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Pcmaker

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#1
My Grizzly G8688 Mini Metal Lathe 7 x 12-Inch just came in this afternoon and I have a few questions

-This is my first ever using a lathe. When I turn the chuck, it seems like it's a tad harder and "rough." I don't know if this is normal or not.

-I bought the 3/8" carbide insert cutters. Which one is which? Which one is for turning, facing, etc.. I know the "E" one is for V grooving.



-The AXA Quick Change Tool Post I bought has a bolt that's much larger than the original tool post's bolt. It will not thread into the hole. Do I get rid of that bottom metal plate that came with the new QCTP?

I was thinking either making the hole bigger where the bolt is supposed to thread into or turning the new bolt and then threading it to where the bottom thread will thread into the hole on the bottom. Or just get another piece of round bar and turn and thread it to where it'll fit the new QCTP but thread into the lathe.




-Is there a way to "zero" the dials without a digital one? Like have the tip of your cutting tool touch the outside of your work piece, then zero the dial?
 

Aaron_W

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#2
I can't help with the carbide, I've only used HSS.


I think AXA is too big for the 7x12, I got the OXA QCTP from Little Machineshop for my Sherline lathe and they recommend the same up to 9x lathes.

LMS recommends AXA for 9-12x lathes.

On my lathe I have zero resetable handles. There is a thumb screw that releases the dial from the handle allowing you to reset the dial to zero. Once set you tighten the thumbscrew make the handle and dial move together. This is an upgrade not included on the basic Sherline lathes. I'm not very familiar with the 7x12 lathes so don't know if they have a similar feature, it may be an upgrade you have to add.
 

Dave Paine

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#3
Another comment that AXA toolpost is too large for your lathe. Also the toolpost screw and plate is made for the plate to be machined to fit a compound designed to use a slot to mount the plate, like my lathe.

Not the best picture but shows my AXA plate which was machined to fit the slot in my compound.

Grizzly_compound_scale_too_short_6356.jpg

You may get more comments on the tools if you also show the top shape.

I use "R" right hand tools for facing and machining diameter and chamfering on left side of a groove, etc.. I use "L" left hand tools for machining and chamfering on the right side of a groove or the right face of a part.
 

Pcmaker

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#4
ugh.. paid $150 for the QCTP from Amazon and I already threw away the original packaging and Amazon will not accept the return if it doesn't include those.
 

RWanke

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#5
ugh.. paid $150 for the QCTP from Amazon and I already threw away the original packaging and Amazon will not accept the return if it doesn't include those.
Ouch. That tool post is probably not going to work for more reasons than the attachment. You may have problems getting your tooling on center too. Might try to resell it and get the correct size.
 

Pcmaker

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#6
Not sure what happened. A poster gave me an Amazon link to the 0XA tool post. I just checked the thread again and I confirmed that it went to an 0XA tool post on Amazon. I used that link to purchase the item. I'm looking at my Amazon order history and it says AXA.
 

Bob Korves

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#7
AL and AR are turning tools. BL and BR are facing tools. E is for chamfering, can be used for larger threading but is not correct. On lathe tools R means it is for cutting toward the headstock. L is for cutting toward the tailstock. All can be used for other things as well. Think of it as which way you are approaching the work from and it won't be so confusing. Most of that is what the manufacturers say. How you use them is your business. There are plenty of tutorials online about recommended ways of using various lathe tools.
 

Hawkeye

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#9
As Bob pointed out, you can use all of the tools for multiple operations. Basically, all of them use the same inserts. The shape of the support bar allows you to more easily set it up in your toolpost. The R and the L are right and left, but instead of meaning 'to the right', it means 'from the right'. The A and B refer to how much angle they are set to.

Just use them in whichever way they are most convenient for the operation. Avoiding collisions with the chuck is a main factor to consider.
 

