Back in the Saddle, 'Bent Mid-drive project!!

[AussieJester]

(I'm still working on that aero-belly and beard! )

hehe...I was going to ask too

Nice looking ride, good to put a face to the name to


KiM

[LI-ghtcycle]

(I'm still working on that aero-belly and beard! )

hehe...I was going to ask too

Nice looking ride, good to put a face to the name to


KiM

Thanks!

Same to you Kim, I wish I had a video cam, I would spin the motor and let you hear it sing!

I'm gonna have to get a stretched frame built with the help of my neighbor and see what I can get out of this motor with 24S soon!!

I'm thinking something along the lines of what Drewjet built as a test mule, and then eventually something more of a CF design to be a best of both worlds between 'bent and a DF bike.

[StudEbiker]

I wish I had a video cam, I would spin the motor and let you hear it sing!

Does your still camera have a video mode? Almost all of them do.

[LI-ghtcycle]

I wish I had a video cam, I would spin the motor and let you hear it sing!

Does your still camera have a video mode? Almost all of them do.

Yes it does, but since the last windows up-date it's really weird, I can't seem to figure out how to load a video anymore, it's only like 20 sec. though.

[LI-ghtcycle]

More goodies!

Just got these today!



Man, that 95 tooth looks like a buzz saw!

I was so excited I rushed it to my machinist, Brad at City Machine in Oregon City, and he's such a kewl guy that he's gonna squeeze it in when he gets a spare moment or two, and I will be bringing the bike in on Friday to mic the shaft on the motor to make sure it's done exactly to size, and then the college will have to make the key-way once he has taken the 10MM D bore out to 14MM.

The 95 tooth wheel sprocket will be bored out to the size of the NuVinci freewheel adapter and then my welder will tack it onto the sprocket for me!

I'm going to eventually have him make me some better mounting blocks too out of billet aluminum so that I don't have to worry about the thin steel square tube eventually cutting into the paint.

[LI-ghtcycle]

Ok so I was having "too much fun" last night blasting along on my way home from bible class and suddenly I heard "CRACK!" when I was on the throttle, I was sure I had just snapped the poor drive chain (it's just BMX chain, nothing heavy duty) and at first I thought it might have been something worse because I lost my pedal power too!

Fortunately, it wasn't anything serious, just my letting things get too loose and when the drive chain got free it smacked the pedal chain over too and it jammed between the frame & freewheel. Fortunately, the freewheels I use are narrow enough that they don't get jammed even when something is right up against them, so no harm done, and today I decided to make a chain tensioner.

I had already started on one earlier and had used a old derailleur for the job, but I was inspired by the fixed one on our old-school tandem bicycle, and decided to make my own version.



Found this nifty little bike rack bracket and it's going to be perfect for my purpose!



Just bent up one end to bolt down, and it's looking and sounding pretty good on no-load testing, gonna get a test in later tonight between rain showers.





Here is a rubber caster wheel from the hardware store that I turned down on my drill press to use as a roller.





For the axle, I used one from the wheel of a roller blade, and the bushings from the wheel I put into the modified caster wheel now roller.





I made the head of the bolt axle's head narrower to fit inside the bracket to lock it into place for tightening.



I then shortened the axle and re-tapped threads for the bolt to use, this way I have a shoulder to tighten against with out tightening up the roller.

(more pics to come)

[LI-ghtcycle]

More pics, tensioner:





I'm pretty happy with it.

It's a bit loud when you just pedaling (I'm guessing since the tension is on the non-motor tension side), but becomes very quiet when the motor is running.

This is just temporary until I have the #25 sprockets & chain, and then I will have to adjust it.

[LI-ghtcycle]

More sprockets!





Here is the 95T sprocket, expertly broached! The NuVinci freewheel adapter fits so snug it's going to be a cinch to have it welded!

Once it's welded, it will looks much like these one from Staton Inc:

[StudEbiker]

That's awesome! If the jackshaft setup on the Bike E craps out again, I'll definitely be looking at going with a setup like yours. The Bike E is back together and ready for testing again with the auto-shifting CVP. Will have some reports tomorrow.

[LI-ghtcycle]

That's awesome! If the jackshaft setup on the Bike E craps out again, I'll definitely be looking at going with a setup like yours. The Bike E is back together and ready for testing again with the auto-shifting CVP. Will have some reports tomorrow.

Kewl man! Get some numbers on efficiency too if you can.

[Rassy]

Hey LI, you may have covered this already but when you originally picked a GM motor you were planning on the 650W. Are you still thinking about trying the 650W? If you were doing it again would you go with the lighter slower motor or stick with the one you have?

I ask these questions because I always figured if I was to do another like mine I would use a little motor like a Bafang instead of the large diameter and relatively heavy 9C.

