jonescg's NEW electric racebike BUILD thread!

[jonescg]

Indeed, being able to catch shit about to happen is better than having shit happen without any warning. Polycarbonate is ideal for electrical stuff too since it has good arc-flash resistance, high melt temp, and it doesn't shatter when it smashes on the ground. I spent today cutting some 50 mm2 cable and crimping lugs on for the main control box. I'm not happy with how it mounts to the box, so I might end up re-making it (again) so it can be fixed firmly to the battery pack.

Randy is due to send me an update Tuesday evening. Apparently some epic snow melt caused his basement to be flooded, so he was busy for a week cleaning that mess up. The CNC guy should have the motor mounts finished, and that includes an adjustable motor height! Not sure where the CoG will end up, but there's a good chance its pretty low which is not ideal for a bike.

 

[jonescg]

Hey all,
I'm starting to put my battery box together sans batteries. The switchyard up top will need some special attention to layout, as there are some high potentials which need to be physically separated as best I can. One of the sticking points I've hit is connecting the 50 mm cable lugs with 8 mm holes to the terminals of the batteries. The solution is simple, but execution is hard. Basically I need insulated busbar standoffs like these:

They are made from glass reinforced polyester (aka fibreglass) and have M8 nuts embedded in either end of them, but with a few gigaohms worth of plastic between them. Perfect, except they are way too tall for my application. These leave the lugs 35 mm off the deck and I need about 15 mm. After searching high and low I can't seem to find any that suit. Not only this, I need a means of fixing them firmly to the 4.5 mm polycarbonate shelf below.

So brainstrust, what do you reckon? Can I build my own standoff with a square pad beneath it which will take four short M4 screws like this?


It would be pretty straight forward- simply set a long nut in glass reinforced resin...

EDIT: Some context for this - My batteries will have forked terminals which head up from the pack and do a sharp 90 degree turn. These will slide inwards with the batteries, with the forks straddling the stainless steel M8 bolt shaft. The 50 mm2 cable lug will be on top, awaiting the forked terminal. This is so that installing the batteries is the LAST thing I do before putting the covers on and sealing it up. It also means I can work on the switchyard (with gloves and insulated tools) from the top after removing the BMS shelf.







I don't want to have to get underneath all this with a 13 mm spanner - too much (or more correctly, not enough) room for shit to go wrong.

 

[RIPPERTON]

You mean like this...

 

[jonescg]

Yeah them's the ones

How's the compression strength of acetal?

 

[RIPPERTON]

its awesome
theres 10mm left between the nut and lug so you will get the required torque on the bolt.

 

[megacycle]

You going to tighten the bolt through the lug and bus into the insulator nut?

 

[megacycle]

Better way would be an insulated stud and tighten the joint between 2 nuts+2 washers.
Could loosen up tightening down on a nut captive in poly.
Hiliarys boat shop has got single stud insuators.
[attachment=0]IS_10MM_1_150.jpeg[/attachmentis
Part no. BEP-IS-8mm-1R

 

[jonescg]

That's kind of what I was thinking earlier. Tension on the lugs between two stainless steel nuts is surely better than tension through a 10 mm section of acetal. Acetal deforms a bit when it gets hot too. I was thinking of vice-pressing the nut into the recess with some epoxy to make sure it doesn't leave. Then I can bolt through the lugs with metal either side. Danny's already got my money so I'll go with his option

But those lugs look ideal. I figured you'd know where to get this industrial electrical stuff, Megacycle

Edit - I just realised they probably assume you can get a spanner around the bottom nut - not possible (or advisable) in my circumstance.

 

[RIPPERTON]

You could put a bolt up through the hex recess then a short nut on top.
Just use your imagination

 

[jonescg]

I'm sure there's bound to be an engineer somewhere who would deem it less-than-ideal, but your shallow nut idea would certainly solve that issue. It might end up being the right height that way too. I'll just have to mount them and see how they look.

 

[RIPPERTON]

Its actually called a half nut
just rmbrd

 

[megacycle]

I'm sure there's bound to be an engineer somewhere who would deem it less-than-ideal, but your shallow nut idea would certainly solve that issue. It might end up being the right height that way too. I'll just have to mount them and see how they look.

Yeh the engineers are in a meeting at the moment gonna get back to you next year.
Meanwhile any stand off is good but theyre used more for bus support.
Could finish the bus on the insulator and drill your hole back from it and lug on there.

 

[Kirbs]

Chris,

Kirby here from the desert... I'm very impressed with your build, it looks awesome. I'm interested to hear more about your BMS you mentioned earlier in the thread. Have you got anymore information on how you are going to set it up and how it will work?

