The 10s lipos turned up today, sweet! However they did have a surprise in store - each pack had 4 discharge leads! I assumed they would just have two but HK split the packs in two 5s halves, on the pack i tested it arrived with 19.13v / 19.12v. Its no biggy, just means extra wiring i hadn't anticipated.
EDIT: Ok serves me 'right for not looking closely at the HK website lipo picture i posted further up the thread - it shows the 4 leads...
I finally got around to doing the wire mod and side cover drilling on the HT3525. For the wire mod i took the easy way out - took the seal out and just cable tied (zip tied) the wiring to the axle. I'm planning on making pinch style torque arms so i'm not worried about axle movement tearing the wires.
Next up was drilling the LH side cover, man those screws are a bitch to get off with all the thread lock they smothered them in! So much so that i buggered up one of the screw heads which then needed to be converted to a flat head with the grinder and a 1mm cut-off wheel
I carefully ground a flat across it and got it off with a large flat head screw driver - phew!
I marked up the holes on the inside of the cover, not paying much attention to their placement on the outside in relation to the disc brake mount or orientation to the 203mm disc thats to go on and this is how it ended up
Almost couldn't have placed them more perfectly behind the disc spokes if i'd tried! I don't know if this will have any consequence in regards to cooling effectiveness but it sure hides them well!
Ok so i've got a decision to make as to whether i'll bother making the frame to carry 10 or 15ah - 4 or 6 lipo packs. I originally planned on 6 which gave the frame a 100mm (4") width and an extra 2.6kg of weight (compared to using just 4 packs). However now i know each pack has 4 discharge leads, its going to get rather cramped in there once i've made a wiring harness up for 12 pairs of leads - 24 leads in total... Plus i'm not keen on the extra weight nor the extra width the frame would need to be - if i allow for just 4 packs (10ah), thats less wiring, weight and a 20 - 30mm narrower frame. Hmmm...
I guess it comes down to whats the highest priority - range or weight / nimbleness / handling. I'll be riding this bike mostly with my girlfriend once i get her Mac build finished. Given she's reasonably new to mountainbiking in general (but picking it up pretty quick), our average speed will prob only be about 25-30kph so i could probably get away with a 10ah pack and still get a reasonable range
I guess i could make some bolt-on side pods to house an extra pack each later if range becomes an issue for longer rides. I think i just answered my own question lol...
That was an interesting read about the overheating of the new crystalyte motors. It seems quite a few people have killed these new motors very quickly. I was debating between a 5303 and an HS3540 but in the end I went for the HS3540 to save some money. I plan on running 88.8v and 50 amps maybe 45 amps but not continuously. I will probably run closer to 2.5 kw continuously with bursts above that here and there while being mindful of the motor temperature. I wonder if side covers machined like fan blades would help with the overheating on these smaller motors. I guess that would add to the complexity and manufacturing costs and probably won't be done but it seems like a reasonable solution. Hoping that isn't too off topic from your build thread.
Hi electr0n, not off topic at all mate. Yeah these H series motors do tend to be prone to over heating when pushing alot of kw through them or alot of hill climbing.
If your running the HS just take extra care if you do alot of hills, it will tend to heat up pretty quickly. Cooling holes, a temp probe and maybe some of these will help you keep an eye on temps - http://www.omega.com/pptst/RLC-50.html
I'll be getting some in the 30-90deg c range.
I guess side covers machined up like a fan blade may be beneficial for cooling but i can't see Kenny implementing that, too costly and for many people putting a sensible amount of power through these hubs (not us on ES lol), heat probably won't be an issue and wouldn't warrent it.. Having said that i think Jay (Hyena) is looking at having some side covers CNC'd with a cooling hole pattern, it might be worth looking into
Have you started a thread for your build yet?
sn0wchyld wrote:ha sorry mate, its a external hard drive power supply, they give you both 5 and 12 volts, really useful in a very small package. doesnt love heavy loads though, when I turn on my 1200lm light I can hear the fans drop to a lower speed . I run the allarm of the 12 volts, since it has a max imput of ~24v, and I dont want it draining off one 8s part of my 24s pack and getting it imbalanced.
Ah ok, your talking to an electrical numpty here lol. It sounds like a handy device - i assume the fan's rpm lowering when your light is on is just voltage sag under load? Thats a good point, too much load on one pack will give you an inbalance in relation to the other packs. Have you thought of using another stand alone pack just for the light and fans?
sn0wchyld wrote:Yea I figured I could always take more out of the side covers, where as filling the holes up is not so easy... I've only taken out 3 x 33mm holes on each side, and then glued in some mesh to stop anything big getting in, so its far from extreme and not the best for free flowing air. before I do any extra holes I might try putting in a array of heatsinks around the inside of the stator, I think it'd really help make the most of the airflow.
Yup, you don't want to be filling these things, cast aluminium can be a bastard to weld at the best of times, worse still when its a poor quality material or casting... 3 x 33mm holes isn't too radical i'd have thought, hell i've just done 18 x 12mm holes on one side - gulp! You could probably
up it to 6 x 33mm holes each side and get away with it (don't quote me though!).
The idea of heat sinks on the stator is a damn good one though, i might even try that without fans inside. Anything you could add in there to help soak up some heat has gotta be a good thing right?
sn0wchyld wrote:had a more aggressive ride the other day, 5-10% grades at wot, maxed out at about 65deg, and drops fast when I stop, slowing down as it reaches about 50. I could probably get it hotter if I actively tried, but under normal conditions I dont think ill have to worry much unless its like 35+ ambient, and then only if im riding like a pig. plans to up the pack to 24s 15ah and ~50A might change that though - but not until i get my RC drive running. Hate having nothing to ride.
Thats 65deg at the windings, not the casing hey? If so thats pretty good going, from what i've read about safe winding temps i'd be happy with that!
You reckon putting an extra 10a through it will make that much difference in temperature? For your sake i hope not
Yeah i hear you re having nothing to ride, i sold my Specialized to Dingo last week and i still haven't found another job yet so i'll be without an ebike for longer than i'd planned for - doh! I've still got a nice normal mtb but its just not the same without a few kw to help get my speed jollies!
Oh sorry for the slow reply boys, my girlfriend's just had a death in the family and things have been a little crazy the last few days. F**king cherry pickers...