# Questions about the PM1236 lathe



## ricsmall (Dec 13, 2013)

Hey guys

Im new here and have a few questions about the PM1236 lathe. Ive seen mention of a pdf manual that Rayc put up but cant find anywhere to reference it, so here goes.



1) Has an outboard spider been added to the PM1236,as there were several who noted the lack of this.


2) Is the actual through bore capacity of the spindle  1-1/2", as one machine I looked at stepped down in the middle, can't remember which one


3) does the PM1236 feature a power cross slide


4) Is the base sheetmetal or cast iron


5) What is the max tool size of the QCTP


6) What threads does the machine have the ability to cut? couldnt find this anywhere ( I found 4-60, but didnt know specifics,mainly concerned with inch threads)


7) I see the PM1236 has 18 different speeds, what are those speeds


8) Do the steady and follow rests have roller tips and if not, can parts be ordered to do so

9) How big of a PITA is it changing from threading gears to just normal working gears, or is this even required

Also, are there any particular likes/dislikes on this machine that I should be prepared for? Looks like a great machine to me for the $$, hope to order soon. Im sure I missed something, if so Im sure some of you will give great guidance

I hope im not asking questions that have been beaten to death, just being a newb!! 

Thanks in advance
Richard


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## dave2176 (Dec 13, 2013)

Hi Richard,

The best advice I could give would be to reach out to Matt with some of your questions and ask for a copy of the current manual to review. Read it cover to cover more than once so you understand how it will function.

The manual will tell you the threads it can cut and if you will have to change gears for any thread for instance. 

I can tell you it has power cross feed and the bore will hold 1.5" The BXA tool holder has a square bar capacity of .625 but you could squeeze a bit more out of it if you were mill yourself one adjusting the position of the opening. The photos don't show an outboard spider or roller tips on the foller or steady rest so ask Matt directly as there may be an option.

Good luck on your research,
Dave


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## Bob S (Dec 14, 2013)

This is a very nice machine. I got mine in the spring and have been enjoying making much larger parts more easily than I expected. I also got the DRO installed, makes me wonder why I didn't go that route years ago! It is very solid and vibration free, the only problem I've even noticed is the paint is chipped several places but I haven't been too worried about that cosmetic flaw.


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## Ray C (Dec 14, 2013)

Gimme a few moments here and there and I'll answer all your questions.  I'm in the middle of cooking on the BBQ (in the snow) and my hands are a little occupied...

BTW:  I have this machine and you'll notice all my projects here are done with it.  I have no complaints whatsoever...  Best buy for the money but if you want an automatic gearbox, you'll need to look at one of the other models...  There are rumors it may one day come with an auto gearbox changeover kit.

Check back every 20 mins or so as I'm chasing back/forth slathering the chicken and ribs...

Ray


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## Ray C (Dec 14, 2013)

Here's the thread that contains some user instructions.  Make sure you get the most recent versions from the latest post.

http://www.hobby-machinist.com/show...ly-Asked-Questions)?highlight=1236+Frequently


Ray


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## Ray C (Dec 14, 2013)

1)  No, it doesn't come with a spider.  But making one is a fun and easy job.

2) The bore is about 1-9/16".  I have on many occasions put a 1.5" shaft in there.

3) Yes, it has a power cross-slide and it's fully operational in forward or reverse and can be set independently (forward/reverse) of the main gearbox direction.

4) The base is sheet metal.  Pretty heavy gauge though but still, I made a very heavy duty base of 1/2" sidewall 3x4 angle iron that weighs about 350 lbs.  A heavy base will improve the performance of any lathe.

5) A BXA QCTP is the way to go.  CXA would be way too big.  I even use an AXA on mine all the time because I happen to have one.

6) & 7)  You'll be able to see the speeds and thread sizes in the user guide that's posted here.  As for fine pitch threads, don't get hung-up on the fact that some other lathes can supposedly do 112 TPI.  Threads much finer than 56 TPI serve no practical use that I know of.  As far as IPR for surface finish, I rarely ever cut slower than 0.004 TPI and I believe the 1236 will go down to 0.0018".  You'll also notice that the gear chart has rounded all the values to 3 decimal places and it looks like several settings will accomplish 0.002 IPR.  In reality, there's a small difference between the settings.  If you look at the metric equivalent on the chart below, you'll notice the difference in posted IPR since metric is about an order-of magnitude smaller in scale than the inch system.

8)  Nope.  No roller tips.  I use the steady and follower all the time as-is and have no problems whatsoever.

9)  It takes about 1-2 minutes to change threading gears.  It would be nice to have an auto gearbox but, I coexist quite well without one.

