Posted: Sun Aug 03, 2008 7:24 pm
Ahhh, nice to see you're here as well Jozzer! You got off lightly with the DVLA, I think. It seems to be entirely down to pot luck as to whether or not you get put through the mill. If you hit lucky, and get someone with more than one working brain cell then you seem to stand a reasonable chance of getting it sorted quickly. If you don't, then it seems that you're doomed to answer daft questions for weeks.........
I think that there is a lot of merit in getting a tame motorcycle mechanic to scribble something, as you did. For some reason they seem more likely to trust their word.
Nigel, I'm near Salisbury. Happy to meet up if you're nearby.
Malcolm, the spot welder took a fair bit of hit and miss to get right. The main snag is that welding test pieces isn't representative of cells and the cells are different from one end to the other (the Headway positive caps are thicker than the negative ends). All told it's not too fussy though and I now have a feel for how to tweak the voltage as the electrodes warm up and for different thickness's of nickel (I doubled up in places to improve the current handling capability.
If anyone wants to make one, then I would be happy to help. You don't need the fancy handle operated electrodes, in fact I've done away with them for the Mk2 and just gone to a couple of hand-held pointed copper rods with insulating handles. The hand-held electrodes make it much quicker to use and also allow better access. I have a few of the big thyristors spare if anyone wants to build a replica, as I bought a job lot of them on eBay.
Here's a pic of some of the welds that this rig produces:
I finished off the battery racks today and mounted the Alltrax controller. I'm pleased with the result, as it is a lot narrower than the previous attempt, so will look reasonable when it's finished (I hope). I also ordered a BMS from Gary Goodrum over on the Endless Sphere forum. This will provide individual cell monitoring during discharge, with a low voltage cell warning that I'm going to use to switch the controller to half power (using the half power reverse input). This BMS also controls charging and automatically limits each cell to around 3.69V before shunting current around it. The best bit was that a 16 channel kit was just over £62 including shipping to the UK, which seems pretty good value. Here's a link to the shop that sells the kit: http://www.tppacks.com/proddetail.asp?prod=EBKE%2DBMS%2DKit
Does anyone know where I can buy some really big heatshrink sleeve? I want to sleeve the battery sub-packs, but the only place I can find that does big (as in around 130mm diameter) heatshrink is ebikes.ca in Vancouver. A UK source would be great.
Jeremy
I think that there is a lot of merit in getting a tame motorcycle mechanic to scribble something, as you did. For some reason they seem more likely to trust their word.
Nigel, I'm near Salisbury. Happy to meet up if you're nearby.
Malcolm, the spot welder took a fair bit of hit and miss to get right. The main snag is that welding test pieces isn't representative of cells and the cells are different from one end to the other (the Headway positive caps are thicker than the negative ends). All told it's not too fussy though and I now have a feel for how to tweak the voltage as the electrodes warm up and for different thickness's of nickel (I doubled up in places to improve the current handling capability.
If anyone wants to make one, then I would be happy to help. You don't need the fancy handle operated electrodes, in fact I've done away with them for the Mk2 and just gone to a couple of hand-held pointed copper rods with insulating handles. The hand-held electrodes make it much quicker to use and also allow better access. I have a few of the big thyristors spare if anyone wants to build a replica, as I bought a job lot of them on eBay.
Here's a pic of some of the welds that this rig produces:
I finished off the battery racks today and mounted the Alltrax controller. I'm pleased with the result, as it is a lot narrower than the previous attempt, so will look reasonable when it's finished (I hope). I also ordered a BMS from Gary Goodrum over on the Endless Sphere forum. This will provide individual cell monitoring during discharge, with a low voltage cell warning that I'm going to use to switch the controller to half power (using the half power reverse input). This BMS also controls charging and automatically limits each cell to around 3.69V before shunting current around it. The best bit was that a 16 channel kit was just over £62 including shipping to the UK, which seems pretty good value. Here's a link to the shop that sells the kit: http://www.tppacks.com/proddetail.asp?prod=EBKE%2DBMS%2DKit
Does anyone know where I can buy some really big heatshrink sleeve? I want to sleeve the battery sub-packs, but the only place I can find that does big (as in around 130mm diameter) heatshrink is ebikes.ca in Vancouver. A UK source would be great.
Jeremy