Grizzly Turning Tool Question?

[twocik]

I've recently bought a set of HSS turning tools from Grizzly (picture below) and was wondering if anyone would be so kind to show me how they're used properly. Up into this point I've used the really cheap carbide tools from HF. These new tools have a little bit of a different design to them. I've found diagrams showing how the tools are should be used, but couldn't find anything on these.

Thank you
Chris

[twocik]

Here are a some pictures of what I'm getting

Material
- 6061 Aluminum
- 3.7" diameter
- 6" length

Grizzly 3/8 HSS Turning Tool ( I think this is the off set left hand tool, but not sure)


Lathe Settings

RPM's - 1000
Gear Box set to Lever 9 - 0.005" (A 28T gear, B 60T gear, C 120T gear)
Taking cuts of - 0.11" (3mm) per pass





My question is why am I getting such a deep grove ?

I'm still learning be gentle...

[twocik]

Anyone??

[cadfish]

I have the same set that you do and looking at the picture that shows the tools I would use the one on the lower left. I use this tool and I dont have a powerful lathe at all but I can take about 1mm off a side cutting steel

[cjdavis618]

I have the same set and get pretty good cuts on everything but the cut off tool.

You didn't mention what type of lathe you have. But I know I won't take cuts of .11" of at a time. Maybe .020 to .030 off onr side but that is about it. I would back the cuts off and try that unless your size was a typo.


I run my lathe around 1000 and below for speed. I am using a 9x21 lathe from Grizzly if that helps at all.

[twocik]

Sorry about that, I'm running a standard 9 x 20 lathe.

I'm using the second to the upper right tool, which I believe is a left hand offset tool, but I'm not 110% sure. I found a few things on the internet, but not much for running a 9 x 20 lathe ( hell I'm still trying to figure out the clutch on this thing ). I found a site that gives examples of how to determine the RPM's to use. Here's what I got


For 6061 T6 Aluminum with HSS turning tools, it says to use 500 - 600 and other sites recommend lower speeds such as 175 - 250. I'm a little lost on this one.

500 CS x 4
------- = 540rpms
3.7 D


Is this right??






I've kind of brushed the surface with the clutch on my lathe, but really didn't understand it. Here's my question

1. When the clutch is engaged (on), does that mean that the piece of rubber inside is pushing on the thin little rpm belt?

2. After starting the lathe and I'm ready to start cutting, do I leave the clutch engaged (rubber piece pushing on the belt) or away from the belt?

[in2steam]

First off the tool you are using appears to be a facing tool but I could be wrong, The pattern in the first part of your post indicates which each is used for, typicaly a LH turing tool is all you will be using besides a facing tool on the conventional tool post, I will repost when I get home so I can look at you pictures a little better they don't come through well here.
As for cutting speed on the lathe with HSS bits I use a very simple rule and it works well,

4 times the cutting speed divided by the diameter, this also works for drills and mills wereas the mills/drills are the diameter for the speed, but not the feed.
I use for the most part unless I really know for sure what the speed is I use


4*CS/D
Alum/wood 200
steel 100
cast iron/bronze 150
brass 200
alloy steel and plain steel to from 1040(shafting) 50 or less
These are just guides the machinerys handbook has all the speeds.
With the case of carbide dry I do normally double speed and feed if possible, I don't use coolant often but when I do I go even faster, but no light cuts.
I go to the next slowest speed if I don't have one within a few rpms, as I face I try and run the speed up some(I have a DC motor now), as the diameter is decreasing resulting in higher rpms.
As for the clutch, you should. start the motor, engage the clutch, cut, you can either leave the clutch in while shutting off the motor, or disengage it first. My lathe(g4000 9x20) will not even spin with the clutch fully disengaged, please note there are a couple of operations that you may need to leave the clutch engaged esp metric threading(refer to manual) and only stop the motor. You can start the motor with clutch engaged but its hard on the motor and belts/gears.

I will try and help with the bits when I get home.


chris

[twocik]

Thank you!! Yes any tips, help would be greatly appreciated.


For 6061 you use a cutting speed of 200?


I notice when I move the carriage by hand slowly toward the chuck, at 600 rpms I get a nice finish. Now when I put it on auto feed, it comes out very groovy and not polish looking at all.


1. When engaged does that mean the clutch lever is toward me or away
- On - rubber pushing on the belt?
- Off - rubber off of the belt?

Basically which way is on and which way is off?

(The I'm using is the 9 x 20 Harbor Freight.)




