Dust Shoe Prototype for the Carvetight

[henry1]

Salen when you try it out, the shoe the top over the shoe will be in the way I did a test run and RC just fits when it take reading

[Sallen1215]

Dan how about this or a jig to do any of the pieces? Its a carve region with 1/8 holes in which you insert dowels to slide into pre-drilled holes in the acrylic.

[bergerud]

So here is the fully installed unit on my machine minus the bit plate which i will install shortly, the weak point in this system is the pipe. but with this corragated hose it allows for the shoe to be built and we redesign the piece to no need the bearing or the pipe.

That would really nice to eliminate the bearing. One would need a very flexible hose and some method to keep it out of the way. Clearance is a problem as well. You must have noticed that the pipe operates in a narrower space because it rotates and gives a little extra clearance when it is horizontal. The bearing was, in fact, the idea which originally made the thing possible.

[DickB]

With the sphere in the cube accuracy and consistency was extremely important. I is very difficult to fix the sphere if even one of the six carves is off. I made a jig into which a 2X2X2 inch cube snugly fits in from the top and is clamped from the front. The cube can be lifted out the top and flipped while the jig stays in the machine. It takes me awhile to set up the initial carve. Using scrap blocks, by trial and error, I find the coordinates corresponding to the center of the block face. After each test carve, I tweak the jog to coordinates from the keypad. (When it and asks to jog to center, I press numbers instead of the arrows.) Once I get a perfectly centered carve, I record the numbers. Now I put in the good wood and carve a pretty good sphere. I just keep using the same numbers. I actually will carve a few spheres once I have the numbers.

Once I remove the jig, turn off the machine, or abort the project, all is lost. It is possible, however, to carve different projects (ie. different face carves) with the same numbers. If for example, one wanted to make a set of alphabet blocks.

Thanks. Got it.

So I'm thinking, for a larger project like mine, (or the dust shoe?), I could build a large sled. It would have something like 10" of dead space at one end. I would machine the back side of my board with a back only project in this sled, using Place On Corner (the project would include the 10" of unused space to the right as viewed in Designer). I would have set up a dummy project to drill a hole 3-1/2" from the end of the sled. When I run that project and it finished, the business end of the sled would be protruding from the machine, so I could flip the project board. If I had drilled a through-the-board index hole in my back project board, and in the sled, I could use it and a jig to position the board precisely in the x-direction on the sled after I flipped it. A rail on the side of the sled would fix the y-position, if I flipped the board end to end, not in the standard way. Then I could run the front project, all without having removed the board.

[bergerud]

Dan how about this or a jig to do any of the pieces? Its a carve region with 1/8 holes in which you insert dowels to slide into pre-drilled holes in the acrylic.

That is what I use. I have a 3 by 4 by 1/2 recess milled for the piece to fit in. Usually I make it a press fit. Sometimes I use tape. I pull out the piece and flip it over in the jig for the second carve. I also have one for 3 by 3 by 1/2 pieces which is only 1/2 inch thick and I flip the whole thing over for the second carve.

[Sallen1215]

with the dowels i would think you can limit the machine drift. Then using jog to center and make the center in the same place on each side

[bergerud]

Thanks. Got it.

So I'm thinking, for a larger project like mine, (or the dust shoe?), I could build a large sled. It would have something like 10" of dead space at one end. I would machine the back side of my board with a back only project in this sled, using Place On Corner (the project would include the 10" of unused space to the right as viewed in Designer). I would have set up a dummy project to drill a hole 3-1/2" from the end of the sled. When I run that project and it finished, the business end of the sled would be protruding from the machine, so I could flip the project board. If I had drilled a through-the-board index hole in my back project board, and in the sled, I could use it and a jig to position the board precisely in the x-direction on the sled after I flipped it. A rail on the side of the sled would fix the y-position, if I flipped the board end to end, not in the standard way. Then I could run the front project, all without having removed the board.

I like that idea. Great idea about having the sled come out of the machine to access. I have been fighting with flipping small projects while the project piece is between the rollers. I have to think about that one!

(Why would you flip the board end for end? I must be missing something there.)

[bergerud]

with the dowels i would think you can limit the machine drift. Then using jog to center and make the center in the same place on each side

I have not had much luck with jog to center. Maybe if you used a sharp pointer instead if the blunt carving bit. I still worry about backlash errors.

[DickB]

(Why would you flip the board end for end? I must be missing something there.)

Now that I think about it, it would be better to flip it the usual way. But the sled would have to be designed such that the board could be adjusted along the y axis. When you flip the board, you could retain the x orientation by locating the board tight against the end of the sled both back and front, but you lose y orientation. The way I make my sleds, the board is clamped against a rail, and can be adjusted in the x direction, so I was thinking flip the board the other way. But that would be counter to the orientation in Designer and cause complications.

[bergerud]

It is interesting that you only get to keep one dimension constant when you flip a board. Flipping end for end keeps the y center the same while the normal flip keeps the x center the same. In my experience the x measurement is uncertain and not adjustable where as the y is more consistent and adjustable (y offset) so I think sticking with the normal flip is best. I do like the idea of having the sled micro adjustable. If you could turn some knobs and tweak the position of the board a 1/8 of an inch each way, the hole drilling method could really work well I think. Or, with some kind of reference like a 1/16 carved dot as the first part of the pattern and a 1/16 hole through the board, one could stop the carve at the start just as it carved the dot and tweak the sled.

I find this accuracy - repeatability problem very interesting. Another thing I have tried is clamping a block to the rear out table. After the first carve I start the second carve but before the second touch, I clamp the block up next to the end of the board, flip the board, dispel the possible board removal message, remove the reference block and start the carve. This way I get to flip the board while saving the x position. For this to work the y offset has to be right. It is very tricky, however to tip the board out and back without moving the brass roller. This idea using a sled would be better.