Good machine shop for a finger brake

[jim31886]

My Grizzly finger brake has the standard sharp edge fingers. I'm tired of dealing with shims and extra metal to get what I need.
I remember years ago we had a similar brake and had a machine shop put a radius on the fingers. It made a world of difference. I'd like to find a decent machine shop that could do it. I've been to a couple here in Waco-Burleson and they haven't impressed me as being able to do it.

Any suggestions in the DFW area?

Thanks

Jim

 

[JonJay]

Not answering your question directly, but I use various thicknesses of rubber sheet between the fingers and the work. Takes a bit of experimenting, and certainly isn’t as convenient or predictable.
Have you tried to sourced radius fingers? I know there available.
Once you radius the fingers, your brake won’t work the same on steel, if you care.
Good luck.

 

[HFS]

The short answer is - any machine shop with the right tooling (and experience) should be able to do this for you. Attached is a pic of two fingers from my Di Acro 36" "leaf" brake, with the nose(s) radiuses to .093"r. This radius allows for braking up to .032" aluminum in the T3 condition, meeting the standard of a radius of 3 x thickness of material being formed. Second pic is a close up of the radiused nose.

The finger with the narrowed down nose is used to brake the flanges on ribs that taper down to a quarter of an inch at the trailing edge - I made two this way for convenience.

One thing you may find, if you do this mod, is that the finger advance may not move the fingers far enough forward on thinner material because it runs out of adjustment. What I did to solve that problem was to make two offset pivot pins that moved the finger platen back to its original position wrt the (now) radiused noses.

And ... do I care if the bend radius may be incorrect for any steel sheet that I might bend - nope, am happy to have an "over" radiused corner on those pieces.

HFS

 

[JonJay]

I like it.

The problem with radius fingers on steel is you may find you don’t have enough clamping pressure for thicker gages. The steel sheet normally gets pinched by the sharp edge. With a round edge, the steel sheet starts to ride up the face of the finger and slides backward.
That’s the experience I had but you may not have that with your brake. I have a 16g Tennsmith.
Still, your post is very helpful.

 

[HFS]

I like it.

The problem with radius fingers on steel is you may find you don’t have enough clamping pressure for thicker gages. The steel sheet normally gets pinched by the sharp edge. With a round edge, the steel sheet starts to ride up the face of the finger and slides backward.
That’s the experience I had but you may not have that with your brake. I have a 16g Tennsmith.
Still, your post is very helpful.

Never had a problem with steel slipping when using my Di Acro brake.

 

[jim31886]

"The short answer is - any machine shop with the right tooling (and experience) should be able to do this for you. "

Absolutely, anybody know who that might be??

Thanks and I appreciate all the help, it's what makes this group great!!

I've looked for ready made fingers and all I can find are for the Mittler Brothers brakes and a set of those is $800+. I don't know if they will fit my brake and I'm working on figuring that out.

I do the rubber or extra material to get what I'm looking for and yes, it's unpredictable.

I did this very thing on an old Tennsmith some 30 years ago and was very pleased with the results.

I’m just looking for a recommendation of a machine shop in the DFW area that has the tooling and experience to do the job. I‘ve already spent some time and miles and haven’t found anybody I’m comfortable leaving my stuff with.

Thanks, Jim

 

[DanH]

The short answer is - any machine shop with the right tooling (and experience) should be able to do this for you. Attached is a pic of two fingers from my Di Acro 36" "leaf" brake, with the nose(s) radiuses to .093"r.

Dave, got any photos or a sketch of the tooling to do it?

 

[digidocs]

Dave, got any photos or a sketch of the tooling to do it?

Try searching for a corner radius end mill. I think one of those with the desired radius and a milling machine will do it. Might be worth checking to see if the fingers are hardened too.

If you provide the cutter, maybe even an uninspiring shop could do it.

 

[cvairwerks]

Jim: The Mittler Brothers finger sections should fit anything that is a copy of the old Pexto brake. I bought a 6" wide section with either a 1/8th or 1/16th radius for my Tennsmith brake. The fingers are avialable in 1", 2", 3", 6" and 12" widths. You don't have to buy enough for full width, if you aren't needing it.

BTW, back when I called to verify they would fit, I ended up talking with one of the brothers and he ran grabbed a finger section and did a quick measurement check for me, right there while I was on the phone. Not a lot of places that will do customer services like that these days.

 

[jim31886]

Jim: The Mittler Brothers finger sections should fit anything that is a copy of the old Pexto brake. I bought a 6" wide section with either a 1/8th or 1/16th radius for my Tennsmith brake. The fingers are avialable in 1", 2", 3", 6" and 12" widths. You don't have to buy enough for full width, if you aren't needing it.

BTW, back when I called to verify they would fit, I ended up talking with one of the brothers and he ran grabbed a finger section and did a quick measurement check for me, right there while I was on the phone. Not a lot of places that will do customer services like that these days.

Thanks, I’ve been incredibly impressed with the Mittler tools I’ve bought. Spoke with those guys at OSH. I’ve got a friend in Kansas that has a Mittler brake. He’s bringing some fingers with him when he comes for a business trip in a few weeks. According to the measurements he gave me they look lIke they will work.

 

[jim31886]

A follow up. I found a machine shop in Azle, Silver Creek Machine. They did an awesome job and very reasonable. Dropped them off Friday and picked them up Thursday.