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Benders and Bending Which bender is best? How do you use a bender? How do you calculate bends? Everything Bender related...


Benders and Bending Which bender is best? How do you use a bender? How do you calculate bends? Everything Bender related...

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  #1  
Old 02-03-2010, 02:36 AM
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Roll bender build. Update 3/10 pics post 39 & 40

Cant update the thread title

Update 3/10 pics post 39 & 40


Well I have started my 3 roll bender build. I don't have pics yet but they will come. I have started machining my plates. I'm using 1" Aluminum. I'm basically copying this build but with a twist.

http://www.pirate4x4.com/forum/showthread.php?t=788408


I was going to do the same thing as this one in the link above with the different finger slots so the rollers can be adjustable. Die set would be in between the plates. But, I have had a major brain storming idea I think will actually be bad ass. I have seen teenycar's 3 roll bender build...

http://www.offroadfabnet.com/forums/...ead.php?t=2887

...with the rollers on the outside of the plate, and with the chain and sprocket power driven setup. I like that and want to do that too. I don't like how his was non adjustable as far as the two lower roller are fixed. I don't know if there is or is not a benifit to the dies being outside the plates other then maybe a quick realease setup.

So I have decided to make mine a duel roller, chain drive, power driven, adjustable quick change roller setup. Mine will have a set of dies inside the plates and outside the plates. It will be chain driven with an electric motor with a forward/reverse power control with variable speed. Duel dies will be a benifit for a couple of reasons. If I'm doing a cage requiring two identical spars like for a buggy style cage, having two tubes rolling at once will make for identical arcs (in theory) I believe it will work. Sure you could roll one tube then roll a second tube and make marks somewhere on the bender so you "repeat" as close as possible but that not a guarantee you will match the first tube perfectly.

Also, If I'm doing say 1 3/4 tube and thats my common tube I'm rolling most, I will leave that size die inside the plates. Then if I need to do another type of tube, square tube or flat bar or whatever, I will have the outside dies to easily change with a quick change setup. I'm going to use the same size shafts as teenycars roller, 1 1/2" keyed shafts. Using the same 1 1/2 bearing blocks too, those are ordered and on there way.

I'm going to power the two bottom rollers but the pressure roller will not be powered. As far as adjustability of the two bottom rollers, I will have two rows of drilled & tapped and Keenserted holes for a 9/16 bolts, 1" on center, so the bearing blocks can be unbolted and moved inboard or outboard by 1" incerments. Will have up to 6" of shaft center to center of adjustment.

I will have to have a chain tensioner to take up the slack as I adjust from the widest adjustment going inboard. I will probably have a couple of chains of correct size to swap as I move the roller inboard. Don't think the tensioner will have enough swing to tension all the slop of the chain as I move it inboard all the way. That is still in the design phase. I will machine a 1 1/2" slot for clearence of the shafts so they can be adjusted and moved out and in.

Where I might need help is in selecting the proper size chain and sprockets. Not sure what size I need/should use. I thinking a duel sprocket on one shaft so I will have a chain to the one shaft from the motor and a chain to the next shaft from the first shaft. OR, I could do single sprockets and have a chain go around all three sprockets. Not sure which is best for adjustability sake. Not to mention torque sake. So what say OFN regarding my fantabulous 3 roll bender idea/build????

Last edited by rdn2blazer; 03-10-2010 at 05:25 AM.
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Old 02-03-2010, 03:41 PM
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No openions???
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Old 02-03-2010, 04:49 PM
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I'm thinking about it... K?
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Old 02-03-2010, 08:43 PM
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I am going to get going back on mine. I will be sharing as it comes along. I already had the 1" thick steel plates water jetted and I bored the places for the massive bearings.

Think yours through especially the center die and how it is forced down. You need to have some serious beef and design in order to keep it from "lifting" as you put downpressure on the tube!.

Grant
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Old 02-03-2010, 09:14 PM
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So I have decided to make mine a duel roller, chain drive, power driven, adjustable quick change roller setup. Mine will have a set of dies inside the plates and outside the plates. It will be chain driven with an electric motor with a forward/reverse power control with variable speed. Duel dies will be a benifit for a couple of reasons. If I'm doing a cage requiring two identical spars like for a buggy style cage, having two tubes rolling at once will make for identical arcs (in theory) I believe it will work. Sure you could roll one tube then role a second tube and make marks somewhere on the bender so you "repeat" as close as possible but that not a guarantee you will match the first tube perfectly.


Don't forget that you will need at the minimum double the power in your motor.
Also don't be surprised if you get two different radius's but otherwise I do like the idea! Personally I would just roll one tube at a time.


I'm going to power the two bottom rollers but the pressure roller will not be powered. As far as adjustability of the two bottom rollers, I will have two rows of drilled & tapped and Keenserted holes for a 9/16 bolts, 1" on center, so the bearing blocks can be unbolted and moved inboard or outboard by 1" incerments. Will have up to 6" of shaft center to center of adjustment.