Likes/Dislikes?   Really no dislikes at all -considering it's cost/value.  This is a very good lathe and it comes with better gears in the gearbox than equivalent models.  They are ordered from the factory that way.   I would of course like a bigger lathe with a 10" wide bed and I keep threatening myself to get the 1440 HD which is an outstanding machine.  Likewise, the 1340GT is top-notch but it too has a 7.5" wide bed.  Given a choice between the 1440 HD and 1340GT, I'd go with the 1440 HD because I happen to like machines to be as beefy as possible.  The 1340 GT is nothing to sneeze at though...


Ray




ricsmall said:


> Hey guys
> 
> Im new here and have a few questions about the PM1236 lathe. Ive seen mention of a pdf manual that Rayc put up but cant find anywhere to reference it, so here goes.
> 
> ...


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## ricsmall (Dec 14, 2013)

Ray C said:


> 1)  No, it doesn't come with a spider.  But making one is a fun and easy job.
> 
> 2) The bore is about 1-9/16".  I have on many occasions put a 1.5" shaft in there.
> 
> ...



Thanks ray and everyone else for the replies.

Agreed Ray on the 112 TPI deal. Wasnt so much worried about that as much as the common threads in doing gunwork. I did finally find the post with the manual you did and that cleared alot of things up as far as threading and spindle speeds. 

The 1-2 minutes will be ok with me on the gear changes. Just needed to ask. As far as the spider, that was my plan after looking at darkzeros photo sequence making his. 

Ray, in your opinion, would I be better off to try and work out a deal with matt to get a bison four jaw instead of the stock four jaw that comes with the machine? Ive been reading all day on here since getting rained out and I read where the four jaws really werent that great and needed balancing, truing,etc. Is this something I would have to do with a bison too?
Hate to ask too many questions, just want to do it right the first time. 

Thanks for all the answers and your time, sure Ill come up with some more! I emailed Matt last friday and havent heard back, figured he may processing shipments and such so ill try and call him soon. Thanks again

Richard


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## Ray C (Dec 14, 2013)

Speaking for Matt, I thank you for being respectful of his time.  He's one of the hardest working people I know and puts in 60 hours a week usually...  At this time, he's got another couple shipments and he's going around the clock getting things checked, doing after-market mods and shipping them out...

Threads:  It will do all common threads and many in half-sizes too (not that you'll ever need them) as well as all common metric.  Trust me, I know... I've cut them all.

I wish I could offer more information about the Bison or the sister brand (MexTec?) but, I've never owned one.  I will say though that it's likely some degree of balancing might be needed because, backplates are usually cast iron which tends to have uneven density.  Due to the backplate alone, some balancing might be needed.  On this topic, perhaps others can comment or, this would certainly be a good question for Matt.

I've written much here about balancing chucks and backplates.  It's not all that hard and the difference is like day and night.  -Well worth the effort and you can always do it at your leisure.  I have no problems with my stock 3J (or 4J).  Each required a little balancing but both were square.  On a related matter, the D1-4 fitting cone on any backplate is likely to be undersized and will need to be fitted.  Again, I have a thread here on how to true it up.  Most people don't know these problems exist -but they do -and they exist with any lathe in this category.  If you want to avoid these problems, you need to look a couple notches-up in price range.  The labor fees involved in getting the factory to do this would blow the price-point out of most folk's budget.

As I've mentioned here before, in days gone by, when equipment like this was purchased, it would be covered under a service contract and a field technician would take care of all these odds & ends.  In the home-shop market, these services are outside of most people's budget...

Feel free to ask any and all questions... I'll answer as best I can.

Ray





ricsmall said:


> Thanks ray and everyone else for the replies.
> 
> Agreed Ray on the 112 TPI deal. Wasnt so much worried about that as much as the common threads in doing gunwork. I did finally find the post with the manual you did and that cleared alot of things up as far as threading and spindle speeds.
> 
> ...


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## ricsmall (Dec 14, 2013)

Ray C said:


> Speaking for Matt, I thank you for being respectful of his time.  He's one of the hardest working people I know and puts in 60 hours a week usually...  At this time, he's got another couple shipments and he's going around the clock getting things checked, doing after-market mods and shipping them out...
> 
> Threads:  It will do all common threads and many in half-sizes too (not that you'll ever need them) as well as all common metric.  Trust me, I know... I've cut them all.
> 
> ...



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


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## tripletap3 (Dec 14, 2013)

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>


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## ricsmall (Dec 14, 2013)

tripletap3 said:


> 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


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## Ray C (Dec 14, 2013)

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




ricsmall said:


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


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## darkzero (Dec 15, 2013)

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.


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## darkzero (Dec 15, 2013)

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


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## tripletap3 (Dec 16, 2013)

ricsmall said:


> 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.


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