Charles Spencer

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#10
This is my first ever using a lathe. When I turn the chuck, it seems like it's a tad harder and "rough." I don't know if this is normal or not.
I know absolutely nothing about your lathe. However, whenever I encounter something that works rough, I try to look and see if there is any obstruction or contamination. I also check to ensure that it is properly lubricated. I've "fixed" many things with those two simple steps.
 

Aaron_W

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#11
-This is my first ever using a lathe. When I turn the chuck, it seems like it's a tad harder and "rough." I don't know if this is normal or not.

I missed this part yesterday. Do you mean when you turn the chuck to open / close the jaws or when you rotate it in the spindle?

It is probably a good idea to take the chuck apart, clean and lube it. They are often packed with grease for shipping and may have more than necessary and / or have old dried grease in there. This seems to be an issue with most machines, but the cheaper Chinese machines in particular are known to come with occasional bonus gifts such as sand, metal shavings and other unpleasantness. One review of a Harbor Freight bandsaw found a piece of iron that resembled a bullet in the saws gear box.
 

Pcmaker

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#12
I'll have to take the chuck apart, and the longitudinal handwheel, too. It's a tad bit hard to turn. Not smooth at all.

-Is there a way to stop the leadscrew at a certain point when it's on automatically feeding? I don't want my cutting tool to hit the chuck by accident.

-I'm assuming that when you're turning something, you pretty much HAVE to use the leadscrew and not do it by hand? I get a very rough finish when I turn the handwheel manually.
 

Aaron_W

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#13
My lathe is 100% manual. You can do it manual, it just requires a stable consistent speed which you can get through practice. Also a touch of fine grit sand paper at the end does wonders. :)

I would think there was a stop available to you. I have an optional hard stop on mine, really its just a couple of different length rods that fit into the head stock and physically block the cross slide. It seems like most machines have some sort of range limiting device, usually a couple of knurled threaded disks on a threaded rod. Even my cheapo drill press has one like that.
 

Pcmaker

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#14
I dont know why, it seems like when I turn the leadscrew off, the cutting tool digs in to the work piece a little bit. Without me touching the dials. What's the correct way of stopping the leadscrew from turning? I've been just pulling the leadscrew lever from autofeed to off.
 

Richard King 2

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Pcmaker

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#16

Richard King 2

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#17
Then sell the bigger one on GL or ebay and stay with the original one. The tool should work on your machine. Buy some aluminum to start turning. If you bought it new from Grizzly they should be able to help you. Call their customer service and ask them.
 

Aaron_W

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Then sell the bigger one on GL or ebay and stay with the original one. The tool should work on your machine. Buy some aluminum to start turning. If you bought it new from Grizzly they should be able to help you. Call their customer service and ask them.
The standard lathe doesn't have a quick change tool post, he is following advice from an earlier thread where several people recommended he replace it.

https://www.hobby-machinist.com/threads/which-lathe-to-get.70509/
 

Richard King 2

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#19
Ahhh, Well then maybe I should step back….or maybe You-all need a different opinion? I see what's happening now. I read what Dabbler said in the other thread to pick a simple project first. I am curious have you ever run a lathe? In School? Or you're a complete rookie?? I think I would follow Dabblers advice and just use what you have with the machine. The 4 sided tool post will be fine until you learn how to run the lathe. Learn to walk before you run. I buy things on Amazon and am a Prime member. I would check with them and say you lost the paper work on the tool post and see if they can help. The vendor should be able to help. If not write a negative review and I bet they will do something. I bought some dog flee collars gave them a 1 review and said how lousy they worked and the vendor returned my money.

I know everyone was trying to help and if all had worked fine we wouldn't be having this conversation. Call Grizzly Tech Service and see what they can recommend on the machine issues. They also want positive feedback and a satisfied customer.

If it is brand new, do that. If it was a used machine you bought 2nd hand then we can help. Good luck. Rich
 

Pcmaker

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#20
I'm supposed to get my 0XA QCTP delivered today. I couldn't zero in my cutting tools and I don't have any shims. I'll just wait to get my QCTP.