Better yet, Power all three rollers make the chain run in a triangle around the three rollers, then put the motor on a slide and have it so that it can be moved in and out to take up the slack.
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Old 02-03-2010, 11:50 PM
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Quote:
Originally Posted by jackalope View Post
Think yours through especially the center die and how it is forced down. You need to have some serious beef and design in order to keep it from "lifting" as you put downpressure on the tube!.

Grant


What would "lift"? not sure what you mean.
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Old 02-04-2010, 12:44 AM
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Don't forget that you will need at the minimum double the power in your motor.
Also don't be surprised if you get two different radius's but otherwise I do like the idea! Personally I would just roll one tube at a time.


Thats why I said "in theory". Something I would like to try to see IF it would work. Still, having a double dies setup would give me the option of different dies for different tubes without having to change as much, thats the cool part really. Only time will tell.




Better yet, Power all three rollers make the chain run in a triangle around the three rollers, then put the motor on a slide and have it so that it can be moved in and out to take up the slack.

I understand the triangle chain setup of course, but not the motor on a slide setup. So the motor would slide up and down with the pressure die moving up and down???
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Old 02-04-2010, 01:04 AM
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No can do... need 2 drive options or clutch 3rd wheel ..


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Old 02-04-2010, 02:26 AM
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No can do... need 2 drive options or clutch 3rd wheel ..


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What?
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Last edited by entropy; 02-04-2010 at 02:33 AM. Reason: need to reverse the 3rd wheel! Duh!
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Old 02-04-2010, 10:10 AM
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I pretty much guarantee your design won't work because you have not taken into consideration the fundamental problem with roll benders that have an outside die set. If you were to try and use just the outter die, the tension the tube would place on the center die (as it resisted the bending force) would definately cause misalignment.

The only way to bypass this with a "simple" design is to build a bender where the dies are located INSIDE the body with equidistant placement and everything is distribute exactly the same.

The only way you can have a die set mounted outboard with success, is to have a SUPER ROBUST design that uses the T slide ogf the front and rear plates. Your does not do this as far as I can tell.
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Old 02-04-2010, 11:07 AM
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Old 02-04-2010, 12:11 PM
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Your does not do this as far as I can tell.
Ok I'll agree to a point, I think there needs to be some more or better description of the design...
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Old 02-04-2010, 01:01 PM
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Quote:
Originally Posted by jackalope View Post
I pretty much guarantee your design won't work because you have not taken into consideration the fundamental problem with roll benders that have an outside die set. If you were to try and use just the outter die, the tension the tube would place on the center die (as it resisted the bending force) would definately cause misalignment.

The only way to bypass this with a "simple" design is to build a bender where the dies are located INSIDE the body with equidistant placement and everything is distribute exactly the same.

The only way you can have a die set mounted outboard with success, is to have a SUPER ROBUST design that uses the T slide ogf the front and rear plates. Your does not do this as far as I can tell.


I'm using 1 1/2 solid keyed shafts that are supported in two places. Granted not in a double sheer on the outside dies but the inside die set will be in double sheer. I think the fact that I'm using large 1 1/2 shafts and I would be putting pressure on the die set in between the plates aswell, it would counter the force effect of the pressure on the outside die set. Your skepticle, I'm thinking outside the box, and I'm willing to fail, but see it through. If it works, I'm stoked, If it does not, atleast I tried. If you never took a chance you will ALLWAYS FAIL. I'm not offended by your skeptisism, Just makes me more determined to make the attempt at making this thing work.

Last edited by rdn2blazer; 02-04-2010 at 03:55 PM.
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Old 02-04-2010, 03:58 PM
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if my thinking is correct the triangle chain won't work because the top roller will be going the wrong direction.

Any rough sketch's of how the center die slide will work.
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Old 02-04-2010, 04:00 PM
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Originally Posted by CarterKraft View Post
if my thinking is correct the triangle chain won't work because the top roller will be going the wrong direction.

Any rough sketch's of how the center die slide will work.


You are correct, part of the reason I though of just powering the two bottom rollers.
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Old 02-04-2010, 04:55 PM
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Originally Posted by rdn2blazer View Post
I'm using 1 1/2 solid keyed shafts that are supported in two places. Granted not in a double sheer on the outside dies but the inside die set will be in double sheer. I think the fact that I'm using large 1 1/2 shafts and I would be putting pressure on the die set in between the plates aswell, it would counter the force effect of the pressure on the outside die set. Your skepticle, I'm thinking outside the box, and I'm willing to fail, but see it through. If it works, I'm stoked, If it does not, atleast I tried. If you never took a chance you will ALLWAYS FAIL. I'm not offended by your skeptisism, Just makes me more determined to make the attempt at making this thing work.
My skepticism is based on your design. There is a thread over on the weldingweb.com maybe the following one that might talk about the problem I am referring to.
http://weldingweb.com/showthread.php...ht=roll+bender

My point in mentioning what I am mentioning is to SAVE YOU TIME. Can I ask WHY in the world would you want to go forward with something if you had not thought it through or if people were pointing out potential flaws in the design?? Look at the machines made by Baileigh and Eagle. There is a reason they are design this way. Same with the one in the link you provided. Two totally different designs but each works the way it is designed to work. The linked one you posted will not allow spiral or spring shaped bends and you must disassemble if you had a ful 360 bend.

