Re: Pump for easel vacuum
Volume needed depends on the vacuum loss due to uncovered holes. If all vacuum holes are covered by the sheet of film, then the volume of air vacated by the pump could be small, if not, the vacuum leakage can put great demands on the vacuum pump. Back in the days using a BIG graphic arts process camera, the vacuum pump for the film back was essentially a vacuum cleaner, not silent in any way. The film back was about 36" x 36" the vacuum leaks depending on the sheet of film used.
Vacuum levels require should be modest as it does not require much vacuum to hold a sheet of film flat.
Bernice
Re: Pump for easel vacuum
I have a 20x24 easel with a vacuum pump, bought it from a friend and while it holds the paper flat especially if you cover all the holes, the pump is loud, so I have only used it once. But has a long hose, maybe put it in another room hmmm. Bought it to do copy work, the first job was old news paper covers to reproduce for a book, was when film was king.
Re: Pump for easel vacuum
The most common problem is too much vac draw. A simple handheld cordless household vac is plenty strong, but tends to wear out batteries quickly. A large corded vac, unless a pro one with variable power, will need an in-line bleeder valve to prevent excess suction. Anything noisy is apt to be archaic. Vacs should generally be in another room anyway to prevent dust getting stirred up from exhaust air. If you want to discuss true cleanroom vacs and have five or six hundred dollars to budget, then there are some wonderful options which are very quiet, extremely clean, and have built-in variable power; good for general darkroom vacuuming too.
Re: Pump for easel vacuum
What I bought for my home made 20x24 vacuum easel. I don't need the manifold gauges, but at this price who cares if they come with it.
https://www.ebay.com/p/3-5cfm-1-4hp-...nid=1907933686
Re: Pump for easel vacuum
That is an automotive AC vacuum pump which has an oil reservoir to lubricate the pumps vanes. Notice the sight glass on the pump end.
It does have 'clean' suction but it will spew oil mist as al pumps have input and output.
Best place it outside the DR.
They are designed to run for hours and pull a high vacuum.
I would install the vacuum gauge inline somewhere it is visible.
I use a dry vane vacuum pump with input and output filters. The vanes wear and and produce dust.
Quote:
Originally Posted by
Rick A
Re: Pump for easel vacuum
Re: Pump for easel vacuum
I make my own vac easels. For one thing, I want built-in masking blades. I also want valve zoning. One warning : Don't use peristaltic vac pumps, which operate via a fluctuating internal diaphragm. They'll slightly jiggle a vac easel surface, and might defeat consistently crisp images.
Re: Pump for easel vacuum
Anyone ever try reversing a pond air pump? They move quite a bit of air into water and you could fit standard size hoses and bleeder valves at the pump rather than at the table. They have a hum much less noisy than a vacuum.
Re: Pump for easel vacuum
Quote:
Originally Posted by
esearing
Anyone ever try reversing a pond air pump? They move quite a bit of air into water and you could fit standard size hoses and bleeder valves at the pump rather than at the table. They have a hum much less noisy than a vacuum.
Are you talking about an aquarium pump or something bigger? The little aquarium pumps are the peristaltic type Drew warned about. Ive seen bigger varieties that are vane pumps, excellent for this. If you want suction with no vibration a turbine pump like the vacuum cleaner is the smoothest and cheapest, though the vane pumps come close.
Re: Pump for easel vacuum
I took a somewhat different approach. My wife had a desk fan left from she worked ~8" blade I see similar at CVS and Walmart for not a lot of money. Took a cardboard box and cut out the front to match the face of the fan when standing on it's base then put the fan in the box then and duct taped to both hold it in place and seal around the unit. Found a hose connector that would connect to a Nauta flexible tank (boating stuff) and a corrugated plastic hose of about the right diameter, cord out of the box through a hole then that and the box sealed with tape.
The camera is an 11X14 process camera, there is enough suction to hold 11X14 or 8X10 film in place I tried a piece of enlarging paper but it had some curl and wouldn't pull flat I suspect some fresher paper without the curl would be fine.