or stall or turn backwards for the first moment until it finds the right rhythm.
On a bike, such a behavior can be very, very dangerous, especially on a high power setup. This is why "sensorless" ebike controllers are called "pedal-first" controllers, since for safety they will not energize without being able to detect rotor pole positions. Our experiences with them argue that the convenience of a sensored motor and controller outweighs any simplicity or efficiency gains from
I think the efficiency gains you mention between sensored and sensorless setups is purely coincidence. RC motors were developed to higher efficiency, and sensors were not required. Less advanced small EV motors are less efficient either because of poor quality, engineering, winding, or manufacturing, but are sensored for unrelated but very practical reasons.
lawsonuw
1 kW
Since this thread is sidetracking a bit on machining, I'll plug the 20+ year old machine my Dad got a deal on. It's a TRAK DPM. It's plenty stiff and all that, plus it has hand-wheels on the X and Y. The control is what makes this machine special though. After using it for a while it's clear that machinist's were involved it the control's design. (it also works as a simple DRO)
Matt: looking at the gear-box mounted in your 'bent I keep thinking how it would look anodized. How about anodizing the supports black, the timing belt pulleys orange to match the motor, polishing up the shafts, and leaving the screws alone?
My 2 Wh
Marty
Matt: looking at the gear-box mounted in your 'bent I keep thinking how it would look anodized. How about anodizing the supports black, the timing belt pulleys orange to match the motor, polishing up the shafts, and leaving the screws alone?
My 2 Wh
Marty
lazarus2405
10 kW
Ahhh. Thanks.
Hello
Yes erm sensorless controllers are a little dodgy on any ebike rig IMHO, its very important esp when pulling across intersections etc that when you intend to go you go and dont stall, most cyclist are hit from behind whilst stationary in traffic or cut up whilst cars are turning, even though matts bent has the freewheel it still make catch him off guard if he expecting 2KW of power and he gets nothing! I had this same problem for a while with my Puma, the nylon gears were worn and it would often slip when pulling out from a standing start, not good news as most e-bikers with higher power setups probably dont bother changing gear making starting up on the peddles tricky.
The peddle first controllers get over this of course, Matt will know how often this happens when he rides the bike and I am sure will address it if it becomes a problem, are there any sensored motors in this range? else maybe he could fit them inside? may be a little tricky.
Hey Matt any more pictures of the build? and some nice pictures of your CNC machines, I am seriously looking in to getting a setup of some sort, Derek who did the machining on the Lemco bike has got a nice business built around his setup, he got hold of an old bridgeport machine and then built his own custom controls around it, he now part time machines these wonderful little magazines and accessories for air rifles and makes nice money from it, somebody should do the same I think for e-bike bits, there must be a market for custom torque arms and other bits? my friends website is here http://www.rowanengineering.com, all the components on the site he makes out of solid lumps!! he even tweaks them to suit different rifles as well, somebody should really pick this kind of market up in the e-biking world as there are so many things you could make, take some of the bikes out of the dark ages a little :lol:
Cheers
Knoxie
Yes erm sensorless controllers are a little dodgy on any ebike rig IMHO, its very important esp when pulling across intersections etc that when you intend to go you go and dont stall, most cyclist are hit from behind whilst stationary in traffic or cut up whilst cars are turning, even though matts bent has the freewheel it still make catch him off guard if he expecting 2KW of power and he gets nothing! I had this same problem for a while with my Puma, the nylon gears were worn and it would often slip when pulling out from a standing start, not good news as most e-bikers with higher power setups probably dont bother changing gear making starting up on the peddles tricky.
The peddle first controllers get over this of course, Matt will know how often this happens when he rides the bike and I am sure will address it if it becomes a problem, are there any sensored motors in this range? else maybe he could fit them inside? may be a little tricky.
Hey Matt any more pictures of the build? and some nice pictures of your CNC machines, I am seriously looking in to getting a setup of some sort, Derek who did the machining on the Lemco bike has got a nice business built around his setup, he got hold of an old bridgeport machine and then built his own custom controls around it, he now part time machines these wonderful little magazines and accessories for air rifles and makes nice money from it, somebody should do the same I think for e-bike bits, there must be a market for custom torque arms and other bits? my friends website is here http://www.rowanengineering.com, all the components on the site he makes out of solid lumps!! he even tweaks them to suit different rifles as well, somebody should really pick this kind of market up in the e-biking world as there are so many things you could make, take some of the bikes out of the dark ages a little :lol:
Cheers
Knoxie
Hi Paul,
I've been testing the same Castle Creations HV controller that Matt is using, it is pretty quick on the uptake - it works out the direction in a fraction of a second
The only sensored RC motor that would be suitable, that I know of, is the MEGAMax: http://www.maxcim.com/MEGAMax.html
I'm considering getting this mill http://www.axminster.co.uk/product-Axminster-SIEG-Axminster-SIEG-X3-Mill-Drill-377295.htm and a kit to convert it to CNC.
