Roll bender build. Update pics post 28

[jackalope]

Lookin' good!

Keep the pics comin' !!

[Nutz4sand]

For those who were talking about the driving three rollers take a look at this.

I got bigger pics of it but I cannot upload them.

I think hes still got it for sale too! But hes only got 1.25 inch dies for it.

http://www.minibuggy.net/forum/sale/...nder-sale.html

[jackalope]

Originally Posted by Nutz4sand

For those who were talking about the driving three rollers take a look at this.

I got bigger pics of it but I cannot upload them.

I think hes still got it for sale too! But hes only got 1.25 inch dies for it.

http://www.minibuggy.net/forum/sale/...nder-sale.html

I emailed him and could use this some other crap until mine is finished.

Grant

[TitanFab]

My roll bender (used for ornamental flats right now, I need to rebuild it) the motor drives all three rolls. with chain and tensioner. Powered down feed with hyd (do not like that part.)If your would like pics I could get some for reference.

[rdn2blazer]

Originally Posted by TitanFab

My roll bender (used for ornamental flats right now, I need to rebuild it) the motor drives all three rolls. with chain and tensioner. Powered down feed with hyd (do not like that part.)If your would like pics I could get some for reference.

Absolutely, if you could that would be awesome, thanks.

[rdn2blazer]

Couple of update pics. I'm having a machine shop turn the 1 1/2" Acme shaft for the jack screw for the pressure roller for me. The lathes I have access to don't have a big enough thru bore on the spindle . So I had to have a shop turn a 1-14 fine thread on one end, and a 1 1/4 hex on the other end for me. After that is finished and I get it back I can finish the pressure roller saddle assembly and it for the most done. Here it is basically put together. Still need to get motor, sprockets & chain and either build a frame or mount it to an existing bench. There is some detail machining I want to do but it's not actually necessary for funtion. Will just make it look trick. Still want to anodize it too.


Finally finished polishing the 1 1/2 stainless steel shafts. That was alot of work but well work doing it. Was going to buy shafts but since I had access to 1 1/2 SS why not. They will never rust. The shafts measured 1.5015 to 1.502. I used a 2 1/2" wide 180 grit belt from a Burr King belt sander, turned it inside out and put an aluminum bar in it to pull on and sand the shaft. Basically lap it down to 1.498 plus minus .0002. When I got down to .001 left I used finer and finer sand paper to lap it to almost a mirror finish. It's plenty smooth enough. It took about 6 hours of lapping to complete each shaft. My hands were sore from that big time. Held about .0004 total diameter variation end to end. Fits in the bearing blocks and rollers perfectly.

The shafts are a little longer then I needed so I had something to chuck on to, will cut to length and chamfer once I have the sprockets and mock that all up. You can see the teeth on the collar is what will drive the front outer rollers. Not a keyway piece of key stock. Don't have access to Broaching and didn't want the keyway cut thru the roller since their Delrin plastic to cause a weak crack point in the rollers. The 1/2 slots for the coller are into the meat, or thickest part of the rollers, and only 3/4 deep. Got all the bearing block bolts cut to length too.

[CAPTAIN CNC]

Somebody has been busy. Looks awesome!!!

[rdn2blazer]

Thanks Captain! I am dying to get this damn thing finished up and give it a whirl. My woman has been bitching at me for weeks to get it off the table and out of the house. I think it's a fine work of art to look at of course, looks good on the table .

[CAPTAIN CNC]

Hell ya! Put it on one of them lazy susan thingies so you can rotate it about and revel in its glory whilst you're eating dinner.Mmmm... SHE may not like that though.

[rdn2blazer]

Originally Posted by CAPTAIN CNC

Hell ya! Put it on one of them lazy susan thingies so you can rotate it about and revel in its glory whilst you're eating dinner.Mmmm... SHE may not like that though.

THAT is actually a brilliant idea! lol!

[patooyee]

Cool build. I think you're really going to regret not using a bottle jack for the top roller instead of the acme screw though. I converted my HF roller over to a bottle jack and it is like butter now! I would never want to go back. I am anxious to see how your plastic rollers work out as I intend to build my own roller eventually also and the dies are the biggest area of concern re cost.

J. J.

[rdn2blazer]

Originally Posted by patooyee

Cool build. I think you're really going to regret not using a bottle jack for the top roller instead of the acme screw though. I converted my HF roller over to a bottle jack and it is like butter now! I would never want to go back. I am anxious to see how your plastic rollers work out as I intend to build my own roller eventually also and the dies are the biggest area of concern re cost.

J. J.

I'll give this a shot first. If it's a PITA then I can always machine up a new top plate for a bottle jack setup. Time will tell for sure. Do you know what pitch your HF threaded rod was? With this pitch of Acme rod I will get .200 on lenier movement on a full turn. Not sure yet how much force should be put on the tube yet of course. But I feel I have alot of leverage with this pitch of Acme rod.

[patooyee]

No, I don't, sorry. All I know is that is stripped out after not much use and I was forced to fix it or go hydraulic. If I had to guess it was probably about what yours is.

The hydraulic is MUCH easier and as nice as your setup is it is a shame to not have it. If you do decide to do it though your new top plate will have to bolt to some add-on side plates which will then bolt to your existing side plates as the jack will be too tall to fit in your current structure. That or you will have to use a ram with a threaded body like one that would go in a tube bender.

I can measure the pitch of that HF rod for you next week when I go to the shop if you want. I know nothing about ACME pitches though, are the threads per inch like a normal screw?

