I've decided to try and build a power ring roller.

[zora]

Some background:

a few years ago I was doing wire sculpture and had to wrap copper wire around a pipe to get rings for my sculptures. After a few hundred rings it got really old so I decided to try and make a small ring roller. After a few attempts I came up with this:

http://www.youtube.com/watch?v=DIxY49m2llo

and it works really well. It rolls 3/32 mig wire (looks like copper wire, but cheaper and stiffer) and I've rolled literally miles of wire with it and haven't had any problems.

The next logical step was to make it bigger, so I bought a HF ring roller and threw a gearmotor on it.

http://imgur.com/GgVi5l.jpg

I posted it in projects (http://weldingweb.com/showthread.php?t=43057) a couple of months ago. And it has worked reasonably well. I've probably run a couple thousand feet of 1/4 CRR through it without much problem. Currently am working on some railings that involve a lot of rings:

http://imgur.com/4RXbL.jpg

And a good friend of mine fell in love with them and wants some, but he wants 3/8 rod (or better) for his.

So here I am. I need an even bigger roller.

I've sketched out my basic plan
http://imgur.com/uxG3p.jpg

I am planning on running it with a 2hp motor (https://www.surpluscenter.com/item.asp?item=10-2381&catname=electric) with a 60:1 gearbox (https://www.surpluscenter.com/item.asp?item=13-325-60-R-56C&catname=powerTrans) with a 50 pitch chain (https://www.surpluscenter.com/item.asp?item=1-1163-50&catname=powerTrans) driving the 2 lower rollers. I'll probably pick the gears so that the final speed is somewhere around 40rpm.
I was thinking that I would use 1 3/8 keyed shafting (https://www.surpluscenter.com/item.asp?item=1-2982-137-3&catname=) and 4bolt bearings (https://www.surpluscenter.com/item.asp?item=1-207-22-4-C&catname=powerTrans) all held together with some 1/2 in plate. To adjust the ring size I thought that some 1 1/4 allthread (https://www.surpluscenter.com/item.asp?item=1-2983-125-3&catname=powerTrans).

I really need it to roll 1/4 round to atleast a 4" ring so I figure that I'll have to move the 2 fixed rollers closer together so that the distance between them is < 4in. And I figure that the vertical travel of the other roller shouldn't have to travel more than 2in down.

Eventually I'll draw the whole thing up in sketchup and have someone turn me the dies and cnc cut the plate. Then I guess it is just a matter of building it.

Some questions I have.
How big of rod do you think it will roll? those are the biggest components I can afford, when they get bigger than that the price really starts to skyrocket. I'm not an engineer (not even close) but in my mind I think that it might roll 1/2" but would be really excited if it could handle something bigger than that.

Is there an optimal size for the dies? I don't have the foggiest idea of how thick/big they should be. Or what they should be made out of. Probably case hardened at the very least.

Is 1/2" plate thick enough? I could gusset it too I suppose.

What should I expect to pay to have someone turn me a set of dies? (I was thinking 3 sets, 1/4, 3/8, and 1/2) 6 rollers total keyed with a setscrew. and to cut the plate?

Anyone know of a good shop in Denver that might help me. I went out a while ago to try and find someone to turn me a bushing and got laughed out of every shop I went into. Seems like noone likes small jobs. I was thinking of rfqwork.com as well.

I hope this all makes sense. I've never really built anything like this before and I'd like to do it right. Am I on the right track? I appreciate any input.

Bryon

edit: sorry for the formatting, inline images are not working nor are the links (they are there, but they don't show up unless you run your mouse across them

[MarkBall2]

I have one of the HF tubing rollers that will roll up to 1.5" round tubing. I'm at the beginning of a entry gate project that requires 1.5" square tubing rolled into an arch for the top of the gate. I have to make the dies for the square tubing.

1/2" plate would be way overkill for up to 3/8" round rod. That stuff bends pretty easy. Now if it were 2" round rod, I would say you would need 1/2" plate, but for stuff under an inch, 1/4" plate should be heavy enough.

The die's shown are for 1/2" square tubing.

[Raul]

that's really nice.

[zora]

1/2" plate would be way overkill for up to 3/8" round rod. That stuff bends pretty easy. Now if it were 2" round rod, I would say you would need 1/2" plate, but for stuff under an inch, 1/4" plate should be heavy enough.


