Heatsink

[Benjahmin]

Todays ride was eventful. I got something stuck in my front brake caliper going down a steep rutted lane - hairy - had to rely mostly on the back brake. New pads should sort it.

The other issue was that my controller went into limp mode because of overheating. It has done this a couple of times before on steep climbs, but only in the height of summer. So this was a bit of a surprise. Was climbing a long haul of varying incline, in total it's about 2.5 miles. I was about 3/4 of the way up, where the gradient kicks up for about 200yds, when the controller wimped out. It was too hot to touch for more than a second or two. Done this climb loads before, never had this happen. Must admit that I think my legs are suffering winter layof blues 'cos I'd got down to 6mph and couldn't maintain my usual 8mph. Stopped for a drink and continued after a few minutes with no further issues. Strange for tis time of year though.
Anyway I thought it might be time to think about fitting a heatsink - but I have no idea where to start.
My controller has a die cast case and is bolted to the underside front of the rear battery rack. The underside of the controller is cast rippled making it difficult to fit anything there. I thought about a plate fitted between the case and rack, extended out sideways and to the front, but I'm not sure a flat plate would give enough surface area.
Anyone got any idea's?
Thanks.

 

[peter.c]

post a pic

 

[Raboa]

Hi, I take heatsinks out of electronics, if you want one of them let me know.

If you give me measurements I will try and get you one closest to them.

Thanks

 

[vfr400]

We need some more details. Which motor? How fast is it? Which controller? How many amps?

 

[Benjahmin]

Thought you might say that




It would seem that the box is bolted on by the two dome heads on the 'cross bar'. Then there's two counter sunk cross heads, one of which you can see just behind the rack top tube curve. It looks like the box is mounted flat underneath the plate of the rack, maybe already functioning as a heatsink, which is a bit worrying. The top picture is with the battery fully slid home.

 

[Benjahmin]

Sorry, just seen the other posts.
It's an Ezee controller and motor. Not sure but I think it may be 20A. However, at the time of the cutout I was using pas 2/5.

 

[vfr400]

The Ezee controllers use speed control, so you still get full power on PAS2 if you go slow enough.

It might be an idea to check your motor connectors, especially the one on the forks if you have it. You'll also get severe overheating if the current can't get through one phase properly.

 

[Benjahmin]

Gotcha, that's one thing that could have changed. When I last took that connector apart (about a year ago) there was some heat malformation in it, I'll have a look.

p.s. slow reply 'cos the power was of for about 6 hours yesterday. But then this area only started to get mains in the 60's and some of the infrastructure is still the same.

 

[Benjahmin]

Finally got round to looking at the motor connector. It is a square rubber looking block with 3 bullet type connectors embedded in it. It is showing definite signs of heat stress, so I'm guessing that there is resistive connection somewhere, that or the bullets just aren't up to it. The white multipin plug has gotten 'glued' to the block with what looks like hot glue. It wasn't like that when I built it.
Haven't opened the bullet block yet because I think I'm going to have to cut it apart.
The connections fit in a little box on the fork (see picture), anyone got a suggestion for replacement?