"I have a DC motor now"

So you made the upgraded, did you do it yourself?




.

[snowshovelbmx]

I would say that for the answer to one of your questions as to why you are getting the large grooves or rough surface finish is because there is a very small, if any radius ground into the nose of that tool you are using. If you are using a 5 thou per revolution feed than you need to have at leat 5 thou of the tip touching the work to give a smooth finish. I would grind a small radius of maybe .03" You can just use a honing stone to do this. Hope this helps.

chris.

[in2steam]

Originally Posted by twocik Thank you!! Yes any tips, help would be greatly appreciated. For 6061 you use a cutting speed of 200? I notice when I move the carriage by hand slowly toward the chuck, at 600 rpms I get a nice finish. Now when I put it on auto feed, it comes out very groovy and not polish looking at all. 1. When engaged does that mean the clutch lever is toward me or away - On - rubber pushing on the belt? - Off - rubber off of the belt? Basically which way is on and which way is off? (The I'm using is the 9 x 20 Harbor Freight.) "I have a DC motor now" So you made the upgraded, did you do it yourself? .

I got a better look at your pics, first things you need to do is make yourself a new compound rest mounting I think you maybe even be able to buy them through LMS now. That will make big difference, Second you need bring your tool into the post as close a possible the more ridgid the better, the chip breaker on the tool you are using indicates that you are using a facing and not a turning tool(its odd either way), lookin down onto the tool you should have a narrow steep left shoulder and broader shallower right the chip breaker should be near parallel to the work piece, although it may not have one at all. Your speed was too fast, and your are heat treating your tool tip which indicates you are rubing more then cutting, you may need to regrind the tool gently and keep it cool untill you are past that the heat treatment. Your grooving indicates that your feed is to aggresive, which means your tool isnt right/ bad angle/or sharp, I would expect that kind of find finish on a piece of 1045 shaft steel.
Also you have to remember if you are not using coolant that your tip will expand as it heats so agresive cuts should be avoided untill you have a good base cut, with a rough cut like that you will hit high spots creating even more heat.
I use a CS of 200 for most of the alum I do(i do mostly sand cast with some bar stock), typically I don't know for sure what the material is so I play it safe which seems to work well for me, its not a die hard rule, if I have finish problems which I often do I typically start to change the speed both up and down and see if it matters. Tool angle is critical with HSS, its not as forgiving as carbide in that right, also making sure you are on center, and of course sharp.
As for when you have the autofeed engaged(and not the screw cutting) that entirely depends upon your feed rate per revolution typically the slower you go the better the finish. Also with a finishing tool, you dish out the tip more then a roughing tool, I don't concern myself with finish on any alum I do, but cast iron I do, there I provide a very braod radius on the tip maybe near half of the tool bit but that is a different animal. So I can't help you much with fine finish on alum I just use a regular turning tool. Also how are are your chips breaking off? you might need to touch up the tool with some grinding wheel on the top to provide better chip clearance.

I suspect there is a problem with your clutch, can you provide a pic? with the lever towards you the clutch is disengaged, with it away the clutch is engaged. There is not any question when its in and when its out, mine stops and does not turn, as it should. The grizzly manual is decent try downloading that and see if gives a clearer picture, I would have to actually look at mine to determine which way the wheels bind up, if memory serves the belt is engaged from the bottom but don't hold it to me. Sorry I have not made it home yet to look, I had to babysit a friends forklift today.

Variable speed yes and no, the lathe I have at work which is a piece of scrap iron with a chuck, has a variable speed motor. My 9x20(same lathe as yours) is still stock but I do have the motor and control(90 VDC 1 HP) to put on, when I get some time I will it should be straigh forward as the motors are nearly the same size maybe a mounting or belt issue, if its not possible with the DC I have a metric 3 phase I will through on instead which is the same frame size(DC would be more fitting for this application). At this point use the machine untill you are comfortable then worry about upgrading, I have not used mine at home all that much( I got it third hand about 3 months ago) I currently use my shaper more then anything, so I have be careful about my HSS tool statements as they are ground different, I still refer to drawings when I have to grind new tools esp the lathe.

Chris

[twocik]

"I got a better look at your pics, first things you need to do is make yourself a new compound rest mounting I think you maybe even be able to buy them through LMS now."



Yes I completely agree. Here are a few pics that show exactly why I would need one. I can't understand why they would sell the machine this way. Only 2 hex bolts to hold it down, what a crock of sh*t.





