Vacuum Easel design

[resurgance]

Hi all,

I came up with a hair brained scheme to build a vacuum easel, after buying a roll of nice curly double weight FB paper.

It seemed like a good idea at the time. It doesn't work.

Please can anyone who has a working easel, preferably a commercial one comment on;
hole size, vacuum pipe size, vacuum pump size (cfm, amps) and if the system has a bleed valve?
General operating principles etc.

I designed the sub channels in a way that all vacuum circuits (there are 4 rows of holes for different paper sizes) are equal in length and fed from a centre point so that the air does not suck more on one side.

The primary problem I believe is that I have a tiny diaphragm pump that doesn't move enough air, and I'm using 6mm pneumatic line instead of the large sizes I am now seeing for commercial units. So not enough air flow.
2mm holes I used, and i suspect that the commercial ones have MANY holes all over the entire surface rather than 'rows' of holes?

I have vacuum solenoid valves so planned to have a footswitch that started timers and pulled down the row of holes at the top of the paper, then 5 seconds later pulled down the middle row, then finally the bottom row so I can hold the line as each one draws down.

Anyway, I should probably just tape the paper down, its just that its so curly and wants to roll up, also I really hate the idea of taking tape off and creating static, fogging the edges from static discharge, creasing the paper etc. Low tack tape still allows the edges to creep up.

The dimensions I use don't help, I want this for Panoramas, so print sizes will be say 1ft x 4ft, 20" x 4ft etc.

Thanks, Stew

[Tin Can]

THis looks like a Drew question.

I have no clue, but my 22x16" NuArc glass topped contact printer uses the OE lab quality vacuum pump pulling through 1/4" plain old air hose. The holes are in a rubber mat, there are 1000's of tiny holes and this thing sucks the glass tight in under 5 seconds to 20 in.-Hg and my hose leaks.

This is not a DIY system. This pump should pull almost 28 in-Hg. Almost like a HVAC standard pump, but oilless and has micron filters.

[resurgance]

Randy my pump pulls down to -85kap which I think is -25inHg? So it must be a cfm thing, or total flow. I don't think the pump has enough flow by a long shot.
Its great to hear that you use standard 1/4 inch line - tell me is that OD or ID?

[resurgance]

This is the pump I am using, but a 240VAC version. Oil-less laboratory style single stage diaphram pump.
http://www.coleparmer.com/Product/Ga...AC/EW-07061-22

Now I am beginning to wonder if it is how I have bonded the top to the base, and if the base is porous. And my pump is too small...

Have had a pretty good track record with successful home builds of some pretty cool stuff, but I didn't really think this one through.... There seems to be a tad more to vacuum than I gave it credit for.

[Tin Can]

Randy my pump pulls down to -85kap which I think is -25inHg? So it must be a cfm thing, or total flow. I don't think the pump has enough flow by a long shot.
Its great to hear that you use standard 1/4 inch line - tell me is that OD or ID?

ID and it's crush proof. Gas station air hose. You can drive over it.

[Tin Can]

This is the pump I am using, but a 240VAC version. Oil-less laboratory style single stage diaphram pump.
http://www.coleparmer.com/Product/Ga...AC/EW-07061-22

Now I am beginning to wonder if it is how I have bonded the top to the base, and if the base is porous. And my pump is too small...

Have had a pretty good track record with successful home builds of some pretty cool stuff, but I didn't really think this one through.... There seems to be a tad more to vacuum than I gave it credit for.

I agree you must have a big leak.

That pump seems expensive enough...

Have you tried the shop vac?

[resurgance]

I didn't pay that for it of course! Less than its worth but more than not much....

No I have not tried a shop vac, I just thought of a quick test, sellotape over each row of holes, and tried it - its my easel. Gauge only just climbs above nothing.

Hmph. Ok back to the drawing board on the easel. Fortunately this was pretty inexpensive.

[Tin Can]

I love DIY projects.

Sounds like you do too.

The second version of anything is better!

[resurgance]

Yup! My last one was making a box for a 50" x 90ft Classic FB roll, I came up with what I like to think of as a good design! Next one after the easel is to come up with some method of automating a panorama print roller for a sort of wallpaper tray. So I do not have to do it manually while selenium toning, washing etc. Kind of like;
https://www.fotoimpex.de/shopen/dark...127-meter.html
Seems like a good idea.
I thought I could use an encoder and counter to motorise it
It may not happen yet....

[Tin Can]

Sounds great. Why not! This stuff keeps me out of trouble.

Maybe...I had a big DIY revelation last night and this one may take 20 years, which I doubt I have. So I need to write it down, sell it, start it and maybe never see it.

So it goes