Commuter Booster - <1kg Friction Drive

Alpha Testers Update

Well it looks like I will be making about 6-8 kits at the moment (with a 3-4 fence sitters). Room for a few more if people are interested in this early release. Still waiting on a couple of people to get back confirming sizes etc, before I pump them out.

New 28.7mm Mount Option
As I had a few requested I went out and go some new tools, so I can now offer a 1 1/8" or 28.7mm seat tube mount option.

Shopping List
Here is a link to the shopping list I created a while ago, which I just reviewed and it still looks correct.
Commuter Booster Shopping List
The main issue is stock levels. Both motor and the two ESC options that I have done all my testing with are in backorder. :x
[EDIT] Oh I should mention that I actually prefer the smaller, cheaper $37 Turnigy Brushless ESC 85A, mainly because it has an on/off switch that the bigger $64 TURNIGY K-Force 100A. It would also potentially be easier to water proof.

So if you are happy to wait for the stock to return you can go the safe option. But if you are impatient you may have to try some new motors are ESCs. I bought all the available alterntives I liked the look of, but haven't received them yet. When I do I'll give them a run and let you know.

Would be great if someone built a high quality build, rather than the cheapskate motor/ESCs I have spec'ed. I just wanted to see how cheap, light, small and robust I could get. So feel free to get a CC-Pheonix 100Amp and maybe a Hyperion motor. Remember the higher the efficiency of your motor the more power you can safely get out of it. :twisted:

CB-5065 & Modified Watt-Meter Update
And for those of you that can't fit the CB-6374, I have just come back from a test ride on the CB-5065 at nominal 500w (900w peaks) limited by my modified watt meter. The ESC was only just warm, and the motor felt hot but no where near melting. May still be a bit high for longevity. With the dialed down power levels it no longer feels like a turbo boost kicking in, but a more like a firm assist. Much closer to what I had originally in mind back last year when this was all just an idea. The 50mm motor is starting to look really viable, and I am getting excited, but still requires something custom made to limit the current, which is a real stumbling block.

The modified watt meter is working a treat now. I used it with a simple on/off button throttle for this test run, as I like it for the road bike drop bars. Was cruising at over 40kph, nicely smoothed out all the hills, the drive is actually quieter now that I have dialed down the power, it smoothly ramps the throttle up and down, power levels appear to have a bit of over shoot but you don't notice it on the bike, didn't notice any tire slip while riding and saw no evidence of it after the ride. The little motor is also more efficient at light loads than the bigger 6374-200kv, probably because it doesn't have that large diameter skirt bearing to turn. One strange thing was it seems to hit some sort of resonance at 33-36kph, and makes a strange sound. :? I am sure my other 5065 didn't do that. I guess that is the sort of quality you can expect from a $40 motor.

If anyone is keen on creating their own modified watt meter, I will write up some instructions. In summary you will need a $30 programmer, obviously a donor $24 watt meter to mod, a few resistors, a pot, and servo wires for throttle in/out. You will need to pry the boards apart slightly to remove a few surface mount resistors, then solder on a few wires, resistors and a pot on the exposed back of the PCB. Reprogram it using free tools and my modified code, then you are good to go.

That's enough of an update for now, need to spend some time with the family so I can get some time to make the kits. :)

- Adrian
 
Thanks for that John. Looks like they have a few motors too, none with skirt bearings. :(

I just pulled apart my "Turnigy" 85a ESC, and found a ATMEGA8. :D
Quick google search found people that have already hacked other ESCs with ATMEGA8s so it looks like the door might be open. :)
 
Shopping List Alternatives

Okay since HobbyKing is out of stock of motors and ESCs, I thought I would have a look around for alternatives for the HobbyKing 6374-200kv.

http://www.leadershobby.com stock the Aeloian motors, that are very similar with skirt bearing support for the can. Kepler has tried the 170kv and gave it the thumbs up. Plus they are all black and look cool. 8)

Kepler if you are listening, could you confirm the hole pattern for these. Is it the same as the HobbyKing 6374's.
$52 - Aeolian C6374- KV200 brushless motor ~40-43kph on 5s LiPo (51 currently in stock)
$51 - Aeolian C6374- KV170 brushless motor ~41-44kph on 6s LiPo (4 currently in stock)
9394001220804_01.jpg


They also stock a few other useful things, so have a browse around for items on the shopping list you may need. Like parallel adapters:
$9 Parallel BMC(x6) great for joining up your pack main discharge leads.
$2 XH Male to 6 XH Female great for joining up your balance wires to make one big pack

Shipping rates appear similar to HobbyKing.

Not sure about the quality of their ESCs, so can't advise on those. I would stick with the one Kepler linked too, since that is the same as the one both he and I have been using without any issues. unless you already have an ESC, or feeling like spending a bit more for quality gear with data logging like the Castle Creations.

- Adrian
 
Yes, the bolt pattern is exactly the same as the HobbyKing version.

One thing I did find with the 170kv motor is that it did seem to loose sync more easily the HobbyKing 63-74 200kv. That surprised me as the winding construction look almost identical. I have placed an order for their 200kv version to see how that goes.

After much testing I am back with the 200kv being my favourite.
 
From me. :D

But I am only selling them as part of my kit at the moment.

You can always make your own, from some acetal.

- Adrian
 
Alpha Tester Update:
I have now heard back from most people, and am half way through making the kits. Hopefully I will get enough time this weekend to finish them off.

