Hello all - ya'll are familiar with the Surface Grinding Attachment several of us have built. The most variety and issues has been in the feed adjustment system. The following is how I handled the system.
Above shows the overhead view - you can just see the 1-1/2" tooling arm it's all mounted on at very top. The first build I did had the adjuster system mounted to the side of the tooling arm because with the contact wheel mounted on a separate tooling arm, it had to be mounted to side. I decided for the extra $60 or so to purchase a dedicated contact wheel and mount on same tooling arm as the adjuster system was worth while. I think it's better. I've still got less than $300 invested in system. Because I mounted the contact wheel on same tooling arm, I reworked the bottom plate so the adjuster system would be centered with the contact wheel. It worked just fine offset to one side, but I like this better.
I removed the dial indicator because I used it for my rise-fall indicator for folder building. After using it some I decided an indicator didn't really buy me much. When I moved the adjuster forward .005" (about max for good feed and grinding), depending on what grit the belt was, it might remove .002", or it might remove .001" or it might remove .003". Never a set amount. Turn the adjuster screw (1/2"X20) and you move it forward .005". Does that agree with ya'll's experience?
The above is the side view showing better the tooling arm with 6" contact wheel mounted as well as the "feed system" (is that a good description?).
Above is a better close up view of the feed system. The big knob at very left is the 1/2"X20 tpi all thread I used to adjust. 20 TPI gives .050" forward movement for each turn. The 1/2" plate at rear is tapped to 1/2"X20 TPI, with the next vertical plate just having a smooth hole with jam nuts so it can turn freely and push the adjuster plate forward, or rear direction. The two brass screws you see adjust the gib to remove all sideways slack from system.
Above is the feed system taken apart to show how it's made. Note the "red" slot? that's a Tee track with a slide nut with 5/16" brass all thread. Just above you can see the furled nut I made that fits the 5/16" brass all thread. From a prior photo you can see the furled nut is on bottom of tooling arm and tightens the feed system. You can see the brass gib inside the feed system to remove slack.
The bottom 1/2" plate is a 3" wide plate and bolted to the tooling arm. The top adjuster plate is also 1/2" X 3" wide with the small vertical plates bolted to the side so they slide and are held in place on the bottom plate.
About the only machinist tool needed is a milling machine, and that's for milling the gib slot and the slot for the Tee track. All the rest of the work is drill press work. My first setup did not have the gib, but only had the top plate laying on the bottom plate and it works pretty good. Especially if you make the Tee track the full length of the top plate and use two nuts in the Tee slot. Take a brass bar 1/4" thick and 1" long. Make the width a snug fit inside the Tee track, but will slide ok. David (OneArmed) used two of those nuts and didn't really need the gib on the side and save a good bit of work. The Tee track is epoxied into the slot.
Above shows the overhead view - you can just see the 1-1/2" tooling arm it's all mounted on at very top. The first build I did had the adjuster system mounted to the side of the tooling arm because with the contact wheel mounted on a separate tooling arm, it had to be mounted to side. I decided for the extra $60 or so to purchase a dedicated contact wheel and mount on same tooling arm as the adjuster system was worth while. I think it's better. I've still got less than $300 invested in system. Because I mounted the contact wheel on same tooling arm, I reworked the bottom plate so the adjuster system would be centered with the contact wheel. It worked just fine offset to one side, but I like this better.
I removed the dial indicator because I used it for my rise-fall indicator for folder building. After using it some I decided an indicator didn't really buy me much. When I moved the adjuster forward .005" (about max for good feed and grinding), depending on what grit the belt was, it might remove .002", or it might remove .001" or it might remove .003". Never a set amount. Turn the adjuster screw (1/2"X20) and you move it forward .005". Does that agree with ya'll's experience?
The above is the side view showing better the tooling arm with 6" contact wheel mounted as well as the "feed system" (is that a good description?).
Above is a better close up view of the feed system. The big knob at very left is the 1/2"X20 tpi all thread I used to adjust. 20 TPI gives .050" forward movement for each turn. The 1/2" plate at rear is tapped to 1/2"X20 TPI, with the next vertical plate just having a smooth hole with jam nuts so it can turn freely and push the adjuster plate forward, or rear direction. The two brass screws you see adjust the gib to remove all sideways slack from system.
Above is the feed system taken apart to show how it's made. Note the "red" slot? that's a Tee track with a slide nut with 5/16" brass all thread. Just above you can see the furled nut I made that fits the 5/16" brass all thread. From a prior photo you can see the furled nut is on bottom of tooling arm and tightens the feed system. You can see the brass gib inside the feed system to remove slack.
The bottom 1/2" plate is a 3" wide plate and bolted to the tooling arm. The top adjuster plate is also 1/2" X 3" wide with the small vertical plates bolted to the side so they slide and are held in place on the bottom plate.
About the only machinist tool needed is a milling machine, and that's for milling the gib slot and the slot for the Tee track. All the rest of the work is drill press work. My first setup did not have the gib, but only had the top plate laying on the bottom plate and it works pretty good. Especially if you make the Tee track the full length of the top plate and use two nuts in the Tee slot. Take a brass bar 1/4" thick and 1" long. Make the width a snug fit inside the Tee track, but will slide ok. David (OneArmed) used two of those nuts and didn't really need the gib on the side and save a good bit of work. The Tee track is epoxied into the slot.
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