Kepler
10 MW
Looking at the PDF, I tend to agree that the straight cut knurl suits our application best. Thanks for the info Miles.
An Advanced Friction Drive System
- Thread starter Kepler
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Kepler
10 MW
EVTodd said:
I'm supprized the 6061 is tough enough but glad to hear it works. Much rather work with aluminium then steel any day.
12p3phPMDC
1 kW
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I saw a "new" style knurling tool that pinches the roller when knurling....it is supposed to require a lot less force
on your lathes Y axis. It looked like a set of fingers or pinch clamps with the knurling dies in the ends of the fingers...
I'll search my machining catalogs.
on your lathes Y axis. It looked like a set of fingers or pinch clamps with the knurling dies in the ends of the fingers...
I'll search my machining catalogs.
Thud
1 MW
I don't know about "new" but these are quite common
http://www.use-enco.com/CGI/INSRIT?PMAKA=505-4515&PMPXNO=951899&PARTPG=INLMK3
I have been watching this thread with great interest. These units look very effective & I love the universal adaptability to it.
good job.
http://www.use-enco.com/CGI/INSRIT?PMAKA=505-4515&PMPXNO=951899&PARTPG=INLMK3
I have been watching this thread with great interest. These units look very effective & I love the universal adaptability to it.
good job.
Nothing. I only posted it as a visual comparison of the knurling styles :wink:EVTodd said:Ok. Someone is going to have to clue me in. What do gate shafts on a vibratory machine have to do with a friction drive system on a bike? I'm serious, I think I'm missing something and if I am I apologize.
I take your point about the tracking issue, EVTodd - I'd forgotten that.
I guess a straight "knurl" could also be done using a normal lathe tool like a planer cutter.
12p3phPMDC
1 kW
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Thud said:
Thanks Thud, that's exactly what I was looking at!!! "new" to me anyway, therefore the quotes...
you da man..
etard
100 kW
Speaking of axial or straight knurles (sp?) These guys have come up with a gas alternative that is top notch:
http://shuttlebuddy.com/index.html
It's hard to see, but the roller they use is VERY sharp on the edges and straight cut AS WELL as being concave to better match the profile of the tire. I believe they make the roller in house and doubt they would ever sell one of us a roller. They also use that tire I posted on your page Todd. They are actually working on an electric version, I think because the gas is getting alot of flack from the Mt. Bike community for obvious reasons. Brilliantly built and designed, except for the whole spewing toxic gas and noise thing. :wink:
Speaking of sleeve, how hard would it be to design one that had an airgap for better motor cooling. The sleeve could also be designed with outboard bearings for long service life, I bet it would take some of the noise out of the outrunner as well. hmmmmm. I am liking this design more and more!! I wonder what that monster Turnigy motor with 12mm shaft would do in this application on a 700 or 29" tire.
http://shuttlebuddy.com/index.html
It's hard to see, but the roller they use is VERY sharp on the edges and straight cut AS WELL as being concave to better match the profile of the tire. I believe they make the roller in house and doubt they would ever sell one of us a roller. They also use that tire I posted on your page Todd. They are actually working on an electric version, I think because the gas is getting alot of flack from the Mt. Bike community for obvious reasons. Brilliantly built and designed, except for the whole spewing toxic gas and noise thing. :wink:
Speaking of sleeve, how hard would it be to design one that had an airgap for better motor cooling. The sleeve could also be designed with outboard bearings for long service life, I bet it would take some of the noise out of the outrunner as well. hmmmmm. I am liking this design more and more!! I wonder what that monster Turnigy motor with 12mm shaft would do in this application on a 700 or 29" tire.
12p3phPMDC
1 kW
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I know that this an electric forum....but I bet that the Personal Shuttle Buddy has great range!
It looks alot like EVTodds setup except I bet it lacks the sliding features.
You could propane that setup or have a dual redundant setup too...
Two rollers, electric for power and gas for range.
It looks alot like EVTodds setup except I bet it lacks the sliding features.
You could propane that setup or have a dual redundant setup too...
Two rollers, electric for power and gas for range.
Then use a regen controller for the electric, and charge the battery while running the gas.12p3phPMDC said:
:lol:
Kepler
10 MW
I wish you could see a bit more detail on that device. From what I can see though, it looks like a basic firction setup in a pretty package. Would be interesting to see what they are doing with their rollers though. It may be a while before we compete with the range of a gas powered unit but thats certainly not my intent. My concept is designed to feel like its not even there when riding unasisted. Range wise and being used as a hill assist, 1.5 kg of batteries is giving me a 40km. I hate hills and the fact that they now feel like flat road makes my rides even more enjoyable plus I am getting the exersize I am after.