Easy is relative, rolling 3/8 rod into 36" circles would be easy, but if I wanted to roll it into 5" rings in one pass it would be anything but. I tried rolling 3/8 with my little roller and I had to practically stand on it to get a 20" ring. I thought for sure that something was gonna snap.

I am going to get a HF roller like the one you have though, I have a gate to build too.

[William McCormick Jr]

When I roll heavy stuff, into tight radius circles. I attach the object I am bending to something circular and then just turn the round shaft. For a single circle with a really tight bend I will even weld the part to be rolled, to the round shaft or pipe I am using. I usually only get a few pieces rolled from one shaft or pipe before it is deformed.

But you may be able to create a shaft maybe 4.24 to 4.5 inches in diameter, that you just stick the end of the rod into, a starting tab. And then just turn the shaft, that does not take an amazing amount of energy to do. Much less then three rollers use in energy. Because you are just continuously breaking the rod over the tangent of the shaft. You could probably put a large captains wheel on it and just spin away.

Basically more of a pipe bender design or function.



Sincerely,


William McCormick

[zora]

But you may be able to create a shaft maybe 4.24 to 4.5 inches in diameter, that you just stick the end of the rod into, a starting tab. And then just turn the shaft, that does not take an amazing amount of energy to do. Much less then three rollers use in energy. Because you are just continuously breaking the rod over the tangent of the shaft. You could probably put a large captains wheel on it and just spin away.



that is a great idea, but i really need something adjustable, I am looking at rolling hundreds of rings from a 4" radius to maybe a 30" radius. I guess I need something like this http://www.bii1.com/images/roll%20benders/rm10-large.jpg but not quite so big.

[forhire]

I think your design is on the right track. Have you been able to source any dies? Do you think simply turning something out of 4130 would work or would they need to be heat treated?

Take a look at this ring roller. He's rolling 1/2 rebar with a 30:1 gear box. This might give you some ideas for your build:
http://bbs.homeshopmachinist.net/showthread.php?t=20335

I foresee a lathe in your lathe in your future :)

[zora]

Take a look at this ring roller. He's rolling 1/2 rebar with a 30:1 gear box. This might give you some ideas for your build:
http://bbs.homeshopmachinist.net/showthread.php?t=20335


That's exactly what I want to build! I was gonna ask him a couple of questions so I looked him up on that board but last post was back in 2007. (I hope he is OK)

Anyways he built his out of 3/4 plate, so I'll probably do the same. I was wondering if there was some advantage of having his pressure wheel swing along a radius. I was just gonna have mine travel vertically.

I've spent some time thinking on the optimal die size. I guess that having a bigger die allows for better traction when driving a rod through, but limits the size of the ring you can roll. I'm guessing that maybe a 3.5" die would be about right. It looks like his are aound that size, (maybe a little bit bigger) but he can roll a 4.5" ring with those so I should be OK.


I think your design is on the right track. Have you been able to source any dies? Do you think simply turning something out of 4130 would work or would they need to be heat treated?

I have not found a source for my dies yet, (I have not really looked either) Ideally I would like to find a small shop here in town that doesn't mind me asking a few questions, or would let me watch, I'd like to learn something too. But short of that, I guess I might post a message on rfqwork.com .

I don't have the foggiest idea what to make them out of. I know absolutely nothing about metallurgy (other than cutting up cheap chinese bedframes on your nice milwaukee dry cut saw will dull the blade lickety split) But I'm open to suggestions, and hope someone here knows.


I foresee a lathe in your lathe in your future


I think the exact same thing when I have my drill in the vice trying to turn something down with an angle grinder. As cool as a lathe would be, my next big purchase will probably be a nice box and pan brake.

[Boostinjdm]

Anyways he built his out of 3/4 plate, so I'll probably do the same. I was wondering if there was some advantage of having his pressure wheel swing along a radius. I was just gonna have mine travel vertically.



It's easier to keep the adjustable shaft parallel to the other two. Another member tried building a roller awhile back and had trouble with shaft deflection because of the way he had built it.

http://weldingweb.com/showthread.php?t=34308&highlight=roller ****! that was a year ago.

The bearings he used aren't really cheap either. If you go with the swinging set up, you could get away with DOM and grease zirks. Wouldn't have to buy a single bearing.

