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Post by tbenen on May 29, 2021 22:19:13 GMT -5
Looking to pick up some new tooling, but there's so many options at so many different prices that it's slightly overwhelming for a novice  . Thought this would make a good general discussion thread about aluminum turning. The only two sources I'm reasonably familiar with are Amazon and McMaster, so if you guys have better sources for tooling do tell!
Amazon has really cheap sets of carbide tooling like these. 30 bucks for a set of general purpose lathe tools is incredibly tempting, especially compared to an economy set from McMaster for upwards of 125. What gives? How the heck do the Amazon holders get away with such a low price? I get the carbide must be lower quality, but it's hard to imagine a single higher quality holder+insert being worth nearly as much as five "do the job" holders+inserts.
Another thing is the economy set from McMaster linked above has the same inserts recommended for turning soft and hard materials. I get general material inserts exist, but I assume aluminum specific inserts would be better. Sharper, more positive rake... Any recommendations?
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Post by Obi-Shane on May 30, 2021 11:10:05 GMT -5
I wrote a whole paragraph of stuff but deleted it. I strayed off topic again.
Cheap tool holders are cheap, that's basically the short answer. I use a cheap set and it for the most part works fine. What tool shank height do you have on your triangular insert holders?
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Post by tbenen on May 30, 2021 12:02:09 GMT -5
I wrote a whole paragraph of stuff but deleted it. I strayed off topic again. Cheap tool holders are cheap, that's basically the short answer. I use a cheap set and it for the most part works fine. What tool shank height do you have on your triangular insert holders? I'm looking at 3/8" shank, downsizing from the 1/2" stuff I used to use on my 7x14. Plus, sherline has more 3/8" holder options if I ever end up upgrading. |
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Post by Obi-Shane on May 30, 2021 16:24:39 GMT -5
I wrote a whole paragraph of stuff but deleted it. I strayed off topic again. Cheap tool holders are cheap, that's basically the short answer. I use a cheap set and it for the most part works fine. What tool shank height do you have on your triangular insert holders? I'm looking at 3/8" shank, downsizing from the 1/2" stuff I used to use on my 7x14. Plus, sherline has more 3/8" holder options if I ever end up upgrading. Man, you can actually run 1/2" shanked tools in your holders and not go over center height? that's impressive. On a 7x14? That's bonkers. Even 3/8" on my setup is too large and I need to modify my insert holders to bring them down 2mm or so. Well, my old lathe is a lantern setup so there's that. Want some advice? Grab this. www.amazon.com/Edge-Technology-Pro-Lathe-Gage/dp/B01M9FK7R9/ref=sr_1_2?dchild=1&keywords=pro+lathe+gage&qid=1622409668&sr=8-2You will be able to setup all your tool heights in seconds once it's calibrated the level to your lathe while it's sitting. If you move your lathe, it could need re calibrating. Anyways, grab it and don't look back. You'll easily be able to dial in all your tools heights to perfection, and also maybe find an area or two were you might be running into issues. Not getting your tool height right can lead to a lot of problems. |
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Post by tbenen on May 30, 2021 22:17:56 GMT -5
Man, you can actually run 1/2" shanked tools in your holders and not go over center height? that's impressive. On a 7x14? That's bonkers. Even 3/8" on my setup is too large and I need to modify my insert holders to bring them down 2mm or so. Well, my old lathe is a lantern setup so there's that. Want some advice? Grab this. www.amazon.com/Edge-Technology-Pro-Lathe-Gage/dp/B01M9FK7R9/ref=sr_1_2?dchild=1&keywords=pro+lathe+gage&qid=1622409668&sr=8-2You will be able to setup all your tool heights in seconds once it's calibrated the level to your lathe while it's sitting. If you move your lathe, it could need re calibrating. Anyways, grab it and don't look back. You'll easily be able to dial in all your tools heights to perfection, and also maybe find an area or two were you might be running into issues. Not getting your tool height right can lead to a lot of problems. Yeaaaaah first machine woes  Hey, that Frankenstein of a tool setup worked well for the most part! Only complaint I had was parting, but I feel like that's a scary operation no matter what with hobby machines.
Hm! Neat tool, I could have used this a lot. I gotta find a suitable quick change tool post that's more to size as well!
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Post by Guylo Ren on Jun 1, 2021 3:44:25 GMT -5
Now this piece of kit would have saved me ages on setups!Cheers for flagging this up,Obi-Shane!ππ»ππ»π |
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Post by tbenen on Jun 7, 2021 11:46:40 GMT -5
Update!
It seems like the "normal" inserts used for turning aluminum are xxGx inserts. Real aggressive lookin guys. Picture is of a CCGT from Tormach. Seems like CCMT holders are compatible with CCGT inserts which makes finding holders a little easier.
