The Hobbyist's Machine Shop – Blog

"One Perfect Part at a Time"

High Speed Spindle

Here in the RD workshop, consideration is being made on adding a one horsepower 24,000 RPM spindle to the Taig CNC Micro Mill. The standard spindle is a belt drive one quarter horsepower unit with a top RPM of 10,000.

The standard spindle and drive is quite adequate for most of the milling work the micro mill is asked to produce. The primary use for one of my mills is wax carving with as small as 0.003-inch milling bits. That size mill bit can best operate at the 10K RPM and higher ranges.

I did some comparison of speeds and feeds in G-Wizard from CNC Cookbook. Doubling the spindle RPM can almost double my rate of travel, within limits of tool deflection, which is not extreme in wax. It will certainly reduce my running time.

The new high-speed spindle is a bit pricy. I’ll know the final cost if I decide to proceed with this quest for rotational speed. The little Taig mill doesn’t need more than ¼ HP for most of the work it performs. The Spindle I am considering is 800 watts which is 1 HP. It requires a VFD (Variable Frequency Drive) that produces 3 phase, 110 volt output and can vary its frequency output from between about 100Hz to 400Hz. The frequency change is what varies the speed of the spindle.

I am a certified commercial VFD start-up/commissioning engineer and have a very good understanding of how VFD drives function. I have not seen the VFD for this spindle, but its (published) operational parameters are familiar.

The spindle may have an issue for some folks. It’s not actually an issue, however. The spindle has an ER11 collet holder rather than the Taig ER16 size. That means the largest nominal size tool the high-speed ER11 collet… Continue reading

Dimensional Decision

I am presently using two very good 3-dimensional CAD programs. They are Autodesk Fusion 360 and Robert McNeil & Associates Rhino3D. I am at a decision point on which one will be my standard go-to drawing program.

I have had the longest association with Rhino. I started with version 3 and version 6 has just been released. Major version number upgrades must be purchased. That’s why I am at a decision point.

Fusion 360 is free for users like myself. That is a major advantage. The Rhino3D upgrade is $375.00.

It seems like a no-brainer to stay with the free one. But for me price is not always the sole determining criteria.

My problem is that both programs are very good. The largest difference is the cost-to-own. If I had to pay for Fusion 360, I must admit that cost would be a very large determining factor. I certainly don’t want to be paying for two programs that are almost equal in results for how I use them.

My decision is to continue using both. I will pay for the upgrade in Rhino. It’s about $1.05 per day for a year. I can live with that. Major upgrades do not occur yearly, so the cost spreads out thinner.

I have no idea if Fusion will remain free. It does seem to be a very friendly marketing strategy.

One hesitation I have with Fusion 360 is it is cloud-based and dependent on a connection to the Internet. It seems to me it access could be shut down very quickly. But every computer activity today depends heavily on an Internet connection.  I feel any change in the free use policy won’t be immediate.

I have just changed my business accounting to a web-based service. It’s how we work today.

What keeps… Continue reading

What Excuse?

Ramblin' Dan

Ramblin’ Dan Today…

I try not to go on guilt trips. The view is depressing, and it doesn’t solve any problems if I am busy blaming myself. I can be guilty of many things, but I don’t have to ride the train… Uh, oh… speaking of trains. That reminds me…

I am guilty of putting my live steam and model trains fun on the back burner. Heck, there are a lot of things back there, just simmering. Some of them may be stone cold… Well, that’s the way it goes. I can’t feel guilty about not being able to eat everything at once.

A few people tell me they can’t imagine doing all the projects in which I have been involved. They don’t see the pile of “round-tuits” on the other side of the stove. That’s OK.

I really want to get back to metal working on the lathes and mills. Usually termed “machining.” Live steam is a great base for justifying detailed machine work. A live steam engine is an exquisite machine in its own right. Lots of moving parts and metal thingies to create from scratch materials.

My interest is as much if not more in the construction process as the finished product. A finished model is a reason to go start another project.

It was that way for me when I was very active in radio control model airplanes. Yes, I flew the heck out of my models, but the construction was where most of the enjoyment was created.

The lost wax silver work I do is the same thing. I like the creative process more than the finished jewelry. I love my creations, but I can’t wait to sell or give them to someone, so I can make more. I don’t collect my finished work.

Most… Continue reading

Live Steam Bait

Live Steam

Live Steam

CliShay

CliShay

Some progress is better than no progress. I have the desire to be back hacking metal parts, but I can’t get my body to do what my mind desires. It’s not a physical thing. Just switching mental gears from what I already do and getting to other things I love to do. I have way too may interests and options. I thought retirement would give me more time. Boy, was I ever wrong!

I just gave myself a Christmas present. I just re-activated my subscription to Live Steam and Outdoor Railroading. That may get the juices flowing. I also ordered the Building the CliShay from the same source. Not that I am going to build one, but I like to study the material and details of any build project.

I kind of like the concept of the CliShay where anything goes, nothing is wrong, do your own thing, that a non-scale live steam project permits.

I viewed an 0-gage CliShay on YouTube that was pretty much a work-in-progress disaster. Flames rolling out, up the outside of the boiler shell and melted off a steam fitting. So inefficient the operator was chasing around with a small blow torch heating the outside of the boiler to keep it running. BUT…

He had a live steam locomotive running and was probably having a great time working out all the issues. He was living the dream, not still in the dream state. Nothing wrong there. I was envious, but still getting a chuckle.

I would probably change places with him for a day…

The Way to Go

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… Continue reading

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