Kepler
10 MW
A quick update on how the drive is going. I have been pushing the boundaries on the motor and ESC and have run up to 2.8 kW through the drive without slipping. Unfortunately pushing the motor this far loosened a magnet but not a major issue with the magnet re glued and all OK again.
I am now only running 5S 5000 mah and maximum power of 1200 Watts. The cheap ESC and relatively small motor seems to cope really well at this power level and with such a light setup, you can't fell the extra weight at all. All up weight in this config is only 2.1 kg with the pack being small enough to attach on the back of the seat post. I have also fine tuned the drive engagement with the pressure to the tire now much more progressive.
Went for a reasonable length ride today with some friends all on carbon road bikes except for me on my slick tire shod mountain bike. With my tiny battery, I managed not only to keep up with them on 50km ride, but also be a position whereby I was waiting for them at the top of a few of the hills. Don’t get me wrong, I rode hard, but I found that not being spent at the top of a hard hill climb meant I could ride harder unassisted and stay with them on flat and mild climbs. Very pleased with the way drive performed.
I am now only running 5S 5000 mah and maximum power of 1200 Watts. The cheap ESC and relatively small motor seems to cope really well at this power level and with such a light setup, you can't fell the extra weight at all. All up weight in this config is only 2.1 kg with the pack being small enough to attach on the back of the seat post. I have also fine tuned the drive engagement with the pressure to the tire now much more progressive.
Went for a reasonable length ride today with some friends all on carbon road bikes except for me on my slick tire shod mountain bike. With my tiny battery, I managed not only to keep up with them on 50km ride, but also be a position whereby I was waiting for them at the top of a few of the hills. Don’t get me wrong, I rode hard, but I found that not being spent at the top of a hard hill climb meant I could ride harder unassisted and stay with them on flat and mild climbs. Very pleased with the way drive performed.
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etard
100 kW
Wow 2.8KW!! That's really hammering that drive, what where you doing when the magnet unloosened? I am amazed at how far you got on that small battery.
I'm not sure how many more rides you will be Invited on though. :wink:
I love the graphics and paint job on your frame, it just looks fast.
I'm not sure how many more rides you will be Invited on though. :wink:
I love the graphics and paint job on your frame, it just looks fast.
lawsonuw
1 kW
Kepler said:
This exactly matches the conclusions I reached from my half-arsed experiments. I.e. LOTS of power, a small battery, minimal weight, and no drag makes one heck of a fun "turbo" button! (5-10min of turbo ai'n't bad either) This also works very well with the human engine. If you look at of of the charts of Human power output vs time to fatigue found via google, it's pretty clear that bursts of peak power tire a person disproportionately fast. Thus 100Wh of LiPo to blast up hills is a good complement to 200-300Wh of human output on a long ride. (and tempting as all heck for me to build myself 8) )
Lawson
Kepler
10 MW
A turbo button is a good analogy with this setup and is good for about 10 hill climbs on average. The small battery keeps you honest and forces you to only us it when really necesary.
In relation to the magnet coming loose, I was really pushing the drive hard above 2 kW for extended periods (with a 10ah pack onboard). The motor is too small for this duty but suits the low power assist application perfectly. If you want to be a passanger with this direct motor contact design, I would go with the 50 series Hyperion motor at around 230kv. This has a 58mm can that is still supported by a large 56mm internal bearing to support the can.
In relation to the magnet coming loose, I was really pushing the drive hard above 2 kW for extended periods (with a 10ah pack onboard). The motor is too small for this duty but suits the low power assist application perfectly. If you want to be a passanger with this direct motor contact design, I would go with the 50 series Hyperion motor at around 230kv. This has a 58mm can that is still supported by a large 56mm internal bearing to support the can.
Kepler
10 MW
After many rides using the drive as a true hill assist I have found that having a twist throttle isn’t always the ideal setup. What I have found is that it can be more advantageous to simply switch the drive to a pre set speed and then concentrate on getting up the hill without having to deal with keeping the throttle balanced to suit the speed.