I am not doubting your desire to build one, I just think you need to think this through more. If you are in a hurry....Knock yourself out!

Grant
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Old 02-04-2010, 04:57 PM
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Originally Posted by CarterKraft View Post
if my thinking is correct the triangle chain won't work because the top roller will be going the wrong direction.

Any rough sketch's of how the center die slide will work.
The 3 chain design can be made to work if there are two tensionersthat push the chain upward AND outward on the center die sprocket simultaneously.

My first problem I pointed out is WAY more important than this one though.... Besides, a two roll drive will work fine.

Grant
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Old 02-05-2010, 12:10 PM
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Originally Posted by jackalope View Post
My skepticism is based on your design. There is a thread over on the weldingweb.com maybe the following one that might talk about the problem I am referring to.
http://weldingweb.com/showthread.php...ht=roll+bender

My point in mentioning what I am mentioning is to SAVE YOU TIME. Can I ask WHY in the world would you want to go forward with something if you had not thought it through or if people were pointing out potential flaws in the design?? Look at the machines made by Baileigh and Eagle. There is a reason they are design this way. Same with the one in the link you provided. Two totally different designs but each works the way it is designed to work. The linked one you posted will not allow spiral or spring shaped bends and you must disassemble if you had a ful 360 bend.

I am not doubting your desire to build one, I just think you need to think this through more. If you are in a hurry....Knock yourself out!

Grant

Grant,

I appreciate your honesty, really I do. For now, we can agree to disagree on this until it is prooven one way or another. The link you posted showing outside rollers looks to have smaller shafts then I'm running. They look to be 1". I didn't read the thread but the pics look like 1" to me. 1 1/2 shafts are WAY stronger then 1". I feel I have thought it thru. In the end, IF the outside dies don't work, I still have a tube roller with inside dies that will work just fine. As far as Spiral or spring shaped bends, That is not my goal. I want to arc tubing, not make spring shaped, or spiral shaped tube. Simple arcs only. THAT I think my tube roller will do well. Same with a 360 deg bend, Not looking to do that.
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Old 02-05-2010, 12:57 PM
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Originally Posted by rdn2blazer View Post
Grant,

I appreciate your honesty, really I do. For now, we can agree to disagree on this until it is prooven one way or another. The link you posted showing outside rollers looks to have smaller shafts then I'm running. They look to be 1". I didn't read the thread but the pics look like 1" to me. 1 1/2 shafts are WAY stronger then 1". I feel I have thought it thru. In the end, IF the outside dies don't work, I still have a tube roller with inside dies that will work just fine. As far as Spiral or spring shaped bends, That is not my goal. I want to arc tubing, not make spring shaped, or spiral shaped tube. Simple arcs only. THAT I think my tube roller will do well. Same with a 360 deg bend, Not looking to do that.

I will leave you alone after this last comment:
You are missing the point of all of my posts...Your design with the center drive is flawed. No matter HOW thick the shafts are, it comes down to design. I am using 2" shafts and bearings that are rated at over 17,ooo lbs EACH. Even if you used my bearings and shafts, you would still not be addressing the center die/up n down slide assebly structure or whatever you want to call it.

I wish I could find the thread that addresses this point as the welding web was not the one I wanted to show. I will keep searching and post it here if I find it.

Grant
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Old 02-05-2010, 04:13 PM
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Originally Posted by jackalope View Post
I will leave you alone after this last comment:
You are missing the point of all of my posts...Your design with the center drive is flawed. No matter HOW thick the shafts are, it comes down to design. I am using 2" shafts and bearings that are rated at over 17,ooo lbs EACH. Even if you used my bearings and shafts, you would still not be addressing the center die/up n down slide assebly structure or whatever you want to call it.

I wish I could find the thread that addresses this point as the welding web was not the one I wanted to show. I will keep searching and post it here if I find it.

Grant

The center pressure roller as I call it will have as close to zero side to side movement as possible. There will be a guide keyed into the plates on both sides locking it into place.I'm going to use Delrin so it slides on the Aluminum plates to minimize friction, but there will be only a couple thousands so the pressure roller mount is not pinched between the plates. All I can say is IF I'm wrong and my design just does not work, I will gladly admit to you you were right.
BUT!, If my roller works flawlesly, your going to have to eat your words my friend. I have 20 years machining experiencs and have developed, designed and machine tooling hundreds of times for hundreds of machine jobs and grinding fixtures for cnc milling and turning and conventional mills and lathes, and plasma spray turn tables. Also, welded many tooling tables and jig & fixture setups. I think I know a thing or two about tool design and what will work and what won't. If I didn't have confidence in what I was doing I wouldn't do it. I don't know one single person who has bent up a full cage manually without software without wasting some tube. I have not lost one single piece of tube, or misbent ANY bends in my quite extensive cage. I think my ability speaks for itself.
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