[forhire]

That's exactly what I want to build! I was gonna ask him a couple of questions so I looked him up on that board but last post was back in 2007. (I hope he is OK)

Here's his photo bucket with a couple more photos:
http://smg.photobucket.com/albums/0903/kcprecision/?start=20


Anyways he built his out of 3/4 plate, so I'll probably do the same. I was wondering if there was some advantage of having his pressure wheel swing along a radius. I was just gonna have mine travel vertically.


I was wondering the same thing. It's possible the adjustment screw has a mechanical advantage in the arced arrangement. I think it would be easier to build straight down. The commercial units are straight down.



I've spent some time thinking on the optimal die size. I guess that having a bigger die allows for better traction when driving a rod through, but limits the size of the ring you can roll. I'm guessing that maybe a 3.5" die would be about right. It looks like his are aound that size, (maybe a little bit bigger) but he can roll a 4.5" ring with those so I should be OK.


From the description I'd guess his are 4.5" in diameter. 3.5" diameter should work but it may require some muscle with heavier round bar. What diameter bar will you be doing? The dies should match the radius of the bar so you may need a few sets or cut multiple grooves in the die.



I have not found a source for my dies yet, (I have not really looked either) Ideally I would like to find a small shop here in town that doesn't mind me asking a few questions, or would let me watch, I'd like to learn something too. But short of that, I guess I might post a message on rfqwork.com .


Working on the drawings. I'll post something later.

[forhire]

This is a render of a 3" roller with the shaft assembly. The die is 2" thick with three grooves, 1/4, 3/8, 1/2. This may be too greedy for one die. 4130 is common in a 3" and a 4" diameter so there is some wiggle room. The shaft needs to be bored and cross drilled for the grease channel. It will also need key ways cut on both ends. It will need to be tapped for the die end.

I guessed at the sprocket. I'd need to do some math to decide on a tooth count.

Enjoy :)

[zora]

It's easier to keep the adjustable shaft parallel to the other two. Another member tried building a roller awhile back and had trouble with shaft deflection because of the way he had built it.

http://weldingweb.com/showthread.php?t=34308&highlight=roller ****! that was a year ago.

First, I'd like to thank you for the tears and headache you just saved me. I had the exact same idea that other guy had. I guess it is one of those things that seems to work great inside your head, but not so well in practice.


The bearings he used aren't really cheap either. If you go with the swinging set up, you could get away with DOM and grease zirks. Wouldn't have to buy a single bearing.

Swinging arm, DOM, and zerks it is. Just one quick question: Can you run keyed shafting through DOM, or would the keyway tear it up. Or do I have to run smooth shafting with keyways cut at the ends?

Thanks

Bryon

[forhire]

Swinging arm, DOM, and zerks it is. Just one quick question: Can you run keyed shafting through DOM, or would the keyway tear it up. Or do I have to run smooth shafting with keyways cut at the ends?


I don't see exactly how the swinging arm works? He has an arc cut into the front plate but not the back plate (that I can see). I'm missing something. Can someone explain that?

In the kcprecision photo bucket he has another roller with adjusters front and back.

I wouldn't run the keyway through your DOM or bronze bushing.

[zora]

. What diameter bar will you be doing? The dies should match the radius of the bar so you may need a few sets or cut multiple grooves in the die.


I have this stash of 3/8 rod I found on craigslist (pic 1) and the artist in me wants to do something really cool with it. But I'd like to be able to roll about any size rod.

I like the 3in1 die idea, but I don't think that it will work. I need the groove to be as close to the outside as you can get so when I roll continuous circles they don't get caught back in the dies when they come around.

Working on the drawings. I'll post something later.

You have no idea how jealous I am of your graphics prowess. For entertainment purposes only I give you a couple hours of my work in sketchup before I quit in frustration and whipped out the graph paper. It's such a steep learning curve and I really need to find the time to learn it.

[forhire]

I don't see exactly how the swinging arm works? He has an arc cut into the front plate but not the back plate (that I can see). I'm missing something. Can someone explain that?

Ah... I see it now. I had to read the description about 5 times. Man I'm slow. :rolleyes:

"The pressure wheel swings from a 1/2 bar located here at the top corner of the side plates."

I'm casting my vote for the swinging arm also.

[forhire]

I like the 3in1 die idea, but I don't think that it will work. I need the groove to be as close to the outside as you can get so when I roll continuous circles they don't get caught back in the dies when they come around.