[LI-ghtcycle]

Hey LI, you may have covered this already but when you originally picked a GM motor you were planning on the 650W. Are you still thinking about trying the 650W? If you were doing it again would you go with the lighter slower motor or stick with the one you have?

I ask these questions because I always figured if I was to do another like mine I would use a little motor like a Bafang instead of the large diameter and relatively heavy 9C.

Good question, and until I get the 650W and test it I won't have a proper answer, but on paper, it looks better than the 800W for casual use. For my design, and wanting to haul heavy loads on this cargo/touring bike, I'm thinking the 800W is better suited.

In a week or so, there should be a 650 Watt at the LBS (Classic Cycle in Oregon City) for testing on a demo bike, so I will have some numbers soon.

Also on order will be a NuVinci Dev kit, and soon a Lyen 12 FET with thumb throttle, and hopefully more to come!

I have a lady I just met that is very interested in a Vision R-40 recumbent set-up very similar to mine too, so I should have a chance to get some good numbers for you on those.

Out first demo bike is going to be a a Schwinn like this one:



We will be using an Amped Bikes LiPo tube battery also, hopefully it turns out to be as clean a build as we hope!

[LI-ghtcycle]

95T Sprocket Welded!





Just need to get my chain and motor sprocket that will be done later this week!

[LI-ghtcycle]

Best Monday ever!

Got my chain in the mail and a call from the machinist!









Time to see how much punishment this Hitachi chain can take (ok not really, only using 1500W peak )

The local machinist gave me the name of another shop the next town over, about 15 miles away that could cut the keyway, as even the college machine shop lacked a metric key cutter, so for another $10 I got it done while I waited for about 5 minutes.

He made sure I wasn't going to put a ton of power to this one as the keyway leaves the wall of the sprocket hub pretty thin (about 1mm ) but I won't be putting too terribly much force on this build, but if it looks to be fatigue in any way, I will have a ring fit to the outside and welded, but I doubt that will be needed.

Now once I get dad's battery mounts finished, I will instal these. Might have to wait until tomorrow to do a proper test since I am going to harden the steel of my torque plate, and make a new one for the right side of the NuVinci, been putting that off.

I have a torque washer on the right side from NuVinci and it has held up very well, just like to have something tighter fitting, especially now that I will have a lot more torque with the motor in a better gearing range.

[LI-ghtcycle]

Ok, just a cautionary thing here, I'm not saying there was ever anything wrong with the sprocket I bought from Staton Inc, but perhaps this one had a bum weld that got missed. I wanted to show my neighbor the original sprocket and ask what he thought of how they welded it, and he noticed this hair-line crack!





If you look really close you can see the cracked weld at the 5 o'clock in the first pic, & 9 o'clock position on the second pic. It's truly hair-line, and I'm not sure what method of welding was used, but my neighbor used a drill to remove metal from both the adapter and the sprocket to make sure he got maximum penetration, and it would appear that the welds on the sprocket pictured were not as deep.

So, just take a look at your sprocket from time to time to be safe, at worst if this failed, I would have to pedal home, but that could still be rather annoying.

[LI-ghtcycle]

Well, I was thinking I really should replace that torque washer, and then I remembered why I haven't, it's working fine so far, and the derailleur as tensioner is part the of the reason I haven't, but I did farmer-john a quick and dirty hardening of the torque plate on the non-sprocket side.

I took out my grand father's oxy/acet torch out and fired it up, my uncle had been cutting metal the last time he borrowed it, so it had that nice large cutting torch tip on for my purposes, just right.

Yeah, yeah, I know you loose some carbon if you don't have a brick furnace, but I'm too lazy, not sure if I could find enough bricks to to it right, but I got it nice and cherry red, checked with the magnet, and quenched it in a tin can of Olive oil.

Man it boiled like crazy! I half expected it to flame, but it didn't and now the plate is "curing" in the oven.

Anyone know how long I need to leave it in the oven? Didn't see that part on the on-line instructions, last time I hardened steel the right way, it was 21 years ago at high school making a screw driver with a gas fired mini oven, and I think I quenched with water with a little oil on top, followed by sand.

Anyhow, it's been at 350 DEG in the over about 20 min now, so gonna check on it.

[LI-ghtcycle]

Well, I have learned the real solution is to get better steel for the torque plate, but I did manage to get mine probably as hard as I can get it, on the surface at least, new torque plates will be a priority with some tool steel of some kind.

No time for pics, about to hit the shower, got everything together and ready to rock! No-load test was very interesting, low end 30 MPH, high 92, (down from 55 & 108 MPH) the #25 chain is definitely making more of a turbine sound, but only at the near 3000 RPM no-load speed.

