Anyone Have Trouble With Threading On 1340 Lathe

vogeldp said:
Hello,

Has anyone had threading problems with their 1340 lathe, such as wrong dial engagement information on the Legond plate or in the manual or incorrect dial gear, leadscrew, incorrect half nut etc. My lathe is made by the same mfg of the PM1340 Liang DEI of Taiwan but is their 1236GH model which in every way identical to the 1340 (same p/n's) . My issue is the engagement info is wrong or incorrect internal parts, according to the manual/dial legond plate to thread a 20 TPI I am to use any number 1-8 on the dial but I get a mess after threading (thread splitting). Upon further investigating I found if I use either 1,3,5,7 or 2,4,6,8 I get a perfect thread. I have checked all parts for correct dial tooth count (32), leadscrew TPI (8). I have had no luck with the company I bought the lathe from , they claim if I am now able to cut threads then use that method but I disagree, I would have to go through every thread TPI to verify the engagement process. Anyone have any suggestions of what may be going on.
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Hi, I have just read your question re. screw cutting. And agree that it would be quite a disappointment to discover your new machine has a defective user manual. In following your post I gather that this sis not an uncommon problem.

However my interest is somewhat different, in your original question you state that your lathe, a PM 1340 is made by the same factory as the Liang Dei of Taiwan. You also say that your 1340 is the same as their 1236. I find this interesting because my lathe is the LD 1216 These are sold here in down under as LD brand machines. It should be the same machine only somewhat shorter bed. Sometimes it's uncomfortably short, but I wanted the largest swing I could get and I had a very short space to put it in so as with everything it is a compromise, I had been looking on this forum for a similar lathe so that I could read relevant comments but no one appeared to have an LD product.

However if you are certain that PM is made by Liang Dei then I have have the group that I need. Thank you. I had noticed that PM lathes looked remarkably similar to mine, but that doesn't mean they are the same. The other thing is that PM products do not appear to be available here in downunder. So there was no way to check.

Unfortunately it would seem that I might have the same problem as you, but as I haven't done any screwcutting yet I can't confirm it, but will be on the lookout for it. So far I am quite happy with my lathe, still getting use to it as I don't get a lot of shop time.

Bob.
 
He doesnt have a PM Lathe, it is a different brand, but I believe he got it figured out. I am guessing though, that if you are in Australia, your lathe is Metric so none of that would apply anyway, but I am not sure? Never thought of it, and just tried to look it up, and I can't figure out if you guys use Metric or Imperial?

But with the PM-1340GT, it has an 8 TPI Main Leadscrew, a 32T Thread Dial, there is absolutely no issue threading with the PM-1340GT .
 
qualitymachinetools said:
He doesnt have a PM Lathe, it is a different brand, but I believe he got it figured out. I am guessing though, that if you are in Australia, your lathe is Metric so none of that would apply anyway, but I am not sure? Never thought of it, and just tried to look it up, and I can't figure out if you guys use Metric or Imperial?

But with the PM-1340GT, it has an 8 TPI Main Leadscrew, a 32T Thread Dial, there is absolutely no issue threading with the PM-1340GT .
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Hi, Many people here in Australia are also confused. We officially changed from imperial (british) system back in 1966 when we changed to a metric currency of dollars and cents. other measurements were progressively changed over the next ten years until all our weights and measures became metric. Having said that we still commonly use both the old british and the american imperial systems side by side with the metric system.

I chose to order my lathe as an imperial machine so all lead screws and dials are calibrated in inches. The cross slide, compound and tailstock also have metric dials, so I can get all the TPI threads I want and also by using the 120x127 change wheel provided and the feed screw gearbox I can also get almost every metric thread that exists. A full imperial and metric chart is provided on the front of the headstock.

My query however is related to the similarity between the Liang Dei lathes and the PM lathes, it appears to me they are made in the same factory and to all intents and purposes, they are identical, can you confirm this? The reason I am asking is that as far as I can see I am the only member of this forum with an LD machine, and I am looking for similar machines to compare with and for picking up hints.

Bob.
 
Hi Bobshobby, Nice you have the same machine as mine. I have a LD1216GH. Mine is metric, has a three phase motor and runs on a VFD.
 
The Princess Matthews Lathes are a step up in Quality and can be used in a pro shop for day in and day out use having the gears Hardened and Precision ground which I know the Liang Dei doesn't as I am in the process of purchasing a Lathe and have inquired about this. The Hardened gears for the Liang Dei start with there 1440 which Eason sells as the 1440e. Which is in competition for me with the Pm 1340gt. Both great lathes now I just need a deal on one of them.
 
bench said:
Hi Bobshobby, Nice you have the same machine as mine. I have a LD1216GH. Mine is metric, has a three phase motor and runs on a VFD.
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Hi, Nice, you are the first person since I joined who has owned up to having a LD lathe, and the fact that yours is a LD1216 GH the same s mine is quite something. How do you like the 3ph motor and VFD. As I said I opted for the single ph and no VFD. Quite happy with my choice. I could have gone with 3 Ph, as I have 3 ph connected here, but just didn't think I would need it. how long have you had your lathe for and have you done much work with it yet?

Bob.
 
pdentrem said:
I ALWAYS use 1 for any thread. Avoids any and all confusion!
Pierre
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Pierre, It's not foolproof, If you're cutting metric threads on an imperial lead screw, or imperial threads on a metric leadscrew it most likely will not work, Also other special situations can apply. much safer to leave half nuts engaged and run lathe backwards to begin next cut.

however in the acse of standard threads where the machine chart shows you can use various numbers it should be safe to do so, and much quicker
 
If cutting threads on the opposite style lead screw than all bets are off of course. You have to leave the half nuts engaged unless you have made a Graham Meek threading clutch which is very high on my list!
Pierre
 
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