Workshop
Letting the Cat Out of the CAD
I am taking an opportunity in my project schedule to try another CAD/CAM package. I had looked at it long ago and it has been around for over 25 years. When I first saw it (back then) I believed it was one of those,”yet another CAD/CAM packages.” I am sure at some point I registered and ran at least the demo, as it seems I have been receiving occasional marketing from them forever. Back in that time, I was looking for a cheap all in one CNC solution. I was still a bit naive of all the requirements. I did find and purchase DeskCNC with its serial port interface. That worked OK but I am now using much stronger and expensive Rhino and Vectric 3D software and MACH3 from ArtSoft. You get what you pay for.
The product to which I am now referring to is BobCAD-CAM. I knew it was created by a guy named Bob (Bob Twaalfhoven) so I assumed he just called it BobCAD after himself. I was thinking simplistically it was Bob’s CAD. Today it is a more professional play on the image of a Bobcat, just change the T to a D. Whatever the thought on the name, it has survived the test of time.
Soon I will see if it survives the test of Dan.
DeskCNC is still around too but the web page has changed little to none. BobCAD-CAM is on version 24 and a first web site look, while allowing for marketing hyperbole, seems impressive.
It will take me a few weeks or a month or so to give it a full workout and use it to construct a CNC project. I’ll probably leak a few comments here in the blog, but I am considering doing a full report, probably… Continue reading
Model Engine Builder
This is not a paid advertisement. Mike Rehmus has no idea I am making this recommendation. I have been reading this magazine since Mike and his wife Toni started publishing. If you are a real machinist and love to make small engines, this publication is for you. But then you would probably already know that. It is also THE publication to get arm chair machinists back into their shops or to get their dream shops assembled.
And… If you really just like reading about the construction of model engines, this is still the publication you need to have in your library. You will definitely save this magazine.
Low volume high quality publications are very expensive to produce. The $10.00 issue price is not someone making a fortune. Oh and I almost forgot, each issue contains a set of CAD plans for the engines presented in the issue. I get model airplane magazines too and the plans are always an extra cost addition. So an MEB subscription and the plans are well worth the investment and a wonderful contribution to building your library of full documented projects.
The website is www.modelenginebuilder.com. From there you can order your subscription or purchase back issues. Remember, this is a publication full of real construction plans and know how. Tell them THMS sent you! It won’t do anything for me except make me a fan-boy.
Woodcarving and Dust Control
As seen elsewhere in this blog, I have been doing some woodcarving. Some of it is done by CNC machine and the rest is done with power hand tools or just knife and gouge. I like them all.
My PN causes some problems with hand (blade) carving but I still like it very much and it is so simple, clean and basic I just keep going back to it.
The biggest problem I have with powered (rotary tool) carving is the fine dust control. I haven’t yet invested in a good dust control system. That’s big money to do a good job. I will probably design my own to control the cost. I just want to be carving things right now so I use a shop vac or a small fan to blow the dust away from me. That isn’t too effective and doesn’t make for a clean shop!
Carving is much more than just wood. Wood is usually the vision a non carver thinks about when they hear the term. What’s not immediately thought about (and this holds true for all woodworking) is the dust issue. Wood dust is not a harmless “natural” material. I remember the years my grandfather (who taught me a lot about woodworking) worked in the dust and he was a smoker. We learned about the hazards of mineral dust because it was more irritating, but wood dust is no safe haven.
I use both the HB2 CNC carving machine and hand rotary tools like the Proxxon, Dremel (not so much) and I really like the 400,000 rpm air powered hand piece. The later is a super fine dust maker but I love the action. They all definitely need a fine dust collection system before I use them much more.
My dust system will… Continue reading
…and a cast of thousands.
That’s a famous movie intro tag from when I was a kid. (Ben Hur, Moses and The Ten Commandments, etc.) In this case the “cast” is a bit different. No Charleston Heston. Yes, a pun.
The process here is casting pewter into a mold. Perhaps thousands could be made given enough time. What I find interesting is the use of a rubber mold. When I was much younger I remember toy soldiers cast in metal molds. (The metal ones are still available.)
The mold shown here looks like it was made with hot vulcanized rubber but hot metal casting process is also shown to work with RTV (Room Temperature Vulcanization) rubber. Of course metal and plaster molds can be used.
You will notice a few have short guns. The pour was a bit too cold and the flow didn’t get to the end of the rifle. Thin parts like that are tough to fill. I cast many more than shown here (just remelted them) before I got the process right.
All I did for the pictures was cut off the sprue while still hot and then file the flash from the bottom so each one would stand up. No clean up of the casting at this point.
My plan is not to make toy soldiers. This is just an inexpensive all-in-one kit I bought on sale to get the “hang” of casting pewter. I plan to make and cast my own mold designs and perhaps offer them for sale (the molds and what they make).
I choose pewter and this variety is lead free. There is so much concern about the “dangers” of lead, it is not a good idea to offer it to the public. Of course the other metals in pewter are not intended for… Continue reading
4″ Mayan in Wax
I use the Mayan calendar as my CNC test program. It is highly detailed and makes the stepper motors really earn their keep. In these photos I show where I have reduced the circle diameter to just under four inches. This is about as small as I can go with this design. I got it off center a skosh. That’s OK, it’s not a keeper. The test is not of the Taig mill but rather the tiny wax profile bit I bought from Bits & Bits.
The bit is 1/8″ in diameter half round with a 15 degree included angle. The end of the tip is 0.005″ It looks and feel like a very sharp needle. The RPM was 10600 (max for the stock CNC Taig) and the feed I had set for 30 IPM. With ramp up it seldom got to 30 IPM except for long paths.
The total run was just over four hours. The Taig and CNC controller took this run without a blink.
I use plain air to clear the wax chips but you can see they still liked to stick around. The problem could be the slow feeds because of the intricate details. I am going to try a faster more aggressive feed on the next Item. I am thinking of trying a small lithophane carved in wax.