Bruce – A fellow named George H Thomas drew up a set of plans that are widely available. Google "George Thomas bending rolls" for examples and maybe even (ahem) a copy of the article.

I made a set from Hemingway Kits; it came with gears, etc, and is very sturdy.

I did do some of the work via CNC – I did put some of the results up on my blog at **LINK** for anyone interested.

Presumably this is what you are looking for?

The short ones are also known as "ring rollers" if you look back at teh M-machine thread from last week you can see Andrews one in action. And a search on youtube for Myfordboy shows his set that use cranks rather than gears getting some abuse!

As JAS say google will throw up the article as a pdf

Edited By JasonB on 05/05/2015 07:31:53

These pics

**LINK**

**LINK**

Myfordboy

Edited By JasonB on 05/05/2015 08:09:24

Bit more about Andrews one here

Edited By JasonB on 05/05/2015 08:13:23

I started off making a set of rolls to that design. Nothing seemed to fit properly, so I gave up. The other issue with the design is that the rolls are pyramid, not initial pinch, so will leave a 'flat' at the ends of the work.

Andrew

Gentlemen,

I make fuel tanks for my Lister's and have been using a modified mangle and angles for bending but this weekend I treated myself to one of these 3 in 1 machines, a guillotine, box bender and rolls, it has a maximum material size of 1mm but for what I need it fits the bill.

Martin P

Bruce; Regarding my latest mill conversion, I purchased a "kit" consisting of mounts, ball screws, for the mill. I'm over in North America, so I purchased the kit from "http://www.automationtechnologiesinc.com".

If you want to do more work, you can make everything, "g0704.com" sells plans, that seem to be well liked.

I went with the kit because, for me, the electrical and programming side of things is the fun bit. Other people have different interests, of course.

The kit is basically a bolt-on arrangement, but for me, the Y axis did not bolt, because of the drunken holes in my mill base. (nothing wrong with the kit)

You will find that the ball screws have a pitch of something like 4 or 5mm, much more coarse than the original lead screws.

Quite a few people like to use "acetal", molding plastic around the current feed screws, for an almost zero backlash nut without changing the feed screw. (but, as you say, you may have some uneven wear there) There was a fellow Canadian (Evan) who did a great job explaining this process on "bbs.homeshopmachinist.net" – can't find the exact link to it at the moment, and heading out to work…

Bruce, sorry for jumping in….John, a question about the gears. I scratch built mine to G Thomas plans, definitely needs the geared top roll. (Plans suggested the gear train may be an additional,extra.) Might sound dodgy, but why not just drive the top roll from the bottom using spur gears meshing nice and deep. The rolls will only ever open to about 2 mm and a bit of backlash is no harm when used at the limit of the machine? Thoughts.

Andrew

Bruce – off topic – but thinking about converting to ball screws for manual operation – you may find that the handles turn the wrong way; computers don't care if they are left handed or right handed feed screws, but we get used to doing things one way.

My Unimat CNC was supposed to be a manual lathe for demonstration purposes, but the feed screws were the wrong way (only on the Unimat mark 1 version…) so it was actually very confusing, so I cnc'd it and "wrong way" handle issues solved.

Just something to think about…

I am puzzled, not difficult these days. On the 5th I added some comments to this thread saying that my MEW index had a section for bending rolls and listing 9 articles on the subject, most with detailed drawings. The entry followed that by Andrew which followed that by Robbo showing a copy of a page from MEW.

On the 6th I again looked at the thread only to find my contribution was not there, obviously, so I thought, I had not clicked on the "Add Posting" link.

I decided therefore to enter it again. However, needing to look back for the name of the OP I was surprised, and not a little worried, to see my contribution there all the while, how did I miss it. I therefore did not post my second attempt.

This evening, the 7th, I again found the entry was missing but on logging on it was there to be seen. I logged on and off a number of times still with the same result. When my entry is there it even then finds the number of contributions too long for a single page and starts a 2nd.

I decided as a result to view another thread I had contributed to, being "screw cutting on warco 220" again with the same result.

The system knows I have added to this thread as it sends me Emails detailing the additions that are being made to it.

Could someone just make an entry saying that they are seeing my comments, for if this does not appear I will know every one is missing them.

Incidentally, this is a copy of my original post.

If you visit my MEW index and click on Bending Rolls you will find there are 9 articles listed. I have not looked at them but from memory the one by David Fenner I think is close to what you are looking for.

Harold