The Bucket Foundry

[Grumph]

Ok, I am not worthy hydroforming is not as easy as I first thought, made a bit of a mess and wasted a day. Bugger that and threw it all in the corner, run out of patience. I think I tried to make the bends too tight. Anyway gone back to my old ways of pipe building, at least it works first time. I'll have another go when I'm less aggravated. The header pipes formed well, I guess that's a start.
Press tools next time!

Join the club...
Back in the day I saw locally made tapered header sections made from pressings. Wood pattern like you're used to, then cast resin dies.
I'm told the resin dies are good for 50 - 60 shots.

[Flettner]

I take back what I said about the Harris gas welding torch, once I stopped the backfiring it's become for want of a better word delightful. Pulling it apart and reassembling it must have either dislodged some blockage or something must have been loose, anyway it's all good now. First pipe is finished up to the reverse cone, now I've calmed down I'm going to have another go at hydroforming the reverse cone (x2) I'll make two back to back as one, then cut them in half.

[Flettner]

Join the club...
Back in the day I saw locally made tapered header sections made from pressings. Wood pattern like you're used to, then cast resin dies.
I'm told the resin dies are good for 50 - 60 shots.

I have done that before using zinc (melted down old carburetors) poured into a header cut in half from an old chamber. Ie zinc dies, they worked ok although the steel did distort a little with the hot zinc on it.
When I was an apprentice, you know back in the day, I saw the toolmakers pour a die using alloy filled resin and get a few blow mold shots off, to show the customer what the finished product would look like, worked great for a short time.

[Michael Moore]

I was told that when Ron Grant had his tuning business here in the SF Bay Area he was forming expansion chambers in concrete dies. I don't know if that was pressings or to constrain hydroformed sections.

[WilDun]

I was told that when Ron Grant had his tuning business here in the SF Bay Area he was forming expansion chambers in concrete dies. I don't know if that was pressings or to constrain hydroformed sections.

Michael, at the time Ron Grant was around, some people were experimenting with explosive forming in concrete dies, unfortunately these concrete dies were not reusable! - I don't know if he was using explosives (maybe just high pressure water),

As a matter of interest, I remember a guy called Bill Boyd from San Francisco, who came over (to N. Ireland) to race occasionally on his Yamahas, probably around 1965 - he even came on his honeymoon! (understanding bride!).
I had heard that he had a horrendous accident in USA, but no more since. Have you ever heard of him?

[Michael Moore]

Sure, I've met Bill, though it has been a long time ago. He crashed on the Sunday Morning Ride in Marin county north of SF and lost a leg. He kept riding after he recovered from that. His son Wade raced solos in our local club, the AFM, and I think has since switched over to racing outfits. He's raced at the IoM 10+ times (I think) and may be going now to the big vintage race at Philip Island too:

https://www.facebook.com/wade.boyd

cheers,
Michael

[WilDun]

Will it not be better if the welding seams were parallel to the gasflow?

Niels, for a long time I have been thinking about that as well - it should be relatively easy to work out the shape and length of the strips (maybe 6 or 8) to suit the curves you require, weld them together (making something like a cucumber) then finish by hydroforming. Surely no more difficult than the traditional way?
Not as elegant looking as a properly hydroformed one of course but possibly more accurate!
- of course, it's just a thought and I probably won't do anything more about it

However, I don't really understand you regarding the wire wrapping and salt - dissolving what?

Have you still got your Boxford lathe? I've just had to sell mine (possibly moving house) but I wasn't all that thrilled with the constantly slipping belt anyway!

[WilDun]

Sure, I've met Bill, though it has been a long time ago.

https://www.facebook.com/wade.boyd

cheers,
Michael

Thanks Michael - often wondered what happened - He was was so keen he also bought a then new Yamaha 100 twin (stock standard) and shamed a couple of guys on 125 Bultaco racers on a small tight circuit!

[Grumph]

Sure, I've met Bill, though it has been a long time ago. He crashed on the Sunday Morning Ride in Marin county north of SF and lost a leg. He kept riding after he recovered from that. His son Wade raced solos in our local club, the AFM, and I think has since switched over to racing outfits. He's raced at the IoM 10+ times (I think) and may be going now to the big vintage race at Philip Island too:

cheers,
Michael

Somewhere here I've got a very old Cycle magazine with a write up on the Sunday morning ride...writer describes being passed by a bike with an artificial leg hung over the licence plate - Bill Boyd.