I felt the simplest approach would be to install a Crystalite 2 speed switch in conjunction with a modified servo tester circuit and utilize the excellent governor mode built into the Castle Creations speed controller. The Castle Creations ESC has a number of governor options. I have set up mine in simple governor mode and utilized the soft start feature to wind the drive up smoothly when switched on. When setup in this manor, the speed controller becomes a fully functional cruise control and as such automatically adjusts the power output to hold the set speed. Speed is setup via two 5K pots with each pot selected via the 2 speed Crystalite switch. This gives me the ability to set two different assist speeds and makes fine tuning nice and easy.
So with this setup I typically arrive at a hill and keep peddling to try and maintain speed. As I start to struggle and my speed drops off, I just flick the switch over to the low speed setting. The drive ramps up smoothly and quickly takes me to the set speed. Its then up to me pedal as hard as I feel is necessary. I have the low speed set to 25 kph and the second speed to 35 kph. I use the 25 kph typically for hills and 35kph for when I just want to ride at a nice quick pace without too much effort.
This setup although not perfect, works surprisingly well. The switch feels like a turbo button and if I happen to be peddling really hard up a hill and then switch to the high speed setting, the combined peddling and power assist will quite often lift the front wheel which is a great feeling of power. There is of cause the safety issue of a switch throttle and there ideally should be some fail safes interlocked with this type of setup. Brake switches are the most obvious safety item but also a speed sensing cut out would useful safety. At this stage though, the switch is very easy to activate and my hydraulic discs can easily overcome the drive in the advent of an emergency stop.
I felt the simplest approach would be to install a Crystalite 2 speed switch in conjunction with a modified servo tester circuit and utilize the excellent governor mode built into the Castle Creations speed controller. The Castle Creations ESC has a number of governor options. I have set up mine in simple governor mode and utilized the soft start feature to wind the drive up smoothly when switched on. When setup in this manor, the speed controller becomes a fully functional cruise control and as such automatically adjusts the power output to hold the set speed. Speed is setup via two 5K pots with each pot selected via the 2 speed Crystalite switch. This gives me the ability to set two different assist speeds and makes fine tuning nice and easy.
So with this setup I typically arrive at a hill and keep peddling to try and maintain speed. As I start to struggle and my speed drops off, I just flick the switch over to the low speed setting. The drive ramps up smoothly and quickly takes me to the set speed. Its then up to me pedal as hard as I feel is necessary. I have the low speed set to 25 kph and the second speed to 35 kph. I use the 25 kph typically for hills and 35kph for when I just want to ride at a nice quick pace without too much effort.
This setup although not perfect, works surprisingly well. The switch feels like a turbo button and if I happen to be peddling really hard up a hill and then switch to the high speed setting, the combined peddling and power assist will quite often lift the front wheel which is a great feeling of power. There is of cause the safety issue of a switch throttle and there ideally should be some fail safes interlocked with this type of setup. Brake switches are the most obvious safety item but also a speed sensing cut out would useful safety. At this stage though, the switch is very easy to activate and my hydraulic discs can easily overcome the drive in the advent of an emergency stop.
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electraflyit
10 W
Hi,
I just love the simple and light design.
Question, What CC ESC are you using?
Also if it needed to climb slower/steeper what would you change, Motor series, Kv, Voltage?
Eddie
I just love the simple and light design.
Question, What CC ESC are you using?
Also if it needed to climb slower/steeper what would you change, Motor series, Kv, Voltage?
Eddie
Kepler
10 MW
I use a CC 85HV ESC. 85 amp peak is plenty for the amount of amps I am pulling. In relation to motors, if you are going for a can drive, you need a motor with a small diameter which is one of the main reasons I went with Hyperion motors. If you are looking for better hill climb ability at a lower speed I would suggest a ZS4045 12 TURN 247KV. This is new generation motor that is rated at 2900w peak. The 247kv rating will slow things down a bit and still has a small diam can (49mm) You might need to go with a bigger ESC for this motor though as this motor will be able to pull some serious amps.
How does the cristalyte switch mate with the ESC? Does the switch have some functionality in processing the signal or are you just using it as a 2 position rocker switch? I'm a little confused.
Sounds like an awesome setup. A friend of mine is looking for a light, fast way to mod his bike to make his slog of a daily commute a little more painless, and this sounds quite promising.
Katou
Sounds like an awesome setup. A friend of mine is looking for a light, fast way to mod his bike to make his slog of a daily commute a little more painless, and this sounds quite promising.
Katou
Solcar
10 kW
Kepler said:
You have discovered the nice feel of current mode control. It enables the motor to progressively add more power the faster you go. It helps to prevent the uncomfortable feeling that the assist has dropped off and left you pushing against a brick wall.