I've been testing the same Castle Creations HV controller that Matt is using, it is pretty quick on the uptake - it works out the direction in a fraction of a second
The only sensored RC motor that would be suitable, that I know of, is the MEGAMax: http://www.maxcim.com/MEGAMax.html
I'm considering getting this mill http://www.axminster.co.uk/product-Axminster-SIEG-Axminster-SIEG-X3-Mill-Drill-377295.htm and a kit to convert it to CNC.
recumpence
1 GW
The issue with startup has been resolved with complex software updates. I have alot of high power setups in verious applicaitons that have no startup hickups what-so-ever. Also, the higher power the setup, the less chance of stuttering at start. I have never had a single startup glitch with this style controller.
I can take more pics of my machines. They are simple Taig machines (4 axis CNC and 5 axis manual mill, both small bench top units). They are fantastic for work like this, though.
I am toroughly familiar with the Trak DPM. Dave (whom I rent my shop space from) is the owner of the building with his own machineshop. We sort of share space, if you will. He ha a HAAS and a Trak DPM. I helped him rebuild that Trak last week. Great machine and, yes, very easy to program.
Sorry there haven't been any web site updates. I was out of town last weekend. But, I have the idlers all finished. I have one simple plastic guide/glide block to make and the chain management portion of the project is done. Beyond that, Ijust have to make a throttle mount and I am finished with the mechanicals. I will post pics when I get more.
I may have it running in less than a week.
Matt
I can take more pics of my machines. They are simple Taig machines (4 axis CNC and 5 axis manual mill, both small bench top units). They are fantastic for work like this, though.
I am toroughly familiar with the Trak DPM. Dave (whom I rent my shop space from) is the owner of the building with his own machineshop. We sort of share space, if you will. He ha a HAAS and a Trak DPM. I helped him rebuild that Trak last week. Great machine and, yes, very easy to program.
Sorry there haven't been any web site updates. I was out of town last weekend. But, I have the idlers all finished. I have one simple plastic guide/glide block to make and the chain management portion of the project is done. Beyond that, Ijust have to make a throttle mount and I am finished with the mechanicals. I will post pics when I get more.
I may have it running in less than a week.
Matt
recumpence
1 GW
Progress is being made!
http://www.wisil.recumbents.com/wisil/shumaker/default.htm
I am actually totally done with all mechanicals. All pics should be up on the site by tomorrow.
I should have it running by the weekend.
Matt
http://www.wisil.recumbents.com/wisil/shumaker/default.htm
I am actually totally done with all mechanicals. All pics should be up on the site by tomorrow.
I should have it running by the weekend.
Matt
csmarr
100 mW
Matt, you have done a beautiful job! I read that you have some concerns with the ability of the rear wheel to handle the torque, I agree. You might want to take it easy and check it thoroughly during the test phase. In the last assembled photo on 4/26 the small outrigger block with two lightening holes and four tapped holes that fits between the motor mounting plate and the freewheel mounting plate strikes me as the weakest point in the assembly. The torque from the freewheel will want to pull the freewheel mounting plate back and up. Can the machine screws in the small block handle this torque? Would it be possible to install two more in the web between the lightening holes? This is the most beautiful pieces of work I have ever seen. I spent twenty years as a machinist and your work is first rate!
Could you use a spring from a cantilever brake for the electric drive idler? Heres to a good test.
Chuck
Could you use a spring from a cantilever brake for the electric drive idler? Heres to a good test.
Chuck
recumpence
1 GW
There is more bracing between those plate than what is seen. It is so tight in there that a good picture is hard to get. :wink:
I (obviously) hope it goes well too. I have about 80 hours in it so far. It really went fast, though. I think I started on it about a month ago.
Yesterday I finished the throttle. It is just a simple thumb wheel. If I deem it necessary, I will make a thumb lever throttle. But, for now, I will try this.
At the end of the day yesterday, I had some extra time. So, I took advantage of that time and fabridated a Delrin fan blade to mount to the rear of the motor. This fan will draw air through the motor can. I do not think I will need it. But, the cooler it runs, the more efficient it will run.
I will post more pics soon.
Matt
I (obviously) hope it goes well too. I have about 80 hours in it so far. It really went fast, though. I think I started on it about a month ago.
Yesterday I finished the throttle. It is just a simple thumb wheel. If I deem it necessary, I will make a thumb lever throttle. But, for now, I will try this.
