Tach recommendations for the PM1340GT lathe?

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Alan H.

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I am evaluating alternatives for a tachometer to put on my PM1340GT lathe that I am outfitting.

I have searched here and found information but it is a bit scattered, therefore this request for recommendations and experience of installing a tach on a 1340.

Please share with me your experience in choosing and installing one. I would really appreciate some photos of your solution.

Thanks in advance for the help.
 
Hi Alan,
I have a MachTach, but almost never use the SFM or other features. I also had some issues with their optical sensor, their hall sensor version stinks and is difficult to install. I would recommend the generic hall sensor tachometers sold on eBay. They fit well in a Hammond diecast box, just mill out base of the box with a window and snap in the tach display. A attach the cover to the bottom of the DRO with a L bracket. The cylindrical NPN hall sensors on these generic tachs are much easier to install than the MachTach ones, it can be mounted with a simple L bracket.
http://www.ebay.com/itm/Hammond-159...x-Diy-Motley-Mods-fast-shipping-/172377067384
http://www.ebay.com/itm/4-Digital-R...all-Proximity-Switch-Sensor-NPN-/232116655283
http://www.ebay.com/itm/Digital-Red...all-Proximity-Switch-Sensor-NPN-/111360403775

Basic generic tach in a Hammond box on Firestopper's lathe.
Paco's VFD Tach.jpg


MachTach in Hammond box.
Mactach Display - 1590B Hammond enclosure.jpg
 
HAHA! I'v been struggling with copy and paste for the past few minutes. Mark beat me to it and did a better job at what I could provide in terms of links.
As far as the pickup goes, I turned a spyder and flush mounted the magnet secured with red loctite. The probe is polarity sensitive to the magnet, so make sure you place it correctly. A red LED light on the pickup probe will lite up when polarity is correct.
Here at 12 o'clock you can see the magnet.
IMG_1447.JPG

A simple bracket secured to the end cover stud holds the probe directly over the magnet. The air gap is a bit over 1/32" and can be adjusted via threaded probe. You can also see the red LED indicating "pick-up".
IMG_1453.JPG
IMG_1454.JPG

If you go with a spyder set up, you will probably need to open up the spindle bore on your end cover as well.
IMG_1366.JPG

IMO, adding a spyder is worth the effort and your killing two birds with one stone. Many others have done this on the same lathe as yours with excellent results.
IMG_1509.JPG

As far as accuracy, I used a hand held laser Tach to verify this $10 tack at different speeds. To my amazement, the tack is darn close.
IMG_1621.JPG
IMG_1624.JPG

If you install a VFD for speed control as well as many other options, a tach is a must.
I hope you can use some of these applications.
Paco
 
Accuracy should not be a problem with any of the digital tachs.
 
Per Mark's recommendation I went with the eBay tach as well. It works great. When running at 60HZ the Rpm's seem to closely match those posted in the manual for the individual gear settings.
 
Thanks Mark, Paco and Brad for the feedback. Ebay is the answer isn't it?

I don't think I would use the SFM function of a MachTach plus Mark's feedback on the sensor helped me eliminate it. Plus I will save a few pennies with the Ebay approach.
 
Remember that motors are often speed rated at some load, perhaps at full rated load for some motors. When idling without a load, most motors will be turning faster than the speed listed on the motor plate. So, do not necessarily blame the tach for a different number than what the motor plate says. Digital tachs will give accurate results by design. Only a very poor design would give an incorrect number.
 
I use a Tachulator which is basically the same as a MachTach.

I LOVE the SFM setting and use it consistently on my lathe. To me its a more direct way of interpretting speed base lines since i have a VFD installed. I just turn my speed dial until I hit the appropriate surface speed for a given material and im off cutting.

Imo the surface speed capacity is even more useful on a mill bc the cutter diameter isnt changing like stock diameter on a lathe. But its still a useful lathe tool.
 
MachTach has always worked well for me. I have three of them. I use Hall effect sensors instead of the optical sensor, usually with 6 magnets attached to the spindle by whatever method suits the particular machine.
 
My MachTach with the stock optical has given me no problems. I use the SFM feature occasionally.
 
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