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- Feb 17, 2021
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- 466
got the impression you changed speeds by changing the belt pulleys
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YOU OWN A central machinery 9x20 lathe???
- Thread starter riversidedan
- Start date
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- Feb 17, 2021
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- 466
yes sir thats the one, will get back to ya cuzz from what Ive seen thiers a special way that attaches with that spring and all......
- Joined
- Aug 6, 2015
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- 3,887
I documented everything in my ownership thread…
My First Lathe - HF 9" x 20"
Yes, do focus. What did you order with the PM lathe? If you didn't get a 4J with the PM, then the one you get now, could be used on the PM. If you just need to practice some and budget is tight, you know your answer. If things are really tight, just use the 3J. A 4J isn't worth marital...
www.hobby-machinist.com
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- Nov 14, 2016
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- 3,005
Spindle speed is changed by the belts, the power feed speed is changed with the gear box.
- Joined
- Feb 13, 2017
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- 2,138
I haven't read more than the first page but can make a few comments. I have a Grizzly G-1550, a Taiwan version. The current Grizzly is a G-4000, made in mainland China. The G-4000 is simply a clone of many 9X19s, they all being essentially the same. A Jet is a cleaner(?) Taiwan version, like my G-1550. Having purchased a HF version when times were flush, I acquired it for extra parts for my contraptions. The cost of the HF as a unit being, at the time, less than all the parts I wanted from Grizzly. Overall, the only difference I ran into was the spindle thread. The Grizzly G-1550 (and JET) are 1-1/2X8 where the Grizzly G-4000 and all HF machines are M39X4.
There may have been a few fasteners that were different, but I never ran into any. The change gears were the same across the board. I did have to "tweak" the inside of some of the HF gears. But that to get them to fit their own banjo, not for interchange. I gave away the HF machine (less a few parts) some 20 odd years back. The biggest reason was the spindle threads, M39X4 versus 1-1/2X8. The guy that recieved it was happy to get something, anything, he could learn on. He may have replaced the parts I kept, he may have dropped the whole idea. I haven't talked to him since.
All of these machines that I have had experience with cut threads, both imperial and metric. There is a 127/120 pair of gears permitting metric. The gears are modulus 1, the 127 tooth being about 4 inches diameter. Any gears missing in a "used" purchase can be acquired from Jet, or my preference, Grizzly. Grizzly has dropped the 1550, way back in the mid '90s. They no longer have the 1-1/2X8 threaded devices. But such can still be found. The HF machine is M39X4 anyway, so parts can easily be found at Grizzly.
The lead screw is a 16 pitch (almost but not quite) ACME. I think, but not sure, it is a trapezoidal form, common on Asian machines. It can be thought of as 1.6mm(?) pitch as well, it is VERY close. There is a Half Norton change gear box, ranging is done by changing some loose gears on the headstock. This is also where the metric conversion gears fit. All in all, after fine tuning, a quite usable, if limited, machine.
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There may have been a few fasteners that were different, but I never ran into any. The change gears were the same across the board. I did have to "tweak" the inside of some of the HF gears. But that to get them to fit their own banjo, not for interchange. I gave away the HF machine (less a few parts) some 20 odd years back. The biggest reason was the spindle threads, M39X4 versus 1-1/2X8. The guy that recieved it was happy to get something, anything, he could learn on. He may have replaced the parts I kept, he may have dropped the whole idea. I haven't talked to him since.
All of these machines that I have had experience with cut threads, both imperial and metric. There is a 127/120 pair of gears permitting metric. The gears are modulus 1, the 127 tooth being about 4 inches diameter. Any gears missing in a "used" purchase can be acquired from Jet, or my preference, Grizzly. Grizzly has dropped the 1550, way back in the mid '90s. They no longer have the 1-1/2X8 threaded devices. But such can still be found. The HF machine is M39X4 anyway, so parts can easily be found at Grizzly.
The lead screw is a 16 pitch (almost but not quite) ACME. I think, but not sure, it is a trapezoidal form, common on Asian machines. It can be thought of as 1.6mm(?) pitch as well, it is VERY close. There is a Half Norton change gear box, ranging is done by changing some loose gears on the headstock. This is also where the metric conversion gears fit. All in all, after fine tuning, a quite usable, if limited, machine.
