Sorry for the duplication with some of the previous post. I have a working machine and a fair amount of new information. SO...
Grizzly G0709
I chose this model because it has a slightly larger bore through the spindle, which did not sound like a bad idea. I’m not a gunsmith and don’t offer any advice thereof.
I chose a Grizzly for several reasons: I had purchased an classic American made lathe on a friend’s recommendation only to find a lot of parts worn out and no replacements available. I contacted other companies and visited owners of other Chinese machines. In general, pretty much everyone had problems of some sort. Grizzly owners were getting the best support. Several people swore by Grizzly knee style milling machines. Grizzly had the most comprehensive web site, parts and accessories availability and the best manuals. The manuals have great photos that are labeled clearly. Many manuals are poorly translated English and stick drawings. Other companies all said Grizzly was their biggest competition. Nobody claimed to be better than Grizzly. One guy who purchased another brand was actually told after he had a problem that to do any repair on his lathe under warranty, it would have to go to back to China and actually take a year at least.
So, I bought it, but what did I get? My situation is a little unusual. I had a health diagnosis a couple months after I received the Grizzly. I knew that I wanted a DRO system so I purchased one with magnetic scales from DRS Pros. The installation went very well and I love that thing. I followed the installation and break in instructions in the lathe manual. I had a little project and I could not get the thread dial to work correctly. A machinist friend confirmed something was wrong with the lathe. I called Grizzly and they were looking into it when I got sick. Two-1/2 years later, a little shop worn but healthy, I resumed my G0719 odyssey.
Thanks to Grizzly support, I realized that the threads were very slightly the wrong pitch. So slight you pretty much need longer than a standard thread gauge to tell. In a combined effort, I identified a gear that was the wrong number of teeth. My parts manual was different from the web download manual and when I took the cover off, I confirmed it. It turns out a small batch was shipped with a wrong gear. I wasn’t notified. The gear, per Grizzly, was matching a metric lead screw for other countries. They shipped me a correct replacement for free. I had removed the old gear. It was simple.
In the mean time, I started to investigate quite a few things about the lathe and this document will describe them. First however, I have to say that to my detriment, I had only casually glanced at the rest of the easy change gearbox. As I started to install the new gear, I realized that one of the other gears was seriously thrashed. In general, most of the gears showed some sign of being abused while the lathe was running. I never shifted anything unless the machine was dead stopped. The one really bad gear was so impacted that it had pieces hanging off the gear teeth. I suspect it was not hardened correctly or at all or was an inferior material to the others. I believe the gears were shifted while the lathe was still moving at the factory.
I heard a lot of stories when I was looking at other brands. I actually had a several hour talk with a guy whose company makes Chinese machine based CNC milling machines. He said every shipment of base machines is a crap shoot even after 5 years of trying to improve relations and quality control. It seems that Grizzly is not immune to it. I have requested a replacement gear. (Follow up, Grizzly covered shipping but not the $27 gear)
As long as we are in the gearbox: the bottom of the gearbox was covered with dirt. It appears the factory does not clean any parts before assembly and whatever rust protections and all the debris caught in it become part of the machine. This was after I had replaced the fluid following the careful break-in described in the manual. (What a joke). Secondly, virtually none of the set screws in the gearbox were actually screwed in all the way. Some are pointed, some are a pin style that may be intentionally set loose but in my gearbox, they were all out several turns. This probably also contributed to the damage. Finally, the front case cover was leaking from when I received the machine. The three top dials are covered with cheesy aluminum stick on disks. The disks cover the center screw. These screws actually cannot be tightened because they will bind with the next inboard part, so they have to be adjusted. They had no locking glue or anything to retain their loose position. Same with the other hole covered, used to set the tension on the detent balls. I eliminated the covers and duplicated the paint scheme on the face of the dials themselves, which are almost uncharacteristically substantial.
The headstock: When I changed the oil in the headstock, the bottom was filthy, the same as the gearbox. I cleaned it with a solvent spray, the same as I cleaned the easy change gearbox. The gasket in the top cover was pooched toward the inboard side, covering the channel that lubricates the rear spindle bearing.
The Apron: I have not taken the Apron apart yet. I’m sure it is filthy as well and I will do it fairly soon when I figure the easiest way to go about it.
The Tailstock: The tailstock works fine but the chuck it came with is a POS. The chuck key does not even fit it. When I measured it, the tailstock was off by about a thousandth. I figured it could easily be perfect. I soon found out that the two seemingly simple adjustment set screws, that are the only thing positioning AND HOLDING the tailstock, had a couple interesting characteristics. First, they do not work intuitive. Secondly, they do not have enough precision for the job. When they get close to tight, they are likely to change direction on the dial indicator you are watching to make the correction. At one point I was cursing myself for not leaving it alone. However, I eventually got it to zero detectible error.
The live center: I give this its own section rather than including with the tailstock because it’s problem are numerous. Disassembly is easy. That’s about the only good thing about it. The housing and end of the center shaft were rusted. The bearings used are very low quality ball bearings. There is a spacer that has a recess in it so that it only spaces out the outer race without touching the inner. No brainer there, but only one side of the spacer is surfaced. The other side looks like a stamped out washer and has about 50% contact. The grease that was in there looked more like dried up boogers than anything you could call a lubricant. This was the reason I disassembled it when it quit spinning after about 5 minutes of work. I thoroughly cleaned it and assembled it. It now seems to be working ok, but due to the cheap nature of the bearings, it has a limited lifespan.
