the end of the madrel shank is on a cable or rod, so the "flexi-*****" is in the same position the entire length of the bend. once you're done bending you simply slide it out the tube. At least thats how i seen it done........

I am mostly done with my frame for my rotary draw bender(no mandrel) although i might have to talk with scaliwag after this about adding one. the only difference is I am using hardwood dies. Lot cheaper than steel... and with my gramp's 48" wood lathe I can make them all day long. If i need to bend something larger, i just get out my chainsaw and get some scrap wood from my backyard

 

good god why! Its only an hour away and at 250...aghh! this sucks *** I want a REPU...but if i show up with another car Mrs. Hans will kill me, no really she'll toss me in a sausage grinder and make my family eat what was me.

 

That is not a dumb question at all. They have a pneumatic mandrel extractor on their site so that tells me they pull out. It would not surprised me if it takes a pretty good tug to get it out though.
If the tube crunches very much at all against the mandrel it would make for a bad time.
As far as those flex disks they just kind of follow along whether you are bending and they flex to the bend or if you are pulling it out. They are just going to take the least path of resistance. Kinda like a big fat Scalliwag that just got back from getting th REPU and strained my shoulder and bicep again
This REPU is so ugly Ms. Scalli has had 3 panic attacks since she saw it
I will post a thread after I hang some wooden blinds for her... that was the deal we made so I could put it in the driveway My arm really does not feel like doing the blinds but I can't really defend myself with one arm if she starts whoop'n my **** either

 

Heck Billy if you get it I can get you a good hookup on transpo and have the driver give you the beer too

 

Damn Hans you really need to come get that REPU!!! That is a helluva deal. It would make me feel alot better knowing that they have their lil' Ms. biting their *** too

The one I got is pretty damn ugly boyz. But tat will just make it even more impressive when it's done.
Wait until you see what the previous owner did to the rear suspension I will save that story for that thread.

 

You should be able to order what you need in a 6061-0. That way you get it before heat treating just delete the t6 or t3 off the your alloy #. Then you dont need to anneal it before working it. You will need to annodize or heatreat after you bend it. You might also look at other alloys that might be more workable Im not familiar with "ns4" but I would recomend 1100 series aluminum it should form easier than 6061. I restore antique lighting and have to bend lots of brass tubing into very comprex shapes. The hardness of the tubing I start with is everything. In the past they used to flow lead into the tubes and then bend. Heating the tubes afterwards to get the lead out . I sometimes use something called ciro for the same affect without the lead when the shape is too compex for a mandral. You would have to use lots of the stuff for such large tubes but it can be reused. Most of the time I can bend it without any tricks over a simple die with the right material. I think just using the right material should do the job and you can probabably skip the mandral. Good luck. Oh and sorry I was was too lazy to read the whole thread so if repeated what anyone said my apologies

 

I talked to the people at Omnibend and the mandrel I need is $532.00 and takes a 1.5 weeks because the particular mandrel is not stocked. They keep standard wall for $512 that are stronger but I would be limited to around 90 degree bends. The one I am getting will let me go up to 180 on the 4" radius die and I will be able to get 90's out of the 2.5.
The risk is breaking a $29 replaceable part if you over stress the mandrel.
I figure I will buy two extra joints and find out fairly early on what the max bends on each die is
These mandrels are more than I was hoping but less than I was expecting. They are hardchromed and a specialty tool made for machines that usually cost over 20k for something that will bend this size pipe so I was expecting the worse.
This will be after Christmas before I can get it Good thing this is not a pressing issue.
The REPU will keep me busy during the downtime

 

now that you have an acount can you find out how much there big mendral bender machine is. the one that can bend up to 3"OD. i am just wondering. I think it would be interesting to size that up with how much you spend on yours. I bet you will be pleezed with it.

 

Well the website has prices on tooling but not machines even with the logon password. But as you said it would be nice to know. So I called back.
The base price without tooling of the OMNI-X model X76H (see this link http://www.omnibend.com/scripts/x76h.asp ) is $50,000. The tooling just for the 2.5" is just under $3000. That includes the bending die, wiper die, mandrel and something but I forgot what she said.
This is a semi-automatic machine. It holds some programs which mine will not be capable of obviously so that has to be factored in also.
Even with all that considered I am real sure even with the setbacks that I will be well under an acceptable expense once this is done. I could easily go another 5k over time and as long as I can make some top quality bends I will be happy.

 

sounds great.....i just want to say thanks agian for doing all the dirty work so that when you are done you can show us exactly what to do to build it. you are saveing us all lots of money. If i was old enuf i would buy you a bear if you came out this way. good luck. i cant wait to see more. me and all my friends cant wait!

 

I better stay away from you then because my wife would throw a fit if I brought a bear home!!! j/k

 

I have been reading those options. Since I have a pretty good hookup on the 6061 T6 I will just anneal it as I need to. It also seems like it would be a bigger pain in the *** to anodize the tubes.
I would like to be able to anodize Al but mainly for dying afterwards.
I wonder if after you anneal you can dye also?

 

Yea, I was thinkin if the mandrel is doing its job,then the tube is gonna be crushed slightly onto it, holding it like GI Joe with the kung fu grip.