Going to be able to do a decent test tonight on my way to class (Financial Peace, Dave Ramsey stuff, highly recommend it! ) so I promise to post some pics tonight! (probably 4 hours from now)

VERY VERY happy with how everything is just barely clearing, I will be adding a tensioner for the chain soon, for now just taking advantage of the new chain and it's being on the tight side letting me go with out one for now.

[LI-ghtcycle]

Ok, got some pics!

First off, I made my first attempt in a LONG time to harden some steel, and so far the results are promising, I will spark test some of the metal tomorrow to determine if it's high carbon or not, but it seems to be doing the trick.



In the pic if you look really close, there are three pin punch marks, the one right is from my first attempt at hardening, pretty useless, second one was better, and the final one barely made a divot on the far left! Hopefully it's truly hardened this time, either way the black look to the metal from the heating then quenching in Olive oil gives it a nice look, and I bet a good protection from rust. It's much harder for a file to touch it or a hack saw blade too.

And here is a pic of the 95T buzz-saw!



This bad boy looks great in black, and it's really very quiet!

New gearing is great so far, tomorrow I hope to take it down & up the big hill to see how well it climbs.

Definitely more torque now with better gearing, and very well matched to the RPM of the motor so pedaling along even at 30 MPH is a breeze!

I might not qualify 100% legal now, I think it might go faster than 20 MPH under just it's own power.

Oh! almost forgot, here some pics to show why NuVinci recommends such a specific gear ratio. (most of this damage was done with just leg power )





Surprisingly the sprocket side which has a larger axle size, same as the typical E-Bike axle, hasn't been damaged or caused any damage even though it is just using a special torque washer that is much thinner than the 1/4 inch I am using for torque plates. Problem with a plate on that side is lack of space with the shifting cable housing right there.

Pics with new gearing & chain on the bike!

[LI-ghtcycle]

I decided the "sweet sounds" of the bushings grating on my ears from the last DIY roller was enough, and decided to fit the bearings from the skate wheel that I got the axle from, and oddly enough, putting the bearings side by side and using the bushings that go inside them, made almost an exact same width of the roller I made from a plastic caster wheel from the hardware store, and when drilling it out to 7/8 inch didn't work, I realized that any old bicycle grip in decent shape would work, and glued one on.



I made the groove with my dremmel and so far it looks great, going to test it out here in a few.

[LI-ghtcycle]

THE JURY IS OUT!!!!

I just got home from a 11 mile trip, using only 3.4 AH's only 15 Wh/Mi. and I have a new record up-hill speed!

I hit 17 MPH going up a 7% grade!!! (moderate pedaling)

I am really amazed at how well this motor performs, and now that it is geared properly, I tried a no-pedal test at where it's a bout 5%, and although it complained some, it went up at 9 MPH almost 10 got a little warm, but did it just fine and immediately cooled down once I got on the flat and pedaled along.

So, even though it won't match the 12 MPH no pedaling that my 9 x 7 Amped motor would, at one third the Wh/Mi, I can live with pedaling, I like to pedal anyway.

[LI-ghtcycle]

Finally installed a kickstand, but the vertical tube I had to install to make it work looks ridiculous!

I'm too ashamed to show any pics yet!

[skaplan]

I have to say that 95t monster of yours came out looking really good, I hope the motor mount on the schwinn works as well.

[LI-ghtcycle]

I have to say that 95t monster of yours came out looking really good, I hope the motor mount on the schwinn works as well.

Thank you! I have to give credit on that to my machinist and welding friends, I'm kind of like the mad scientist that plans this stuff out, but they do most of the hard stuff (well, I have welded, and run a lathe, but they are experts, I've learned better to get an expert do it once right than try to become an expert in too many things )

I'm trying to find a picture of the KHS hybrid bike frame I just saw today at the LBS, it's PERFECT for mounting a motor, all inside the front triangle and even a compact Amped or HK LiPo set-up would fit there nicely, but I haven't seen one yet ... kind of aggravating ...

I also got to see & ride two models of Rans Crank Forward bikes, and MAN they have sooooo much room for motor like the ones we are using, it's screaming for a E-Bike build too!

More on that tomorrow, too tired to post pics yet.

[LI-ghtcycle]

Finally have a solution I am happy with for chain tension, if I only had one chain ring up front, and horizontal drop-outs, there would be no need, however, I use a very wide ratio for my front chain rings, 22T - 48T, so I have been suffering with a typical derailleur on the back shoe-horned into the gap between the drop-out and NuVinci pulley system.

Look here for pics:

http://endless-sphere.com/forums/viewtopic.php?f=3&t=33690

In the future I will use off the shelf stuff to do the same thing (hopefully! ) and keep the custom one-off components to a minimum.

[jmygann]

are you using a front derailer ?