seedsbelize 

+1

NoReg

Plasma cutter. I just got one, and have yet to try it. Bring her around...

hillzofvalp

currently trying the half round idea, but I'm not sure if I should just use the fine or start with coarse first. Also I can't really see what I'm doing when I put it down there so I'm worried that I'm going to dent something.

BTW, why do these little mounts look like socket hex bolts from the inside?

unterhausen

if you are using a half round, best to cover the sides and end with duct tape or you are going to cut through the tube like I warned you earlier in the thread. Not sure about the shape, all the brazeons I have seen have been round.

I would go with a bastard cut file

hillzofvalp

it seems to be going well, but I didn't pick up copper tubing earlier so I don't know how well I'll be able to get close/parallel enough to the steel tubing walls when I'm finishing up. The only way to get the file to stay on when dowel is drilled near perimeter would be the copper tubing. Thanks!
update:
Tada!


Used a drill extender to get closer since I didn't have copper tubing handy. worked like a charm with a hex skateboard ratchet on the end. It's from 10 years ago when I was a middle school skateboard punk, and kept it since then thinking I would finally use it some day, and I did. It's pretty well made, actually (bones).



Next issue is that even though the pack fits, the tubing does ovalize a bit more than I thought. This keeps the pack from continuing 5cm or so. HOWEVER when I remove electrical tape, it fits just fine (prone to shorts). Does anyone have a suggestion for the last cell.. ie thin insulation that's thinner that taut electrical tape? The only other option is to file down the frame a hair, but I rather not do that!

NoReg

Thin coat epoxy?

unterhausen

the heat shrink that they use for most battery packs is pretty thin. Not sure if it's thinner than electrical tape, but you don't need any overlap. A good hobby shop catering to model aviation will have various sizes of it.

hillzofvalp

I'll give heat shrink another try, first, but I'm doubting that it will be thinner than .6-.7mm electrical tape. Last time it was about 4 times thicker than electrical tape, but that was because I went with 1.5" that reduced to .75". Was the only one that I could get in a 4 foot length (don't need that anymore).

unterhausen

There are two kinds of heat shrink. One kind is rubbery and usually black, and is mostly used on wires for insulation. You don't want that, it's too thick. The kind that they use on batteries is much thinner, and is more rigid.

hillzofvalp

I'm going to try kapton tape first.

I just bought this cannondale r900 frame on ebay for $90 shipped new. Not a bad deal to me if it's an '05. It's on the small side for me so hopefully it works out ok in that respect (58 vs 59). I know it's a little late that I went at my bottle mounts on my steel bianchi, but I think I want to use this yellow frame as my project frame.

One of my goals is to get batteries in the down tube. I automatically think that the bottom bracket will be the only way. It would require drilling a big hole in the lower rear portion, and inserting the pack in through that way.

The other way is the do the same in the head tube. Maybe a bit more safe (to my knowledge), but less aesthetically pleasing.

Any thoughts? I may consider starting a new thread, but this will be the first step.