GoldenMotor.com Forum
General Category => Magic Pie & Smart Pie Discussions => Topic started by: Andrew on December 14, 2010, 07:51:19 PM
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Adding a Pie wheel up front.
How easy is it to do?
how safe is it on the road?
can it be done on one GM 48v battery?
Would it be easy to disconect and just run one pie again?
If, for instance I bought a front pie wheel with internal controller, what else would I need?
Andrew
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From what I understand from Gary at GMCANADA, its only a matter of splitting the black and white wires from the throttle, plus spliiting brakes, cruise control and whatever other controls you wish, but thats the basics, ( including power of course)
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that sounds promising. Lets wait and see what Gary has to say. I'd love to try it ;D
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Andrew, you might want to check out this post (http://goldenmotor.com/SMF/index.php?topic=2133.msg13893#msg13893) for more details.
It might be better to disconnect the throttle, rather than the battery, just to ensure that any generated voltage from the disconnected motor will always have somewhere safe to go.
You might have to use a double throw switch to swap between the throttle control signal and a fixed ~1V supply to prevent the disconnected Pie from going into throttle failure mode. This would be easy enough to do using a 2.2K and 10K resistor in series (or a single 10K pre-set variable resistor) connected between the +5V and 0V on the throttle.
If you used a double pole double throw switch, you could automatically disable the regen on the disconnected motor as well (if you preferred).
Alan
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Thanks Alan. I've pretty much read the full thread, and from what you've said, do you believe there is no chance of an accident occuring if the motors runs at differing speeds, or if say, one cuts out?
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if one cuts out it will only create a little bit of drag, unless it cuts out like it get's stuck and won't turn again but that hasn't been reported here.
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At times with a quick press of ebrake to toggle cruise control sometimes one of my wheels keeps wanting to go. Easy enough to push the ebrake again...
Same thing with enabling cruise, now for each button I give them a longer press (about half a second) to make sure they both engage at once. Maybe I'm just too quick for the buttons sometimes lol
Hey Andrew, I don't think you will be disengaging one of the motors anyway. Once you have 2 you sorta don't go back!
+ you will probably find your power consumption to be the same if not better with the increase in efficiency
Just make sure you lower the regen% of each wheel before you ride it haha
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Hey Andrew, I don't think you will be disengaging one of the motors anyway. Once you have 2 you sorta don't go back!
+ you will probably find your power consumption to be the same if not better with the increase in efficiency
Just make sure you lower the regen% of each wheel before you ride it haha
Well, at the moment I don't have any regen, but i'm sure it becomes very important once two motors need to be stopped! Plus, having two motors = two generators.... I suppose ;D
I will be adding regen again via one of the button controls. I currently have the red button set for cruise control, if I unplug it at the wiring nest can I just use the same red button wire and plug to connect to the motor braking plug? and then have regen again? or am I missing something?
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I currently have the red button set for cruise control, if I unplug it at the wiring nest can I just use the same red button wire and plug to connect to the motor braking plug? and then have regen again? or am I missing something?
Andrew,
If the plugs are the same (apart from the colour) then you can connect them without any problem.
I have my regen connected to the brake levers and also to the red on/off switch located on the throttle housing (I simply connected the two sets of wires in parallel) and I find it very useful, particularly when I'm walking the dog.
If I leave the regen switched On and then twist the throttle four times, the controller beeps and switches to brake switch failure mode. While in this mode, I can simply press the cruise button for instant half throttle, which enables me to easily ride around the field, using my left hand for brake, steering and throttle, keeping my right hand free to use the ball flinger for picking up and flinging the ball without stopping.
When I'm going down steep hills (at tired doggy speed) I leave the switch in the On position, which gives me permanent regen, and anti-lock braking on the rear as well. Sometimes I even pedal against the regen to go slightly faster just to keep my legs active. ;D
I also make sure the switch is On and activate the brake switch failure mode before I set off downhill with a freshly charged battery. This automatically disables the regen and prevents it from overcharging an already full battery pack, which could be very dangerous for my Lithium Polymer battery pack!
Pressing the switch again at the bottom of the hill (back to the Off position) automatically returns the throttle and regen functions to normal.
I now intend to wire the unused horn button into the regen circuit as well, so that I can use the horn button for intermittent braking, instead of the continual pulling and releasing of the brake lever which I have to do quite a bit when the regen braking is too strong.
Alan
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Wow :D, seems like you've put plenty of thought into how to use the various controls you have at hand! I hope your dog appreciates it :)
You have (sort of) anticipated my next question.... On the two button control, is the red a 'switch' and the green(horn) just a button? I guess so? Which would mean that regen for me would be better if connected to the horn button, as I would not want to constantly activate/de-activate by clicking a switch.
just to add, I suppose it will be fine still keeping cruise on the red button whilst having regen on the horn? and does it matter what way around the wires connect at the plugs?