At the end of the day yesterday, I had some extra time. So, I took advantage of that time and fabridated a Delrin fan blade to mount to the rear of the motor. This fan will draw air through the motor can. I do not think I will need it. But, the cooler it runs, the more efficient it will run.
I will post more pics soon.
Matt
recumpence
1 GW
It run, it runs, IT RUUUUUNNNNS!!!!!!
Yee HAW! Holy ****!!!!
It pulled 3000 watts accellerating to 30 MPH then required 450 watts to sustain that without pedalling. Not the most efficent, but phenominally powerful! The frnot wheel began to lift when the main belt skipped. It just sucks me back in the seat and ROCKS!
I will post more soon.
Matt
Yee HAW! Holy ****!!!!
It pulled 3000 watts accellerating to 30 MPH then required 450 watts to sustain that without pedalling. Not the most efficent, but phenominally powerful! The frnot wheel began to lift when the main belt skipped. It just sucks me back in the seat and ROCKS!
I will post more soon.
Matt
lazarus2405
10 kW
Congratulations on your first ebike grin. 
csmarr
100 mW
WAY TO GO!!!
Need more data.
Congratulations!
Need more data.
Congratulations!
recumpence
1 GW
Thanks Guys.
OK, here is some more data for you;
It took exactly 750 milliamps to go a shade over 2 miles. So, that calculates to a max distance of about 20 miles without pedalling (10 AH pack) leaving 20% to 25% capacity in the pack. That should be enough. But, hey, if I can scrape together more cash, I would love to double my capacity. I do not think that will be neccessary, though.
I need to program throttle ramp up in my controller. There is one advanced program feature that allows the user to program in a slow ramp up. This may be needed. The main belt skips under very hard accelleration. But, the torque is so violent, I do not want to just eliminate the skip for fear something in the driveline will break. So, I will gear it up (it is a little to low), reduce the belt skip tendency, and program in throttle delay. I think 6 seconds to full throttle (probably about 35 mph with intended gearing) should do it.
This controller, tiny though it is, is absolutely seamless and perfect! It runs cool (no heat build up at all), buttery smooth, SUPER responsive, and incredible to program. I cannot say enough good about it.
The motor runs nice and cool. I do not think I need to keep the fan on it. But, it is good to have on there to prevent debris from entering the can. Plus, it is a good safeguard, I guess.
I found that the bike pedals just fine without the motor running. It feels like a normal bike (no addition drag) that weighs 45 to 50 pounds. Kind of like riding a trike, a touch heavier than a standard bike, but nothing to complain about. It also runs fine with just the motor alone. But, what is really cool is pedalling with the motor running. I choose a speed that I like, pedal along for some excercise and increased range, and just let the motor pull me up the hills while I keep putting in my 100 or so watts from my legs. Very nice. Also, if I go up a steep hill, the controller kicks in extra in an attempt to mantain a constant speed. Also very nice!
I have yet to encounter a problem with it, with the exception of the belt skip. Again, that is probably a good though. I will work on that Monday.
Oh, I may build a slipper clutch for it as well. That way I can adjust the "Launch" characteristics. :wink:
SWEEEEET!!!!
Matt
OK, here is some more data for you;
It took exactly 750 milliamps to go a shade over 2 miles. So, that calculates to a max distance of about 20 miles without pedalling (10 AH pack) leaving 20% to 25% capacity in the pack. That should be enough. But, hey, if I can scrape together more cash, I would love to double my capacity. I do not think that will be neccessary, though.
I need to program throttle ramp up in my controller. There is one advanced program feature that allows the user to program in a slow ramp up. This may be needed. The main belt skips under very hard accelleration. But, the torque is so violent, I do not want to just eliminate the skip for fear something in the driveline will break. So, I will gear it up (it is a little to low), reduce the belt skip tendency, and program in throttle delay. I think 6 seconds to full throttle (probably about 35 mph with intended gearing) should do it.
This controller, tiny though it is, is absolutely seamless and perfect! It runs cool (no heat build up at all), buttery smooth, SUPER responsive, and incredible to program. I cannot say enough good about it.
The motor runs nice and cool. I do not think I need to keep the fan on it. But, it is good to have on there to prevent debris from entering the can. Plus, it is a good safeguard, I guess.
I found that the bike pedals just fine without the motor running. It feels like a normal bike (no addition drag) that weighs 45 to 50 pounds. Kind of like riding a trike, a touch heavier than a standard bike, but nothing to complain about. It also runs fine with just the motor alone. But, what is really cool is pedalling with the motor running. I choose a speed that I like, pedal along for some excercise and increased range, and just let the motor pull me up the hills while I keep putting in my 100 or so watts from my legs. Very nice. Also, if I go up a steep hill, the controller kicks in extra in an attempt to mantain a constant speed. Also very nice!
