Questions about the PM1236 lathe

[ricsmall]

Ray is quite the guru when it comes to the PM1236 and he really covered it. Since you noted that you would use it for gunsmith work and that is what I use mine for 99.9% of the time I thought I would add a few specific things I have found. I have found that a outboard spindle spider on this style of lathe is useless on all but the longest of barrels (24" and up) due to the long headstock. I chose a PM1236 but I quite frequently use a Grizzly G0709 in a gun shop and can tell you that the bolts in the outboard spider have been long lost. The only time I have used them has been for chambering long Remington 700 barrels and although I wish I could say I have done lots of them, in truth I haven't. I do use my homemade inboard spider constantly. Here is my take on the roller tips as it refers to gunsmithing. Roller tips are very nice to have but they STILL will scratch and mark a barrel plus they limit the capacity of the steady rest as I found out making my inboard spider. I found out that I needed a set of both types so even if I had bought a lathe with roller tips I would have bought a set of brass tipped ones anyway. The better option is to make a much nicer set of rollers yourself. The ones I bought have some play in them and don’t seem to be well made. I think this is what does most of the marking on the barrel so I am going to make my own. I also might try to make some sort of hard plastic ring on the outside of the bearing as well.
Changing gears isn't the most convenient thing but, the gearbox on the PM1236 is laid out pretty good for the gun threads I use most, so I do not change the gears that much except for Metrics (14x1 mm left hand). That just requires a gear spacer change. BTW You have to spend $$ and go up a few lathe sizes to get totally away from gear changing. <o></o>

Great feedback Tripletap. I was kind of leaning toward the inboard spider similar to the one the viper venom guy (Carol Pastor ?) uses. Its too easy to buy a barrel already profiled now to plan on profiling all the barrels ill do, so my steady rest use will be limited somewhat. Im convinced the PM1236 is the right machine for my uses, but being a DIYer, I have to overthink everything, which is good sometimes I guess.

Richard

 

[Ray C]

It just so happens that Matt's prices on Bison and the Tool-Mex (sister brand) are the best you'll ever find but... I think you'll be well served by the stock chucks. A high-end Bison will cost a lot of money and if you're new to this game, there are other things you might want to consider like basic shop tools and supplies.

DRO... I have the iGaging scales on mine as of a couple months ago. They work fine for my purposes but, I think my next lathe will have full-blown DRO installed. Again, I wish I could give better opinions than that but, in all honesty, I lived w/o scales for the longest time just fine. The iGaging scales are very helpful but, when it gets right down to it, when I want critical measurement, I use the correct measuring tool, micrometer etc... Having a DRO is not going to help you cut a diameter with greater precision. -For that, you need to know your machine and the metal you're working on and know how much to dial in when you're taking the last cut and going for the kill. That comes with experience because, the amount you dial in is not necessarily how much comes off (tool deflection, toughness of material, overall DoC, density variance in the metal etc). When the cut is done, you say a little prayer then measure with a mic.

The same is not true with a fully CNC lathe as, in that case, you live and die by the quality of your DRO and/or measurement system. -Different ballpark.

All that said, I couldn't live w/o DRO on my manual mill. -Again, a different ballpark because you're dealing with 3 axis at one time and no matter how good your leadscrews are, the dials don't tell the full story.

Ray

Ray

again thanks for the info. Im still in the PM subforum reading and trying to glean as much as possible.

After more reading and some thinking, I may just try the factory chucks and true up as you talked about. Ive got a ways to go and the machine will be better than I am out of the box, so it will all be a good learning experience for me, and I dont think Ill have any trouble finding help or the answers here.

Now, off to ponder the question, DRO or no DRO!

Richard

 

[darkzero]

In regards to gear changes since you ask how much of a PITA it is or if even needed. To clarify, you don't actually have to do gear swaps when changing between threading & feeding. The couple of minutes is just a matter of turning knobs. The only time you would actually have to swap gears is for metric and some of the uncommon thread pitches. Well I can't really say uncommon as that depends on the pitches you would be using most. But in the stock configuration that covers most of what I thread commonly. With that said it not a full quick change gearbox and the lathe does come with the other gears to cover all of the lathe's capable thread ranges.

I got my lathe without a DRO but the DRO is one of the best things I have added to mine & I love it. I have pics of my install in my thread also. I went with a lathe specific display rather than a universal/mill DRO to minimize clutter of functions that aren't applicable but that's no big deal. Many of the DRO display's functions are very useful, saves a lot of time & I'd hate to be without mine now.

My stock 4 jaw was pretty sloppy & wasn't smooth. Cleaning & deburring it helped but I still wasn't happy with it. I don't use the 4 jaw that much so I couldn't justify getting a high quality replacement but I did replace the stock one with a Fuerda (Gator). I went with a direct mount which eliminates the need for a back plate so that's less weight & it's easier to grip when moving around because of the casting. I couldn't be happier with it. Fuerdas are pretty nice for the price & being a Chinese import. The prices keep going up on them & the price on my chuck has gone up a few times already since I got it.

I kept the stock 3 jaw though. Again, cleaned & deburred & modified it to be a poor man's adjustable TIR chuck. I get just under .001" TIR. I don't recommend this kind of mod for heavy use but I kept it around to only use for sanding & polishing. When I got the lathe I immediately got a Bison 6-jaw Set-Tru chuck for it & is what I use 80% of the time. I had the same chuck on my mini lathe except in 5" so I had to have another. But I used to do a lot of flashlight work & is why I went with the 6 jaw.

 

[darkzero]

The 18 spindle speeds, you get 9 speeds & to use the other 9 speeds you have to change the belts on the pulleys, high & low range. I posted the actual speeds that I measured on my lathe in the low range. I never used the high range yet.

Post # 12

 

[tripletap3]

Great feedback Tripletap. I was kind of leaning toward the inboard spider similar to the one the viper venom guy (Carol Pastor ?) uses. Its too easy to buy a barrel already profiled now to plan on profiling all the barrels ill do, so my steady rest use will be limited somewhat. Im convinced the PM1236 is the right machine for my uses, but being a DIYer, I have to overthink everything, which is good sometimes I guess.

Richard

This is the one I made. It cost me about $20, not including a new set of boring bars that I got to keep. I just put it in the three jaw to take the photo but I normally use it in my 4 jaw.