Dust Shoe Prototype for the Carvetight

[JLT]

You only need a small cyclone. See my cyclone for the dust cap made out of a pop bottle. I have been using it ever since I made it. I just looked in the mini vac after months of use and only found some pieces of tape, some large shavings, and a little dust.

With respect to the cyclone, I've already downloaded your MPC for the cyclone. (Thanks for posting!) Just have to go grocery shopping for an appropriate plastic bottle...

I could not see a brush. Does you experience indicate that horse power eliminates the need for a brush? I remember thinking that no air flow from a vacuum could stop chips coming off of a 20,000 rpm bit. It seemed to me that the chips have to be physically stopped before being vacuumed up. (That is why I do not think the overhead type can ever really get all the chips.) Are you seeing any escape under the shoe?

With respect to a brush, I don't use one on the shoe I created. On an earlier post with images of my shoe, you can see a large channel to the right, which given the spin of the bit is generally where the chips fly (as you are obviously aware based your design). Additionally, with a 0.8" I.D. hose, the abundant volume of air being pulled seems to be more than adequate. That being said, I've only used this style of shoe for ~2 hrs of carves and cutting, so I don't feel that I'm reporting with sufficient experience. There is a very small amount of dust that escapes with the 1/16" carving bit, particularly near the edges of the board. The 1/8" four (4) fluted cutting bit though, when cutting four (4) passes through 13/16" hardwood, spits up shavings through the small hole in the dust cap (probably <2% of the dust), which of course escapes the vacuum.


I have no illusions that I'll be able to get 100% of the dust. My main concern is to limit the amount of dust that collects on the Y and Z belts, and in particular the dust that accumulates around the poorly sealed X gear assembly. Before these last few carves with the dust shoe, I would visit the machine every ~15 minutes, and with a small vacuum attachment, reach in through the top while the carving was underway, and suck up what I could from the mounds of dust building up. I will of course still visit the machine every ~15 minutes during carves, as high speed moving parts and shavings equals a fire hazard, but instead of being on dust patrol, this time I will simply enjoy watching the carving...

[Sallen1215]

I am working on a new procedure (as I was commuting to work.) to do accurate (small) double sided carving independent of machine calibration. When I test it, I will start a new post.

The idea is this: Put in the carrier board and measure its length and width. Divide those numbers in half and write them down as the approximate coordinates of the center. Drill a hole using these center coordinates. (Use jog to center but plug in the numbers.) Now measure the distances from the hole to the sides of the cavity. Take that difference, divide by 2 and add (or subtract) from the approximate y center number. (Who cares about the x since it is constant when the piece flips.) You now have the y center coordinate required to carve in the center of the cavity. These coordinates can be used to carve many different parts as long as the carrier board stays in the machine. One chooses jog to center and instead keys in the same coordinates for each side of each carve.

It takes a little effort to set up but the results will be consistent and fairly machine independent. Many parts can be made using the same numbers. I will try it tonight.

Did your procedure work out like you thought? Also was curious if you have the new design for the Rock chuck ready to post as i would like to try it on my machine. going to make a new pipe with different measurements tomorrow and see how it turns out with your sled design.

[bergerud]

Two things.

First: The procedure works great but it takes some effort to set up and one wrong button push and you have to start all over again. Not only could be frustrating but also required manual measurement. I think I now have a better one. Here it is:

Before carving anything, load a project that just drills a shallow 1/8 th hole in the center of the 3X3 piece using my carrier board.

1. When the question comes to 1) Center On Board choose instead to 2) Jog To Position
2. It will ask for the 1/16 carving bit (to jog with) but put in the 1/8 cutting bit.
3. Press STOP when it starts to bob to touch the board. You will get the option to 3) Jog.
4. Jog to the approximate center of x with the arrow keys and write down the x center coordinate from the display. Accuracy in x is not crucial.
5. By hand move the carriage to the hole in the carrier board on the keyboard side and push the bit down and up against the 3X3 side. Write down the y coordinate on the display. (Call it a.)
6. By hand move the carriage to the hole on the other side of the 3X3 and measure up against it. Write down the y coordinate. (Call it b.)
7. Calculate the y center (a+b)/2. You now have the x and y coordinates of the center of the 3X3 piece. (Independent of whether the cavity was even cut in the center!)
8. Now move the bit by hand or with the arrows to a place to touch and press enter.
9. After the touch you will be asked to Jog to project, choose 2) Center.
10. Instead of using the arrows, key in the x and y coordinates you have written down. (Careful: the first digit has to be pressed twice. Once just to change the mode. If you screw up, you can press STOP.)
11. Press enter and it will ask for the 1/8 cutting bit - just keep going and drill the hole.

Get out the calipers and check that the hole is really in the y center of the 3X3 piece. It will be. Now you are set set up to do accurately centered carves using those same x and y center coordinates with the Jog To Center option. These numbers will be good as long as the carrier board is in the machine. (Unless you abort a project whereas all will be lost!) The thing is that you have to be able to hold the piece in the carrier board and also be able to easily get it in and out of the cavity while in the machine. Screws in the side or a clamp or something. This is also another job for the jog. You can use the jog to move the piece to an accessible x position. It does not matter when you flip the piece so start the second side project and then flip the piece later during the jog to touch step.


Second thing: I realized when I was experimenting with these methods that I am the one who has been carving the pipe incorrectly. With the 12mm thick acrylic in a 1/2 inch cavity, I was touching the carrier board on both sides. This effectively adds the difference between 12mm and 1/2 inch to the thickness of the pipe. When I do it right - touch the acrylic on one side and the carrier board on the other side (touches 1/2 inch apart) I get a thin pipe indeed! The machine always seems to cut a few thou deeper than the mpc and the pipe cannot handle that. I am so sorry that I did that to you guys. My bad. I do not, however, think that that was the only problem. Line up of the two sides is also crucial and I think the above procedure will fix that. I will rethink the pipe and fix it up. It may be a few days before I get the new stuff up. (My wife has returned from a trip.)

Edit: I now remember how I used to carve the pipe. It was on a 1/2 inch thick carrier board with the cavity right through and I would flip the whole carrier board. I would touch on both sides of the carrier board but so that the fact that the acrylic was only 12mm did not matter.

You can carve the pipe the way I did or wait for a new mpc. Also, here is the body mpc for you to experiment with (the only part that uses a 3X4 carrier board). I cannot guarantee that it is the final version. The top mpc is first (touch on the piece where the bearing hole will be) and the bottom is second (touch on the carrier board).

[henry1]

I just carved the shoe body and maybe because I didn't jog it, this what I got, I did not get the full effect of it also do we use the same dust cap for the top Dan

[bergerud]

The front and back did not line up. How did you carve it? You should have been able to carve it just the same as you carved the first prototype.

The top of the shoe is quite a bit different than the first one.

[henry1]

I think it my fault , when it was telling me the y belt had skip working on that now , the shoe body top do you have to put a circle so to carve it out ?? also I did carve the same a before I have the arcri; exact 1/2

[Sallen1215]

HOORAY!!!!!! Here is my results with the new information and the new sled carriers provided

[henry1]

glad you got it step

[bergerud]

HOORAY!!!!!! Here is my results with the new information and the new sled carriers provided

Alright! I guess I have to get to work on the top. I am having a strange problem with positioning which I think has to do with the puffing. I think I have to delete the puffing to get it to carve right. It may be a puffing bug. Hopefully tomorrow.

[Sallen1215]

the bearing fits nicely, this is a clean and fast carve. not sure whats different but it is a much faster carve