Vacuum pump

[LF_rookie_to_be]

Could anyone provide some more information on a Thomas vacuum pump? Here are the specifications from the Gardner Denver site:

Model Number: 007CDC19
Product Family / Type: Diaphragm
Operating Mode: Vacuum
Medium: Gas
Vacuum Flow Rate: 0.7 cfm / 18.4 l/min
Vacuum Continuous: 23.0 in.Hg / -780 mbar
Max Intermittent Vacuum: 23.0 in.Hg / -780 mbar
Max Vacuum Restart: 23.0 in.Hg / -780 mbar
Energy Supply: DC
Voltage: 12V
Motor Rating: 22.4 W
Current Drawn: 3.8 A
Motor Type: Permanent Magnet
Motor Protection Class: F
Speed: 2800 rpm
Weight: 2.90 lb / 1.30 kg
Ambient Temperature: min.50 °F / 10 °C
Ambient Temperature: max.104 °F / 40 °C
Stroke: 0.20 in / 4.8 mm

My questions are:
1. Is it perfectly safe to power it using a 12V/60W/5A AC/DC protected converter for halogen/LED lights?
2. Does it look powerful enough to give enough pull for, say, a 30x40" FB double-weight sheet (horizontal projection)?
3. Do the length and bends in the hose affect vacuum pull?

Thanks.
LF_rtb

[Erik Larsen]

I'm not sure about the electrical requirements, but I think you would want a vane pump and not a diaphragm for an easel pump. A diaphragm pump would work for a contact frame to suck glass down but I think the pulsing on an easel would not be ideal. I could be wrong however
Regards
Erik

[LF_rookie_to_be]

Erik, do you mean the pull of this type of pump isn't completely constant and continuous for a vertical easel?

[Erik Larsen]

That right, it pulses as the diaphragm moves vs say the continuous suction of say a vacuum cleaner.
Regards
Erik

[LF_rookie_to_be]

Thanks, Erik.

[Sevo]

That right, it pulses as the diaphragm moves vs say the continuous suction of say a vacuum cleaner.

Enough of a buffer space will settle that issue. Membrane pumps are standard wherever a modestly strong vacuum pressure is needed and not much air transport is required - using anything else for an easel would not save money, and nonetheless have more issues and worse results.

[LF_rookie_to_be]

Sevo,

How to create buffer space and what volume is needed for this purpose and size?

[Sevo]

Sevo,

How to create buffer space and what volume is needed for this purpose and size?

I use a empty 100cc gas-washing bottle (from a laboratory glassware shop) with my darkroom easel, as that was cheap and available off the shelf at the place I got the pump from. But even a longer bit of hose would probably do the job.

[LF_rookie_to_be]

I use a empty 100cc gas-washing bottle (from a laboratory glassware shop) with my darkroom easel, as that was cheap and available off the shelf at the place I got the pump from. But even a longer bit of hose would probably do the job.

Sevo, thanks for this bit of advice, I'll try to tame the pulsing with a gas-washing bottle.

[Jim Jones]

A vacuum chamber can filter out pulsations from the diaphram pump. Kinks in a vacuum line would affect performance, but modest bends won't. The vane type vacuum pumps I once used for 32x40 graphic arts film were much larger, with maybe 1/4 HP motors. They would draw down to about 24 PSI. Requirements for contact printing halftones is much more stringent than holding photo paper in a vertical easel. EVen a lowly vacuum cleaner might work for a well designed easel. You may need a clamp to hold the top of the paper during draw-down.