The Spindle: When I was measuring a part, I realized that every time I manually pulled on the chuck to rotate it, I was getting a one thousandth axial deflection. I decided to follow the manual’s instructions to adjust the spindle endplay. This turned out to be one of the best decisions ever. First, I needed a spanner wrench so I made one because I didn’t want to wait for one to be delivered, or pay for it for that matter. Coincidentally, I found a cheap forged plumber’s spanner in my toolbox for kitchen sink drains that is the same size. So, I then had two, which is kind of necessary unless someone is helping you that can blunt chisel the retaining nut on. I ignored the manual’s instructions to put the indicator on the spindle face and used the side instead because I could apply sideways force to read the play of the tapered bearing. This worked out very well. The manual’s way would require you make it too tight, IMO. Every time I adjusted it, I had to run it for 20 minutes to see if it overheated. When I finally got to .0001, I decided to go with that for now. From .001 to .0001. It ran at least as cool as it had before I started. I may have achieved close to .000 but somehow, the bearings lost 90% of their resistance after my last adjustment and I didn’t want to lose that. Now I can easily spin it with a finger when disengaged or in a higher gear. Somehow, the bearings have taken a seat that is dramatically better. It is a pleasure to handle now. And remember, no heat generated. The spindle stays cool and the housing is only slightly warm after 20 minutes of highest speed running. If anything, it’s cooler at .0001 than it was at .001.
The Cross Slide: I took this completely apart to clean it and try to reduce the backlash of .012. The gib had been hand scraped, which I found interesting. It turns out that you absolutely cannot use the lock set screw as it immediately locks the slide up (even though I had drilled a hole through my DRO scale for the wrench). The end adjusting screws work well though. About .007 of the backlash was in the front of the screw where the bearings are for holding the screw in position. These are inexpensive bearings for a fairly important job. This is easily adjusted with a set screw in the middle of the handle (reference 646). The manual does not describe this adjustment that I could find. So, I had .005-.006 actual backlash after I took the clearance out of the handle. I found it to be impossible to improve upon this with the sliced nut adjustment. I had made a tool so I could adjust it without removing the retaining bolt.
The Compound slide: Seems to work fine, eventually I will clean it as noted for the Cross Slide.
The electrical system: The control panel is a very flimsy thin gauge aluminum cover. I pop riveted (4) an aluminum angle to it to fit in the pocket that the switches fit into. (Approx. .032 X ½ X 1” X width) The first time I used the brake, it worked very well but the machine turned off and then would not reset. This tuned out to be the micro switch attached to the linkage in the lower left compartment. A factory worker that didn’t have a clue inappropriately positioned it and the switch arm was bent around itself. I straightened it and put it in an appropriate position. It now works fine. The manual says that you only have to switch the spindle ON/OFF lever to the central position to reset but you also have press the Power Button. Otherwise, the electrical system, motor, switches, relays, have been fine.
The 3-Jaw Chuck: The three jaw chuck came with a faint primary position indication that consisted of a faintly stamped 0 (zero) on the spindle and chuck. I could hardly see it and could not feel it. I installed round head brass pins I made that are visual and tactile.
The 4-Jaw Chuck: The screws would barely turn on the chuck. I removed the jaws and flooded with solvent while I turned the screw fast with a 3/8” impact wrench. I then ran the jaws in and out a dozen times or so, each, with the air impact. Then I could easily run them in and out by hand smoothly. Then I realized that the outer edges of the chuck where the jaws insert were as sharp as a knife. With a small stock inserted, these edges could take a hand off if careless or even cause quite a gash when manually turning the chuck. I ground and sanded the edges to a smooth touch. Clean and lubricate again. Now, it was time to screw the locking pins in and insert their rotation lock screws. Five out of six would not go in far enough. (there is an index line) The 3-jaw and plate chucks did not have this problem. Eventually, I resolved that the threads were simply not cut far enough into the chuck. The next day I bought a $17, 12.1 metric bottom tap because I did not have one. That cured the problem. When mounting, I only had to turn one pin out a thread. One of the locking screws did not engage the pin properly. This is dangerous because if the pin rotates, it is possible that you might not be able to can get the chuck off. I put a lock washer that was the same size as the head under the head and that solved it.
The External Gear Set: This set allows three arrangements without additional gears. This is cool. However, the gears are time consuming to change and adjust. I was told and sent a picture of a broken bracket. I’ve smoothed the sharp edges.
Would I buy the machine again? Up to finding the thrashed gear, I was saying yes. Now, I honestly would have to say, only if I planned to take it completely apart and resolve the inevitable problems. I know some people have purchased these lathes and swear by them. Maybe I got a machine that was poorly assembled on top of having the wrong gear.
Drain plugs: I purchased ¼ X 1” neodymium magnets off Ebay. They are amazingly strong. I took a brass ½” NPT square head plug and center drilled for the magnet. The magnets turned out to be harder and more durable than I expected and I was able to press the magnet into the plug with a press fit.
Covers: The cork gaskets seem to be a problem for leakage and positioning. I installed them with “fuel lube”.
I have a fair amount of pictures of the things mentioned here. I posted them to Photobucket. PM me if you like and I’ll send you the link and password.
I really like the Grizzly folks and their philosophy. I just suspect they have become somewhat powerless over quality with their Chinese counterpart. They bring machines to thousands of people that can’t afford new American made machines and don’t know how or want to consider used equipment, and don’t need production rated equipment. Unfortunately, the buyer has to work some on the machine to make it work correctly. I think most people think a new machine will be usable when delivered but I think you might be better off expecting some problems and necessary modifications such as with a Harbor Freight item.
