Posts Tagged ‘machine tools’

It’s no secret one of my lusts is machining in metal and wax. Actually, machining any material is fine with me. Wax became my favored material because it machines so well, especially with very small tool bits. Primarily, jewelry CNC carving for lost wax casting (LWC).

But I have also machined wax for LWC casting in brass, and that also works very well. I am not involved with casting large objects. At least not yet. But I don’t have an interest in doing large scale sand mold type casting. That’s a whole ‘nother sideline.

My light weight Taig equipment is perfect for machining wax. Taig tools also do an admirable job on small metal cutting as well. I have milled everything from stainless steel to cast iron. I have had no problems with brass, at least the types I have machined. Like most metals, there are many alloys. I choose the easy to machine.

I recently viewed a railroading model project (a hand-car)* made by an old friend Ed Hume. It got me re-considering my old lust for live steam engines and locomotives. They are machined directly from metal. That fanned the embers again and created a bit of remorse that my metal shop hasn’t been productive as was intended, except for the LWC silver work.

*Don’t know how long this link will last.

I designed my shop and machine equipment size specifically to create model train and model engine components. Not (what I consider) full size, or real life-size components. The term often used is “Model-Engineering” workshop.  

I recently dusted off one of the machines, the Proxxon PD400 mini-lathe and turned down some leaded steel stock into a mandrel and cap for my wax carving. That effort really felt good, experiencing those perfect cuts and shavings (chips) coming off the steel. I didn’t even mind the stinging burns on my arms from the hot chips. Enjoying pain may be a bit deviant but goes with the work. Also reminds me that I should wear burn proof long sleeves in the shop. Hard to do when my garage shop is 90 degrees+ in the Texas summers.

So, I mentally struggle again for a direction for my future activities. I became very serious with my LWC silver casting. I believe I create very professional silver cast jewelry work. But I am realizing I am not going to move up to the level of a manufacturer. I dislike making multiples of the same thing on a large-scale production. I do love specialty designs and very limited runs of multiples when there is a reason. I don’t want to build stock just for inventory. I’d say I am always a Hobbyist at heart.

My problem is I get bored once I have something mastered. I want to move on to new challenges. That has me looking back at the one-off model maker. Every part is a new experience. Sometimes there are multiples, but they are a part of a single creation. Like wheel sets on a train car or locomotive.

Will I fan the coals, and re-stoke the fire? I’ve said that before. Just check back in the archives of this web site. All I need is a little push and I’ll be over the edge again.

I have the machines and the workshop. I have the time, that is if I manage my time wisely and don’t try doing too many things at once. It’s called maintaining focus. It’s one of my moto’s I really have to practice. “One perfect part at a time.”

At my age I remember the Ed Sullivan Show on TV and the act where the fella has about a dozen plates spinning in the air on long vertical sticks (The record is 108). The big job was keeping them spinning so none fall off. Probably a visual metaphor now lost on today’s young folks, about doing too many things at once.

My brother and I each had one plastic plate and a stick as manufactured toy. The only thing difficult was keeping a lot of them spinning.

For me it is too many hobby interests at once. When I turn one off, I want to add another plate.

 

Using 4 axis milling, requires a CAM software system to create the necessary CNC G-code. It’s not something one can easily hand code when doing 3D designs. Simple level surfacing could be hand-coded on a 4thaxis, but probably lathe turning would be far easier.

Aspire, a three-dimensional CAD/CAM produced by Vectric can produce G-code for the 4thaxis. It is one of my go-to programs. However, I don’t design everything in Aspire CAD. Fusion 360 and RhinoCAD are also programs I use for design.

Both these programs have 4 axis CAM built in. Fusion 360 has a built in CAM, and with Rhino5 I have a plugin RhinoCAM 2012 w/4axis.  In Fusion the 4thaxis CAM is 2.5D and cannot produce 3-dimensional 4thaxis G-code. I added 4thaxis 3D CAM to RhinoCAM 2012 but find it extremely difficult to produce quality cut pathing. It seems to contain some very strange algorithms producing highly fragmented pathing.

This has led me to another 3rdparty CAM software (from the Netherlands) called DeskProto. It can take input (in the proper format) from any CAD software. (I won’t be getting into describing the process here.)