What about reversible dies? This one is 0.5 and 0.375. Might need to increase the shaft from size but it should work.


You have no idea how jealous I am of your graphics prowess. For entertainment purposes only I give you a couple hours of my work in sketchup before I quit in frustration and whipped out the graph paper. It's such a steep learning curve and I really need to find the time to learn it.


I've heard good things about sketchup. I use Alibre design. I bought it about 3 years ago... it collected dust for a year. About the time me service contract was due I decided I better learn the thing. The learning curve was long and painful. I now use it all the time. It helps me visualize the concept entirely... something napkins never forced me to do. I've also learned that it cuts my prototyping time and cost. I make a lot fewer test parts.

Here is the pinned double die. The shaft has a pin through it and the die has a slot milled into each face. I'd likely rotate the slots 90 degrees out from each other... I got lazy with the drawing.

[Boostinjdm]

I don't see exactly how the swinging arm works?

I'm not going so much off that guys actual roller, more off of the concept. Think of it like the swing arm of an ATV. Instead of tires, you would have the die on one end and the sprocket on the other. Both sides move together as long as that arm is stiff enough to resist twisting.

In the thread that I linked to both sides of the shaft had to be supported because there wasn't anything to resist the twist. To me, the swing arm is a simple, cheap, and effective cure for that problem.


EDIT.....Didn't read all the posts. I see you got it now.

[zora]

What about reversible dies? ...

Here is the pinned double die.

brilliant!!

You guys here are amazing. I've got lots to think about. I'll keep you updated as I make progress.

Thank You.

Bryon

[forhire]

Zora, I was going to send this mock up as a PM but decided to post it for everyone to comment. All three rollers are 3.5". Spacing of the bottom rollers are 6". I suspect that a 2.5" upper roller might be better suited for the tight diameters you want. Kick it around and I'll re-model it once the dust settles. :D

The body is 12"x12"x4" plate. The holes are for the driven rollers... I think they need to be at a 45 degree angle... still thinking...

[zora]

I hope you didn't mean 4" plate :) I think that a 2.5" upper roller would roll rings that are plenty tight.

No swinging arm? I am still wondering how the commercial rollers (http://www.eaglebendingmachines.com/neweagle08/index.html)work in that configuration without the deflection problems.

[forhire]

I hope you didn't mean 4" plate :) I think that a 2.5" upper roller would roll rings that are plenty tight.

No swinging arm? I am still wondering how the commercial rollers (http://www.eaglebendingmachines.com/neweagle08/index.html)work in that configuration without the deflection problems.

I drew it as 4" plate. I'll adjust it based on what I have in the scrap pile. It's a fairly small piece. I might be able to get by with 2" or even less.

The swinging arm really causes me grief when I model the various roll diameters. There is always one roller that is slightly more distant. I think there is a reason the commercial rollers use even spacing.

Commercial rollers use a large block that keep the upper roller square (see image below). The roller previously discussed had a number of issues that when combined caused the deflection, notably, self aligning bearings being the biggest problem. An under sized frame and poor screw placement didn't help.

This is a roller built from stock 15mm (~5/8) plate. Note the block and screw placement.
http://www.mig-welding.co.uk/forum/showthread.php?t=4966&highlight=ring+roller

I've attached the center roller block. The body will be faced to accept this H section.

[forhire]

Here's is a render that may give you a better idea. :cool:

[zora]

duplicate

[zora]

Here's is a render that may give you a better idea. :cool:

Wow! I'm speechless. Simplicity is king.

My original idea probably had a hundred or so parts (bearings, nuts, bolts, spacers, plates, etc...) and you've managed to distill it down to about a dozen.

It reminds me of that adage that says "perfection is achieved not when you can add nothing more but when you can take nothing away."

[Boostinjdm]

Wow! I'm speechless. Simplicity is king.

My original idea probably had a hundred or so parts (bearings, nuts, bolts, spacers, plates, etc...) and you've managed to distill it down to about a dozen.

It reminds me of that adage that says "perfection is achieved not when you can add nothing more but when you can take nothing away."

Yes, but......half of those dozen parts are massive chunks of steel that most people don't have access to.

[zora]

Yes, but......half of those dozen parts are massive chunks of steel that most people don't have access to.