 

You can anodize it whatever color you want after you anneal it. I just suggested anodizing because it heat treats the metal and keeps it from oxidizing in the future. Your part is really not structual so I would say just skip the 6061 and use something a little softer. Your tubing needs to streach on one side and shrink on the other and thats why the hardness of your metal is soo important . You can form 6061 but it really isnt the best aluminuim for the job. I think its more a pain to anneal than heat treat. Racecar engineering did a article on mandral bending tubing about a year ago if I remember right you might want to check into that also.

 

two days with no update or pics on bender. what will i do with my life. Hey just wondering whats up. With nothing to look at i dont know what to do in study hall at school.

 

There won't be any until after Christmas. That is when I can buy the inside mandrel ($532) without having Ms. Scalli give me a vasectomy in the middle of the night
If you want to hook me up with a loan though we could get it going sooner j/k
Nobody wants to see this going faster than me though.

 

you should set up a paypal thing for donations. this makes me sad. but you getting a vasectomy would be worse.....well at lest for you that is. lol..... well hows the ceramic sprayer thingy comeing along.

also on another point my friend and i are building a home made welder with alternator and battering and stuff. just wondering what you use for all your welds. i gusse its a MIG.

 

Haha!!! A PayPal donation account. That is not for me. There are MUCh more worthy charities for people to be giving their money too. Scalliwag would rate somewhere below a "Save the cockroach" charity

As far as welders go for straight up mild steel I have a Hobart AC/DC stick welder. For aluminum and thin stainless I have a small Lincoln MIG welder.
It is more of a pain in the *** than it is worth to change the rollers and liner out to switch to steel with the MIG and I can weld better than average with a stick anyway. Welding for a living all those years paid off I guess I REALLY want a TIG. Nicer welds and since you hand feed the filler rod switching materials is a non-issue.
I have not played with the ceramic sprayer yet. Since I got the repu since I hit the dead end on the bender I went straight to it. Actually more helping Chris get the motor running. I will peel away from that though also.
I have the two jugs of powder to test with as well as another auction I won of actual ceramic powder http://cgi.ebay.com/ws/eBayISAPI.dll...ory=34096&rd=1
When that gets here I will be a little more motivated since I actually have a concept of what to use it on.
That first powder is an abradable material and I can't find anybody willing to let me spray the inside of their turbo
The only thing I can think of using that for in a practical situation is where someone shelled an impeller and dogged a housing. If they have an extra impeller I could give it a shot on coating the inside of the housing and see if it works. Any volunteers?

 

Scalliwag, you need some hobbies What you do right now looks too much like work

 

Haha! But my work is too much like a hobby!!! Playing with computers all day leaves too much penned up aggression to feel as though I am actually feeling productive.
That's not to say I am not productive at work. They get what they want. But the end result is an untangible to show for all of it That ain't much to show off now is it? At least except the check Ms. Scalli gets for it

 

for me and my friend to split do you think we shoudl
1. home made like i said befor
2. stick welder
3. MIG
4. save up for a TIG....we will be building roll cages sometime and aluminum. and from what i hear TIGs are the best for aluminum. and much much better/cleaner for all welds. but they cost so much for two 18 year olds.

 

A homemade welder does not sound very appealing to me especially using an alternator. If you are talking about using a standard automotive alternator that is not very good at all and I really can't see how that could be accomplished.
A selenium rectifier based welder would be more practical and there are plans out there. Finding a large enough rectifier is usually expensive and in the end your money and time would be better spent on a good used AC/DC stick welder.
I would not wait to save up for a TIG. You won't be out much money on a used stick and they are always useful. Even after you do have a TIG you will want to have a stick electrode holder coming off of it and you will probably be using it more often than the TIG gun.

There are tons of online information and until you get more experience welding you are spinning your wheels. It is kind of like reading a book about how to draw and expecting to make a decent drawing when you are finished. As long as your expectations that reading is going to help you understand what you are looking to accomplish but are not a substitute for practice you will be fine.

 

Here is a real good read by this guy that built his own MIG welder. As he says at the end though he had most of the stuff already. It sounds much more like a project that was done mainly from curiousity.
I think english may be this guy's second laguage because his spelling on words like "maybe" is "maby" but a look at his schematics and the work he did on the welder he's not a novice hack for certain.
As a matter of fact it looks as though this may be a lot better unit than most low end MIG's like Campbell Hausfield, etc.
http://home8.inet.tele.dk/jan_p/welder/mig1.htm

 

But if you want a tig welder, get a stick welder, then simply buy an adaptor kit for it.

It's a tungsten tip that gets held in place of the electrode - but you may want to get a gas MIG welder instead to get the adaptor kit for, then at least you'll have the gas supply from the tip of the electrode

But yeah, TIG welding gives way better results than stick or MIG could EVER give you. TIG is best used on stainless steel, and Aluminium

 

That really only applies to a higher end stick welder though. A welder that is made for TIG generates a cleaner wave than a crackerbox welder. As long as you point that out then I agree 100%.
The newer square wave welders are super smooth. They cost so much because the components are very high tech.
If the weld can be made with a MIG or stick use them because they are faster. Depending on the material, thickness, and whether the weld is structural or cosmetic determines the best type weld.
But I would still trade all my welders for a TIG