Helicoils in Cell Terminals

[ArthurEld]

This was supposed to be here-

I just went and did the other one

Hole drilled. Ground off drill. Doesn't need to cut in the center. Good thing

Flat bottom hole

Rotate by hand in drill press to start tap exactly perpendicular

Removed from drill press to finish by hand

Cut off 2 threads

Finished with ugly countersink. I'll do better next time

Finished product and tang

 

[schmism]

They also make a thing called a tap follower.

Amazon.com : tap follower

You chuck it in the drill press, and then the spring loaded point is put into the divit on the back of the tap. This keeps it lined up straight with the hole you just drilled. Run the tap with the tap handle.

 

[Luthj]

These are an option as well, (properly insulated!).

 

[FilterGuy]

This was supposed to be here-

I just went and did the other one

Hole drilled. Ground off drill. Doesn't need to cut in the center. Good thing
View attachment 35088
Flat bottom hole
View attachment 35089
Rotate by hand in drill press to start tap exactly perpendicular
View attachment 35090
Removed from drill press to finish by hand
View attachment 35092
Cut off 2 threads
View attachment 35093
Finished with ugly countersink. I'll do better next time
View attachment 35094
Finished product and tang
View attachment 35095

Please write this up as a resource and put it in the resource section!!!!!

 

[ArthurEld]

Please write this up as a resource and put it in the resource section!!!!!

You got it bud. Thanks for all the work you do here

 

[BiduleOhm]

NB: you're supposed to chamfer before you tap

 

[ArthurEld]

NB: you're supposed to chamfer before you tap

What is NB? I did chamfer before I taped. It bounced around.
A helicoil doesn't need much of a chamfer. I could have done better with a knife.
Functionally it doesn't make much difference. It is the best hole of my 132.

 

[BiduleOhm]

Ok, then try to go slower on the drill RPM, it should cure the bouncing problem

Yep, the smaller the chamfer the more material you keep (which usually isn't a big problem but here we don't play with much material...).

NB: https://en.wikipedia.org/wiki/Nota_bene

 

[ArthurEld]

Ok, then try to go slower on the drill RPM, it should cure the bouncing problem

It was the lowest setting. I'll use a knife if I ever need to do one again. Or just turn the countersink by hand
This aluminum is so soft you could countersink it with your fingernail

Yep, the smaller the chamfer the more material you keep (which usually isn't a big problem but here we don't play with much material...).

It'll handle 70 inch pounds the way it is. The rest of my holes aren't likely to. Even the virgin ones

NB: https://en.wikipedia.org/wiki/Nota_bene

That must mean something to people smarter than me.

 

[Hedges]

What is NB? I did chamfer before I taped. It bounced around.
A helicoil doesn't need much of a chamfer. I could have done better with a knife.

Basic cone-shaped countersinks will do that. I usually a larger bit, and if it hit hard enough it centers and drills. But you have little meat to work with.

Here's something the would be cleaner (has a cylindrical nose to center it)

https://www.northerntool.com/shop/tools/product_200451725_200451725

Another kind. As part of the drilling process, not good for this particular short hole application:

Sears.com

 

[Hedges]

<NB>

That must mean something to people smarter than me.

My Latin is rusty. It was interesting to see what that translated as.
I use "i.e." and "e.g." much more.

 

[BiduleOhm]

Or just turn the countersink by hand

Given that aluminium is very soft it's a good idea

That must mean something to people smarter than me.

It's a very common expression we use to add something to a text who isn't as important as the rest. A bit like "BTW something something..."

 

[ArthurEld]

This is the tool for the job. The terminals are as soft as led

 

[Sky-HHI]

Nice job ArthurEld , It is great to see someone do the work and include pictures. So many people on the forum only have idea or opinions but never try something constructive. Good luck with your battery project.

 

[FilterGuy]

What is NB? I did chamfer before I taped. It bounced around.
A helicoil doesn't need much of a chamfer. I could have done better with a knife.
Functionally it doesn't make much difference. It is the best hole of my 132.

Thanks for all the gret info @ArthurEld !! please be sure to put all the tips and tricks into the resource write-up! It is going to be a life-saver for a lot of us!!

 

[Luthj]

 

[ArthurEld]

View attachment 35105

The one I took the picture of was out of my dads tool box. It's probably 30 years old. I like the ones with the ball on the end
The hand chamfer tools work great. I'd use a countersink on a CNC machine and I could line up perfect to the hole and go exactly the right depth. And about 50 RPM

 

[Luthj]

I wonder if an aluminum stud with flat base could be friction welded with a milling machine? I guess it depends on how much force the terminal can take, as most machines can't get to crazy high RPM.

 

[ArthurEld]

Thanks for all the gret info @ArthurEld !! please be sure to put all the tips and tricks into the resource write-up! It is going to be a life-saver for a lot of us!!

I'll put it together in a Word file tomorrow and save it as a PDF. It will have all the details and pictures.
And I can update it if something isn't clear.
Eventually, I'll probably have to do another one and I can get a few more pictures.

 

[BiduleOhm]

I wonder if an aluminum stud with flat base could be friction welded with a milling machine? I guess it depends on how much force the terminal can take, as most machines can't get to crazy high RPM.

I like you thinking... unfortunately I don't think the terminals will handle that...