Scalliwag

This was talked about in too many threads to mention. Now that the dies are ready I can post a thread of it's own and not piggyback it on one of my other projects.
Some of you are up to speed and I guess there will be some that haven't seen anything on it.
To recap I wanted a mandrel bender that will make true mandrel bends with no crunches.
Any of you that know much about mandrel benders they are really expensive and take up a lot of room. Some of the ones that people linked me too that were smaller still did not fit either my budget or my idea of what I wanted.
Everything that could bend over 2" pipe was especially high.

I know it would be inherently heavy but I at least want it to be relatively easy to break down small enough to put in the back of most vehicles and have wheels so it could be pulled around to the car and put out of the way easily.
This may not look like much but it is what I am building the bender around. I wanted to get the first set of dies done before I started getting the frame finished so I could doulble check my layout. Most of the arms, supports, etc. are cut to length and need to be marked and drilled.
I have to pick up the hydraulics so this still has some time left before it will be ready.
The way this works is that one die gets pushed around the other to make the bend. For a tight radius the small die is stationary and for the large, the large is.
Since the dies are on bearing and will freewheel it will reduce scuffing on the pipes.
The dies are high to have made because 8" diameter rod stock is high and cutting all the metal out to make the radius is time consuming.
But if I am going to tie money up in something I at least want it to be the way I want it when it is done.

I will post the pics of the dies and then post pics of the dies with the pipe rest and point out some details in that.

Scalliwag

In the ollowing pics you will notice that the rest is a larger diameter than the 2.5" tube. There is also a smaller radius half pipe (actually not quite a half but I could not find the piece that goes there )
I wanted that so I could just change the inserts out for future dies I use.
The two dies are going to be connected with a arms and the hydraulic pushes the arm. The pipe rest locks in place and absorbs the pressure during the bend.

pinkfloyd

wow....how did you mill that agian. i know nothing about makeing mendrell bends. i am going to search now. that is pretty sweet. keep us updated

pinkfloyd

more pics...weeee

Scalliwag

The dies were cut on a much larger lathe than what I have. I will post more pics once I get the dies mounted and it starts coming together. Dies are going to cost a lot to have made

Scalliwag

I am building an automated tubing polisher next that will mirror finish from 1" to 6" diameter (smaller and larger than I will need) tubing or pipe up to 8' lengths.
The pipe spins like it is on a lathe and a high speed buffer that travels the length of the tube.
It is built on a 10' aluminum I-Beam. So it is pretty light to move around. Trust me in my garage that is really important It was a high dollar piece of beam though.

The tubing I have will be polished before it is bent so it will not be a bitch to polish later. If I have a scuffing problem during the bending I will spray a clear acrylic on it and that would at least reduce it. Then the acrylic could be cleaned on with solvent later.
I am really glad I got my mini bead roller now

I also have a game plan for people that want one piece multiple bend pipe. They could send me a pipe made from PVC (plumbing for the few that would ask ) pipe and fittings (90's, 45's etc.) I could then make a one piece pipe that matched the PVC version. I can also expand ends for those that have at bigger fitting on one end. That seems to be pretty common.

pinkfloyd

your my hero. i wish you lived closer. good luck. not that you need it, you seem to know exacly what you are doing. about how much do you think this bender will cost in the end

artowar

iTrader: (1)

Hey Scalliwag, I may be one of those guys. I want to change the way my IC is mounted, so I'll eventually need some different piping. If it matters, it will all be 2.75" OD.

Scalliwag

Damn I hope Ms. Scalli does not see this The two dies were $400. The hydraulics are $300. The misc. bearings and materials so far are about $100 I guess.
Every set of dies I add are $400 unless I get a bigger lathe and make them myself. But even an experienced machinist spent about 11 hours to cut them. I am not sure I want to spend that much time on something like that.
The bigger die weighed 63 lbs. before it was cut. The material for both of them cost about $80. The rest of the cost was machinist hours.
Not counting my labor and powder coating I will be at least $1000 into it by the time I bend my first pipe.
I can try to source materials later and try to save a little by quantity if I build and sell some.

Scalliwag

Yep, that matters. The dies have to be made for that. If I get enough requests for that size I would get some dies made though.
I won't know how to set a price until I do some bending.

