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Truss presses?

Posted: Fri May 22, 2009 10:54 am
by krp8128
I might have missed it, but how come nobody has tried a press frame built with steel trusses?

Seems like it would be pretty cheap to get a bunch of short angle or square pieces, plus it would be fairly light.

Posted: Fri May 22, 2009 1:50 pm
by twizzstyle
"Fairly" is a relative term, its still going to be heavy as a bitch.

It would probably work just fine, you probably just don't see it because of the complexity in the design and fabrication of it (i.e. lots of cutting, lots of welding). Its a lot quicker to just use some giant I-beams.

Posted: Tue May 26, 2009 9:26 am
by Craig
involved in building of a truss press this past winter. OK, I didn't actually build it, but collaborated on the design. I haven't even seen it in person yet, I build skis with a friend across the county - he and a friend put it together (the arrangement worked better when we both lived in S Lake Tahoe). Its first pair of skis should get pressed this week. I'll try to post pics soon

our old press was big heavy I beam, we built this new one because we wanted a press that 1) didn't deflect noticeably, 2) accomplished this without having supports over it lengths that blocked side loading, and 3) was relatively lightweight (it weighs around 900 pounds, including hydro bottle jacks - our old I beam press, which definitely deflected at 75 PSI, weighed about 1400) for mobility - we wanted each pound of steel put to better use.

ps It has 40-50 individual, miter cut, welded steel pieces. It took my co-builder and our friend, an expert welder, a solid work week. nice guy right? Its definitely quicker to use I beams, but if you have time, necessary skills, but not too much money (it doesn't cost much more), its not a bad option.

Posted: Tue May 26, 2009 3:51 pm
by Craig
Image

Posted: Wed May 27, 2009 12:34 pm
by krp8128
Craig wrote:Image
Shockingly similar to what i have in my mind!

The advantage that i see here is that (for me) it tends to be easier to find 12" or so tube stock scraps, rather then 10' W-beam

Posted: Thu May 28, 2009 5:44 pm
by Craig
metal availability definitely played a role in the design here

Posted: Thu May 28, 2009 6:35 pm
by doughboyshredder
what are the bottle jacks for? I don't get what you got going on here. The top is all gnarly and solid, but then the bottom is square tube on bottle jacks?

Posted: Thu May 28, 2009 7:16 pm
by Craig
Basically, the press is built so we can eventually scale up to a full hyrdaulic system.

the the bottle jacks are for height adjustment only (cavity size adjustment), and are in excess of what is necessary when running a single bladder (what its built to function for right now). When we upgrade from using a single bladder to a full hydraulic press with molds, there will have to be modifications to the bottom (we plan on this, it is actually a separate assembly on rails), the top is already sufficient to handle the additional pressure. but even so, the bottom still has a strong truss system in place right now, it just doesn't look as built up.

also, not pictured are the re-enforced perches that the bottle jacks ride on, as well as adjustable side supports. its kind of a work in progress, and I hadn't planned on posting about it until it was done - but then up came a topic about building a truss press....

since its posted now, though, I certainly welcome any thoughts or ideas, this is definitely new territory for us

Posted: Thu May 28, 2009 7:37 pm
by doughboyshredder
The bottle jacks and the frame sitting on them just seem like a weak point.

It looks like you guys are doing a great job, I look forward to seeing it when finished.

Posted: Mon Jun 01, 2009 6:31 am
by rockaukum
Hey Craig,
Press looks good. I went ahead and did a simular idea with the press I got from you. Using botle jacks at the ends with 1" pins on each of the four legs of support to lock it all into place. The movable portion is the top on mine but the idea is the same. The holes for the pins have all been sleeved for added strength. Sure is nice having alot of room when putting the lay-up into the press, then lowering the top down (raising the bottom for you) and having the hose only need to inflate a small amount to fill the cavity.
RA

Posted: Wed Mar 11, 2015 4:04 am
by motoman
Really nice construction. I wish to build the same! But before I have to perform some calculations.

Posted: Wed Mar 11, 2015 9:33 am
by mammuth
Why you didnt connect the upmost beams to the side?

Re: Truss presses?

Posted: Wed Mar 11, 2015 2:54 pm
by MadRussian
krp8128 wrote:I might have missed it, but how come nobody has tried a press frame built with steel trusses?

Seems like it would be pretty cheap to get a bunch of short angle or square pieces, plus it would be fairly light.
him I think I-beam press to make. 4 sections of I-beam two more for spacers. With Magdrill should take no more than a day to put one together.

trusses press like in the picture lot more complicated a lot of welding not to mention accuracy needed in fabrication. I'm not talking about time it probably took to put press in the picture together… Happy Monkey design press simple and effective which is a winner in my book