[Grumph]

I was told that when Ron Grant had his tuning business here in the SF Bay Area he was forming expansion chambers in concrete dies. I don't know if that was pressings or to constrain hydroformed sections.

Hydroforming I think. I was standing on the bank talking to him and both of us trying to work out what the problem was when Cathcart finally fell off the Britten....

[Niels Abildgaard]

Niels, for a long time I have been thinking about that as well - it should be relatively easy to work out the shape and length of the strips (maybe 6 or 8) to suit the curves you require, weld them together (making something like a cucumber) then finish by hydroforming. Surely no more difficult than the traditional way?
Not as elegant looking as a properly hydroformed one of course but possibly more accurate!
- of course, it's just a thought and I probably won't do anything more about it

However, I don't really understand you regarding the wire wrapping and salt - dissolving what?

Have you still got your Boxford lathe? I've just had to sell mine (possibly moving house) but I wasn't all that thrilled with the constantly slipping belt anyway!

Hello WilDun

I imagine making a former in either salt or alu and then plank it with iron ,steel or titanium.It will not be nessecary to hydroform afterward as gas feels no difference going through an octagon or a circle.Salt can be dissolved in water or alu in a caustic soda solution.
Motorbiking was getting to unsafe due to age (of me,not bike) but I still run my Boxford as You can see and belt does not slip unless I make something really stupid and then it is a good thing.




http://i.imgur.com/kjnlMT9.jpg

[Frits Overmars]

hydroforming is not as easy as I first thought... header pipes formed well, I guess that's a start. Press tools next time!

I would not choose hydroforming when building a straight pipe. Cutting, rolling and welding segments is simpler and quicker. But hydroforming is fine for curved headers. And when you do that, it's logical to make the complete pipe that way.

Pressing can work too. But you don't need a die. You will need a massive positive of the pipe, same as you would when pressing in a die. You can make that positive on a lathe and then heat it red-hot and bend it (the old-fashioned laborious way) or you can CNC it (and then you'll only need the lower half of it).
Next you'll need a hole through which you press that positive.

[husaberg]

I would not choose hydroforming when building a straight pipe. Cutting, rolling and welding segments is simpler and quicker. But hydroforming is fine for curved headers. And when you do that, it's logical to make the complete pipe that way.

Pressing can work too. But you don't need a die. You will need a massive positive of the pipe, same as you would when pressing in a die. You can make that positive on a lathe and then heat it red-hot and bend it (the old-fashioned laborious way) or you can CNC it (and then you'll only need the lower half of it).
Next you'll need a hole through which you press that positive.

Frits my understanding is the ROC bike frame components, were made with a press into conctrete form based on some French arospace practice
Do you know anyone that could confirm this?

[Flettner]

I would not choose hydroforming when building a straight pipe. Cutting, rolling and welding segments is simpler and quicker. But hydroforming is fine for curved headers. And when you do that, it's logical to make the complete pipe that way.

Pressing can work too. But you don't need a die. You will need a massive positive of the pipe, same as you would when pressing in a die. You can make that positive on a lathe and then heat it red-hot and bend it (the old-fashioned laborious way) or you can CNC it (and then you'll only need the lower half of it).
Next you'll need a hole through which you press that positive.

Hydroforming is truly an art, I respect those that can achieve good results with this system. I usually, as Frits said, just roll the cones on my cone roller then cut, turn, weld and beat with a dolly to get the curves I want.
Ironically the next hydroforming I did this afternoon I accounted for the 30% tighten up of the curve, didn't happen, and the formed shape is the same curve as the cut out shape. Go figure? Never the less the forming process worked well and the shape formed as I expected (apart from the non tighten up). I have to keep reminding myself that this is just an experiment, all I want is two chambers the same and if they don't look so good too bad. If the miraculous happens and the engine runs well I'll make up some more tidy pipes, well that's my story anyway right

[Frits Overmars]

Hydroforming is truly an art, I respect those that can achieve good results with this system. I usually, as Frits said, just roll the cones on my cone.

A cone roller, no less. You live a life of luxury Neil. I never owned or even used anything that posh, I used my thumbs and an old front fork tube.
But then I always tried to avoid mass production .

Frits my understanding is the ROC bike frame components, were made with a press into conctrete form based on some French arospace practice. Do you know anyone that could confirm this?

Sorry, I don't, Husa. My understanding is that concrete dies were mainly used in explosive forming of large objects. For small parts like pipes and frame segments I think I would first look at rubber cement (or wood, that is how the original Porsche bodies were made). But I have zero experience and I don't know anybody who does.