I have a quick question for everyone: Does the length of the cables from/between the batteries have an impact on something? Ofcourse theoretically the batteries will be at a different voltage if a resistance is between them and a current flows through it, but can’t that be neglected unless you have several orders of magnitude lengthier wire.
I’m asking because I might place the batteries in length along the roll axis of the board.
Dries
If it does … It shouldn’t be detectable … And shouldn’t affect anything
Just make sure that the cable length between batteries and the VESC is not too long. Else you might need to add capacitors in front of the VESC to avoid difficulties.
How long it’s too long?
Depends on the cable type used. In general I think that everything up to 20-30cm is still ok with a good 12AWG cable for example.
re wire length, in this thread is some info re this, especially the external link posted by trbt555 is quite interesting.
Thanks @shred and @elkick. I thought so that I read something about wire length. I’ll try and keep myself to the max30cm allowed. I suspect that ought to work.
nws, just found another link re VESC and wire length http://vedder.se/forums/viewtopic.php?t=46
@shred, I’ll read up on that! Right now everything is going into high gear. Everything arrived.
I went to meet trbt555, to go buy the 3*4S 10000mAh batteries and the enertion steez remote from him. It was nice meeting him, a friendly and down-to-earth guy who gladly shared some advice regarding DIY esk8s with me.
While I was expressing my worries with him regarding my backorder on HK of the 149kV, the shipping gods must have heard me and not even 30 minutes later the motor, XT90s and cables arrived.
When I find the time I’ll read up on the cable length, but I don’t think it’ll be an issue. I’m thinking of placing them behind each other as in the picture, but then I’d have to probably use fiber glass for the enclosure as finding ABS to vacuum form the entire length is gonna be quite difficult. Other tips are welcome. (Yes I know the board is upside down 
just for reference (board is 36"/96cm). I’ll also be using risers)
They’re very big, its gonna be a tough fit but doesn’t matter, we’ll make it work.
OK, update: I managed to config the VESC succefully, I have full control and managed not to blow up the DRV chips or screw up the firmware.
I do have a question though: I used a single 4S lipo for the setup and motor detection. But as I’m going to use 12s, I set the battery cutoff start at 42V (3.5V) and the battery cutoff end at 38.4 (3.2V). This gave me the thought that as soon as I write the config, I won’t be able to drive it with the 4S connected battery, as the voltage is lower then the end cutoff.
This isn’t the case though, I can still run the motor with the remote and with these settings. How can the VESC know that I only have 4s installed, or where did I go wrong.
Dries
Would be good if you can provide some screenshots from your settings.
Sure, but i don’t have access to it now. All the other settings are default though, I only changed to battery cutoff start to 42V, cutoff end to 38.4V. max voltage is default (57) and min voltage is default (8V). The battery and motor currents are also default. After that I only detected the motor and set the PPM enertion remote.
Hi @3sly, it was nice meeting you, a pity I didn’t have more time to chat. Maybe we can ride together when your board is finished.
Personally I’d stay away from fiberglass and epoxy. It gets really messy really fast. And it isn’t all that cheap either. I think thermo-forming an enclosure will give you better results. Just search ebay.be for “ABS sheet” and you’ll find plenty of matrerial, mostly in the UK so without taxes to BE.
Made that experience today - absolutely correct! It’s a mess and not drying anymore, made some boxes last year without problems, but now…
@3sly don’t worry, that corridor for cut off start/end is disregarded if your voltage is lower than that, since it only serves as limit for cut off. It will work with your 12s nevertheless. in the expected way. But don’t use FOC on your setup please, it’s safer on BLDC for now.
Which height/thickness do you use? 3mm? 5mm?
Hey all!
Big update. The board is as good as finished. I’ve made a temporary metal housing out of an old metal gutter. Lot’s of elbow grease, but I’m happy with the result. In the long run I plan on vacuumforming an ABS housing, just like @trbt555 suggested. The downside though is that I need plates larger then A4 for adequate room for the batteries, and sheets that are large enough are hard to find and very expensive. I’ve contacted the Wauwer plastics 5 (a local shop), but I noticed they only have HDPE to vacuumform, which is pretty difficult to work with.
I am very aware about vibrations and metal edges, so everthing is properly insulated with very think insulating tape and even some sealing agent (window sealant) around the edges. The batteries are on standoffs of velcrotape and over half a cm away from any (insulated) edge. There are also no moving parts near the edges that can get cut through due to vibrations and the parts fit snug inside so they don’t move around.
Took her for a 3km spin and WOW! This must be the most fun toy I’ve ever owned. It takes getting used to to stay balanced and at high speed the thing shimmies if you don’t relax. But I think that’s to blame on the use of the 1/2 (necessary) spacers and the shorter wheelbase. But I’m learning, I notice that when I relax my lower legs, I can keep it under control.
Small problem though: Belgian roads are infamous for there lack of quality and my street is a prime example of this. The harsh vibrations make my mount screws come loose, which I noticed because after a while accelerating/decelerationg makes the belt skip, even though I used some 243 loctite. I don’t know what to do next, I’m almost tempted to use some 648 that I used for the motor pulley.
A second question: I’ve heard that the circlip holding the stator in needs to be rotating freely. But as you can see there is not enough room for the shaft. It isn’t pinched or anything so when wiggling the shaft forward and back, it moves along. It just doesn’t complete an entire rotation and thus doesn’t rotate freely. I don’t see this as an issue though, but I’d thought I’d ask anyway.
Here are some pics of the 2 housings:
In the meantime I cut the right holes to connect the cable and finished everything up. (I made sure the cables are: inside spiral cablebinder, then taped and then in an electricity tube. It should also be noted that none of the components touch the sides. No chafing of the cables in the passthrough holes can occur)
How does that 149k motor work for you. I have the same one but am still waiting on parts to assemble mine. Is the speed adequate on a 12s set up? I’ll be running 6s so I was curious.
It all depends on the gearing you use. I have 149KV at 6S but with a 20/28 gearing ratio. Top speed is ~40km/h
nice man, good work, happy riding! 
hey that’s pretty good. I might have to low my gear ratio then. I’d be running 20:36