I'm going with CCXT inserts since I can have the same insert for both profiling and boring so I don't have to overspend on different shapes. CCXT boring bars also have a smaller min diam which matters a lot to me and my limited drilling sizes.
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Post by Obi-Shane on Jun 7, 2021 17:56:56 GMT -5
Update!
It seems like the "normal" inserts used for turning aluminum are xxGx inserts. Real aggressive lookin guys. Picture is of a CCGT from Tormach. Seems like CCMT holders are compatible with CCGT inserts which makes finding holders a little easier.
I'm going with CCXT inserts since I can have the same insert for both profiling and boring so I don't have to overspend on different shapes. CCXT boring bars also have a smaller min diam which matters a lot to me and my limited drilling sizes.
Yeah I use these too , and you're right the boring bars use the same ones and also why i went with these. i have others as well but it's nice to have several tools that use the same insert. These have a very high positive rake which makes them very sharp, but watch your feeds and depth of cut, they will want to dig into the material. What you will notice immediately is how they cut, you won't even detect any tool pressure when you begin the cut, they cut like butter and hardly make a sound. |
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Post by Ben Solo on Jun 9, 2021 8:09:25 GMT -5
Update!
It seems like the "normal" inserts used for turning aluminum are xxGx inserts. Real aggressive lookin guys. Picture is of a CCGT from Tormach. Seems like CCMT holders are compatible with CCGT inserts which makes finding holders a little easier.
I'm going with CCXT inserts since I can have the same insert for both profiling and boring so I don't have to overspend on different shapes. CCXT boring bars also have a smaller min diam which matters a lot to me and my limited drilling sizes.
Yeah I use these too , and you're right the boring bars use the same ones and also why i went with these. i have others as well but it's nice to have several tools that use the same insert. These have a very high positive rake which makes them very sharp, but watch your feeds and depth of cut, they will want to dig into the material. What you will notice immediately is how they cut, you won't even detect any tool pressure when you begin the cut, they cut like butter and hardly make a sound. You cut like butter and hardly make a sound |
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Post by tbenen on Jun 9, 2021 21:02:28 GMT -5
For those of you who are looking for where to get stuff, this is the carbide I ordered: ccgt 21.51 I also got holders from shars: RH LH Boring
I'll send an update in this thread when I see how things cut. I appreciate everyone's help!
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Post by tbenen on Jun 12, 2021 7:22:56 GMT -5
The Shars holders ended up being a bit too long for what I'm doing but that's not much of a problem. Gotta say, these CCGTs are absolutely magic. The chip breaker especially makes a HUGE difference. Less strings of sharp swarf and more tight ribbons or even actual manageable chips. Incredible. You can see the surface finish and get a glimpse of the chips under the chuck in this picture. The piece of alu is about the size of a pinky finger for scale. |
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Post by tbenen on Jun 12, 2021 15:10:06 GMT -5
Alas! The alu scrap I used to test the new carbide must've been a free machining alloy. Going to the stock I make my sabers with results in difficult to deal with strings of chips that get caught and ruin the surface finish or spin with the chuck. Honestly similar behavior to my old cutters, but this is a different lathe so I don't get to do any direct comparisons. I do know that these CCGT inserts work miles ahead of the CCMT that the holders came with. I've got more tinkering to do with feeds and speeds before I get something that works, or maybe make my own chip breaker somehow. Less good news is still good news!
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Post by Guylo Ren on Jul 2, 2021 1:18:08 GMT -5
Sounds a really obvious thing to ask,but were you still using plenty of coolant?In what little experience I've had,I found exactly the same thing was common until I used a ton of coolant.No one cutter proved to be The One for me,but using coolant flow changed my cutting massively (granted,I've also had the luxury of the biggish lathe at work).
I still had strings of ali coming off the work,but it tended to somehow hold together better & run off away from the cut when flowing the coolant,rather than doing that huge spool of razor death thing around the chuck.
For me,& the toolmakers also warned me it would behave like this,aluminium tends to cut like chewing gum,sticking to everything & quickly clogging the cutting edge,spooling round the workpiece as you describe etc.But,loads of coolant does ease that problem hugely.On big CNC machines of course the RPMs are ridiculous,which is better for ali finish too,so I learned to try not to expect those results,for myself!π
As you say,the grade of alloy will also affect the outcome too- my hilt stock is all 6000 series of some description (mostly eBay sourced once I got going on the build),& I did observe different tubes cutting completely differently even with the same feed & speed.