"Second you need bring your tool into the post as close a possible the more ridgid the better, the chip breaker on the tool you are using indicates that you are using a facing and not a turning tool(its odd either way), lookin down onto the tool you should have a narrow steep left shoulder and broader shallower right the chip breaker should be near parallel to the work piece, although it may not have one at all. "



Yes that's what I have been reading. What if it can't reach, like when parting. Speaking of which my parting tool isn't working to great, well not really working at all. In the pictures below, you'll see a really chopping surface. I'm guessing it's the compound rest that I need to upgraded.

BTW I'm only seeing the 7 x 10 compound rest, not 9 x 20 over at LMS. I really don't have any time right now to make a Compound Rest as I have a critical deadline for the products I sell. However I might have to make some room for it, I can't have a finish that looks like this. Do you know of any other stores that sell any?

It's too bad that know didn't upload there Gcode file for a micro/mini CNC mill, but that would be to easy.




"As for when you have the autofeed engaged(and not the screw cutting) that entirely depends upon your feed rate per revolution typically the slower you go the better the finish. Also with a finishing tool, you dish out the tip more then a roughing tool, I don't concern myself with finish on any alum I do, but cast iron I do, there I provide a very braod radius on the tip maybe near half of the tool bit but that is a different animal. So I can't help you much with fine finish on alum I just use a regular turning tool. Also how are are your chips breaking off? you might need to touch up the tool with some grinding wheel on the top to provide better chip clearance. "




I read all night after I posted, and found that my speed was to high, and my feed was to fast. I didn't know that if you have a feed of .005" the tool needs to be in at the same distance. Very helpful, thank you!!!

I've read on finishing tools, looks like a really round edge (almost ballnose). I have a blank, so maybe I'll try to make one.


"Also how are are your chips breaking off?"


Well with the parting tool, they break off into little 2mm - 3mm chips, but it chatters like hell as I move in. With the facing and turning tool, long spirals, not chips.




"I suspect there is a problem with your clutch, can you provide a pic? with the lever towards you the clutch is disengaged, with it away the clutch is engaged. There is not any question when its in and when its out, mine stops and does not turn, as it should. The grizzly manual is decent try downloading that and see if gives a clearer picture, I would have to actually look at mine to determine which way the wheels bind up, if memory serves the belt is engaged from the bottom but don't hold it to me. Sorry I have not made it home yet to look, I had to babysit a friends forklift today."


Yes, below. In the one picture below you'll see the clutch disengaged, is the belt suppose to be that loose? I'm turing the material at 600 rpms, but with the clutch engaged. Now when I have it at 1000rpms, no slack at all. In the picture I'm pushing on the belt with my finger to tighten the slack, I'm pushing in about 2 inches or so.





"Variable speed yes and no, the lathe I have at work which is a piece of scrap iron with a chuck, has a variable speed motor. My 9x20(same lathe as yours) is still stock but I do have the motor and control(90 VDC 1 HP) to put on, when I get some time I will it should be straigh forward as the motors are nearly the same size maybe a mounting or belt issue, if its not possible with the DC I have a metric 3 phase I will through on instead which is the same frame size(DC would be more fitting for this application). At this point use the machine untill you are comfortable then worry about upgrading, I have not used mine at home all that much( I got it third hand about 3 months ago) I currently use my shaper more then anything, so I have be careful about my HSS tool statements as they are ground different, I still refer to drawings when I have to grind new tools esp the lathe. "


Keep me updated on this, I'm very interested!!!!

[Runner4404spd]

I think your problem comes from lack of rigidity. basically your tool is bouncing off the work peice.

1. check your spindle bearings and make sure they are tight. (my 9x20 was loose from the factory.) you want the head to be really warm to the touch when running about 1000 RPM. you may want to pull the spindle out and lube the bearings prior to this.

2. i found the my compound was flexing. buy a quick change tool post with a larger diameter shank down the center. the stock one i think is around 8 mm. i currently use a 13 mm post down the center of my quick change tool post.

3. add a larger diameter handwheel to the cross slide feed. you can replace the lead screw as well but i noticed the largest difference with the larger hand wheel and tightening the gibs.

4. get some carbide tooling. do not get the brazed carbide get the inserts. there are inserts specially designed for aluminum and they are well worth the money.

5. after the mods above i can take .150 per pass when turning. thats about .300 of mterial removed from the diameter. (i did upgrade to a 3hp motor and a vfd for my lathe.)