Opinions please , Vacuum ?

[Wood spinner]

Hi

Any thought on how much vacuum you need to work a vacuum chuck ?

I am concidering making one if the vac pump I have is sutable

Thanks

[Lazurus]

I use mine loads both on the vacuum chuck and chamber, my guage pulls almost a full 30 on the chamber, but on the chuck drops to around 25 - 27, never been a problem. even on awkward seals where it has been lower still plenty of "suck" to keep work safely in place. My pump is not the biggest by any stretch but works well.

[Lazurus]

Its 4cfm I made all the fittings myself so cost was minimal

https://www.awgb.co.uk/awgbforum/index.php/topic,5177.0.html

[Wood spinner]

I use mine loads both on the vacuum chuck and chamber, my guage pulls almost a full 30 on the chamber, but on the chuck drops to around 25 - 27, never been a problem. even on awkward seals where it has been lower still plenty of "suck" to keep work safely in place. My pump is not the biggest by any stretch but works well.

Sorry to ask , but 30 25 / 27 what ?

[Lazurus]

Sorry, I think it is inches or mercury the measurement of vacuum with 30 being the best possible at sea level, most gauges are marked with this

[seventhdevil]

psi i presume?

could be atmospheres though?

[Alan Fordham]

Paul Hannay has all the information you need to make a vacuum chuck on his website

[julcle]

I believe that 1 Bar is 27" so -30 will be just over 1 Bar or 15Lb per 1" square

[Lazurus]

What ever it is its pretty dam efficient and will suck a golf ball up a straw, all homemade and very simple to do and use on any lathe with a hollow headstock, I made the chucks to, the cost was around £20 including chucks and fittings.

[Wood spinner]

OK thanks
I have a old brass gauge and a pump , I will see if I can find some pipe switch it on and see what it reads

[Wood spinner]

Looks like I have success

Motor is 1/4 HP 240 volt
IMG_3690 by , on Flickr

Pump / Vac unit is
IMG_3692 by , on Flickr

And when running givs 30  inches of mercury
IMG_3691 by , on Flickr

Will in the future have a go at making everything else

Thanks all