Setting-up the PM 1236-T Lathe

[StevSmar]

@Titanium Knurler , how did your stand work out? Are you able to move it and not have the alignment of your lathe needing to be re-adjusted?

 

[Titanium Knurler]

StevSmar, I have only needed to move it a couple of times since I set it up but it moved easily and stayed aligned…I guess every dog has his day

 

[StevSmar]

…it moved easily and stayed aligned…

I tried aligning my PM-1224T for twist and it was hard to see any difference. I didn’t know if to put it down to bad technique or the more rigid 24” bed…

 

[Titanium Knurler]

I tried aligning my PM-1224T for twist and it was hard to see any difference. I didn’t know if to put it down to bad technique or the more rigid 24” bed…

I am uncertain as to whether you didn’t see any change in the twist with adjustment or you didn’t see much effect(change of taper) from the adjustment.

If you didn’t see much change in the twist with your adjustment then it is possible that your level is not quite sensitive enough. When I make adjustments I use a Starrett precision machine level(model 199Z) that is unbelievably sensitive and unfortunately pricey. I got mine used from eBay. It is almost too sensitive and will pick up very small changes(.0005”/foot). I guess the other possibility is, as you mentioned, you have a really rigid bed and it just doesn’t change much with adjustment.

If you didn’t see much effect from the adjustment, I.e., no change of taper with a two collar test, this would not be entirely unexpected since the untwisting of the lathe has a pretty insignificant affect on taper unless there is a really large adjustment needed. If you go back in this thread you will see Dr Jackson’s nomogram for vertical misalignment(twist) vs. taper vs. diameter of workpiece. It shows that one gets a surprisingly small amount of taper when a lathe is twisted or vertically misaligned especially with larger diameter workpieces.

I hope that is helpful I didn’t muddle things up for you.

Bottom Line: If you don’t have much twist I wouldn’t worry about it unless you are getting an unacceptable amount of taper for your projects.

 

[Just for fun]

So, I'm getting around to really trying to align the lathe. When I first got it, I leveled/took the twist out of the ways. Now that I have had it for a while and spend a little time learning how to run a lathe. I have decided it is time to re-address the alignment. I have learned that when I thought I had it level I had performed the function incorrectly. That being said I don't know if I ever had it correct. I had laid my precision level across the V-Ways.

So, my one question before I get head deep into this alignment issue. On the headstock end there are four feet, do they adjust the headstock up and down in relationship to the tailstock? You may have covered it earlier in this thread, I'm back on page 18 still trying to absorb all the information.

Tim

 

[Titanium Knurler]

So, I'm getting around to really trying to align the lathe. When I first got it, I leveled/took the twist out of the ways. Now that I have had it for a while and spend a little time learning how to run a lathe. I have decided it is time to re-address the alignment. I have learned that when I thought I had it level I had performed the function incorrectly. That being said I don't know if I ever had it correct. I had laid my precision level across the V-Ways.

So, my one question before I get head deep into this alignment issue. On the headstock end there are four feet, do they adjust the headstock up and down in relationship to the tailstock? You may have covered it earlier in this thread, I'm back on page 18 still trying to absorb all the information.

Tim

Hi Tim,

I think the answer to your question depends on your set-up and whether are you referring to the bolts that hold the headstock to the cabinet(red oval) or the leveling bolts(green oval) at the bottom of the cabinet:



Maybe you could show us a photo of your setup?

There are several places that you can place your precision level when checking for twist in the bed but I prefer to place it right on the saddle and leave it in place. My reasoning is that picking up the level and placing it in different positions can introduce some error. In addition, your cutting tool will always run parallel to the path of the saddle. I am sure others have a preferred method but that is my reasoning for placing it directly on the saddle and just leaving it there during the adjustment.

 

[Just for fun]

It's just the standard welded stand that I got from PM when I got my 1236T. I was refering to leveling bolts on the stand. I just adjusted them so all four had about the same tension when adjusting them.

It wasn't just you, I have read other articles that state using the flats on the saddle not the V ways.

 

[cobraJack]

That was my wife and I last September running in the 105 mph class at the Silver State Classic run in Nevada. They close off 90 miles of two lane highway and your goal is to average your class speed over the 90 miles. Our target time was about 51 minutes and 25.714 seconds. We won our class, we were slow by 0.0373 seconds. She has two stop watches and every mile tells me if we are fast or slow and by how much. With a half mile to go she figured we were 0.100 seconds slow, so By the time everything computed in my head, I pushed the speed up to 118 mph.

We trailered the car from Ohio, 5,000 miles round trip. My Corvette is a 2015 Z06 with some mods, it has 620hp and 635 ft-lbs at the rear wheels. The record run over the 90 miles was in the unlimited class and that car averaged 217mph with a top speed of 242 mph. That was done by a repurposed NASCAR car.

Firstgear- have you ever run the BBORR (Big Bend Open Road Race)? I've been running it since 2012. Started in 115 class and now run the 130. As you know, it's a blast!

JT

 

[tredding]

I. Unpacking, cont’d

If you look at the photo of the stand in the last post you will see that the headstock side has four areas for support at the base for leveling mounts and four at the top to mount the lathe to the cabinet. Similarly, the tailstock end has two. The PM Manual recommends that if one uses leveling mounts that they should be rated for 250 lb each. Since I was planning on adding casters and machine mounts for the mobile base I wanted to get a pretty good idea of the weight of the headstock and tailstock ends. I used a trailer tongue weight scale to determine the approximate weight while the lathe was on the pallet.

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As you can see this is a pretty good recommendation:

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If you fast forward to when the stand is complete and the lathe is mounted on the mobile base you can see that the 250 lb/mount recommendation is still pretty reasonable:

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However, as you will see in the next section I used casters and mounts that are rated for at least fours times that amount.

Well, enough about Unpacking. I promised at the beginning I would list what I(TK) would do differently and would make recommendations for the manufacturer,Liang Dei(LD) and PM. So here they are:

TK- none this time but there are plenty coming up

LD-better packing to avoid scuffs and scratches
-better engineered latches or at least ones that do not need to be modified
-COSMOLINE TO THE SPINDLE BORE

PM-get labels correct, straight and centered
-make touch-up paint available

Pretty minor stuff. Next I will discuss making the mobile base. I am very interested in your feedback on this!

I am glad to see your solution included casters. I put them on the PM-728VT and plan to use them with the TM-1236. https://www.amazon.com/gp/product/B09V6GCLXN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[Dabbler]

@tredding i had a solution for my 12 X37 that you'd might appreciate. I had to fabricate my own stand, and so I made some blocks under the headstock that would take 1" NF bolts, I found some 4.25 inch phenolic wheels with a 1" bore. When I have to move the lathe, all I do is lever up, put the wheels on, and then drive it across the shop like a shopping cart. The tailstock end is easily light enough to lift and push/pull, even for an old guy like me.

-- if you are interested I could take a pic or 2 and post here.