Also the two dies are not going to be touching like they are in the pics. There will be a gap to allow more leverage for the bending. There is a few unknowns to me on this prototype. Just like the mini bead roller and most of the other things I have made I am sure the second mandrel bender is the one that everybody wants

Scalliwag

Well I woke up this mornig with a cold still ragging on my *** so I stayed home. I got feeling *good enough* to go out in the garage and start putting the mandrel together.
The first pic is actually the aluminum I-beam for the polisher. The all-thread is 1" grade 8 so it is some really good stuff. I won't use all-thread on the final fixture once I work the bugs out. All the holes that pivot will have bearings on the final as well.
As tight as that smaller die is it will take some serious force to push that bend. So I have to figure out how far from center the hydraulic ram has to sit in order to have enough force to bend. The further out the more easier it will bend but the more pushes it will take per radius.
So finding all these points with different radiuses, wall thicknesses, types of metals will definately be an adventure.
The current fixture will have so many changes during the time that I doubt any of parts other than the dies will be used on the final fixture.
The ram attaches between the bottom tube and top tube. I have to make the mounting once I have the ram.
The pipe rest (that half moon piece) will have a locking mechanism.
Everytime the ram is extended the pipe rest will have to be rotated and locked down.
That is probably a little hard to follow. You will figure it out after I get the ram in place and take pictures of it actually bending.

banzaitoyota

What are you using for a "Chaser" to prevent crushing?

nimrodTT

So if I understand your concept right (which I don't believe I do), you would just swap your large and small die positions to achieve the bend differential? If that is the case, why not use a pin-guided system for pivoting your die arm that would allow you to change from a tight radius to a wide radius by pulling and replacing a single pin that acts as the pivot on the axle of each die. Also, why should you have to move the pipe rest if the pivot point stays constant? I don't see how the load bearing would change once you extended the ram.

Have you considered dual action air powered rams that would be lighter and faster than hydraulic?

Scalliwag

I am *hoping* that since I had the radius cut exactly to the size of the tube it won't need one. Time will tell on that. I expect to have to work out bugs. Hell I never get anything right the first time, second, third, etc., etc., etc.
I have to get some heavy flat bar. Like 3/4"X 2" to anchor all the studs at the tops. With the pressure everything is going to try to spread at the top.

To make it easier to figure out what areas I am talking about I numbered the arms. The #1 arm will have to have a riser so I can attach a heavy flat bar between those points. The 1/4" flat in the picture has to be replaced with the heavier bar as well.
Hopefully that will stiffen it up enough to handle up to 10 tons multiplied by the distance from the pivot point Now that's a scary thought.

Scalliwag

The pin idea sounds good but there is a lot of heavy material to go through by the time it is fully decked out with the top braces. Plus you would have to reverse the position of the pipe rest to the opposite side and the pipe would be bending from the opposite direction.
The big die still weighs about 45 lbs so I am a little more comfortable putting it on a fixed stud. My luck I would knock it on top of my foot trying to pin it

As far as why the rest has to be moved it is because the ram pushes straight ahead. You can only go so far with a bend pushing straight ahead. By rotating the rest it keeps putting the pipe in a position to be bent further.

On the air powered rams I guess it is my being unfamiliar with them. I have not seen any that did more than reposition and light work on the few automated systems I have been around.
I talked the Harbor Freight manager into selling me their 10 ton portable (reg $159, usually goes on sale for $99) for $89. It's funny when I go there because all the people that work there know me. I've spent a metric shitload there The manager always hooks me up on prices so that is really cool.
So now I just have to get a motorized hydraulic pump because that hand pump won't cut it. This should get me through the test phase but I plan on a better hydraulic system later on.

Here is the link to the hydraulic kit I got http://www.harborfreight.com/cpi/cta...emnumber=44900

Mr BiG G

scalliwag....start makign headers....u got the madrel bender and u got the ceramic coater....u probably have the pipe expander and u can easily put all this together and make a pretty penny...how much do u expect to sell one of these for? and upt o how mcuh diameter are u gonna be able to bend....i guess that depends on ur die's right....and i have a suggestion...u know the scrap metal u get...why don't u use that for ur die's instead of spending 80 dollars just for the material of the die?

