Nuthin' Fancy - But I'm Makin' Stuff

Bill Arnold

1974
Staff member
Messages
8,622
Location
Thomasville, GA
Along with doing a few updates to my SO2 cnc, I've actually been a little productive about making things. I've done some practice with engraving and v-bit lettering but need to work on that a bit more.

One area of focus has been getting SketchUp and SketchUcam working together to make 3D. Below is an example of today's effort. I drew a small rosette in SU2015 (3.5" diameter), then kept playing with settings in SUcam until I got usable gcode. Don't fuss about the blue faces on the SU drawing - that's the way SUcam works - ask the developer! It turned out there were a couple of stray artifacts in the cut. If you look at the upper right corner, you'll see a small cut that shouldn't be there. SUcam added some lines of code that, in essence, dragged the bit along the face of the workpiece. After removing the erroneous code, a test trace using OPENscam was clean. I cut the rosette in mdf using a 1/16" ballnose bit and 20% stepover; next time a smaller stepover will reduce sanding. I haven't done any sanding on this sample piece.

Rosette_01_a.jpg Rosette_01_skp.jpg


Another thing I have been working on for a while is a ZCI for my table saw. Sounds simple enough but the scaling wasn't right. Even after checking and re-checking the calibration of my SO2, the insert was too small. That's when I found out about which end is up with SUcam. Or, actually, which face it needs to reference - which is the blue face. Don't ask me - ask the developer. I posted the issue I was having on Phlat Forum along with graphics and that's when they told me the blue face has to be out, whether it's a 2.5D or 3D project. So, alrighty then, I turned blue, re-generated gcode and get perfect fitting ZCIs. The one on the right got a coat of poly from the remains of a rattle can.

TS_ZCI_G0690.jpg


If the items below seem familiar, they are spindle mounts for my SO2. Yep, I made some with white HDPE a few weeks ago; they work but were a bit rough because of a brain freeze I had. Now that the spindle is spinning the right way, the bits cut much better!

CNC_SpindleMounts.jpg


Anyway, just wanted you folks to know I haven't been totally lazy - except at times!
 
Way ahead of me already Bill.

Saw some neat cheap software posted yesterday.. Can't find it now but will get back when I do. You are doing much better with your simple software than many that spend 00's if not 1000's. I really like your inserts...
 
Bill i think you have really shown just what is possible with your cnc. I honestly never thought that a cnc at its pricepoint would cut so well.
Those latest spindle mountings are incredible. The finish of cut on the edges is remarkable.
Can you mention if you recall just how long some of these items took to cut from the time you hit the go button.

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Leo not wanting to hijack Bills thread but those bandsaw inserts do you not find that the holes cause small bits to get stuck and make a problem for ongoing sawing when cutting something that has small bits coming off? At first i was going to steal your idea of the holes because i can see it being handy to get rid of the sawdust but on second thoughts wonder about the jamming up.
 
... Saw some neat cheap software posted yesterday.. Can't find it now but will get back when I do. You are doing much better with your simple software than many that spend 00's if not 1000's. I really like your inserts...

Cheap (free) software can be OK and the more I work with it, the more I learn.

The ZCIs probably took about the same amount of time as using a pattern router, then drilling holes, etc. Much easier to stick a piece of mdf on the cnc and press GO. ;)
 
... Can you mention if you recall just how long some of these items took to cut from the time you hit the go button. ...

I didn't log any of the times but, as I recall:

a) the rosette took about 1.5 hours. I set the feed speed to 30ipm and could go faster next time - didn't want to press my luck with a 1/16" bit. For four 1/8" deep passes, the gcode is 97,800 lines.

b) ZCIs took about 25 minutes to cut two of them. I set up the drawing to make two with a 1/8" two flute bit and feed rate of 20ipm. I could step up the feed rate without a problem, I think.

c) spindle brackets took about 35 minutes at a feed rate of 30ipm with a 1/8" single flute bit.
 
Leo not wanting to hijack Bills thread but those bandsaw inserts do you not find that the holes cause small bits to get stuck and make a problem for ongoing sawing when cutting something that has small bits coming off? At first i was going to steal your idea of the holes because i can see it being handy to get rid of the sawdust but on second thoughts wonder about the jamming up.

I don't know about Leo's experience with your concern, but I've never had any chips get stuck in the holes of the insert on my 17" bandsaw. I've had it for about 14 years so far.
 
not wanting to hijack Bills thread, do you not find that the holes cause small bits to get stuck?

No I don't want to do any hijacking either. I have not had any trouble with the holes. I copied the original Grizzly insert

That's one of the next thing I need to tackle. I've bought a couple of replacement bandsaw inserts and haven't been satisfied. What bit and feed speed do you recommend for brass?
If using brass use alloy 360 as it is free machining. feed and speed is machine dependant I would go with 8,000 RPM and about 20-30 IPM to start. I have cut as high as 45IPM with a 1/32 cutter


I didn't log any of the times but, as I recall:

a) the rosette took about 1.5 hours. I set the feed speed to 30ipm and could go faster next time - didn't want to press my luck with a 1/16" bit. For four 1/8" deep passes, the gcode is 97,800 lines.

b) ZCIs took about 25 minutes to cut two of them. I set up the drawing to make two with a 1/8" two flute bit and feed rate of 20ipm. I could step up the feed rate without a problem, I think.

c) spindle brackets took about 35 minutes at a feed rate of 30ipm with a 1/8" single flute bit.

Bill, at some point you should try a tapered ball end mill. They come in a 1/4 shank and taper down to a ball nose. I have 1/8 ball nose, 1/16 ball nose and 1/32 ball nose. The tapered mills are incredibly strong - as compared to a straight end mill. What thet means is that you can push them a lot faster. I sometimes cut at 125 IPM with a 1/8 tapered ball. I would not hesitate to push the 1/32 at the same rate. That rosette would then be 10 minutes or so.
 
Try as I may not to look in on these threads, it's like a car wreck on the free-way...gotta peak at least...:D...looking great Bill! Thanks for the dream food :D

You should give it a go, Ken! You sure wouldn't have to try to figure out what to do with your time if you built one of these things!!! :rolleyes:
 
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I use both brands and they are equal in quality.

I go for the less expensive

You do NOT need coated cutters.

Thanks, Leo. Those are some long bits. My spindle holds about 3/4" of the shank, so a 3" bit would be sticking out a long way. I'll look at their range of product and see what they have.
 
Thanks, Leo. Those are some long bits. My spindle holds about 3/4" of the shank, so a 3" bit would be sticking out a long way. I'll look at their range of product and see what they have.

Yeah - they are a bit long.

I actually had some of them cut shorter at work. Fortunately we can cut carbide.

I did recently get some new ones and didn't need to cut them. I think they were the Burchett ones
 
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