Precision Matthews PM-728VT CNC conversion

For the standalone controller, I built my own using Arduino as the processor. I can send you the Arduino code for it. You will need to determine which size motor would best fit your particular table, probably a NEMA 17 or 23

Arduino Rotary Table for Dummies

Ive had a few people tell me that they like the project (http://www.homemodelenginemachinist.com/showthread.php?t=25783) but dont feel comfortable with the electronics. Ive been playing around to simplify it down to where I feel anyone who wants to could comfortably build the controller. With...
www.homemodelenginemachinist.com www.homemodelenginemachinist.com

For my TIG welding rotary table (BTW my TIG welding talent is pretty atrocious), I bought this one on Amazon and did a few tweaks mainly beefing up the commutator arrangement for the work-clamp current flow, and replacing the speed potentiometer with a 10-turn pot for finer control

tig rotary.jpg
Commutator.jpg

More stuff on it here:
forum.langmuirsystems.com

Cletus' Crossfire Build n Mods

Oh yes, he has good videos. Also, I look at this and weep!
forum.langmuirsystems.com forum.langmuirsystems.com
 
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Cletus said:
For the standalone controller, I built my own using Arduino as the processor. I can send you the Arduino code for it. You will need to determine which size motor would best fit your particular table, probably a NEMA 17 or 23

Arduino Rotary Table for Dummies

Ive had a few people tell me that they like the project (http://www.homemodelenginemachinist.com/showthread.php?t=25783) but dont feel comfortable with the electronics. Ive been playing around to simplify it down to where I feel anyone who wants to could comfortably build the controller. With...
www.homemodelenginemachinist.com www.homemodelenginemachinist.com

For my TIG welding rotary table (BTW my TIG welding talent is pretty atrocious), I bought this one on Amazon and did a few tweaks mainly beefing up the commutator arrangement for the work-clamp current flow, and replacing the speed potentiometer with a 10-turn pot for finer control


More stuff on it here:
forum.langmuirsystems.com

Cletus' Crossfire Build n Mods

Oh yes, he has good videos. Also, I look at this and weep!
forum.langmuirsystems.com forum.langmuirsystems.com
Click to expand...
I have read your thread on the Langmuir forum and it is very impressive! Setting the bar up high for the rest of us.
 
Deos anyone know what is the thread size for the drain hole on the right side of the table? I thought I saw it mentioned in one of the threads, but searching does not retrieve it. I am very confused about pipe threads and sizes.
 
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koenbro said:
Deos anyone know what is the thread size for the drain hole on the right side of the table? I thought I saw it mentioned in one of the threads, but searching does not retrieve it? I am very confusing about pipe threads and sizes.
Click to expand...
be careful. Many non US machines actually use British tapered pipe threads. Japanese machines do, as do some Taiwanese. The Germans do to although call it G1/8. Any ways its has the same OD dimensions as NPT but is 19 threads per inch instead of 18. So it screws in about 3 threads, you put a wrench on it and tighten, and end up damaging the threads. Don't guess, get a threads per inch gauge and use it.
 
koenbro said:
Deos anyone know what is the thread size for the drain hole on the right side of the table? I thought I saw it mentioned in one of the threads, but searching does not retrieve it? I am very confusing about pipe threads and sizes.
Click to expand...

Probably 3/8" NPT, other PM mills are.
 
Firebrick43 said:
be careful. Many non US machines actually use British tapered pipe threads. Japanese machines do, as do some Taiwanese. The Germans do to although call it G1/8. Any ways its has the same OD dimensions as NPT but is 19 threads per inch instead of 18. So it screws in about 3 threads, you put a wrench on it and tighten, and end up damaging the threads. Don't guess, get a threads per inch gauge and use it.
Click to expand...
Yeah, that is the most likely explanation. I got a brass 1/4" NPT and was able to thread it maybe two revs before it got stuck. Have placed an order for a BSPT-threaded plastic elbow from McMaster -- will report back on the fit.
 
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:offtopic: Serviced and re-calibrated my CNC Mini-Mill today. Here’s the second pass making a bolt-circle in a test coupon (1/4" Drill)
 
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