DeskProto’s claim is that it is CAM software for creative people and not the die-hard machinist. I find agreement to that statement. I find details missing with some lack of particular seldom-needed features perhaps needed by a high powered VMC machinist. For the rest of us common users, making things (on up to 5 axis milling systems), DeskProto gets the job done without micro-managing every single minor detail.

Having made that (limiting) statement, there remains plenty of useful variables that will insure getting the results a user like myself desires.

I will admit I put off choosing this program, as I had access to the “professional” CAM in my existing CAD programs (described above). I discovered I didn’t need all the hard-to-use and “understand” details of those programs. Pride goes before failure. I failed in easily getting what I wanted from the other systems.

I downloaded and installed the unlimited use DeskProto trial software. I had full access to creating 4thaxis output. It does imprint a large “X” (trial copy) in the output file and is seen on the visual display. But I was able to produce some very clean and sensible G-code pathing.

Since I am a hobbyist user, I decided DeskProto was an excellent value CAM addition for my 4 axis needs. It is an improvement of what I get from Aspire on 4 axis output. I paid for the highest-level version of DeskProto and (of course) the registration removed the trial edition “X” without re-installing the software.

Now that I have a full non-obfuscated version of DeskProto installed, I will run some real projects.

My first task is to machine a suitable mandrel to hold the wax I intend to 4thaxis machine. The picture is a 3D printed example of the mandrel I will make with 12L14 carbon steel. I will be posting 4thaxis cut wax examples sometime soon…  

 

Wax swarf blower system

The blower that was added to the Taig spindle on the original WAX milling system has been updated to operate on the new high speed water cooled spindle. A full article with pictures can be found here: https://thehobbyistmachineshop.com/cms/projects/wax-fan-v-2-0

This is not a dimensional, How-To article. It demonstrates how 3D printing can be utilized to add accessories to the Taig mill and a high speed water cooled spindle.

The parts arrived yesterday. Exactly as shown in the previous post. I placed an order for some four conductor cable for the wiring between the Variable Frequency Drive (VFD) and the spindle motor.

I needed to see the clamping size of the spindle’s electrical plug connector. I didn’t want to select and order a cable that would not fit. The cable is on they way to me, so I created the adapter I needed to mount the new spindle on the Taig Micro-Mill.

The picture shows the results of my work as the spindle is now nicely mounted on the mill.

After I am finished with all the mounting, wiring, and set-up… and I have the new spindle working, I will write a detailed report on the mounting plate and all the work required in making the conversion.

I think the spindle looks like it belongs on the Taig!

Choosing Proper Machine Way and Screw Lubrication.

RDS processed a half dozen orders for the new Taig ball-screw micro-mill. A question came to me from one of the customers, about proper lubrication requirement for the ball screws.

I have always used a 20 weight non-detergent oil on all my machine tools, which is packaged in small cans for the lubrication of electric motor bearings. I apply it on the ways as well as the screws and crank bearings.  I did not know what Taig recommended for the new ball-screws and bearings.

I contacted Taig and a staff person gave me two options. One was #2 way-lube and the other was automatic transmission oil. The transmission oil was a surprise to me.

I check on the way-lube and discovered most suppliers sold it in 5-gallon pails for a bit over $100. Five gallons on a Taig mill is a lifetime supply. My lifetime anyway. I found a supplier on eBay that was selling it in two one-pint bottles. They are shown in the picture.

In the meantime, I had the transmission oil in my shop so I tried it. It is very slippery and seems to hold a good film. I didn’t test it in long term use. One slight drawback is the unique odor of transmission oil, and this brand was colored red. (That’s so car mechanics can tell by the color what oil is leaking.)

Taig recommends either oil but I think my preference is for the Mobil Vactra No. 2 way-oil. It’s the real thing. The five-gallon pail was a killer amount for me until I found a lower packaged quantity, but more expensive for an equal amount.

I thought of repackaging for my customers, but I am concerned about the shipping regulations. The oil is non-hazardous, but any leakage in shipping might get nasty with the regulators.

You can’t see it in the picture, but my standard Taig CNC mill is now slathered in Vactra No. 2 oil and it is loving it.

I use the pump can for application and it will force the oil through spring ball oil ports found on many of my non-Taig machines. The can holds a half pint, as can be seen it the top picture.

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