[Scrapyard]

Anyone have any info about this process. Some time ago I saw some DIY info on hydroforming exhaust pipes and tubes. Can't seem to dig it up now. I did see a vid that some guy made an expansion pipe for his 2 stroke. Looked like he welded it all up and then hooked up a pressure washer to expand a metal.

Woundering what kind of presure and fittings could be used to accomplish this.

 

[Truckinduc]

oh oh oh pick me!!!!

Ive helped a good friend Hydroform a megaphone for his 450 ducati.

The megaphone wraps around the the rear shock, Its trick as hell.

Sorry though this was about 4 years ago so i cant remember the specifics.

Ill see dude in a few days so ill ask him for you.

 

[Scrapyard]

Hell yeah, find out what you can. I want to make some megs myself.

 

[Truckinduc]

Here is a shitty picture. The shroud kinda covers it up. Ill take better pics soon.

 

[Scrapyard]

That looks pretty cool. I like the diffusers in the end.

 

[Greencheezeeta]

I'd like to know a little more about this also.

 

[bwesky]

i just did a brief search on youtube, didnt really find much, but machines doing it, or the final prduct. i would like to know more, not that i plan on persuing it, just to have a basic knowledge of what it is and how to do it... info needed!

 

[Scrapyard]

Seems like a lot of the big production stuff is high pressure die formed. They crimp the material in a die and then fill it with 5000-10000psi of water pressure. Depending on the thickness and size of material.

I've seen some DIY stuff with thin gauge steel that is welded tight and then pumped into shape with a pressure washer. Pretty cool.

I'd like to find out what gauge material and what amount of pressure is needed to acomplish this.

 

[SEBSPEED]

I think what you guys are talking about is different from what my company does. One of the ways we form parts is with a large hydroform press,

What happens is, a male die is placed on the loading tray with a piece of material on it, then the tray slides into the machine where hydraulic oil is pressurized and pushes a large rubber bladder over the die, effectively forming the sheetmetal over the die. Most of the time these parts have to be "over-formed" to account for material springback and usually extra time is taken by the operators to check and straighten the parts to match a form tool.

 

[Newman]

I haven't read the whole article but it covers the process.

http://www.eurospares.com/frame8.htm

 

[BigBellyRacing]

Harley uses that process to make the frames for the vrods.....pretty awesome to see it done.

 

[swampy]

On youtube I've seen a guy that does ghetto mandrel bending of exhaust pipes by taping the ends of the pipe with duct tape, filling the pipe with very wet sand so that there are no air pockets and the pipe is completely filled, then tape the pipe closed. After that, he just used a regular bottle jack tube bender. The sand on the inside keeps the pipe from deforming much, and he got a pretty good bend in the tubing. You'd think the pressure of the sand would blow the tape off, but it didn't?
I'll look for the link.

 

[Scrapyard]

Thanks Newman. That's what I was looking for. High 5 tou you bud.

 

[fslflint]

hydroforming is fun...... explosive hydroforming is TOOOOOOOOONNNNNNS of fun

 

[Newman]

On youtube I've seen a guy that does ghetto mandrel bending of exhaust pipes by taping the ends of the pipe with duct tape, filling the pipe with very wet sand so that there are no air pockets and the pipe is completely filled, then tape the pipe closed. After that, he just used a regular bottle jack tube bender. The sand on the inside keeps the pipe from deforming much, and he got a pretty good bend in the tubing. You'd think the pressure of the sand would blow the tape off, but it didn't?
I'll look for the link.

I think the posters name on those youtube videos is dopescustoms. i tried the wet sand and duct tape on some exhaust tubing and it didn't work. It might work for thicker wall tubing.

 

[Truckinduc]

you usually have to pack the sand very tight and weld caps on the end. That technique has been around for a while.

 

[Truckinduc]

different angle

 

[Truckinduc]

 

[Truckinduc]

and the subframe and full exhaust with megs on his moto guzzi

 

[Truckinduc]

^ sounds like death is coming to get you when its going down the road