Newbie question: How to attack this project?

[Dale_z28]

I'm attempting to make new dies for my tube roller, similar to the one pictured but with a flat bottom (for 2" square tubing). My challenge (I probably should say my FIRST challenge) is holding the blank and still be able to turn the bearing pocket (so I can chuck it internally later).

In other words, my 3" chuck isn't capable of holding my 4" workpiece. I have a backplate and can drill centers in the part (I'll figure out a way to drive it once it's between centers). My idea is to bore most of the bearing pocket so I can use my chuck jaws to hold it from inside the pocket, then I'll finish the profile. I'll have to do this on both sides of the roller die, obviously.

I am closely watching ebay for an inexpensive chuck large enough to hold these 4" diameter chunks, but for now I want to make chips!

I don't think I have to explain my reasoning for spending twice as much $$ for the lathe and steel as a set of new dies. After all, I will still have my lathe for future projects! (Forgive me, I'm used to explaining my logic to my wife)
Any suggestions welcome, and please pardon me if I posted in the wrong place... Thanks in advance!

 

[umahunter]

Is this for a harborfreight roller if so they have a flat die set for I think half inch square you can just widen

 

[umahunter]

http://m.harborfreight.com/3-piece-die-set-66598.html

 

[GK1918]

I would= as what you have, bore a hole thru the blank in a drill press to what ever maybe 1/2" then turn a 1/2 mandrill. Put the now drilled blank into the mandrill either press it glue it
what ever it takes only to make it kind of firm and put that between centers and drive this blank with a dog. OK so far: then go online to How to run a lathe S. Bend this will show
you how to turn concave and convex using the compound rest mothod. Note its not mentioned, but I slightly tighten the compound with a silight drag, cause you will be swingin it.
back and forth to machine the female concave or convex. Any drill press and any lathe will do this. I aint good at explaing and this computor refuses my cambra but I show ya in
two seconds If you were here in our shop. So ya got a small chuck so turn a 60 * center and chuck it. Dont worry bout dogs- muffer clamps & a bolt / I myself over the years
made, can't count machining dies for a bead rollers with this method way back when, days of pay phones and no calculators.. I'm tryin ta help ya try it.

sam and get back

 

[Dale_z28]

Is this for a harborfreight roller if so they have a flat die set for I think half inch square you can just widen

Thanks, I was aware that HF made other dies besides the ones that came with the roller (for round pipe/conduit) but I didn't know they were this cheap!
I paid that much for the steel bar to make the new ones.
I kinda do things the hard way sometimes, and this will give me some practice (and an excuse to work in my shop).
I appreciate the tip. I wish the nearest HF was closer...

 

[Dale_z28]

I would= as what you have, bore a hole thru the blank in a drill press to what ever maybe 1/2" then turn a 1/2 mandrill. Put the now drilled blank into the mandrill either press it glue it
what ever it takes only to make it kind of firm and put that between centers and drive this blank with a dog. OK so far: then go online to How to run a lathe S. Bend this will show
you how to turn concave and convex using the compound rest mothod. Note its not mentioned, but I slightly tighten the compound with a silight drag, cause you will be swingin it.
back and forth to machine the female concave or convex. Any drill press and any lathe will do this. I aint good at explaing and this computor refuses my cambra but I show ya in
two seconds If you were here in our shop. So ya got a small chuck so turn a 60 * center and chuck it. Dont worry bout dogs- muffer clamps & a bolt / I myself over the years
made, can't count machining dies for a bead rollers with this method way back when, days of pay phones and no calculators.. I'm tryin ta help ya try it.

sam and get back

Thank you. I hadn't thought of the mandrel idea, that would work better since there's a thru-hole anyway. I think I'll go this route. I just need flat-bottomed grooves 2" wide so the concave/convex stuff won't affect me until another project down the road.
I appreciate the help!

 

[Andre]

Can you flip the jaws around in your 3 jaw?

 

[davidh]

i would atttempt to mount it on a center and using a face plate,and drive it with a lathe dog using a substantial sized drill bit as the dead center and just drill away.
someone tell me if that would work ? :noidea:

 

[Dale_z28]

Can you flip the jaws around in your 3 jaw?

That's what I had planned to do, but the chuck jaws don't extend out to 4" before coming out of the chuck:thinking:

 

[Dale_z28]

i would atttempt to mount it on a center and using a face plate,and drive it with a lathe dog using a substantial sized drill bit as the dead center and just drill away.
someone tell me if that would work ? :noidea:

I'm not sure I understand exactly what you mean.
I have center-drilled both sides of my work and it is supported in the lathe. Driving it with a hose-clamped piece of cold-rolled for now but have not made a cut. This lathe is so small it is going to be very tight getting the toolpost around the work. The 4" diameter of my tube-roller-die-to-be just barely clears the carriage, so that's good.... It looks like I'll be making small cuts and moving tools quite a bit.