Any way to make carriage bolt holes without machine shop?

[belfert]

I woould like to use carriage bolts to anchor some aluminum angles around my battery bank.  Is there a way to make square holes for the carriage bolts without a trip to a machine shop?

I would like to use carriage bolts if possible so the batteries sit level and the bolt heads don't wear a hole in the batteries over time.

[Dreamscape]

Drill the hole then use a Dremel tool or file to square it out. I'm cheap, that's how I would do it!

Paul

[gumpy]

Just use a small file to square off the drilled holes. Don't have to be completely accurate.

Not sure if Greenlee makes a square punch die set. They make all sorts of round dies for electrical knockouts, but I've not seen a square one. Might look in McMaster Carr or Grainger. 

[gumpy]

I reread what you are trying to do. Maybe a better solution would be to use tapered head machine screws and just taper the holes in the aluminum.

If you do end up with carriage bolts, you should put a piece of plywood cut to fit inside the angle iron.  Even the round heads of the carriage bolts will eventually wear through your batteries.

Or, you could turn the angle iron around and bolt the flange on the outside perimeter of the batteries. Then you could use regular bolts and washers.

[Dallas]

Or just use stove bolts built like the cariage bolts without the square piece on the end.

[luvrbus]

A hammer on the head of the bolt works for me if the metal is not thick     
Good Luck

[belfert]

I thought about a Dremel tool, but the bits I have for metal are all too big really.  I never thought about a file, but that would be the best solution.

I think I'll just use regular bolts and place plywood with holes on top of the aluminum.

[Utahclaimjumper]

You can also buy a stove bolt with a flat flush head, works well.>>>Dan

[Dallas]

Brian,
Instead of plywood, which will deteriorate over time from contact with the battery acid, why not get a couple of those nice plastic cutting boards they sell at the dollar store and rip pieces out of them to countersink your holes in to. That stuff will never deteriorate, and if you put 2 or 3 layers together, you could do without the angle iron at all.

Just thinking inside the battery box here. LOL

I thought about a Dremel tool, but the bits I have for metal are all too big really.  I never thought about a file, but that would be the best solution.

I think I'll just use regular bolts and place plywood with holes on top of the aluminum.

[gus]

I agree with Dallas. Never tried plastic because I didn't have any handy.

I use thick rubber when I can find it or thin strips of wood lathe otherwise. Plywood will come apart or mash flat over time.

I never place any battery directly on metal if I can avoid it, it is too good a place for corrosion to form. The more air it can get the better.

[belfert]

Brian,
Instead of plywood, which will deteriorate over time from contact with the battery acid, why not get a couple of those nice plastic cutting boards they sell at the dollar store and rip pieces out of them to countersink your holes in to. That stuff will never deteriorate, and if you put 2 or 3 layers together, you could do without the angle iron at all.

I was actually at Dollar Tree last night looking for a cutting board for something else without much luck.  Of course, I was looking for the really thin plastic cutting boards that can be rolled up. 

If I ever have battery acid on this surface I will be in trouble as these are AGM batteries.  I will stop at Dollar Tree again this evening on my drive home and look for a regular thickness cutting board.

[bruceknee]

[Use a square drill bit

[kyle4501]

I don't like square bits, you have to push too hard. 

[NewbeeMC9]

if you don't want to push too hard you could us a jig,

That is

"Jig-a-Mortis! "

depends on what your tendons to do



also

http://www.makezine.com/extras/15.html

[Dreamscape]

Shoot, with all of our expert help you should have the problem solved by now!