Sunday, November 18, 2018

Taig to "Taigmach" Mill

November 18, 2018

I have updated this "blog" post so there will be a single place where you can go to find most of the details (or at least links to other posts in the series).

I've had a Taig CNC mill for over 10 years. This has been a really great machine and has worked well for making small injection molds. About a year ago, I upgraded to ball screws, which has given it new life (the backlash with the lead screws was getting pretty bad). I documented that upgrade here:
Later, as described in sections below, I also upgraded the frame and spindle. Here are the rest of the videos in the series:

Tormach Envy

However, recently I've been having a serious case of Tormach envy. I've had my eye on a PCNC 770, and now 770M mill. This provides a little larger work area than my Taig, as well as other features. But there is a huge price difference. I purchased my Taig for about $2,000 (would be about $3,000 today). Whereas the 770M is about $15,000 for what I would want. That's a huge difference.

So let's take a look at what I found so compelling about the Tormach that I don't have today with my Taig.
  • More powerful spindle
  • Spindle on/off and speed control
  • A little more Y movement
  • TTS tool holding
  • Power draw bar
  • Haimer or ITTP probe
  • Fogbuster
  • PathPilot
Before I got into the details, there is one major thing that kept me from buying a Tormach. We're currently in a rental house while we wait for our new house to be ready, and I don't have room for a Tormach right now. This has kept me from taking the plunge. But while talking with Kevin, another hobby CNC machinist at work, he mentioned that Tormach has had serious problems with backlash. After doing a bunch of research, I came to the conclusion that this seems to impact a very small number of machines, and seems to be a result of poorly scraped ways. You can find more in this post: Facebook Post. And also in my video below:


So after a bunch of research, I learned that there are other upgrades for the Taig for the spindle motor, the frame, and the spindle. Once I'm done with these upgrades, I'll have most of what I wanted in a Tormach, but for a lower price (less than $2,200 for the upgrades). Sounds compelling, right? Let's take a closer look.

Specs Comparison

Movement
MachineXYZ
Taig12"5.5"6"
PCNC 44010"6.25"10"
PCNC 77014"7.5"13.25"

Note: I can add a .75" extension for Y on the Taig, providing a total of 6.25" travel.

Spindle Motor
Taig: 1/4 hp
PCNC 440: 3/4 hp
PCNC 770: 1 hp
770M 1.5 hp

So in many respects, the 440 is pretty close to what I would get from upgrading my Taig. Therefore, I looked at the price of a new 440 with PathPilot and a power drawbar (but no encloser, base, TTS sets, etc. so it would be a better comparison). The total came out to $7,850.

On the other hand, the Taig upgrades (new frame, TTS spindle, power draw bar, new spindle motor) come to about $2,150. This of course, is using my existing 5019CNC mill ($3,000 today) and computer. If you factored in a cheap computer and stepper controller and you started from scratch, it would probably cost about $5,000. That's still an extra $2,800 for a 440. That's probably worth it if you just want to make chips. But if you're willing to do some work, you can get a nice machine for less money. And it will be lighter and easier to fit into a small space without an engine hoist.

PCNC 440: $7,850.90

  • PCNC 440 Base Machine: $5,995
  • PathPilot Controller: $795
  • Power Drawbar: $695
  • Standard LCD monitor: $195.50
  • Keyboard, jog shuttle, etc.: $169.40
Taig: $5,145
  • Taig 5019CNC: $2,995
  • Consew motor, pulleys and belt: $150
  • Frame upgrade: $500
  • TTS spindle & power drawbar: $1,500

Spindle Motor Upgrade

The stock spindle motor on the Taig is a 1/4 hp motor, whereas the Tormach PCNC 770 has a 1 hp motor, and the 770M has a 1.5 hp. That's a pretty big difference. The Tormach also has spindle speed and on/off under software control. Whereas, on my Taig, I have to flip the switch for on/off control, and change pulleys to change speeds. The pulleys give me 6 different speeds, from 1,050 to 10,600 RPM.

After doing some research, I stumbled upon the Taig Lathe And Mill Owners Club on Facebook. This is a pretty active community, and finally got me onto using Facebook. There I learned about a very inexpensive motor upgrade using a sewing machine servo motor. The Consew CSM1000 motor is a 3/4 hp motor, so the same as a PCNC 440 and close enough to the PCNC 770. I purchased one from Amazon for about $100 and some pulleys and a new belt (another $50):
Note: If you have an R8 spindle (see below), see that section for the correct pulley and belt to use.

The first motor was defective, so I sent it back and got a replacement that works. For the price, the hassle was OK.

In order to use this new motor, I needed to mill a motor mount, order some pulleys and belt, and the bore out the larger pulley to fit the Consew motor shaft. I found a motor mount in the Facebook group that also had the CAM already set up (but you'll need to use less aggressive feeds with the stock motor):
Here are the two videos I created covering making the plate and boring out the larger pulley:



Frame Upgrade

Stuart Andrews has created a very nice upgrade to the stock from. For $500, you get a stronger frame, plus some much needed room in the Y and Z directions. You can find more information here:

I've received this frame and have installed it. You can find the videos here:




The frame is a huge improvement for several reasons:

  • It's more rigid, which allows more aggressive cuts
  • It doesn't have the ability to rotate, which allows getting it precisely aligned without worry that it will shift
  • It's taller, and therefore provides more clearance in Z
  • It allows moving the X/Y assembly further from the column
All of these improvements allowed me to have better clearance for my vise. Which in turn allowed me to use the full Y travel with the vise mounted, something I'd never been able to do before.

Spindle Upgrade

The final piece, which took this machine to an entirely new level, was to upgrade the spindle to an R8 spindle that supports TTS (Tormach Tooling System) along with a power drawbar. The power drawbar makes tool changes very fast. And you can pre-measure all of your tools, which allows for much faster, more enjoyable, milling projects.

The spindle and power drawbar together were $1,500, and well worth it. You can find more about this on the Taig Lathe and Mill Owners Club on Facebook page under announcements:


Note, this is a private group, so you'll need to request access and answer some questions (you won't be granted access if you don't answer the questions).

The R8 spindle requires a different set of pulleys from the stock spindle. The spindle itself has a 30-tooth pulley already attached. Here are the pulley and belt you'll need for the Consew motor:
I documented installing the spindle and power drawbar here:

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