I want to take the lathe apart, wipe everything clean and reapply new grease. My 3 jaw chuck feels gritty, so I took it apart. Everything looked clean, but very dry. I had to carefully use a punch to get the bevel gear out, I applied 5W-30 oil on all the mating surfaces, but still feels gritty. Not sure why you need a punch to get the bevel gear out. Is this normal? It looked clean to me and it's still a "tight" after I added oil in.

Also, what's your guys' opinion on using BrakeClean to clean parts before applying grease?
 

Richard King 2

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#21
Don't use grease as a lubricant, buy some Vactra 2 way oil. Grease will act as a lapping compound and catch the chips and dirt and ruin your new friend. Think about the gear as a bearing in your car, if it's to loose it will flop around. If the gear turned a little tight that is good as if it's to loose it will unwind. Make sure you didn't burr up an edge when taking it apart. Be sure to wear some Nitrate or leather gloves when you take it apart. Those imports have razor sharp edges sometime. Buy a small sharpening stone and stone it just to remove the sharp edges and burrs. I would not take apart the head-stock, carriage without getting the go ahead from Grizzly, as you might be voiding the warranty . As I said I would follow the MFG. instructions. I read on their website there is a warranty card, better fill it out and call http://www.grizzly.com/customerservice

The bad thing about brake cleaner is it can goof up the paint. Ask Grizzly what product they recommend. I hate to say this but I have never been a real big fan of Grizzly but I want to help you now that you have it. Rich

PS: Be sure to wear safety glasses when you use the punch and when you run the lathe.
 
Last edited:

SamI

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#22
I dont know why, it seems like when I turn the leadscrew off, the cutting tool digs in to the work piece a little bit. Without me touching the dials. What's the correct way of stopping the leadscrew from turning? I've been just pulling the leadscrew lever from autofeed to off.
When you make a cut in the lathe the tool deflects slightly under the pressure of cutting. What is happening is that when the leadscrew is disengaged the tool is still contacting the workpiece with pressure behind it and is essentially making a plunge cut into the material. Smaller lathes are much more prone to this than larger, more rigid machines. Try taking lighter cuts on finishing passes to minimise this and retract the cutting tool slightly as soon as you disengage the leadscrew.

As a note, you will find it difficult to repeatedly hit a finished size on a small machine if you only take a single finishing cut. As mentioned above the tool deflects when contacting the workpiece. This deflection will be greater for a larger depth of cut so, if for arguments sake you are taking 0.020" roughing cuts then you take a single 0.005" finishing cut chances are you would end up with a part that is under sized (as during the 0.005" cut the tool wouldn't be pushed away from the workpiece quite as much). It would be good practice to take two or three finishing cuts at 0.005" so you have the chance to account for this. In my experience with these smaller machines a greater depth of cut tends to leave a poor surface finish unless it is perfectly adjusted. This is because you are relying on the machine being perfectly adjusted to keep everything rigid. On a larger machine you have mass on your side to help prevent chatter. That being said it's down to you to experiment to see what gives acceptable finishes for your part(s). Sharp tooling and a well maintained machine will give dramatically better results. Sadly my mini lathe is not exactly well maintained!


I'm supposed to get my 0XA QCTP delivered today. I couldn't zero in my cutting tools and I don't have any shims. I'll just wait to get my QCTP.

I want to take the lathe apart, wipe everything clean and reapply new grease. My 3 jaw chuck feels gritty, so I took it apart. Everything looked clean, but very dry. I had to carefully use a punch to get the bevel gear out, I applied 5W-30 oil on all the mating surfaces, but still feels gritty. Not sure why you need a punch to get the bevel gear out. Is this normal? It looked clean to me and it's still a "tight" after I added oil in.