Mr BiG G

i saw a how dynatech makes headers video on spike tv and i kinda understood the whole concept of mandrel beanding....they had the exact same stuff u had with the hydraulics and the arm and all their stuff was nice and powdercoated if i dint have to save up my money for the mortgage and school and insurance and all i would prolly buy one off u jus to keep ur tinkering funds up but i guess the closest im gonna get to this is....prolly try to make my own setp....it doesn't look too hard at all but if i get around to doing it it will prolly be in like a couple years....so u dont have to worry...no competition for u

good job,
laters

Scalliwag

The trouble with that is finding it in a scrapyard. When you compare the 4" and larger diameter solid bar to other metals like tubing, plate, angles, I-beams, there is not nearly as much of the big stuff out there.
Plus just that 4.25" long piece of 8" weighed 63 pounds. The scrapyards are not very accomadating for either cutting or helping pick the stuff up.
Let's say I got lucky and found a 2' piece. It weighs really close to 500 lbs.
Even if I did get it home my bandsaw is not big enough to cut it. Hell it would collapse from just the weight
The best thing about getting it from Metal Supermarket is that they cut it to length on a really nice saw. The part that sucks is it is a little high. But if I ever bought in quantity they do have price breaks that jump a pretty good bit.
So even if I don't get all my dies machined at once I will buy all the material for several sets after I get through the test phase and just leave the extra blanks with my machinist and call him to get a set started as I need them.
The machining part cost me the same no matter how many sets I get knocked off. Not much time can be saved doing those back to back like with some machine jobs.

nimrodTT

Now that I think about it more, you could have a pin on the axle of each die that went through tube #3 (refer to the picture two posts up). Envision the pins in the same place your all-thread currently is. These pins should both be able to extend below the tube they are mounted on and also retract so as to still support the die without interfering with the area below tube #3. Now add in a tube #4 that goes between #2 and #3, this will be your new pivot arm. Tube #3 will be your die attachment tube - it will have a center pin in between the two pins on the axles that will allow you to spin it around and change the positions of the dies. The die attachment tube will be held to the pivot arm by it's center pivot pin and also the outside (the die that is not stationary) retractable pin that extends through the axle on the die and tube #3 into tube #4. Then you add in a sliding arm for your pipe rest that could accomodate the turning of the die attachment tube which would also enable an easy position and size switch when swaping dies, positions, and pipe sizes.


That isn't too clear to me. Refering to the picture above again, I'll try to explain how I see this set up, correct me if this is not what you had in mind: the smaller die is stationary in this position but can still spin, the pipe rest is also stationary and the ram is connected between tube #1 (on the end closest to the camera) and tube #3 (to the far right end). As the ram extends the pipe is pushed laterally against the pipe rest and the portion of the pipe rolling between the dies bends conforming to the arc that the pivot arm is traveling in. As the pivot arm goes along, the pipe rest shouldn't need to be moved because that end of the pipe should stay stationary while the other end conforms to the dies. Correct?

nimrodTT

Is he using a CNC lathe or a manual?

If you tell me the dimensions and material you want for the dies I may be able to save you some money by running these through my Dad's shop.

Scalliwag

Yes and no. Yes it does push and form just the way you said. But if you did not reposition the pipe you could not get but about a 35 degree bend. There is not a way to make it wrap all the way around otherwise.
Just picture the ram just like you correctly described it pushing arm 1 and arm 3 away from each other. At the farthest point die has not travelled very far.

nimrodTT

Wouldn't you just feed the pipe through a little more and hit it in a spot that's still straight? Plus if you reposition the ram you should be able to get a 90 degree bend easily - assuming the ram is powerful enough and has enough travel.

Scalliwag

He has a manual lathe. I made the first set with 5" and 8" diameter stock. Just a plain mild hot roll steel is all we used. The finished height is 4".
For future dies I want to up the 5" to a 6" because the 5" I think is too tight for most bends.

So in sets of one 6" and one 8" (4" tall so they always center with the pipe rest) I will get these radiuses in probably this order:
3.5"
3"
2.75"
2.375"

I really have them cut to a sample piece of pipe so those are actually approximate. If your Dad can do them cheaper factoring in shipping charges I am definately interested. Thanks

Scalliwag

I am following you now. The way I have it setup I feed through the length I want to bend and the pipe stays at the same point for each bend. There are pros and cons to having the bearings in the dies. The con is that they will not pull the pipe. The pro is that the pipe should have less scuffing.

Here is a video similar (but not exactly) as you describe. It is similar only in that the pipe feeds into the bender
http://www.pro-tools.com/video/erc.mpg

coldy13

Damn man, that looks great. Very nice and simple.

I can check with my dad to see what price his shop would charge to make the dyes. He is foreman at Mid-Ohio Products.

Actually, if I can get 240volts to my garage, I could make them myself on the lathe out there