CNC
Design Study
Hmm…
I have the design of my Taig CNC mill to CNC lathe conversion further along. I have the few scraps of the non-Taig material in hand and I placed an order for all new Taig components I will be using. I had an eight year old spindle and a 3,000 rpm Dayton motor but I decided to design with current parts and slower motor so there would be no surprises if I put together a kit. I also have a new idea for the tool mount that will be much easier and probably cheaper to implement.
The CNC lathe conversion is ultra easy and low cost if you own the CNC mill. I will dare call it a quick change process. It consists of mounting the Taig lathe bed on the Mill table, removing the mill spindle and motor assembly in one piece, and clamping on the lathe tool holder on the Z axis. I will be using a standard lathe 3/4 -16 spindle with a 1/5 hp mill 1750rpm motor to power the spindle with standard mill belt drive. I like the fact that the standard Taig tailstock can be used if required. There is plenty of working room above the lathe with the mill head removed.
Lathes should not be spinning at 10,000 rpm so the smaller mill motor will be a good choice rather than using the faster CNC mill motor, at least for the prototype. Of course testing is needed to prove this point, but it only makes good safety sense not to spin too fast.
Future development could be with a geared drive for slower rotation and an rpm reader to allow for thread cutting.
I decided to design and build this conversion mostly because it seems so easy to do. I don’t have… Continue reading
Taig CNC Lathe Ideas
Thanks to the contribution by George Moorehead of Gig Harbor, Washington, I see an excellent platform for creating a Taig CNC lathe. My vision is to use mostly Taig components. It is a similar basic idea that other creators have embraced (like Tormach Duality Lathe)* when creating a CNC lathe machine. I am not thinking of the entire lathe, just the head as George has done.
*Tormach seems to be phasing this Duality lathe-on-bed (LOB) product out with preference to their new Slant Bed lathe. At least it is no longer prominent in their product offers. But for the Taig, the lathe head design on the mill table seems like a very practical way to achieve CNC lathe operation.
I have often studied the Taig micro lathe trying to imagineer how to make it a CNC lathe. Many folks have accomplished the task. But George and even Tormach with their new slant bed design have raised a good thinking outside of the box point that a CNC lathe doesn’t have to look like a converted conventional lathe. The head-on-bed (HOB) is a superior approach for Taig components. Of course this has been done by many others, so no originality is claimed or credited to anyone. The Taig factory could be doing it.
My point is any home machinist can do this and thanks to George for getting the juices flowing and blowing away my image of a converted Taig micro lathe.
I have all the major spare parts needed. Even an old style Taig CNC mill head (Non ER) and an A/C mill motor. I just need to design a few mounting plates. I can see that this would also make a great 4th axis with the proper stepper motor.
I am only discussing ideas here. As a dealer,… Continue reading
CNC Wax Bell
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- Proof of concept
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- Stem turned on lathe
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- Inside
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- Bell on sprue
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- 201 grams of brass.
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- Web Wax
Yes! It can be done, as if there was any doubt.
I started with a 2″ diameter 3″ long wax cylinder. On the Taig micro lathe I turned half the length down to just over 1″ (not critical) so it could be held in the self centering 4 jaw chuck shown here. Once in this chuck it was never removed until finished.
I machined the inside on the Taig CNC mill as a 3D pocket. Then I switched to the 4 axis setup and ran the outside profile. When finished is shown in the first picture. Note the smooth finish that is possible.
Then I went back to the lathe (still in the original chuck) and turned down the stem and top of the bell. It would have been too weak if I had done this earlier. The big end will be cut off before spruing for the cast.
Not bad for a first try but still a lot of things to tweak.
The next bell I will spend more time on the CNC picture taking. I’ll do some video of the machining action. There was quite a pile of wax chips and turning ribbons. That green wax is a joy to machine. The bottom three pictures shown are more fitting I suppose for the lost wax casting over in “Ramblin’ Dan’s Workshop” than here in the machine shop blog but to get to this point there was a whole heck of a lot of CNC machining and some manual lathe work.
4 Axis Spruce-up
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- Centering Axis
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- Looks Good
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- Chuck Adapter
I have found a good project for my 4 Axis CNC mill and also my Rhino 5 software. If you have read recent posts I have mentioned I am pursuing carving some small bells from wax for lost wax casting. Here I am re-configuring my original Taig micro mill back into 4 axis operation.
I need the tailpost to be able to slide into any length position I need. The stock Taig slotted table is perfect for that. I don’t need the multi hole set-up table for 4-axis. I set the rotary table up so I can just slide the tailpost against the back of its slot and it is in perfect Y alignment. The height is taken care of by the shims and the small adjustment in the tailpost itself. After this set up it will be a very quick reset for the tailpost.
You can see I have placed a Chuck adapter in the middle of the table. I will use that (with a chuck) to hold the wax cylinder as I mill out the center of the bell.
I have a few seconds of video I made of a dry run of the 4-axis profiling run. It makes some interesting sounds as the X axis is moving very slowly and sometimes “jiggling” a bit. Not sure why, but it is playing that CNC music. You will have to imagine all the missing parts. Hey! Just do it! 🙂
Bells and CNC Thoughts
example
I have found a niche for my casting and CNC machining desires. It is the designing and creating small custom bells to be cast in silver, brass and bronze; also using bell metal if I can find or make it. Bell metal is high tin content brass.
I am currently working on obtaining the correct wax for CNC detail machining of the designs. My two Taig mills, one of which set up for fourth axis millings are perfect for the size of bells I am considering. That is, bells with a diameter between one and two inches at the open end. I figure they may be one to two times the diameter in height for the bell section. Then whatever is used as the handle or bell mount.
I will pocket mill the bell interior from the end of the wax cylinder, probably using a ball end 2 flute tool. Tool size will depend on the bell diameter and depth. Perhaps 0.250″ on larger size bells down to 0.125″ on small bells. No interior details, just hollow out. The 2nd set-up to do the exterior will be milled on 4th axis rotary, roughed with perhaps 0.25” ball end before details. As far as the detailing I have used as small as 0.003 tapered wax milling bits Like an engraving bit (many hours of run time) making medallions. That is probably not typical for my bell project but could be the extreme. Most likely I will use 0.010-0.020 mill end sizes. I buy my wax bits from Bits&Bits and they are especially made for detailed wax carving, spiral open flutes, etc. Initial trial runs will not be detailed. Just get something basic to carve then cast and see results.
I am thinking this is a perfect combination of my skills and… Continue reading