Also, what's your guys' opinion on using BrakeClean to clean parts before applying grease?
I'd say go for it although with any degreaser / cleaner you need to be sure to wipe any bare metal surfaces with way oil otherwise they'll begin to corrode very quickly. You may also find brake cleaner to be uneconomical to use for this purpose. I used citrus degreaser when getting my new machine and I was pleasantly surprised at how effective this was. If any surfaces are coated with grease use a plastic scraper to get the worst off then go to town on it with the degreaser and some old rags.

As for shims, get a set of feeler gauges off of ebay or amazon for a couple of quid (dollars for the American readers!), take them apart and use those. Obviously if you've got your QCTP then all the better but the feeler gauges work well. Failing that i made some out of old beer cans to shim the gibs under the carriage (swapped out the adjustable grub screws because they were fiddly and annoying). They were a pain to make but can be cut to virtually any size / shape needed for your application.

I hope all of the above makes sense!
 

royesses

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#23
Brake cleaner should be ok. I have used it with no problems. I usually use CRC electro-mechanical cleaner available at O'Reilly auto parts and other auto parts stores. This evaporates quickly and won't harm any electrical parts.

The 0XA qctp is perfect for your machine. It was designed for mini-lathes. You will love it. The only problems you may encounter are the hold down screws for the tool holders. Some of them might have damaged threads or sockets. This seems to be a some do-some don't situation. I ordered a dozen screws from LMS and just replaced the defective ones.

Roy
 

SamI

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#24
The only problems you may encounter are the hold down screws for the tool holders. Some of them might have damaged threads or sockets. This seems to be a some do-some don't situation. I ordered a dozen screws from LMS and just replaced the defective ones.

Roy
+1 except I ended up replacing all of mine with stainless set screws rather than just the defective ones. I found that the hex heads were poorly formed and eventually rounded. For the sake of a couple of quid replacing all of them is well worth it IMO.
 

Bob Korves

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#25
Stainless might not be the best choice for tool post screws. It likes to gall, depending on the alloy. I would (and did) purchase some good quality carbon steel screws, like Holo-krome.
 

SamI

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#26
Stainless might not be the best choice for tool post screws. It likes to gall, depending on the alloy. I would (and did) purchase some good quality carbon steel screws, like Holo-krome.
That's a good point - I must admit I usually pop these things into ebay and buy the first thing that comes up and didn't give much thought on the material for these. I'll bear this in mind for future purchases though so thank you for your comment.
 

markba633csi

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#27
Pcmaker: I use camping fuel aka white gas, naphtha, Coleman fuel to clean and degrease parts. It's mild and not too toxic. Brake cleaner often has toluene or xylene and has strong fumes, eats paint, dries out your skin badly too
Walmart, sporting good stores have camping fuel
Paint thinner works too but not as well
Mark
 

Pcmaker

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#28
Thanks, guys. I just got my QCTP. MUCH better...

Another question. I know if you're turning and the length of your workpiece is more than 4x the diameter of it, you need to use the dead center and the tailstock.

What if you're facing? Obviously you can't use the tailstock at all. Do you go from the center of the workpiece to out so it pushes the work piece "in" while you're working on it?
 

Silverbullet

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#29
Many of the import machines use plastic gears , for lube I wouldn't think of grease , a good tacky machine oil is what you want . Like a thin honey sticks but slides off too. Like the Lucas oil additive display they use to have showed.
 

markba633csi

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#30
Age-old dilemmas; if you can tolerate a centering hole on the end of the workpiece then do that in combination with a tailstock center, or use a steady rest.
If you take light cuts you can hang it out there pretty far, but it's hard to advise how much is too much- we all ruin a few parts sometimes doing it
Another thing to be careful of, trying to grab a workpiece in the chuck that's too large for it- you can break the inside tooth of one of the jaws when there isn't enough of the jaw for the scroll to grab
You often see used chucks for sale with this kind of damage
 
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