Yeah, I was curious and a piece of plate that size is about 160#. Doesn't really look like it in the picture

but the design is suited to mass production. Machine one 12x24 plate then cut it in half and voila! maybe sell the other half.. wink... wink... :)

[zora]

What do you suppose the minimum thickness for the plate might be. I have this piece of plate that about 30x40x1.5 machined flat and square with 1/2 in grooves down each side. If I torched it up and rearranged and welded it right I could conceivably build the whole chassis without a mill. If 1.5in is too thin, I suppose I could double it up to 3".

A good idea, or am I just inviting failure?

[forhire]

What do you suppose the minimum thickness for the plate might be. I have this piece of plate that about 30x40x1.5 machined flat and square with 1/2 in grooves down each side. If I torched it up and rearranged and welded it right I could conceivably build the whole chassis without a mill. If 1.5in is too thin, I suppose I could double it up to 3".

A good idea, or am I just inviting failure?

Did you look at the roller from the guy in the UK? His machine is only 5/8" plate. I suspect the design could be modified to use the 1.5 plate. Remember I designed the spindles and then created the platform to test spacing. For fun I finished the basic design. Still haven't done the driven output rollers.

Another option would be turn some spindle tubes and use thinner plate front and back. DOM pipe could be used. Any idea the number of pounds the rollers are subjected to?

[1-800miner]

That is a rendering? It looks so real that I want to reach out and touch it!

[forhire]

The driven rollers added a new level of complexity. This is a quick mock up. Any thoughts? What is the ideal angle and distance for the driven rollers? They are at 25 degrees as drawn. These are in the retracted position.

[zora]

You'll have to forgive me, but I don't see how the drive mechanism works. Are you driving all 3 wheels Could you rotate your model so I can see the back.

[tapwelder]

where the previous post? Says today at 3:30am by Zora. ...or said...

[forhire]

where the previous post? Says today at 3:30am by Zora. ...or said...

The threading doesn't appear right on this thread. I can view all the posts if I switch my "Display Mode" to hybrid.

[forhire]

You'll have to forgive me, but I don't see how the drive mechanism works. Are you driving all 3 wheels Could you rotate your model so I can see the back.

I was planning to drive the two lower wheels. The model shows the upper as having a sprocket because I recycled the shafts and didn't remove it. It may be possible to drive all three. Not sure how to do it (haven't really thought about it). I haven't modeled the chain and such because the sprockets may not be right... I grabbed a stock size and threw it on :eek:

[zora]

that's what I thought. So what are those "struts" along the sides, and why the angle. they look like brackets for some sort of guide? I've seen them on the commercial machines, but I'm at a loss as to what they actually do.

B

[forhire]

that's what I thought. So what are those "struts" along the sides, and why the angle. they look like brackets for some sort of guide? I've seen them on the commercial machines, but I'm at a loss as to what they actually do.


What you call struts are called driven rollers. They are used to create spirals. They force the pipe in the Z axis. Imagine the machine laid on it's back, the arc or hoop is on the X/Y axis. By forcing the out feed up (Z+) you create a spiral shape. They are not needed if all your doing are flat circles.

[zora]

Ok, I've finally gotten around to cut my plate. I kinda made a mess of it, but nothing a few hours with a grinder can't fix:( . The important edges are already done though:drinkup:

Does anyone know if 1.5" will be enough support for the dies or should I cut another set and double the thickness. Also I would I need bushings/bearings for the spindles, or just drill holes with zerks?

[forhire]

Ok, I've finally gotten around to cut my plate. I kinda made a mess of it, but nothing a few hours with a grinder can't fix:( . The important edges are already done though:drinkup:

Does anyone know if 1.5" will be enough support for the dies or should I cut another set and double the thickness. Also I would I need bushings/bearings for the spindles, or just drill holes with zerks?

Looks great. I've been thinking about the 1.5" since you first mentioned it. I think it should work fine. One of the home made units was only 5/8".

I'd use bushings as they are likely cheaper and easier replace. The RPM is low. Bearings are an option but may add more cost. Are you using a 1" or 1.125" shaft? Any guesses as to the pressures involved? Bronze bushings P Max is about 4000. Shaft diameter plays into this like: PSI = P max × bearing length × shaft diameter.

I've attached a sample center piece.

[zora]

Looks great. I've been thinking about the 1.5" since you first mentioned it. I think it should work fine. One of the home made units was only 5/8".