I have yet to encounter a problem with it, with the exception of the belt skip. Again, that is probably a good though. I will work on that Monday.
Oh, I may build a slipper clutch for it as well. That way I can adjust the "Launch" characteristics. :wink:
SWEEEEET!!!!
Matt
Ypedal
100 TW
May i have your attention please... i have an announcement to make ;;
WE HAVE ANOTHER ADDICT ON BOARD !!!
Gotta love that silent power !
WE HAVE ANOTHER ADDICT ON BOARD !!!
Gotta love that silent power !
safe
1 GW
- Joined
- Dec 22, 2006
- Messages
- 5,681
If you live anywhere near Oregon you need to check the "E-vents" section. There's a recumbent/electric bike race going on at the Portland International Raceway later this month. Your bike could win... you never know...
I'm effectively banned from the race because my battery is too big and I don't have pedals.
(it's too far for me anyway)
I'm effectively banned from the race because my battery is too big and I don't have pedals.
(it's too far for me anyway)
RLT
10 kW
Glad to hear of the success!
recumpence
1 GW
I'm in Illinois. So, it is too far for me as well.
Anyway, yes, I am totally hooked. My efficiency is not the greatest. But, the horsepower is insane! Too much, actually. I am looking at another AXI that is half the can length. That motor should be far more efficient at moderate loads. Heck, I haven't even touch the capabilities of this motor!
I have one guy on a Yahoo group that is hassling me about my efficiency. But, hey, for a first time bike project, I am thrilled! I overshot the field on motor size and power. This thing has twice the power I could ever use.
I just came back from a ride of about 8 miles or so. It is on the charger now. I found that the bike (being a recumbent) coasts for a LONG time at 30 mph. I actually use the motor very little. Heck, I can sustain 20 mph just pedalling on flat ground. But, on hills, lets crank up the power!
I have a data logger with digital display. That item displays many parameters, one of which is cumulative MAH used. I will use that as my "Gas guage". I will mount that this week.
Matt
Anyway, yes, I am totally hooked. My efficiency is not the greatest. But, the horsepower is insane! Too much, actually. I am looking at another AXI that is half the can length. That motor should be far more efficient at moderate loads. Heck, I haven't even touch the capabilities of this motor!
I have one guy on a Yahoo group that is hassling me about my efficiency. But, hey, for a first time bike project, I am thrilled! I overshot the field on motor size and power. This thing has twice the power I could ever use.
I just came back from a ride of about 8 miles or so. It is on the charger now. I found that the bike (being a recumbent) coasts for a LONG time at 30 mph. I actually use the motor very little. Heck, I can sustain 20 mph just pedalling on flat ground. But, on hills, lets crank up the power!
I have a data logger with digital display. That item displays many parameters, one of which is cumulative MAH used. I will use that as my "Gas guage". I will mount that this week.
Matt
recumpence
1 GW
You know him?
What a jerk. All he does is rag on people. The guy really needs an attitude (FACE) realighnment.
I'm sorry, if I lived in Maui, I would not be such a complainer.
Anyway, every time I run teh bike, the efficiency goes up. I just recharged it after a 6 mile ride. It only took 1964 Milliamps to go those 6 miles. So, my range looks to be roughly 25 miles on a charge.
I think the cells are "Waking up".
Matt
What a jerk. All he does is rag on people. The guy really needs an attitude (FACE) realighnment.
I'm sorry, if I lived in Maui, I would not be such a complainer.
Anyway, every time I run teh bike, the efficiency goes up. I just recharged it after a 6 mile ride. It only took 1964 Milliamps to go those 6 miles. So, my range looks to be roughly 25 miles on a charge.
I think the cells are "Waking up".
Matt
safe
1 GW
- Joined
- Dec 22, 2006
- Messages
- 5,681
He has a reputation of being someone that everyone hates. I just never had the direct contact with him, so I can't really say.recumpence said:
We usually express things here in terms of Watt Hours in the battery and peak Watts from the motor. The efficiency ends up being the difference between what the battery provides and what the motor delivers. I've got my bike completely modeled in a spreadsheet and that helps me with a lot of predictions about behavior. Once you get a good mathematical model of your machine (with all the factors like power, voltage, weight, wind resistance, etc) and you have tested it in the real world to make sure they agree then you can start finding where you are missing some things. There's a feedback loop that gets set up between "theory" and "track testing". The better your models and measurements the easier it is to spot opportunities to make improvements.
Trust me... now that you are addicted your next step will be to improve the product/bike. It's the R&D cycle.
lazarus2405
10 kW
Sounds great.
Methinks a series of top speed tests are in order, at various gear ratios. I want to see it do 50mph. :lol:
Methinks a series of top speed tests are in order, at various gear ratios. I want to see it do 50mph. :lol:
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