- always best to ask!
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Ok, I've done it! ;D ;D
What probably seems very simple to other members on here is truely a triumphant moment for me.
Horn button now controls motor braking, and red button/switch still for cruise!! thanks to GM for including some spare pastic connecting plugs 8)
Andrew
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I suppose it will be fine still keeping cruise on the red button whilst having regen on the horn? and does it matter what way around the wires connect at the plugs?
Andrew,
It sounds like you've already got it sorted, but for the sake of other members who may be considering something similar, the horn button works in exactly the same way as the cruise button, and it doesn't matter which way round the two wires are connected at the plug, because the switch simply completes a circuit between the two wires when it is pressed.
At least now you'll be able to test your anti-lock braking with all the slippery snow and ice we're currently experiencing in the UK. I had to go for a drive in the snow yesterday to get our Christmas tree, and I struggled in a few places trying to get home again, and getting my van back on the driveway was almost impossible. I ended up taking the Pie to work last night rather than risk getting stuck in the van again, but it was a lot of fun riding home on the snow and ice just after midnight. ;D
Mind you, it must have been at least sixteen years since we've we had temperatures low enough here to actually burst a copper water pipe. (Yet another job I could have done without!) ???
Alan
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The South west certainly seems to have been hit with a white out. Here in S.Wales we got a good 12 inches of snow on friday over a 12 hour period. my car has 4 wheel drive, but no number of driving wheels will ever get you anywhere without winter tyres on, something that is very alien to us Brits. I believe you have to have them by law in some northern european countries.
I'm not sure my Schwalbes semi slick 'balloon tyres' would be good in snow on my bike,, then again if I deflate them to about 20psi they maybe quite good. I'd be tempted with some Schwalbe metal spiked tyres if they weren't so expensive but I bet they turn any bike into a bone shaker on the road.
i tried to get to my local postal sorting office today to pickup a 7 speed freewheel with a small 11 tooth cog on the end which has arrived from the U.S. i was turned back after half a mile due to lorry that was in danger of over turning on a hill. The freewheel and gripshift will have to wait to monday >:(
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Awesome I've been looking for something with teeth as few as 11 !
Can I ask where did you got it?
Hey also can you fit a 7 speed cluster on the wheel okay? I mean, should there not be any clearance issues, is there a maximum you can run on the pie?
For example, if somebody had a newer frame with 145mm dropouts, and used spacers past the cluster - would a 8spd+ fit?
Cheers
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i believe a 7 speed will fit. have a look here for the width of the DNP 7 speed freewheelhttp://endless-sphere.com/forums/viewtopic.php?f=2&t=18314&p=276576&hilit=dnp+freewheel#p276576 (http://endless-sphere.com/forums/viewtopic.php?f=2&t=18314&p=276576&hilit=dnp+freewheel#p276576)
The DNP freewheel is 36mm wide
My shimano 6 speed is only about 3-4mm less.
i got it from here.... http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=230554863188&ssPageName=STRK:MEWAX:IT (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=230554863188&ssPageName=STRK:MEWAX:IT) although it's from the U.S.
I paid the company their international shipping fee, but my local postal sorting office is charging me for the postal fee not being paid,, so beware! i will get more detail on monday over the charge and will be contacting the seller. I bet they only paid a domestic shipping fee, and then sent out to me.
Fortunately for me the exchange rate is always in my favour with the dollar
BTW, my bike originally had a 9 speed cassette, but I think it is a 135mm spacing. 8 speed and the pie might be pushing it. But maybe possible if you don't have disc brakes.
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quote from GM website.....
Model: MagicPie Hub Motor
Programmable built-in controller
Accept versatile voltages: 24/36/48V
Regen braking and cruise control
60mm thin hub for common bike frames
Support disc-brake and 7-speed sproketPower Rating:250W-1000W
Weight: 7.5 Kgs (including internal controller)
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I love the way they offer two different units, a standard 11-28T or the 11-34T "Mega Gear" option, yet the picture actually shows a 11-30T unit:
(http://pictures.kyozou.com/pictures/_10/9626/9625966.jpg)
Hey also can you fit a 7 speed cluster on the wheel okay? I mean, should there not be any clearance issues, is there a maximum you can run on the pie?
For example, if somebody had a newer frame with 145mm dropouts, and used spacers past the cluster - would a 8spd+ fit?
