Pm-1228vf-lb

What you are describing is how I would expect someone to build the control. IE, not trying to make a frustrating system that people will hate.

Hopefully the 1228 controller is made the way you describe; the system I describe is (probably) not seen very often as nobody in their right mind would buy it. Especially when really you only need to dial speed to the nearest 50 rpm on a lathe. More precision is kind of pointless.

Franko- You got any pictures of the lathe you are buying? Sounds like you chose wisely.
 
thanks very much for the clarifications, mksj and Tim. My Grizzly G4000 has a threaded back plate with a set screw.

I watched a video on the Sieg SC8 and it seems like I remember that he had to twist a knob several turns up from zero every time he spun it back up. It seemed like not such a good system. I think the reasoning was to ease the strain on start-ups.

My mill has touch pad controls. You just push and hold the button until it speeds up to the desired RPM. Then it remembers that speed until you change it or turn off the power switch.
 
Congratulations on your new lathe choice. I also have a 1127 ordered and thought about changing it to a 1228.
I emailed and got the information on it. I like the d1-4 spindle but I noticed it has no threading dial. Also it looks like to
change lead screw direction for left hand threads or feed you may have to open the door and move a tumbler. I also like the way the
1127 gets bolted to a stand better. I think if you have to shim it the bolts being on the outside of the bed may work better than in the center.
I decided to wait for the 1127. The 1228 does have more power and does more threads but I think the 1127 will work fine for me.
It will be a learning experience for me as I have only run cnc machines at work and that was a long time ago.
 
It's not like I cut left hand threads very much (never, so far). I didn't notice the mounting bolts. My Grizzly G4000's bolts are between the ways and barely reachable. Hopefully the wider ways will mitigate that.
 
I don't think you could go wrong with either machine. I'm going to give Matt a call tomorrow and get whichever one has the shortest lead time.
 
I've been designing digital pretty much since it was invented. Now that we've got that out of the way... :)

Most digital controls I have used and designed will only increment a pre-set amount with a momentary push (usually a rising edge in positive logic circuits). If held than a pre-defined time period a series of pulses is generated for as long as the button is held. Can't speak to the LMS lathe as I have no experience with it but it 'could' be a simple latch circuit that generates one pulse per rising (or falling) edge regardless of how long it is held. I've seen high school students design better circuits than that, but whatever. Call it what you want. I'm done here.

The LMS 8.5x16/20 is like your first example. It increments 10rpm with each momentary push of the up or down buttons. But, if you hold one of the buttons in, it smoothly accelerates or decelerates until you let the button go. It took me about 5 minutes of playing to get used to mine after having had a mini with the typical speed control knob that you had to start from zero every time you stopped it to take a measurement. The LMS restarts at the same rpm it was turning when you hit the stop button. (Unless you hit the emergency stop, then it restarts at 100rpm.)

Tom
 
The LMS 8.5x16/20 is like your first example. It increments 10rpm with each momentary push of the up or down buttons. But, if you hold one of the buttons in, it smoothly accelerates or decelerates until you let the button go.
Sounds better than the report I heard, but I would still prefer a rheostat. Twist of the wrist and you got the speed you want.

Changing speeds in 10 rpm increments is kind of overkill; don't need that kind of accuracy when you are work material that is tabled as "100-250 sfm" or "200-800 sfm".
 
To counter a wild rumor propagated earlier, the PM 1228-VF-LB comes equipped with a threading dial. It isn't shown on the picture or the data sheet, but Matt assured me this afternoon that it is so equipped.

My mini mill and lathe have potentiometer speed knobs and they work fine. But, neither has a tachometer, so you don't know what speed either is running. I never saw a touch-pad machine that didn't have a data screen and tachometer. I am not saying that I couldn't rig up a tach on those machines, but what I am saying is that operationally, touch pads are not inconvenient to use.
 
Good to hear it has a treading dial. I wasn't trying to spread any rumors just reporting what I saw. They should list it on the data sheet so a person knows.
I think you made a good choice. It has a lot of features I wish the 1127 had.
 
I purchased a PM1127VF-LB from Matt 2 1/2 years ago and I love it. Matt was also great to deal with as well. I had to wait about 3 months for mine to deliver - but it was worth the wait (I also have a Lagun Mill and 1 16" South Bend lathe shoehorned into my garage).

Over the next few months and then added a DRO, and then decided I needed more power. Mine had come with a 1.5 hp permanent magnet DC power motor and variable speed control. So I did some fitting and installed a 2hp 208vac 3-phase motor and a Variable Frequency Drive that gave me much more control, torque and power while also allowing me to run on 208vac single phase power. I also changed pulleys and belts.

Now I truly have the perfect machine.

As a side note, I'm in the machine tool business and have to attend the Machine tool shows where I've discovered that the machines apparently are originally built by a Taiwanese company named Weiss ( http://www.weiss-us.com) and they have more options available to them such as spring steel ball screw covers. Perhaps the Weiss is the 'Cadillac' of the line while Precision Matthews is the 'Buick'.

I've never spoken to Matt about them but he might be able to order those options or parts too, and if I ever decide to add those I will try to do that because Matt did treat me well.
 
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