Dave's 80:1 RC mid drive kit build log
- Thread starter tangentdave
- Start date
cr0m08
1 W
One empty box is 695 grams, with the two Multistar LiPo's is 3.8Kg. So that gives me a total of 7.6Kg for the two boxes, or 12s 24AHr. I'm not using a BMS with this battery, as the CA V3 controls the Low Volt Cutoff and the cells are balance charged by the smart charger using the balance leads. The charger is the iCharger 3010B, so its capable of parallel charging all four 6s packs at once with 30Amps, which is less than a 1C charge ( 0.625C ).
BTW I don't advocate not using a BMS, I'm just saying I'm not personally using one. I like the modularity of 6S bricks. If my logic is correct, I could choose to run 6S 48AHr, of course at half the power, half the speed but twice the distance? Maybe somebody can tell me if that is correct? I see a previous post from Iroise2000 is running on 7S.
BTW I don't advocate not using a BMS, I'm just saying I'm not personally using one. I like the modularity of 6S bricks. If my logic is correct, I could choose to run 6S 48AHr, of course at half the power, half the speed but twice the distance? Maybe somebody can tell me if that is correct? I see a previous post from Iroise2000 is running on 7S.
cr0m08
1 W
Yes it is a bit heavy, Multstar LiPo is not know as a high quality product & I think there would be higher charge density LiPo available. I chose them cause they are stupid cheap when you buy during a sale period, they cost me AUD $343.
aCeMadMod
1 kW
hi I been ride with 8 kg for years. or more in backpack ,, it fine
just need the right bag, this week after year more 1 year look for hardcase backpack
I got 2 in 1 day. 2 hand they cost $300 plus au each
my new lipo wight same has old one but wow from 16 ha. to 28 ha
I hate see in 3 more year how big we get
just need the right bag, this week after year more 1 year look for hardcase backpack
I got 2 in 1 day. 2 hand they cost $300 plus au each
my new lipo wight same has old one but wow from 16 ha. to 28 ha
I hate see in 3 more year how big we get
cr0m08
1 W
Ah ok then. Yeah I meant that I would not change the amp draw, so changing to 6S would halve the wattage. eg; (12S) 44.4V x 60A = 2664W. Then change to 6S 22.2V x 60A = 1332W. That's what I meant by half the power. Of course the speed is also halved because voltage being halved. I have 4 bricks of 6S 12AHr.So I can have a battery of 12S2P = 44.4V 24AHr or I can have 6S4P = 22.2V 48AHr.
cr0m08
1 W
"Less wind resistance though..."
hahaha True that! but too much for my brain to work out :lol:
hahaha True that! but too much for my brain to work out :lol:
Animalector
10 kW
Twice the time isn't really true, how often are you really at max rpm?
Animalector
10 kW
Yep. True that.
tangentdave
1 kW
The 3210 is just so...quaint.
aCeMadMod
1 kW
hi. what motor cores are they in pic above ? 
1.5 rev gearbox 2.0 rev how your along to waiting shop customs.. list is done
I want know when to pay
I found a cheap back pack copy of the Gt 20 it cost $120 us
too bad I got 2 hand real Gt bags .
can't wiat to try your gearbox , my bike going to odd the sound be should Very low 8) hope your gearbox dose not cook in the pot
keep up the great work if you know how to cut Ti what speed and cooling . tell me thank you
1.5 rev gearbox 2.0 rev how your along to waiting shop customs.. list is doneI want know when to pay
I found a cheap back pack copy of the Gt 20 it cost $120 us
too bad I got 2 hand real Gt bags .
can't wiat to try your gearbox , my bike going to odd the sound be should Very low 8) hope your gearbox dose not cook in the pot
keep up the great work if you know how to cut Ti what speed and cooling . tell me thank you
cr0m08
1 W
Hey Dave,
I'm wondering about these Boblbee GT20L backpacks you are using and how much battery space is inside them. Would it be possible to fit 4 bricks of the 16AHr Multistar 6S packs inside?
I'm wondering about these Boblbee GT20L backpacks you are using and how much battery space is inside them. Would it be possible to fit 4 bricks of the 16AHr Multistar 6S packs inside?
tangentdave
1 kW
Boblebee FTW. Packs designed for motorcycles, crash protection, battery protection, expandable. Here's the 20L size with a 14s8p pack with cell holders. There's enough room that I added foam padding on the bottom and sides. This would easily hold six 6s bricks of 20Ah multistars.
I'd also recommend the big waist belt, it takes all the weight off your shoulders and holds the pack firmly against you.
