need to bounce some ideas...

[vinman]

I have found a 32 foot section of 6 inch square tube steel (3/8 inch) that I can buy for $170. I'll cut that in four 8 ft sections for my cavity top and bottom like ON3P's original press. Now what should I use for side pieces and how tall should the cavity be. I am thinking it should be about 14 inches.....??

The same steel yard has lots and lots of I beams and some more tube steel. I saw an 8 inch sq. section and possibly a 12 inch sq. section. The also have some C stock that is 15 inches but it is pretty rusted.

So should I go with I beam sides or square tube sides?

Also I was thinking about creating a center support to prevent deflection like the stock version of the one on snowboardmaterials dot com. Ideas for this?

Thanks in advance.

[skidesmond]

14 can work but it depends on the size/dimensions of all the other "stuff" you need to put in between the opening.

I made my opening 16 inches which turned out to be too big. I made it 16 because I hadn't figured out the dimensions of the top and bottom forms, tip/tail blocks, cat track, and what size hose I was going to use, so I allowed for a bigger opening. So the more planning and designing you do up front the better idea you'll have on the size of the opening.

Mine still worked out ok. After I finished building the press the opening ended up being about 3 inches to wide. I used 4 - 2x8 to close the gap. 2 side by side and another 2 on top of the first 2.

I would leave about at least a 3 - 4 inch opening for sliding the layup in and out.

Hope this helps.

[vinman]

Thanks. So 14-16 inches is reasonable. I'm not building the frame for z bit yet but I wanted to see what others had done.

I am planning on a cat track. I also have to decide on welded vs bolted. I have a coworker who is a welder, skier and is willing to weld for me.

I guess I need to research mold dimensions.

[vinman]

I just stopped by the steel yard today. they will be cutting my 8 foot tubes this week. now I just have to go find some side pieces. I'm still thinking 14-15 inches would work. the have C stock in 15 inch as well as some i beams in 14.

If 14 is a fairly common inside dimension I think I'll go with that.

Any ideas for me?

[doughboyshredder]

Draw everything out first.

Your cavity dimension is dependent on quite a few factors, so settling on it because you think it will work is probably not the best idea. Do you know what size hoses you are using? Do you know what material you are going to build your molds from?

[vinman]

I have a 6 inch wide PVC lay flat hose rated for 150 psi. I may need another one...

I'll be making a cat track out of broken hockey sticks that I'll collect from the local arenas and high school teams. I'l likely need 30-40 hockey sticks. I should be able to get 2-3 12 inch cat track pieces out of each one.

I'm waiting to hear about molds from my friend that works in the snowboard bizz.

I'll eventually be using heater blankets on top and bottom as well.

I'll be making skis and maybe the occasional snowboard.

[nate]

Keep in mind a 6" hose will lay flat at 9.5" or so.

Multiply the diameter of the hose by .5 pi (which is 1.57) to get its width flat.

Hockey sticks is a clever idea for cat track.

[vinman]

9.5 inches = ~23 cm/230 mm. To get full coverage on a snowboard or 2 skis I'll likely need another hose. or would this be enough with a cat track to spread the force out?

The hockey stick idea came to me as I was looking at someone else's press pics and I noticed they had rectangular aluminum tubes for a cat track. Since ALU is way expensive and robs heat from the blankets I figured broken hockey sticks would work pretty well and be generally free if I can find enough of them. It may take me some time to get enough of them though. I may have to contact a couple more rinks in the area.

[nate]

I'd be inclined to think you'll need another hose. Not entirely necessary though I suppose. If you're confident in your cat track's strength you could press things wider than your hose. You'd just have to up the pressure in the hose to get the same pressure on the laminate.

Oh, and and as far as cat track materials. I cut up 2x4"s for mine. I have yet to test it, but it feels quite sturdy and was free and easy.

[skidesmond]

The hockey sticks is a great idea!! The wood is already ready smooth and edges are rounded. I'm sure it's strong enough. I used left over MDF and it's holding fine.

You really should draw and dimension everything out first. You'll save your self a lot of head aches. If you're going to be pressing 2 skis at a time you'd want the forms to be at least 12 inches wide. As for the cat track, make it wider than 12 inches, 14-16in. That will give you room to figure out how to assemble the cat track and determine how to attach it to you press.

I don't know how much energy the cat track can transfer outward. I think you'll need 2 hoses. I use 2 - 6in hoses for my press. Keep in mind when you pressurize the hose you don't want to inflate it so it's a circle, obviously. I would guess mine inflates so it's about 3 - 3.5 inches in thickness.

Hope this helps.

[vinman]

good points both of you. I do think that we'll end up ordering a second hose. and I will definitely be cutting my track a bit wider now. I still think I can get up to 3 track pieces from each stick at 14 inches wide It will be close I think.

My buddy in the snowboard bizz confirms 13-14 inches for the cavity height.

BTW the guy at the steel yard had an idea for using air bags from a dump truck suspension to create air pressure instead of hoses. these are cylinders that comes with pressure fitting and can hold upto 150 psi. it is a good idea from someone and could possibly be used to create a moveable cavity/lift table style press. I did not do any R&D on this idea but there is potential. Each bag costs about $60-90 depending on size.

[vinman]

They cut my steel today. I'll be picking up four 8 foot sections of 6 x 6 tube steel this weekend plus 2 sections of 14 inch tall I beam for the sides.

The guy welding for me has some 4 x 4 tube and angle iron that we'll use to create the center posts to prevent deflection with.

Next up is 4 grade 8 pins to secure the front-center post in the brackets. The back post will probably end up being welded in place.

[vinman]

I now have 16 hockey sticks to be cut up for my cat track I may need a couple more depending on how wide I cut my track. If I go 14+ inches I may need another 2-4 sticks to have enough for a 84 inch track. Each stick is 1.25x .75 inches. I'l use the 1.25 width thru most of the track and the .75 width at the tip and tail. Best part is these were free. I have been emailing 2 rinks in my area and the managers are saving them for me. For the track I just need some cable, some springs and maybe some slotted alu or steel to attach the springs.

My steel is waiting to be welded, which may happen this weekend as the weather here in the Northeast currently sucks and opening day for my hill has been delayed until at least Sunday. If my welder is free we may try to get it done.

I have also bought 4, four inch, 300lb casters. 2 rigid and 2 swivels with locks that will get mounted so this thing can be moved.

Now I just need someplace to house all of this stuff. I'm considering building a 12x 12 addition to my shed...

[vinman]

We got 95% of the welding done today. The only stuff left is some reinforcements and center deflection post on the back and the casters. The I just need to figure out how to get this monster home. Big progress today!!!!

[rockaukum]

Sounds like you are well on your way. On the casters. I did the same thing with one fixed and one swivel. I will soon be cutting off the fixed casters and installing another set of swivels. I have found that it will be much easier to move the press around. Just food for thought.
ra