How to make a band cutting mandrel

[Tor R]

I used a 3* cutting angle Tor

View attachment 26574 View attachment 26575

thanks Al.
3° cutting angle from the center and out? Or 3° seen from the side as in picture1?

 

[Lootbug]

How then do you guys cut the base? Isn't that sort of part 2 of cutting a squish?

 

[drf256]

thanks Al.
3° cutting angle from the center and out? Or 3° seen from the side as in picture1?

Picture one. The cutter is tilted back 3*. Higher in the front (where it cuts)

 

[drf256]

How then do you guys cut the base? Isn't that sort of part 2 of cutting a squish?

Can do it either way.

With mandrel cutting, I find it much more exact to measure squish, then cut the base, then cut the band.

 

[Brewz]

Deets, the best I can match your 90* mill bit with is a hack saw, angle grinder and a file.

Al, nice taste in beer!

Thanks for the info so far folks... keep it going cause it looks like there are a lot of members interested in learning this stuff!

 

[Tor R]

Picture one. The cutter is tilted back 3*. Higher in the front (where it cuts)

thanks Al for taking your time to explain it so nice.
Used to work on a place where they have all the equipment for making mandrels for me, they sure gone work a bit lol
242,254,262 is my main saws to do some serious work with

 

[Deets066]

Deets, the best I can match your 90* mill bit with is a hack saw, angle grinder and a file.

Al, nice taste in beer!

Thanks for the info so far folks... keep it going cause it looks like there are a lot of members interested in learning this stuff!

Just use the grinder, grind you a slot across the top of the mandrel. Leave it a little under sized and install HSS with a BFH

 

[drf256]

Just use the grinder, grind you a slot across the top of the mandrel. Leave it a little under sized and install HSS with a BFH

I drilled a set screw. How do you change your cutter Deets?

I get about 10 bands out of a cutter

 

[jmssaws]

I cut a groove with a cut off wheel and drive a cutter in with a bfh like deets said.
No set screw.

A set screw would make it easier to angle your cutter if you want to.

 

[Deets066]

I drilled a set screw. How do you change your cutter Deets?

I get about 10 bands out of a cutter

I made my groove a fuzz small and tap the cutter in.

Same to remove it

 

[Lootbug]

Can do it either way.

With mandrel cutting, I find it much more exact to measure squish, then cut the base, then cut the band.

Sorry, bad wording on my part. Let me rephrase that; I'm wondering how you guys cut the base if you don't have a lathe?

 

[mdavlee]

I wish I had a way to cut the base without a lathe but the things that would do that are about as expensive as a small lathe.

 

[mdavlee]

I drilled a set screw. How do you change your cutter Deets?

I get about 10 bands out of a cutter

I have set screws on mine. I can shim them with a piece of paper or sandpaper for angle if I want some.

 

[drf256]

I have set screws on mine. I can shim them with a piece of paper or sandpaper for angle if I want some.

I've done the same with slivers of brass shim material

 

[drf256]

Sorry, bad wording on my part. Let me rephrase that; I'm wondering how you guys cut the base if you don't have a lathe?

I think @czar800 used a surface sander very carefully and then block sanded the base to its final dimension.

I wouldn't feel comfortable with anything but a lathe or a precision milling machine. If you're off at even the slightest angle with your base, especially side to side (and not perfectly 90* to the bore), I'm sure the saw will run for a good amount of time. But, it's gonna place unnatural loads on the piston and I suspect eventual failure.

My OCD-ness just won't allow it.

 

[ABarrick]

I have set screws on mine. I can shim them with a piece of paper or sandpaper for angle if I want some.

Don't know if it would be worth the effort or not but how about a set screw positioned vertically underneath the cutter in the tool slot? You could set it at or below surface for a 90 degree cut or back it out incrementally and then lock the cutter with the other set screw to the angle desired.

 

[mdavlee]

I could do that. Might try on one

 

[Brewz]

I ordered a couple $6 Chinese 066 piston kits and will use the pistons as sanding blocks.

I don't have any old ones sitting about so I tacked them onto an order I was placing

 

[GoBigBlue1984]

These are neat and all and I've actually considered making one and seeing how well they do. I'd like to see some pictures of a band cut with the mandrel. For me though, the ten minutes it takes to set it up in the lathe and cut it I can't bring myself to try anything else.

 

[GoBigBlue1984]

If I didn't have a lathe though I'd be all over trying this out