Grizzly G0750G - Basic mods for usability?

[dnellans]

I recently picked up a new to me G0750G with aftermarket DRO for a steal that is less than 2 years old. I'd been waiting to try and find a 13x40 Clausing for over a year but then this came up 15 minutes down the road from me - 2 hours later it was in my shop.

After a good cleaning and alignment it appears the bed has a slight spring in it that I still need to get sorted out for working down the bed, but through the headstock all indicates as well as I might have hoped.

I've come across two things that seems like obvious design flaws for a "gunsmithing" targetted lathe though. Well maybe not design flaws, but large annoyances. They must affect anyone that has this class of machine that is a clone, so wondering what people are doing for fixes/improvements.

I'll let it slide that the tipped screws that come with the lathe are so long they interfere with the cover when supporting anything .75 or over (you know, like a barrel). I drilled and swaged some copper into shorter ones, that when I realized that you can't remove the end gear cover to change gears without removing the spider screws all together... Ugh. Any reason I I shouldn't just take a hole saw and drill that sucker out to be the full diameter of screws?



Second thing I didn't notice when looking at the lathe initially was that the cross slide is indexed 90 degrees of the other lathe I've been using. This means for threading I am at 60.5 degrees on the face, not 29.5. I can live with that. But I haven't quite figured out how I'm going to get to crowning angles reliably (and quickly) without the scale going to 90. I could come up with some form of witness marks at 10 degree but that doesn't help me much beyond a one or two specific angles. Am I having a brain fart here or is there an easier way?



If anyone has other gotchyas I'm going to encounter on this machine, please feel free to chime in!

 

[spitfire_er]

congrats on the new lathe. I have noticed the index marks for the compound on several import machines are set up like that. Would seem like a simple fix to change the design. I have a few lathes, but my south bend 10L has 3 zero marks for the compound which is very nice!

 

[Dusty Stevens]

Congrats on the lathe. Holesaw on the back is a good idea, but how often do you think youll change gears?
witness marks on the compound is a perfect idea as is using a protractor and indicator if you need to know down to the degree. If its that critical youd need to use an indicator anyway

 

[liljoe]

I have a Jet that has the same index markings. I used a small sharp chisel and made another mark on the compound.

Joe

 

[dnellans]

Thanks for the replies guys!

I'll be changing gears more often than I might like, but fine for my non-commercial shop where time isn't money, its just one less beer... Switching between 16, 18, and 24 TPI all require at least one, if not both end gears to be swapped. Unfortunately, the gears for 24TPI on muzzles aren't shared with any common tenon pitch.

I thought about how many holes I would have to cut to get at both the gear ends, but with the lash adjustment required, it will start looking like swiss cheese. The actual swapping isn't particularly troublesome, but I worry about leaving the cover off entirely and having the end gears exposed 100% of the time, not to mention if/when they start splattering.

The removal of the spider screws is just annoying - everyone in the world with this class of machine must have run into this...

I can hit 60.5 (and checked its true) with just a nudge past 60 on the scale, but hitting something repeatably for a crown with out breaking out the protractor is what what I'd like to be able to find a good solution to.

 

[dnellans]

I have a Jet that has the same index markings. I used a small sharp chisel and made another mark on the compound.

Joe

Can you post a picture Joe? Did you witness the compound round itself? Marking that at 90 unfortunately puts the scale largely underneath the slide itself which makes it a PITA to read.

 

[Simont]

For an 11 degree crown, count back back 19 degrees and make a mark to then roll around to 60

 

[Dusty Stevens]

Thanks for the replies guys!

I'll be changing gears more often than I might like, but fine for my non-commercial shop where time isn't money, its just one less beer... Switching between 16, 18, and 24 TPI all require at least one, if not both end gears to be swapped. Unfortunately, the gears for 24TPI on muzzles aren't shared with any common tenon pitch.

I thought about how many holes I would have to cut to get at both the gear ends, but with the lash adjustment required, it will start looking like swiss cheese. The actual swapping isn't particularly troublesome, but I worry about leaving the cover off entirely and having the end gears exposed 100% of the time, not to mention if/when they start splattering.

The removal of the spider screws is just annoying - everyone in the world with this class of machine must have run into this...

I can hit 60.5 (and checked its true) with just a nudge past 60 on the scale, but hitting something repeatably for a crown with out breaking out the protractor is what what I'd like to be able to find a good solution to.

I meant cut one big hole where the spindle comes out so you can open the door with the screws in there just open it over the screws, like make that spindle hole twice as big. Ive never seen a lathe you had to change gears like that- usually its just for metric/ sae change over. It looks to me like your 16,18&24tpi is nothing but a dial change. Here is a picture of the diagram: AC4V is 16tpi and AC1V is 18tpi all on the same gears. You set the speed on the top 2 levers, the one below sets travel direction, and the 4 knobs below are what you set the threads to going by the top diagram on the plate on the left

 

[DR_2297]

Looks like a and b (drive and driven) gears have to change for each of those TPI. Weird.

 

[Walt Krafft]

I would change those spider screws to socket head set screws that are short enough to fit through the existing hole. I don't think you need the lock nuts on them. You could do some experimenting to see how critical the 11 degree crown angle is. Let us know what you find.