I'd use bushings as they are likely cheaper and easier replace. The RPM is low. Bearings are an option but may add more cost. Are you using a 1" or 1.125" shaft? Any guesses as to the pressures involved? Bronze bushings P Max is about 4000. Shaft diameter plays into this like: PSI = P max × bearing length × shaft diameter.

I've attached a sample center piece.

I been trying to find the one built out of 5/8 plate but can't seem to find it. there is this one (http://www.ratrodbikes.com/forum/viewtopic.php?f=1&t=13307&st=0&sk=t&sd=a&start=0#p134304) and this one (http://bbs.homeshopmachinist.net/showthread.php?t=20335) but is there another that I'm missing?

Anyways I think 1.5" will be fine. If not, well, like everything else I build, I'll have to do it twice ;)

I send an email to the people at eagle bending (http://www.eaglebendingmachines.com/neweagle08/tooling08RAY33.html) to see what kind of "stock" dies they carry and work backwards to a shaft.

I think that I found a machinist here in town. He doesn't mind small jobs and is gonna mill/drill the holes for $55 so if that works out, I might have to hire him to turn me some spindles. Anyways I'll keep you posted.

[forhire]

I been trying to find the one built out of 5/8 plate but can't seem to find it. there is this one (http://www.ratrodbikes.com/forum/viewtopic.php?f=1&t=13307&st=0&sk=t&sd=a&start=0#p134304) and this one (http://bbs.homeshopmachinist.net/showthread.php?t=20335) but is there another that I'm missing?

Anyways I think 1.5" will be fine. If not, well, like everything else I build, I'll have to do it twice ;)

I send an email to the people at eagle bending (http://www.eaglebendingmachines.com/neweagle08/tooling08RAY33.html) to see what kind of "stock" dies they carry and work backwards to a shaft.

I think that I found a machinist here in town. He doesn't mind small jobs and is gonna mill/drill the holes for $55 so if that works out, I might have to hire him to turn me some spindles. Anyways I'll keep you posted.

I posted this while the site was broken, it's a link to one made from 5/8" plate:
http://www.mig-welding.co.uk/forum/showthread.php?t=4966&highlight=ring+roller

I'm thinking 1.25 shafts using 1.5" bushings... If I did my math right each shaft should carry about 7500 lbs at zero rpms. A 1 inch shaft will do 6000 lbs. There are some bronzes that have a P Max in the 4500-6000 range also but the 4000 range is inexpensive.

If the load is divided equally across all three shafts then 1.25" could do 11 tons and 1" could do 9 tons. This is the loading capacity of the bushing not the shafts.

As reference, I have a big greenlee bender for up to 2.5" rigid. The shoes are cast aluminum and they ride on a 1.25" shaft... no bushings, aluminum to steel. No idea what kind of forces are at work.

Might be able to get by with 1" shafts.

[forhire]

Might be able to get by with 1" shafts.
Use some bushings like these for 1" shaft. They are 3/4" long, flanged. One front, one back and the flange provides a thrust surface. Need 6 total. $6.44 each. This gets you into 10 ton on the smaller shafts. http://www.mcmaster.com/#bronze-sleeve-bearings/=96jd6d

[fredschrom]

Sorry to dig up this old thread but it was this or start a new one.

Did the geometry on the triangle of these rollers get figured out. I am aware the top is variable, but for giggles lets say nomilly 5 to 5 1/2 inches. Two bottom drive rollers at 3 1/2 to 4.

So I know this is going to have to do with how tight a radius I want to bend, how far apart do the two bottom rollers need to be apart? Then how far does ( + / - centerline of bottom drive rollers ) does the top wheel need to come down.

Last question is about the 25 degree driven rollers ( ? ). Do they need to adjust in out from the face of the machine? I see them in the drawing, and I see them on commercial machines but no detail pics isn't helping much.

I tried to find a manual on one of the commercial machines on line to sort that out, but didn't have any luck.

It wasn't on this post there was another old post where the top roller was twisting don't know if it was ever sorted out. After looking at that closely I am not building mine that way....but 4 ea "T" bolts like on a mill table, 8 bars running vertically with standoffs behind so the "t" has clearance with a matching hole for the end of the rod to fit through. Bummer is the back bolts are going to be a little hard to set, but adjusting the threaded center bolt and locking down the " T " bolts will stop the twist and save remaking that whole center assembly and cradle.