I'd also recommend the big waist belt, it takes all the weight off your shoulders and holds the pack firmly against you.
cr0m08
1 W
Awesome, thanks for that Dave and really great with pics too. Cheers!
aCeMadMod
1 kW
hi Dave any way you could reply my Questions
thank you 8)
thank you 8)
Can I get a few recommendations for a DH bike which will fit the motor inside the frame without ("much") modification. I've read through this entire thread a few times but maybe someone would have picked a different bike having had to do it over again. Looking to spend 2-2.5k for a used bike. Feel free to PM responses if you want. I don't have the tools or mostly the time to do custom fabrication. I mostly just like the look inside the frame, so feel free to convince me otherwise if under the frame works best.
Thanks,
Eric
Thanks,
Eric
tangentdave
1 kW
Ace, those motor stators are for the 2nd gen units. They're epoxied straight to the Tangent housing (all bearings are still accessible on the motor and gearbox side). I'm way behind shipping the initial customer units but they are going out, 10 more kits and I'll be caught up. The workflow is smoothing out, becoming faster, but it's still slow as I have to stop assembly and head out to the CNC machine regularly to make a few of whichever part I need at the moment. There will be 20 kits in the hands of customers shortly- after we've proven this design with enough thrashing, the next step is paying production shops for these CNC parts (which means I can assemble and ship kits 10x faster). Step after that is get the CA off the handlebars (lightly modified VESC?).
Also, Ace, do you know about G-wizard? https://www.cnccookbook.com/feed-speeds-calculator-gwizard/
As for which frame, DH/Enduro is the way to go. DH frames seem to take up the space around the BB with suspension hardware, enduro bikes are little more open. https://www.pinkbike.com/buysell/list/?category=1 Pinkbike used section is a great place to start; mounting the unit below the downtube doesn't harm ground clearance since the mounts are about 10" long. Frames that don't pedal well tend to work well with a motor (less anti-squat maintains suspension compliance under power over rough). It would be helpful to maintain a list of donor frames and their performance under power. I'll start on that too, in all this free time that I have...
Also, Ace, do you know about G-wizard? https://www.cnccookbook.com/feed-speeds-calculator-gwizard/
As for which frame, DH/Enduro is the way to go. DH frames seem to take up the space around the BB with suspension hardware, enduro bikes are little more open. https://www.pinkbike.com/buysell/list/?category=1 Pinkbike used section is a great place to start; mounting the unit below the downtube doesn't harm ground clearance since the mounts are about 10" long. Frames that don't pedal well tend to work well with a motor (less anti-squat maintains suspension compliance under power over rough). It would be helpful to maintain a list of donor frames and their performance under power. I'll start on that too, in all this free time that I have...
cr0m08
1 W
Hi Dave,
If you get a chance, I'm just wondering if you have changed the shunt you are using? I only just recently noticed your signature has changed to say 8KW and I'm curious how you are getting that? I have only got 99.9A set from my CA V3 using the supplied potted shunts. Can we put more through these shunts or do they need to be changed out?
I know Dave is busy so maybe someone else knows and can chime in here?
If you get a chance, I'm just wondering if you have changed the shunt you are using? I only just recently noticed your signature has changed to say 8KW and I'm curious how you are getting that? I have only got 99.9A set from my CA V3 using the supplied potted shunts. Can we put more through these shunts or do they need to be changed out?
I know Dave is busy so maybe someone else knows and can chime in here?
tangentdave
1 kW
I'm using the small shunts from Grin, 100A continuous. I've moved from the potted shunts to the bare shunts to eliminate the small gauge wire they use on either end (now it's 8ga OFC from the ESC to the battery). I do 'sometimes' like to turn the max amps up to 150, no ill effects to report. These big currents are really just spikes, even with a big 150A throttle, majority of the time is ~3kW or zero. Of course it's possible to over-gear the motor and maintain huge current draws, this is where the small components get into trouble. Keep the big current spikes short-ish and the small components can deal with it.
You can run more through the potted shunts, no worries. Switch the CA into Hi range to be able to set Max Amps higher than 99. Go and set the proper values for these settings after switching into Hi range: Max Amps; Again; Fast Threshold (throt out->fast threshold)
You can run more through the potted shunts, no worries. Switch the CA into Hi range to be able to set Max Amps higher than 99. Go and set the proper values for these settings after switching into Hi range: Max Amps; Again; Fast Threshold (throt out->fast threshold)
cr0m08
1 W
Thanks for the clarification Dave. I will be having a play with this when I get clearance on my shoulder from the doctors and also get my V1.5. Excited anticipation!
tangentdave
1 kW
A few pics of a raw special order 3210 unit headed to South Korea. 83mm BB.
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