MM, Erik managed to squeeze a nine speed freewheel onto a Magic Pie, and this was with one of the early Pies which had the off centred rim:
(http://lh3.ggpht.com/_wZ7Ft9fTv0U/SxJqAa2L9dI/AAAAAAAAAbM/pflkmzT7pXQ/IMG_3952.JPG) (http://goldenmotor.com/SMF/index.php?topic=1527.msg7604#msg7604)
Alan
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worst case scenario..... If the 11 tooth cog rubs or touches the axle frame in any way, I bet a 3mm torque washer can be squeezed on after the freewheel.
:D p.s. about the DNP F.W being 30-11.. I noticed that too! :-\ but to be honest I wil only ever use the last 3 or 4 cogs.
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Cool geez I wouldn't have guessed 9spd, determination!
Can't say for sure, but doesn't look like there is a disc brake on there, but could be wrong. It's nicely squeezed on there :)
Actually Andrews cassette he found would suit me a treat.. Don't tell me you guys actually counted the teeth on the picture??! lol
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Can't say for sure, but doesn't look like there is a disc brake on there, but could be wrong. It's nicely squeezed on there :)
Actually Andrews cassette freewheel he found would suit me a treat.. Don't tell me you guys actually counted the teeth on the picture??! lol
You're absolutely right, there's no disc brake fitted on Erik's dad's wheel, but that doesn't mean that it wouldn't fit.
The freewheel (http://pictures.kyozou.com/pictures/_10/9626/9625966.jpg) in the picture looked too small for 32T and too large for 28T so I had no option but to count the teeth.
Counting all the way up to 30 is really not that difficult, you can simply use your fingers once and each of your toes twice! ;D
Here's an alternative method you might like to try: Counting to 30 (http://www.youtube.com/watch?v=MApaegDL6a0) (You'll find it easier if you practice a few times).
Alan
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fingers crossed I will be able to tell you tomorrow that the 7 speed fits and that is with disc rotor that has about 3-4mm of washers pushing it wider out on the axle
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Anyway, back to the point. So in the opinion of those who have used and are using dual pies, is there no problem with turning? for example does the back of the bike want to keep going straight and can this be felt at all?
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hey lol that's what my brother kept saying before I bought the front wheel.
and "oh but what if the back wheel is spinning faster than the front" etc.
I actually feel 10x safer with the added weight, and I would say I have more overall traction too.
Before I got the front wheel, on a paved bike track going around a corner on a sunny day my front wheel lifted a bit, then with the rear wheel driving I speed wobbled and the bike went underneath me... Lol it was a pretty bad stack
Don't have to worry about that anymore... Actually I'm still struggling to find a downside apart from weight and the fear of damaging one of the wheels.
So turning is okay, but I don't recommend doing it in reverse. Then you will find some trouble ;)
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well, just to keep you up to speed. I picked-up the DNP freewheel today. it looks like it has been heavily injected with grease/lubricant which is nice and should keep it quite quiet. However, the freewheel remover tool I have is for a shimano splined cassette and not a screw on freewheel, there is only the slightest of difference between the two threads on the tool >:(. So at the moment I have a freewheel remover that does not have a 14mm hole to fix over the axle, and a cassette remover that has a 14mm hole but does not grip the freewheel properly to undo it :-[
i've ordered the proper tool today but it probably won't arrive until the post starts again after christmas.
just for forum users future reference, if you have a shimano screw on freewheel you need a remover tool that is 'UG' compatible and not 'HG' - which is for a splined hub and cassette removal.
I think Shimano UG is ultra glide ?
HG is hyper glide ?
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Anyway, back to the point. So in the opinion of those who have used and are using dual pies, is there no problem with turning? for example does the back of the bike want to keep going straight and can this be felt at all?
I find the added weight balances it out more. My front battery does add to this as well. You can really feel the battery weight if your sitting still and swing handlebars back and forth but not the wheel. Its center of gravity is low. Sorta feels like a small motorcycle. Make sure you have good forks, mine are rock solid!
Gary
Gary
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quote from GM website.....
Model: MagicPie Hub Motor
Programmable built-in controller
Accept versatile voltages: 24/36/48V
Regen braking and cruise control
60mm thin hub for common bike frames
Support disc-brake and 7-speed sproketPower Rating:250W-1000W
Weight: 7.5 Kgs (including internal controller)
I have only ever used 6 speed freewheels. I have heard some 7's are the same width as 6.
Gary
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comparing my DNP 7 speed f/w with the shimano 6 speed, there is at most 4mm difference. I hop and think I should be able to find that amount of space :)
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next question. What would happen if I put a 1000w 48v HBS motor up front and not a MP. Would it not work due to different windings and speeds?
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there has been reports of different speeds between mp and hbs 1kw at same voltage, it could be done, but one motor will work more then the other.