- Adrian
 
Request for help

At the moment the kit requires that you reuse one of the collars that comes with the motor, as the securing collar on the main pivot shaft of the Commuter Booster. This is great in terms of re-use of a bit that you would otherwise throw away, but it causes a few issues:
1) it means that you need to buy a motor with the same shaft diameter as the main pivot shaft
2) it comes with the motor, so the person that buys the motor needs to drill the hole.
3) it means I am making the main pivot block with two different main pivot shaft diameters 8mm (5065 motor) & 10mm (6374 motor).

If I could find a source for buying these, I could include the main pivot shaft, and this collar as part of the kit.
Otherwise I would have to buy the motor, provide the kit with motor installed, and end up charging people more due to double shipping, and extra stuffing around.

So anyone know where I can buy something like this with a 10mm internal diameter for cheap?
10mm collar.png

- Adrian
 
Oh and since most of the time is in setting up each manufacturing step, I decided to make a few more parts than I needed. :D
 
adrian_sm said:
Request for help

At the moment the kit requires that you reuse one of the collars that comes with the motor, as the securing collar on the main pivot shaft of the Commuter Booster. This is great in terms of re-use of a bit that you would otherwise throw away, but it causes a few issues:
1) it means that you need to buy a motor with the same shaft diameter as the main pivot shaft
2) it comes with the motor, so the person that buys the motor needs to drill the hole.
3) it means I am making the main pivot block with two different main pivot shaft diameters 8mm (5065 motor) & 10mm (6374 motor).

If I could find a source for buying these, I could include the main pivot shaft, and this collar as part of the kit.
Otherwise I would have to buy the motor, provide the kit with motor installed, and end up charging people more due to double shipping, and extra stuffing around.

So anyone know where I can buy something like this with a 10mm internal diameter for cheap?


- Adrian

Try Servocity, they are imperial measures but they have a range of split collars that should have plenty of adjustment http://servocity.com/html/collars.html
 
I bought a precision 10mm drill bit from McMaster-Carr. fast and pretty cheap. I can mail you my barely used bit if you need something fast to get you started.

http://www.mcmaster.com/#drill-bits/=ca5dyh

SDP-SI has sleeves that can make a 10mm hole into 8mm. Its a split-bushing so you squeeze it a hair to get it in the hole. They are also cheap. With these you could drill all the units with a 10mm hole and include the 8mm bushing so the customer could swap between the two shafts at will.

http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=7192&start=30#p311888
 
Thanks guys. Still not quite what I am looking for unfortunately. :?

@41south
The imperial sizes are just too far off.

@spinningmagnets
I really want to avoid making the collars myself, so thanks for the offer of the drill bit, but it wont be necessary. And I already have one.
As for a sleeve. I really wanted to standardise the shaft, and provide the collar. So people could then bolt on what ever motor they want, and not have to worry about getting one with a 10mm shaft to make sure they get the collar, which they then need to drill a little 3mm hole in.

If I standardised on 8mm instead, I could buy these 8mm collars from hobby king.
8mm shaft mount for Towerpro & 24g motor
tp_mount.jpg


But it won't be as neat once I drill the spring hole in it, and I prefer the 10mm from a strength and spring support perspective.

Grrrr. If HobbyKing only stocked what I want it would only be a $2 part.
 
Found some for a decent price but of course they are in the UK.
http://www.onlinebearings.co.uk/shaft-collars-metric-pr-16498.html
http://www.bearingboys.co.uk/CABU10Z_-__10mm_Shaft_collar_-40268-p

Surely I should be able to get these local.
 
I can get them here and send them to you. I get 60% discount at Fedex so shipping is cheap 8) :D

http://www.anzor.co.nz/?t=24&PCT2=114
or
http://www.i-trans.co.nz/category0055.php

I can ring them both on Monday and get pricing if you like.
 
Time to invest in a hobby lathe Adrian. :) Although I prefer to find the parts ready to go like you, sometimes with small simple parts like this, its a worth your while to make them yourself. Also saves you having to wait.

Surely, we have these collars locally though. Have you tried Bayswater Bolts?
 
Thanks everyone. I checked out a couple of local bolt type places including bayswater bolts, and nobody stocks them. Best price still looks like the uk mobs ~$1.6 +shipping. Will need to check out how steep shipping prices are. But if I buy 30+ it should work out alright.

Lathe would be great for protos, but I really can't be bothered making little stuff like this, it is just not worth my time.
 
Adrian, here is another link if you are still looking. The price for 10 seems reasonable.
Robbo
http://www.nutsandbolts.com/set-screw-shaft-collars-black-oxide-metric-c-288_297_302.html?zenid=k6k2j0rgbe8u2jnirlsv6rnj85
 
CB Alpha Tester Update

CB_alphas_1.jpg
CB_alphas_2.jpg

- Adrian
 
:)

Spoke too soon. Finally looked at the hex, and disassembled code. It is all gobbledegook.

Looks like the lockbits have been set. :cry:

Hopefully I have more luck with the Turnigy Super Brain 80A Brushless ESC.

Maybe I should just approach one of the manufacturers with a request to make some custom firmware for me. Wonder what I would have to promise for them to take me seriously.
 
adrian_sm said:
:)

Spoke too soon. Finally looked at the hex, and disassembled code. It is all gobbledegook.

Looks like the lockbits have been set. :cry:

I've been there and you'll find it very challenging to get access to the source of a commercial controller!

I eventually designed my own with all the features I needed and wrote the software from scratch, I have recently released the source for it here: http://endless-sphere.com/forums/viewtopic.php?f=35&t=27538

Hope this can help!
Laurent
 
Back
Top