 

[DR_2297]

I would change those spider screws to socket head set screws that are short enough to fit through the existing hole. I don't think you need the lock nuts on them. You could do some experimenting to see how critical the 11 degree crown angle is. Let us know what you find.

Call me crazy but I took the back cover right off of my g4003g. I was sick of my compadre not checking to see if the spider screws were still in the spindle and firing the lathe up to do something and then damn near grinding a hole in the aluminum cover. Plus now you can get to all 4 easily that way. Life is better now, just not as pretty. Yeah don’t go sticking your hands or clothing in the gears while she’s running...

 

[dnellans]

For an 11 degree crown, count back back 19 degrees and make a mark to then roll around to 60

Thats the kind of witness marking I was hoping there might be a better solution to. While effective for -one- mark, as soon as I've got 2 plus a formula to follow to know what its for, it will get error prone.

 

[dnellans]

Looks like a and b (drive and driven) gears have to change for each of those TPI. Weird.

Yup - Dusty overlooked the A/B gear marks above the gearbox settings. 4,8,16,32 and 5,10,20,40 are the only threads that share a common gearset (60,60). Definitely not the most user friendly, but when shopping on the cheap everything is a bit of a compromise.

DR_2297 - Taking the end cover off all together do you have issues with a lot of splatter or dust/grime/chips getting in the end gears? I'm not too concerned about the safety side of it, it was more about one more thing to have to keep clean(er).

Dusty - yea, I was just thinking about a hole that follows that odd bump out they've got that limits the spiders. I will probably make some slightly smaller ones yet again, but I had those screws in a drawer so just drilled 'em out and drove 4g copper into them. Sheesh that those grade 12 screws are hard too! It would be even better if it was a door that just "swung" open but its actually cover you have to pull off and hold.

Maybe I should fab up something a little more custom that gives me front/rear/top splatter shielding but just leaves the gears open. Thats one step beyond the hole saw for now...

 

[liljoe]

Can you post a picture Joe? Did you witness the compound round itself? Marking that at 90 unfortunately puts the scale largely underneath the slide itself which makes it a PITA to read.

I can take a picture tomorrow. I can't remember exactly how I did it.
I guess im not sure why the angle of the crown is that important? All of mine are flat. I guess I missed the magazine article.

Joe

 

[dnellans]

I can take a picture tomorrow. I can't remember exactly how I did it.
I guess im not sure why the angle of the crown is that important? All of mine are flat. I guess I missed the magazine article.

Joe

I don't want to dive into that rat hole since the question is really about how to get the most from the machine. The annoyance is that the scale/witness layout makes it difficult to do anything between 0-30 degrees from the work-piece axis.

 

[Dave@MAM]

Thanks for the replies guys!

I'll be changing gears more often than I might like, but fine for my non-commercial shop where time isn't money, its just one less beer... Switching between 16, 18, and 24 TPI all require at least one, if not both end gears to be swapped. Unfortunately, the gears for 24TPI on muzzles aren't shared with any common tenon pitch.

I thought about how many holes I would have to cut to get at both the gear ends, but with the lash adjustment required, it will start looking like swiss cheese. The actual swapping isn't particularly troublesome, but I worry about leaving the cover off entirely and having the end gears exposed 100% of the time, not to mention if/when they start splattering.

The removal of the spider screws is just annoying - everyone in the world with this class of machine must have run into this...

I can hit 60.5 (and checked its true) with just a nudge past 60 on the scale, but hitting something repeatably for a crown with out breaking out the protractor is what what I'd like to be able to find a good solution to.

Congrats on the machine! You are correct on the gear change drill. My older G0709 is set up differently and you only have to change gears for metric or some large threads. Friend had one like yours and didn’t realize that issue until he set it up to use. If I am correct, yours has a 2” headstock bore opposed to my 1-9/16”which I liked. (He wound up selling it and getting a Sharpe).
As Simont mentioned, I simply used a protractor and made my 11* mark for my crowns and it is very repeatable. I use this machine specifically for barrels and smaller stuff so I never have to change gears for its purpose.

 

[ridgeway]

The degree scale is simply rotated 90°. All you have to do is understand if your angle comes off the spindle face or axis. Not an issue at all. No need to scibe lines, lol. Basic math...

 

[DR_2297]

The G4003G is the same way. I have a few reference lines stamped info the compound for various angles also. If it’s important I break out the measuring tools.

the first line is stamped where the angle reading begin.

 

[pdhntr]

......Am I having a brain fart here or is there an easier way?

Salvation lies within.



And if you are worried about taking the side cover off, I have found on my machine, if I can learn to keep my fingers from the moving parts on the right side, the left side takes care of itself.

And if I have "splatter" from the gears, I have WAY too much lub on them.

Jim

 

[akajun]

Congrats on the lathe. Holesaw on the back is a good idea, but how often do you think youll change gears?
witness marks on the compound is a perfect idea as is using a protractor and indicator if you need to know down to the degree. If its that critical youd need to use an indicator anyway

You’d be suprised
I have to change mine to do Mauser threads
Idk why Grizz does that I’ll never need to thread anything at 100 tpi they should have made the general range lower