Kepler
10 MW
The Crystalyite switch interacts with the servo tester circuit by switching in separate pots so you can set two different max speeds. The actual switch is a 3 position 3 wire rocker. Centre position is open circuit across all 3 wires. Switch to the left is closed circuit between common (wire 2) and wire 1. Switch right is closed circuit between common and wire 3.
The servo tester controls the ESC by varying voltage? Less voltage from servo tester = smaller PWM from ESC?
If that is the case, you could have a multiple position switch with many, many presets, just having one pot set just so for each setting.
Thanks,
Katou
If that is the case, you could have a multiple position switch with many, many presets, just having one pot set just so for each setting.
Thanks,
Katou
Kepler
10 MW
Servo tester uses 5K pot for adjustment. 0 ohm = 0 throttle position. You still could have a multi position switch with different fixed resisitors or adjustable pots though if thats what you were after. 2 speeds is OK though. 3 could be handy also.
Kepler
10 MW
Just clocked up 1000km with the friction drive onboard. This has given me time to refine the drive and assess component reliability. Mechanical failures have been far a few between with problems only occurring when pushing the drive far harder than needed. Some of the drive is definitely over engineered with other components a bit on light side and in need of beefing up. Driving off the motor case directly was always going to be a gamble however, besides issues with loose magnets, the motor and bearings are holding up extremely well. There is no real wear on the motor casing even with much of its operation being performed without the rubber sleave. I ended up removing all the magnets and re gluing them and since then, the motor hasn’t missed a beat.
The drive in general has been very reliable and the performance quite amazing. I have now settled on a 2 speed switch arrangement rather than a twist throttle as this allows me to concentrate on riding the bike hard up the hill without trying to balance a twist throttle in the best position to match the speed. Safety wise, the switch is in the perfect place to de activate with my thumb but in an emergency stop, my hydros easily overcome the drive if needed.
With most of the bugs ironed out, I am now fully rebuilding the drive using all that I have learnt so far. Advanced Friction Drive Mk2 will use the same motor and direct drive together with the over centre lock arrangement.
Changes will be as follows:
> The new drive will be shrunk to half the original size.
> Strength and rigidity will be improved without impacting on overall weight.
> Throttleizer will be deleted (Great product, just not needed in this application)
> Castle Creations 85A ESC will used. (Best soft start in the business.)
> Simple servo tester throttle interface will be used with fixed switchable resistances to set speed.
> Side plates will become part of the ESC heat sinks allowing electrical components to better hidden.
Work has begun and the original drive now de commissioned. I will post up some pictures showing components before the drive goes together. It’s surprising just how many parts are needed. Should see some progress in the next few days as the new parts start to come off the mill.
The drive in general has been very reliable and the performance quite amazing. I have now settled on a 2 speed switch arrangement rather than a twist throttle as this allows me to concentrate on riding the bike hard up the hill without trying to balance a twist throttle in the best position to match the speed. Safety wise, the switch is in the perfect place to de activate with my thumb but in an emergency stop, my hydros easily overcome the drive if needed.
With most of the bugs ironed out, I am now fully rebuilding the drive using all that I have learnt so far. Advanced Friction Drive Mk2 will use the same motor and direct drive together with the over centre lock arrangement.
Changes will be as follows:
> The new drive will be shrunk to half the original size.
> Strength and rigidity will be improved without impacting on overall weight.
> Throttleizer will be deleted (Great product, just not needed in this application)
> Castle Creations 85A ESC will used. (Best soft start in the business.)
> Simple servo tester throttle interface will be used with fixed switchable resistances to set speed.
> Side plates will become part of the ESC heat sinks allowing electrical components to better hidden.
Work has begun and the original drive now de commissioned. I will post up some pictures showing components before the drive goes together. It’s surprising just how many parts are needed. Should see some progress in the next few days as the new parts start to come off the mill.
I'm really looking forward to seeing your next design. You will really like that Castle esc too, I sure do!
You should try a thumb throttle. I've found mine to be very easy to control in all situations. I'm not a big fan of twist throttles on a bike. They just don't feel natural to me for some reason. Actually, I would like to try a trigger throttle. They seem like the most natural position for your hand while riding. Just don't confuse it for a brake. lol
You should try a thumb throttle. I've found mine to be very easy to control in all situations. I'm not a big fan of twist throttles on a bike. They just don't feel natural to me for some reason. Actually, I would like to try a trigger throttle. They seem like the most natural position for your hand while riding. Just don't confuse it for a brake. lol