[fredschrom]

" Last question is about the 25 degree driven rollers ( ? ). Do they need to adjust in out from the face of the machine? I see them in the drawing, and I see them on commercial machines but no detail pics isn't helping much. "

I found the detail on this...acme screw thread, pushing the rollers out.

[forhire]

Did the geometry on the triangle of these rollers get figured out. I am aware the top is variable, but for giggles lets say nomilly 5 to 5 1/2 inches. Two bottom drive rollers at 3 1/2 to 4.

So I know this is going to have to do with how tight a radius I want to bend, how far apart do the two bottom rollers need to be apart? Then how far does ( + / - centerline of bottom drive rollers ) does the top wheel need to come down.

They are 7" on center. Remember that you can change the rollers. I don't recall if I used an industry standard or made something up. I looked a A LOT of commercial machines while designing this.

Last question is about the 25 degree driven rollers ( ? ). Do they need to adjust in out from the face of the machine? I see them in the drawing, and I see them on commercial machines but no detail pics isn't helping much.

The driven rollers are used for rolling spirals like railings and large springs :laugh: I planned on adjusting the depth using a bolt or something but really never working it out.

It wasn't on this post there was another old post where the top roller was twisting don't know if it was ever sorted out. After looking at that closely I am not building mine that way....but 4 ea "T" bolts like on a mill table, 8 bars running vertically with standoffs behind so the "t" has clearance with a matching hole for the end of the rod to fit through. Bummer is the back bolts are going to be a little hard to set, but adjusting the threaded center bolt and locking down the " T " bolts will stop the twist and save remaking that whole center assembly and cradle.

There are a lot of ways to address the flex issue. I was planning on making some patterns and having the foundry cast mine from cast iron. This part is big as designed. In the end I may opt to make it like a sandwich, 1/2" plate, 2" plate, 1/2" plate. Your method sounds do able also.

" Last question is about the 25 degree driven rollers ( ? ). Do they need to adjust in out from the face of the machine? I see them in the drawing, and I see them on commercial machines but no detail pics isn't helping much. "

The driven rollers adjust out. They put pressure on the rolled part to make it a spiral.

[fredschrom]

" In the end I may opt to make it like a sandwich, 1/2" plate, 2" plate, 1/2" plate. Your method sounds do able also."

Actually I am working on a modified sandwich design myself. I saw a comment earlier on in the thread about your design using too big of steel and I think it was wrong. I have been looking at commercial units also, in short they are big heavy and massive, or they are little and no capacity.

What I have going so far is using 1 1/2 x 8 inch bar stock. 2 ea. standing vertical on a 1 1/2 x 8 x 22 horizontal bottom. I am looking for 5-6 inches in thickness as width is what partially keeps that top block from torsionally twisting.

Oh concerning that block I looked at your concepts, which are fine in concept bad in execution. Make your block a sandwich also with two over large pieces on the outside, it will save you having to mill that groove down each side. Using the 6 inch number from above 3 ea 2" blocks about 6" tall. 2 inch hole in the center and two pieces of drill rod through all three blocks, then cover with the bread so to speak in 1/2. I am going that way as big beefy cuts on my mill are bad, and need to be done in a lot of smaller passes.

What did you have planned for shafts? I was thinking 2" drill rod.

I got a good set of pictures of a ercolina and those driven rollers are definately acme screw
to adjust them in and out. My plan is to make the mounting to put 1-1 1/8 acme screws later if I need them but leave it out just do the mounts for the time deing.

Last question is what are you thinking for driving this? This is one of those more than on way to skin the cat scenarios, I was thinking a 1 1/2 hp motor into a 60 to 1 reduction box, driving a chain with a 4 - 5 reduction. Hydraulic would work also but I didn't fiddle with that. A cheap route might be a truck starter or a winch motor ( DC doesn't excite me though )

[forhire]

What did you have planned for shafts? I was thinking 2" drill rod.

I might be wrong but drill rod may be too brittle. I was thinking 4140 shafting. Of course I'll likely use what I have laying around. :laugh:

Last question is what are you thinking for driving this? This is one of those more than on way to skin the cat scenarios, I was thinking a 1 1/2 hp motor into a 60 to 1 reduction box, driving a chain with a 4 - 5 reduction. Hydraulic would work also but I didn't fiddle with that. A cheap route might be a truck starter or a winch motor ( DC doesn't excite me though )

I have a hydraulic unit that I plan to use (if I ever get around to it). Gear drive would work also.