 

[jonescg]

Hey Kirby! How'd those boards go? Manage to unsolder those 6s packs?

I've asked EV-Power to build me a BMS. I actually asked for a fully custom one, but Rod had already started work on a modular 12s system which can work for any lithium chemistry (just set the jumpers in the right spots). They are very small, and all they do is warn you if a single cell is above or below the safe zone. No balancing or anything. I'll let you all know how it goes. There's a chance it won't work out in my situation, at which point I will definitely get my fully custom BMS. But if it works out well and fits snugly in the space above then all is well. Just a matter of try and see at this stage.

Randy promised me some pictures of the battery frame cradle but I've not seen them yet. Maybe tonight.

 

[jonescg]

I had a very pleasant surprise in my inbox this morning!

Randy has finished the battery cradle and it simply bolts in place between the headstem and the motor cradle.

It looks like it hangs down a long way, but the base of the cradle should be about 130 mm off the tarmac.

Lots of options for attaching the fairings as well as the radiator up top.

Nice and rigid. Looks like a bit of a fatty, but it's no wider than a Kawasaki 636.

I also got a picture of one of the motor mounting plates!

This fits between the swingarm pivot and the motor, and gives me a few options for moving it's weight higher or lower, depending on how it feels.

And then this afternoon I check my emails for the surprise of a lifetime -

Justin kindly hacked the CA so it will read 700 V from a voltage divider and still give me good data on Wh/km etcetera. Even cooler - Abraham (Voicecoils) will be muleing it back in to Australia for me!

I wasn't originally planning on using the CA as the voltage division stuff was pretty hairy, but with a splash screen like this, how could I not?!!

 

[SplinterOz]

Very cool!!! All of it.

 

[Farfle]

That is SO SICK!!! can't wait to see it go! Frame looks like a tank, chromo trellis frames ftw.

 

[RIPPERTON]

Wow that thing is built like a tank
well at least it will be crash proof.
I sent off my AASA license renewal and Wakefield entry form today Chris.
That should make you jealous.

Also got some inside info from my spys that Varley will be doing a ride day down at Wakefield next Wednesday
so might go down and do some spying myself.

 

[jonescg]

Wow that thing is built like a tank
well at least it will be crash proof.

An important trait when pushing stuff to the limit More crash proof than a dual Indian smoke machine anyway. Remember, it's holding 9 kWh of LiPo, 150 kW worth of motor and hopefully tipping in at 200 kg. So strength is a good thing.

I sent off my AASA license renewal and Wakefield entry form today Chris.
That should make you jealous.

Mate, I got a couple of beers in me after a day of marking first year biology assignments, fixing a couple of e-bikes and sorting out the comms on an EV charge point. Not much will motivate me right now

Like I said earlier, I'm a good $15k from where I need to be. I don't want to rush anything, and for the first time I might actually have some time to do some testing before a race. As Catavolt taught us, reliability can win races!

Also got some inside info from my spys that Varley will be doing a ride day down at Wakefield next Wednesday
so might go down and do some spying myself.

Do snoop - I'm keen to see how my competition will shape up

I got your acetal blocks in the post this morning. Hope to find some time this weekend to install the electrics. I might try to fit a shunt in there now that the CA is ready. Oh and I stuck your Ripperton sticker on the lawnmower. I'll electrify it once the fuel or oil runs out (which ever comes first).

 

[RIPPERTON]

You mean like this

 

[megacycle]

Sacrebleu !!!
That thing would mow a hole in the fabric of the universe

 

[jonescg]

I managed to install most of the switch yard today. I shortened my 50 mm2 cables by a lug length and they fir the terminals perfectly. You have to twist them down into the hole to get them to line up, but it's all good.

I've almost finished my main control box (again). I'm waiting on some epic power resistors so I can build a voltage divider to go beside my precharge relay. It all gets covered by the sheet of FR4 with the relay logic. I'm hoping I won't have to disassemble it too often, but at least I know it's pretty straightforward to do.

The charge leads are a pain in the arse. I will have to route them out between the main power leads or something.

 

[megacycle]

You using spiral wrap and flexy conduit?

 

[jonescg]

Yeah I will be making one ground, three power and three signal wires, so 7 wires which need routing out of the box and into the main control box. I'll be stuffing all of this into that split conduit stuff. The charge leads are a pest as they are using 8 gauge wire (12 would have been fine, but the only finger-proof, pilot-plug enabled Andersons I could get came with 8 gauge).

 

[megacycle]

You going to splice down in guage to 12, the charging amps about 10?