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- Apr 14, 2014
- Messages
- 3,156
I wouldn't hold my breath waiting for parts from HF. I have a couple of their hydraulic tables. The 1,000 lb. capacity one started leaking fluid and wouldn't stay in the up position shortly after I purchased it. Rather than replace it they just wanted to order a new hydraulic cylinder. It took over 6 months to get the new cylinder. This was long before there were any of the current "supply chain problems".
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- Aug 6, 2015
- Messages
- 3,887
Same lift table, same problem... but mine was leaking due to the fill hole plug... I had to make another one as I got tired of waiting...
For the 9"x20" best to just order from Grizzly...
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- Dec 18, 2019
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- 6,453
I have a G0752Z which is a G0602 with a couple of options. It is a 10 x 22 lathe, basically in the same class of lathe as the 9x20.
To cut threads you need to change gears. It also has a QCGB, but it only has two knobs to set. Each knob can change into three positions. (A,B & C and I, II, & III). As a beginner, I found the terminology of QCGB confusing. I initially thought it meant no manual gear changing. At least on the G0602/G0752Z that is false. A QCGB on a higher end lathe probably does mean no manual gear changing, but on lower end machines, it does not mean that. Blame marketing and liars on that.
Parts for these lathes can be found by looking to see if there is an equivalent to the Grizzly model, or some other manufacturer that is still in wide spread production. I do know from experience, that simple parts like change gears are reasonably priced. I can get parts like gear shafts, gears, handles, dials and clips in about a week.
My G0752Z has a 3 phase motor and VFD from the factory. I can vary the spindle speed with a knob over a range. However, like the G0602, there are belts to change speed. I have a 3 sheave pulley to change major speed ranges. One does want to change the belt to get the speed range needed. Generally operating at the lowest speed for a belt configuration results in the lowest torque at the spindle (for a 3 phase motor). This is due to the motor characteristic.
My G0752Z is decent. I picked it up used from an HM member. It's not a high end rigid lathe, so if you need to thread 2.5 TPI threads, look elsewhere. But it is fine for my needs right now. There are numerous improvements that can be made to these lathes, but they are not necessary initially. As you get more experience with your lathe you may want to fix or augment its abilities.
To cut threads you need to change gears. It also has a QCGB, but it only has two knobs to set. Each knob can change into three positions. (A,B & C and I, II, & III). As a beginner, I found the terminology of QCGB confusing. I initially thought it meant no manual gear changing. At least on the G0602/G0752Z that is false. A QCGB on a higher end lathe probably does mean no manual gear changing, but on lower end machines, it does not mean that. Blame marketing and liars on that.
Parts for these lathes can be found by looking to see if there is an equivalent to the Grizzly model, or some other manufacturer that is still in wide spread production. I do know from experience, that simple parts like change gears are reasonably priced. I can get parts like gear shafts, gears, handles, dials and clips in about a week.
My G0752Z has a 3 phase motor and VFD from the factory. I can vary the spindle speed with a knob over a range. However, like the G0602, there are belts to change speed. I have a 3 sheave pulley to change major speed ranges. One does want to change the belt to get the speed range needed. Generally operating at the lowest speed for a belt configuration results in the lowest torque at the spindle (for a 3 phase motor). This is due to the motor characteristic.
My G0752Z is decent. I picked it up used from an HM member. It's not a high end rigid lathe, so if you need to thread 2.5 TPI threads, look elsewhere. But it is fine for my needs right now. There are numerous improvements that can be made to these lathes, but they are not necessary initially. As you get more experience with your lathe you may want to fix or augment its abilities.
- Joined
- Feb 9, 2017
- Messages
- 5,249
So the reason it leaked down was the fill hole plug was leaking? How’d you figure that out?
Mine leaks down too but I use an beam clamp on the side rail and it holds the rollers in place. I mostly use it was a portable welding table/work table so it’s always up. But still works for the occasional lift duty and indispensable for that.
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- Aug 6, 2015
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- 3,887
Looked at it while it was raised... this, after finding a puddle of oil under it... Teflon did not work, tightening did nothing... was able to find another plug that worked... one that had a groove for an O-ring on it... that did the trick... I am a sucker for that lift even when it leaked. It is the only one that would slide in between the engine stand... makes it so easy to place and remove the engine from the stand...
