double cutting

[daves]

in the first photo is the stern of a model ship, my thumb will give you an idea of its size. In the close up of the carving you can see where the carving is missing or chewed up. To fix the problem of getting better detail i need a 1/32 bit. Problem is a 1/32 bit only has a cutting depth of 3/32. This entire stern arches from side to side 5/32. So i can create a surface set the depth at 5/32 then merge the pattern on to the surface. This will work with a larger bit like the 1/16, but the 1/32 bit can not cut deep enough to cut the surface arch. What i would like to do is first cut the surface arch and the arched piece the carvings are on with a larger bit. Stop the cutting file after the first cut, change the bit to a 1/32 and continue cutting in the finer detailed carvings.

to create a new cutting file with just the scroll work i still need to merge it onto a curved surface. loading this file into the machine, the machine thinks it is starting from scratch and recuts everything.

now are you as confused as i am?

[daves]

oops i thought i uploaded photos in the last post. i must of did something wrong
oh my photo was to big

i need to correct that

[daves]

ok i think i got it here are the photos

[bergerud]

I would try this: First carve the pattern with the 1/16 bit but use a spacer (a box cutter blade for example) under the bit touch down to trick the machine into carving the spacer width higher. After the rough carve is done, put in your 1/32 bit and carve the same pattern again. The 1/32 bit will only have to carve the depth of the spacer. It is important not to release the board between carves, otherwise, the machine will remeasure the board (bad). It is also important to stay under the rollers during the whole process so that the brass roller keeps acurate track of the board position. I have used this trick with a 1/16 diamond burr to finish sand. I plan to try it with 1/32 bits when they arrive in the mail.

[bdehoyos]

I have never tried that tactic to sand a finish carve, (using a diamond burr), I assume you use a dremel bit for that. It’s very in interesting approach . I think I might try it on my next carve.

[Pratyeka]

I would try this: First carve the pattern with the 1/16 bit but use a spacer (a box cutter blade for example) under the bit touch down to trick the machine into carving the spacer width higher. After the rough carve is done, put in your 1/32 bit and carve the same pattern again. The 1/32 bit will only have to carve the depth of the spacer. It is important not to release the board between carves, otherwise, the machine will remeasure the board (bad). It is also important to stay under the rollers during the whole process so that the brass roller keeps acurate track of the board position. I have used this trick with a 1/16 diamond burr to finish sand. I plan to try it with 1/32 bits when they arrive in the mail.

Interesting idea, but will double the carving hours for every projects.

[bdehoyos]

Actually I was thinking on creating 2 projects one of them with a .002” deeper than the first tis way there is no need for a spacer to “trick the machine”
Partayeka is correct it would be double carving time but the results might be good I saw some diamond dermal burs with a 600 grit, that a very fine sanding that will follow the exact path of all the carvings.

BDH

[HighTechOkie]

For the first pass, you could probably run it in Draft quality. On the second pass use Normal or Best. I would suspect the results to be as good as Optimal yet at less overall time.

Rob

[bdehoyos]

For those who use this technique, what type of burrs work best? I found this site but I'm unsure.


http://www.widgetsupply.com/page/WS/CTGY/dremel-diamond-cone-1

[bergerud]

I have tried this with an 1/16" ball diamond burr and even though the result was smooth, some detail was lost. I have 1/32" burrs on order and will report on the how these work.

[bdehoyos]

hmm I see you are talking about “fooling” the machine with spacer at the touching plate according to mi caliper that’s about .016” and I’m thinking of creating a second project with only .002” deeper, that might be way to go. I too will be making tests and them we can share results.

[www.go3d.us]

Dave, have you try adding draft to the pattern. Adding draft may help with pattern like this one.

[bergerud]

When I said to fool the machine with a spacer, I meant when the bit touches down on the wood not at the bit plate. There are some advantages to fooling the machine this way. You have precise control over the difference in cut depth whereas the program makes jumps ( to the nearset 1/128" ?) . Changing the depth in a complicated pattern may introduce even more unwanted changes. Fooling the machine is simple, you use the same file and you know exactly what you are going to get.