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.
EVTodd said:Anyway... Back to Kepler's build... If you want to try different sleeves I would recommend 6061 aluminum. I had pretty good luck with it on my last drive. You mentioned tire wear. I've found that the knurled aluminum will wear before the rubber on the tire. I would just re-knurl it from time to time. It never lost it's diameter so I assume the knurls would just get pushed down after a while.
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.
Thud said: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.
Then use a regen controller for the electric, and charge the battery while running the gas. :lol:12p3phPMDC said:Two rollers, electric for power and gas for range.
Kepler said: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.
Kepler said: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.