After receiving so much help from everyone here on vacuum chuck system design, threading wooden faceplates etc, I thought I'd post a short pictorial WIP of the build.
It's not far from finished, so I can cover a fair bit of ground in this first post.
This is the 3.3cfm vacuum pump I'm using. A cheap score from eBay at $100:
b. 3.3cfm vacuum pump.jpg
These are the main components below. Top left is a micro-adjustable needle valve, a bleeder, for adjusting the vacuum level.
At the top right is a lever-operated ball valve, another bleeder, for releasing the vacuum. I used a separate valve for this so that the needle valve could be left as-is after adjusting, while releasing or re-positioning a work piece using the lever ball valve.
Bottom left is the vacuum gauge, 0-30 inHg. (-1 bar)
At the bottom right is a sintered bronze 40 micron inline filter, intended for use with a spray gun:
c. Main components.JPG
I'm still waiting on a couple of small sintered bronze 1/4" BSP filters to go into the inlet side of the bleeder valves, to keep the crap out. The main filter is set up to only filter the air from the vacuum chuck.
The other main component is the bearing assembly for the rotary adaptor that attaches to the handwheel. This is two 47.5mm x 13mm bearings, pressed side-by-side onto a hollowed brass rod with a 1/4" BSP tapered female thread cut into one end to take a brass hose fitting. My mate Jack in Sydney knocked this up for me - the heart of the adaptor. Before I assemble everything I still have to grind a small flat on each side of the protruding part of the brass rod, to get a spanner onto for tightening/loosening the hose fitting. Jack left that bit to me.
a. Side.JPG b. Top.JPG c. Back.JPG
To make things easy, I've gone with 1/4" hosetails on all parts, so I can use cheap 6mm ID silicon vacuum hose to connect everything and for the chuck seals, I bought a metre of 2.5mm closed cell neoprene foam:
d. 6mm ID silicon vacuum hose.JPG e. 2.5mm closed cell neoprene.JPG
The first of the vacuum chucks, a flat disc 230mm in diameter. Actually, not quite flat - I dished it very slightly, about 1.5mm deep in the centre, so it could hopefully hold flat discs better. The small green thing in the centre is a pre-filter - two 1" discs cut from a Scotchbrite scouring pad and glued around the outer edge to hold them together. It'll hopefully stop so much junk from reaching the main filter.:
f. Flat vacuum chuck - Front.jpg g. Flat vacuum chuck - Back.JPG
A test-fit of the main parts. I made a plywood stand to hold everything together:
h. Main parts test fit.JPG
The next step is the rotary adaptor for the handwheel. Finally, a bit of turning. I'm using a two-piece assembly. The main part, containing the bearing, fits up onto the front of the handwheel with a neoprene seal to prevent leakage, and is held in place by a clamping ring behind the handwheel. To clamp the two halves together I'll drill four 6mm holes through both pieces, thread some allthread into one half, then use countersunk nuts with washers.
So far, I've turned the recesses in both halves for the handwheel and the bearing. I only need to reverse-mount the main part tomorrow and cut an access hole for the brass fitting to protrude from. The Gods were with me and I got a beautiful firm sliding fit for the handwheel and the bearing.
i. Handwheel adaptor 1.JPG j. Handwheel adaptor 2.JPG
k. Handwheel adaptor 3.JPG l. Handwheel adaptor 4.JPG
To be continued......
It's not far from finished, so I can cover a fair bit of ground in this first post.
This is the 3.3cfm vacuum pump I'm using. A cheap score from eBay at $100:
b. 3.3cfm vacuum pump.jpg
These are the main components below. Top left is a micro-adjustable needle valve, a bleeder, for adjusting the vacuum level.
At the top right is a lever-operated ball valve, another bleeder, for releasing the vacuum. I used a separate valve for this so that the needle valve could be left as-is after adjusting, while releasing or re-positioning a work piece using the lever ball valve.
Bottom left is the vacuum gauge, 0-30 inHg. (-1 bar)
At the bottom right is a sintered bronze 40 micron inline filter, intended for use with a spray gun:
c. Main components.JPG
I'm still waiting on a couple of small sintered bronze 1/4" BSP filters to go into the inlet side of the bleeder valves, to keep the crap out. The main filter is set up to only filter the air from the vacuum chuck.
The other main component is the bearing assembly for the rotary adaptor that attaches to the handwheel. This is two 47.5mm x 13mm bearings, pressed side-by-side onto a hollowed brass rod with a 1/4" BSP tapered female thread cut into one end to take a brass hose fitting. My mate Jack in Sydney knocked this up for me - the heart of the adaptor. Before I assemble everything I still have to grind a small flat on each side of the protruding part of the brass rod, to get a spanner onto for tightening/loosening the hose fitting. Jack left that bit to me.
a. Side.JPG b. Top.JPG c. Back.JPG
To make things easy, I've gone with 1/4" hosetails on all parts, so I can use cheap 6mm ID silicon vacuum hose to connect everything and for the chuck seals, I bought a metre of 2.5mm closed cell neoprene foam:
d. 6mm ID silicon vacuum hose.JPG e. 2.5mm closed cell neoprene.JPG
The first of the vacuum chucks, a flat disc 230mm in diameter. Actually, not quite flat - I dished it very slightly, about 1.5mm deep in the centre, so it could hopefully hold flat discs better. The small green thing in the centre is a pre-filter - two 1" discs cut from a Scotchbrite scouring pad and glued around the outer edge to hold them together. It'll hopefully stop so much junk from reaching the main filter.:
f. Flat vacuum chuck - Front.jpg g. Flat vacuum chuck - Back.JPG
A test-fit of the main parts. I made a plywood stand to hold everything together:
h. Main parts test fit.JPG
The next step is the rotary adaptor for the handwheel. Finally, a bit of turning. I'm using a two-piece assembly. The main part, containing the bearing, fits up onto the front of the handwheel with a neoprene seal to prevent leakage, and is held in place by a clamping ring behind the handwheel. To clamp the two halves together I'll drill four 6mm holes through both pieces, thread some allthread into one half, then use countersunk nuts with washers.
So far, I've turned the recesses in both halves for the handwheel and the bearing. I only need to reverse-mount the main part tomorrow and cut an access hole for the brass fitting to protrude from. The Gods were with me and I got a beautiful firm sliding fit for the handwheel and the bearing.
i. Handwheel adaptor 1.JPG j. Handwheel adaptor 2.JPG
k. Handwheel adaptor 3.JPG l. Handwheel adaptor 4.JPG
To be continued......
0 commentaires:
Enregistrer un commentaire