The jack I used is a simple 8-ton unit that I also got from HF for $25 and it is more than enough to do the .120 wall tubing that I do. It could probably do .25 but my shafts would bend. (They are only 20mm.) The 8-ton is the largest one that would fit between the plates in my setup. Yours could probably easily fit a 12 or 20-ton.

J. J.

[rdn2blazer]

Originally Posted by patooyee

No, I don't, sorry. All I know is that is stripped out after not much use and I was forced to fix it or go hydraulic. If I had to guess it was probably about what yours is.

The hydraulic is MUCH easier and as nice as your setup is it is a shame to not have it. If you do decide to do it though your new top plate will have to bolt to some add-on side plates which will then bolt to your existing side plates as the jack will be too tall to fit in your current structure. That or you will have to use a ram with a threaded body like one that would go in a tube bender.

I can measure the pitch of that HF rod for you next week when I go to the shop if you want. I know nothing about ACME pitches though, are the threads per inch like a normal screw?

The jack I used is a simple 8-ton unit that I also got from HF for $25 and it is more than enough to do the .120 wall tubing that I do. It could probably do .25 but my shafts would bend. (They are only 20mm.) The 8-ton is the largest one that would fit between the plates in my setup. Yours could probably easily fit a 12 or 20-ton.

J. J.

I doubt the HF threaded rod is near the quality of US Acme rod I bought. It's precision Acme rod, not general purpose rod, with a beautiful machined finish on every surface. Radiused edges on the threads at the root and thread corners and it's smooth a butter. Here are some specs on the rod I bought.
1 1/2 - 5 rod has 36,000lbs static load and 11,300lbs operation load. Was the HF rod Acme thread or standard "V" threads? "V" threads don't take the same load Acme will. "V" thread is for clamping, not actuation, radial to linier motion, under no load to it's working range of recommended load. My Bronze nut it whats ment to wear, not the threaded rod. Nut replaces easily, although their not cheap.

Yeah, I figure I will have to add taller mounting plates if I go Hydraulic. Actually half way thru the build when I thought about going hydro I though about making new plates. I had already had these machined though and did not want to start all over. I could make new plates as I have access to lots more material. Conventionally on our Bridgeport my plates were about maxed out unless I moved the plate over and picked up the cut. Don't really want to deal with that either. Makes it alot tought to do the job having to cut something half way, stop, move it, re-indicate it in and finish cutting it.

[patooyee]

Actually, it wasn't the screw that stripped out, it was the threaded bore in the top plate. And yes, the steel quality is terrible. That's not why I wa saying you'de regret it though. Just turning that screw by hand sucks compared to a jack. You can't get nearly as much bend out of a single stroke simply because you dont' have humanly strength to do so. And I was using a 24" cheater bar.

Believe me, on a roller hat nice, once you try hydro, you'll have wished you had done it. But its easy enough to retro fit so don't think I'm raggin on ya. Fawseom build. I like it and really want to know how those dies hold up for my own reference.

J. J.

[jten]

I have a similar design for a roll bender and had 1/4" plate water cut and have already assempled everything. My immediate issues, its all manual and would take forever to get the desired radius. What motor/gearmotor is anyone using to power the bottom rollers on a chain? There are too many to choose from at Grainger or McMaster carr and needless to say im not for spending the money on something that wont work for this project.

Sorry, not meaning to hijack the thread...

[Nutz4sand]

Due to the loads implied it would always be small but one might look at a riding garden tractors tranny (Garden tractors have stronger trannies than Lawn Mowers only but a lawn mower tranny might work) Even Lawn mowers push hundreds of pounds around and since you would likely want it geared slower anyways it would be eaisier on the tranny.

Some of the riding Lawn tractors I have seen have pretty tiny trannies but they are still stout. Some feed right out to tires so a common shaft would have to be used fed by each side then to the rollers off this shaft (no biggie) but some feed out off a little sprocket to a diff on the mowers axle and are smaller boxes that would be easy to make look nice or cover.

Plus most are belt drive on the input so even an old washing machine motor would do the work. Or a large drill. Any large variable speed reversing tool would likely do it.

Be pretty easy to make it fancier with a reversing AC motor setup if you did not want to shift the tranny back and forth. Or get a Hydrostatic tranny. Then you just move the lever back and forth.

[rdn2blazer]

Originally Posted by jten

I have a similar design for a roll bender and had 1/4" plate water cut and have already assempled everything. My immediate issues, its all manual and would take forever to get the desired radius. What motor/gearmotor is anyone using to power the bottom rollers on a chain? There are too many to choose from at Grainger or McMaster carr and needless to say im not for spending the money on something that wont work for this project.

Sorry, not meaning to hijack the thread...

I've kinda hit a slow spot on this build. Need a machine shop to turn a shaft locally and can't find one willing to do such a simple small job, freaking rediculous if ya ask me but ohwell, some one will at some point, or I will finally buy my own damn lathe and do it. The lathes I have access to don't have a large enough thru spindle.

Anyways, regarding motors and chains, I have not figured out what is necessary regarding torque and power requirements. There is a calculator I found to figure all that out but there are values I just don't know so figuring that out will just be a guestimate to a certain degree. Actually one company I called, the guy I talked to said he could help me figure that out. It was a place specializing in Geared electric motors. Thay know how to figure out final drive ratios and sprocket teeth could/desired RPM and all that crap.

Yeah, if you just look for sprockets & chain, it's overwelming the quantity available.

[patooyee]

You can get a pretty good idea if you check my roll bender thread out ...

J. J.

[rdn2blazer]

Originally Posted by patooyee

You can get a pretty good idea if you check my roll bender thread out ...

J. J.

True, I have it saved for refference, Thanks.