Sorry for the delay. Here are some photos of my home made system...
Handwheel uses the NovaDVR original hand wheel, some thin mouse mat for seals, wood internals, sealed bearing at the outside end, sealed bearing where the wood insert meets the inside edge of the hand wheel, standard copper water pipe running through the construction and ending at the inside edge of the bearing.
Outside view of the hand wheel showing the bearing, copper pipe and mouse mat.
You don't actually need any of this but it's useful!
On/off switch (with a light to remind you that the vacuum is on) - saves you reaching to the vacuum pump switch.
The clear tubing is special vacuum tubing with wire strengthening (not sure how important this type is but I got it from the vacuum pump people).
The brass fittings are standard compression type from B&Q.
White plastic tubing from same source.
To the left below the gauge is a small length of tubing which has a home-made air filter constructed from vacuum cleaner filter.
Vacuum gauge from Ebay - new@99p + £2.75 P&P. Bargain! Very useful for checking if you have a leak in your system during construction and in use. Also indicates how good a hold you have on your piece and how gentle you need to be with your cuts.
The valve top right is a gas tap from B&Q again.
The silver connector was from the bargain bin at B&Q - £1.
Back of one of my chucks.
Mounted on a Record faceplate. I cut a recess into the wood the exact size of the faceplate and then placed a layer of mouse in it before placing the faceplate.
The 8 screws are as big as would fit through the holes but make sure they don't come through the other side of the wood. The area around the head of each screw was painted with some sort of sealer from the shed (can't remember which!). I was probably being paranoid about loosing vacuum through them.
The 4 other screws hold the front side of the chuck in place.
The yellow tube is, I believe, gas pipe. Really useful stuff as it's strong, can be turned easily, can be screwed.
I cut a recess into the wood for inserting the pipe.
Put polyurethane glue into the recess before placing the tube and screwing it into place from behind.
Put a bead of sealant around the inside join of the pipe and the wood.
Once that's done seal the wood. I used varnish as that's what was spare.
The pump is the smallest one of
these. I can't remember how much it cost. There are plenty of pumps on Ebay but I don't know much about them.
The chuck above is about 20cm across and if a piece has a good seal I can't remove it using as much force as I dare to try with. I have 2 smaller chucks - one of ~15 cm and one of ~10. The smaller one won't hold for anything other than sanding, although I did once get a good enough hold to turn with. I know this is down to the surface area but I can't help wondering if a stronger pump would help.
For holding the work I place a piece of thin neoprene mouse mat (2 for £1 at the bargain shop) against the chuck, hold the work against it and then switch on the pump. If it's not centred release some vacuum with the valve until you can move the piece a little, close the valve.
I don't use the system a lot but it is useful for removing chucking points. Most of the things I use it for could be done with other (cheaper!) methods but the vacuum chuck is pretty quick. For the platter challenge I had a thin blank that I didn't want to waste any of by using chuck points so I thought I'd try my hand at just using this system and not bothering with a regular chuck. Luckily it worked. I could have gone down the glue block route but I wanted to do it there and then.
[I was only using B&Q because it's easier there to walk round and try to fit random components together]
