Grizzly G0750G metal lathe preliminary observations

how is the G4003G in regards to treading? Is there a lot of gear changes too?



There seems to be some "new machine" bugs with the 750G. I don't know if I just got lucky but my G4003G that I bought a few months ago was near perfect. The setscrew on the motor pulley was loose and one of the cam studs on my 3 jaw needed to be turned in 2 more turns for a full lockup. Other than than that, it was good to go.
 
how is the G4003G in regards to treading? Is there a lot of gear changes too?
For SAE threading there's no gear changes at all from 4 to 112 TPI. For metric threads, there are some gear changes, but not that many as there's only 6 change gears. I think each gear setup does about a third of the pitches. I'm just going by the owners manual and threading chart on the machine. I've only cut SAE threads to date.
 
If I have to send this machine back (still a possibility) I think I'll get a 4003G instead. All these gear changes for SAE threads is bad.
 
Man, sorry to hear your troubles with the lathe, I have a 4003 I have had for 9 years and its been a very good little machine, only had to replace a motor starter on it in all those years, it has paid for itself many times over. It sounds crazy that you would need to change gears for standard threads, that would be a deal breaker for me. Sounds like Grizzly got lazy and didn't do the research on this new model they are selling....sounds like they have a fair amount of bugs to get worked out.....I think the Chinese are like others, some plants make good machines and some make whatever they can get out the door....I would like to know how many different companies in China are making lathes for Grizzly
 
It's strange that the 750G needs gear changes for SAE threading when the transmission has 4 knobs on it. You would think that would be enough control to make gear changes unnecessary. The PM 1236 transmission looks similar with 4 knobs and even though I don't have one I haven't heard anyone complaining about gear changes. Is it possible the manual is wrong?
 
Yes, the 1236 does require some gear changes. There are (I think) six change gears. They all can do certain ranges of threads by changing the lower knobs on the gearbox but, some gear changes are needed when you go outside that range. It's all printed on the gear chart.

All lathes that have the same gearbox type as the 1236 will work this way. As a matter of fact, this is one of the cost differentiators for lathes. If you want a fully "automatic transmission" it takes more gears and there's more to assemble -and thus, pushes you into the next price-range of a lathe.

...

All factories in China and Taiwan offer machines by what options you want and what quality control measures and re-work the distributor is willing to pay for. Stuff that doesn't make the top grade gets sold at lower prices to other distributors.


Ray



It's strange that the 750G needs gear changes for SAE threading when the transmission has 4 knobs on it. You would think that would be enough control to make gear changes unnecessary. The PM 1236 transmission looks similar with 4 knobs and even though I don't have one I haven't heard anyone complaining about gear changes. Is it possible the manual is wrong?
 
Yes, the 1236 does require some gear changes. There are (I think) six change gears. They all can do certain ranges of threads by changing the lower knobs on the gearbox but, some gear changes are needed when you go outside that range. It's all printed on the gear chart.

All lathes that have the same gearbox type as the 1236 will work this way. As a matter of fact, this is one of the cost differentiators for lathes. If you want a fully "automatic transmission" it takes more gears and there's more to assemble -and thus, pushes you into the next price-range of a lathe.

...

All factories in China and Taiwan offer machines by what options you want and what quality control measures and re-work the distributor is willing to pay for. Stuff that doesn't make the top grade gets sold at lower prices to other distributors.


Ray
Didn't know that, Ray, thanks for the update. I guess it's no big deal as I've never heard a bad word about the PM 1236.
Ed P
 
And one more thing... There are only about 5-6 basic styles of lathe bed and gearbox among the "modern" machines and this is true of lathes, mills and similar equipment. There are a smaller number of foundries in China and Taiwan who produce the raw castings. From there, there are a few more manufacturers who purchase the raw castings, do the heat treating, grinding and final assembly. You'll find that the beds among say a 36" lathe is the same as what's used on many brands. The differences are the selection of knobs (fancy vs. basic) and other basic options such as spindle bore diameter, variable speed options, paint job, etched numbers instead of labels etc... From there, a US distributor gets to pick the quality level which includes the level and consistency of heat treating, quality in closeness of grinding specifications and quality of leadscrew. Think about a 1911 pistol... The pattern is made by many and the parts are (with a little fit and finish) interchangeable. You can buy custom parts or generic stuff that fits every frame. It's pretty-much the same deal with this kind of equipment...

The quality that ends-up in the customer's hands depends on what the importer pays the factory to produce and how much of a relationship they have with the manufacturer to ensure good quality. Some US distributors check each and every machine before they go on the truck. Others don't and play the numbers game that some flaws will go undetected by less experienced users.

Also keep in mind there are "light industrial" lines of equipment and "pro-quality". Pro-quality stuff will weigh a little more, the gears in the gearbox will be heavier duty, you'll have chromed leadscrews, better scraping under the carriage, higher rockwell on the hardened parts, balanced internal gears, wider roller bearings or three or four bearing on the spindle instead of two, higher horsepower motors, pressurized oil systems instead of splash distribution etc. This pushes you about up about 30% - 50% more in price.

Both types of machines are only as good as the operator and both cut well. The main difference is what you need/want. Toyotas have always been good enough for me and a Mercedes would only interest me if I were a wealthy traveling salesman who drove the Autobahn every day...


Ray
 
Boy, for once impatience has paid off. I was "jonesin" for a G0750G when the whole back order thing came about. They told me Nov.-Dec. 2013 for delivery. Since I had sold my Logan I could not remain idle for that period of time. I decided (or they did for me) to go ahead and get the G4003G. Great decision I was forced into. I have had it about 2 months now and have not had a single issue. Every thing arrived very promptly, was packaged securely with no damage and assembled quickly and easily (cleaning every thing as I went).

I had some fringe comming off of the drive belts and did the same thing as mentioned. Cleaned the pulleys and adjusted the belt alignment and tension and problem solved. I will look into the new information on the lube holes that are not exposed.

I was the original post response on the Power Punch. That can be found a most NAPA stores and many transmission and differential repair facilities. I worked for Chev. as a master certified tech. for 13-1/2 years. I was specialized in undercarriage work doing auto.trans, manual trans, differentials and transfer cases. I used this product extensively then and still do. You may try shaking up the bottle some before installing especially if you use only half of it at a time. There will be as stated a darkening of the sight glasses, but the level can still be monitored easily. I am happy this has worked out for those who have given it a try. I know it has always worked for my needs.

Good luck with the G0750G. I hope you can resolve the issues, but if not I would not hesitate on the G4003G. There are not any threading issues with mine, although I do stay within common sizes.
 
Update on progress: Grizzly people have been very cooperative and want to resolve the problems. They agree that the headstock on the 0750 is different than the 4003, and that the part numbers listed in the manual are wrong. They are working to update their database with correct part numbers. In the meantime, they've initiated a high priority request for a new headstock cover from the factory as they don't have one in stock here in the US. This may take up to 2-1/2 weeks (worst case) they say. I'll continue to call them every few days for progress report.
 
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