But overall for me,the biggest help for that better finish,with more manageable chipping/stringing?Coolant!ππ»
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Post by tbenen on Jul 2, 2021 15:33:46 GMT -5
Sounds a really obvious thing to ask,but were you still using plenty of coolant?In what little experience I've had,I found exactly the same thing was common until I used a ton of coolant.No one cutter proved to be The One for me,but using coolant flow changed my cutting massively (granted,I've also had the luxury of the biggish lathe at work). I still had strings of ali coming off the work,but it tended to somehow hold together better & run off away from the cut when flowing the coolant,rather than doing that huge spool of razor death thing around the chuck. For me,& the toolmakers also warned me it would behave like this,aluminium tends to cut like chewing gum,sticking to everything & quickly clogging the cutting edge,spooling round the workpiece as you describe etc.But,loads of coolant does ease that problem hugely.On big CNC machines of course the RPMs are ridiculous,which is better for ali finish too,so I learned to try not to expect those results,for myself!π
As you say,the grade of alloy will also affect the outcome too- my hilt stock is all 6000 series of some description (mostly eBay sourced once I got going on the build),& I did observe different tubes cutting completely differently even with the same feed & speed. But overall for me,the biggest help for that better finish,with more manageable chipping/stringing?Coolant!ππ» That's a good point, I actually wasn't using coolant like I usually do since my coolant bottle broke. I should get that replaced and do some more test cuts on the bigger stock. Thanks for the advice! |
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Post by Weaver on Jan 2, 2022 10:19:01 GMT -5
Some good information here...
Am I reading the description of that lathe gauge correctly in that it only calibrates for tool height? Do they make something like that for angles as well? Parting off is one of my weakest areas on the lathe and it would help me plenty if I could perfectly square the bit. I'm still using the old "loosen the tool holder and run it up against a machined surface to square it" method.
Being that tooling was one of the stumbling blocks that stopped me making anything of decent quality, what's the chance we could get a resource list going? A list of links to high-performance bits, tool holders, etc?
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Post by Obi-Shane on Jan 2, 2022 21:42:08 GMT -5
Some good information here... Am I reading the description of that lathe gauge correctly in that it only calibrates for tool height? Do they make something like that for angles as well? Parting off is one of my weakest areas on the lathe and it would help me plenty if I could perfectly square the bit. I'm still using the old "loosen the tool holder and run it up against a machined surface to square it" method. Being that tooling was one of the stumbling blocks that stopped me making anything of decent quality, what's the chance we could get a resource list going? A list of links to high-performance bits, tool holders, etc? Yes, tool height only. To get your angle right, you are going to want to indicate it in. That's how you do it "the pro" way. What you are doing now, tailstock quill bumping, or chuck bumping, was the quick and dirty way that I also used to do which I learned from Caz ages ago. But don't anymore mainly because MY setup won't allow that but also because I thought I should try and do it the "right way". You'll need to re-do it every time you loosen your tool post nut or adjust your angle on your compound slide. Doing it the quick and dirty way works for the most part tho. Spent about 15 min looking for the darn video showing how to indicate in your TP so it's square to your work but couldn't find one of the ones I've seen. Basically. Put a tool holder in your QCTP, lock it in, but leave your tool post nut loose but a little snug so you can spin it a little. You put your mag base on your lathe bed, lock it down, indicator tip on your tool holder edge, left side. Ideally on the ground area, preload it. Than traverse cross slide in and out (not back and forth) or "plunging your cutter into an imaginary work piece", like you are pretending to part something, you are looking for ZERO movement on you dial. When you got that you'll know that you are dead square. Note: parting off is the weakest area of any lathe. Things to strive for are sharp cutters, low spindle speed when parting, and steady high pressure to help avoid chatter. Part close to the chuck at all times, if its far away you'll want to support it. Part wet to help clear chips when you can and to avoid chip welding. |
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Post by Weaver on Jan 2, 2022 22:36:24 GMT -5
Thanks for the advice, Obi-Shane. I'm still very new to machining and greatly appreciate anything that might help me along.
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Post by Obi-Shane on Jan 4, 2022 7:16:44 GMT -5
Thanks for the advice, Obi-Shane. I'm still very new to machining and greatly appreciate anything that might help me along. Ok. Found a quick and straight to the point video that illustrates kinda what I was talking about. This video is about compound angles not exactly what youβll be doing but kinda similar. |
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Post by Weaver on Jan 4, 2022 8:47:10 GMT -5
Ooh...more vids.
There are a couple of older gentlemen on YouTube that I've taken a liking to, because of their no-nonsense, straightforward approach. I'll see if I can dig up some of their vids as well.
EDIT: First impressions? This guy looks like he could be J.K. Simmons' brother.
I used a similar method to square up the spindle on my Grizzly G078 mill table the other day. Amazon sold a device with two dial indicators for the purpose, which fits directly into the spindle collet. I'm still off by 0.004" over 1.71" of travel, but I think that's because I had to maneuver behind the machine in order to set up the second dial. I picked up some telescoping inspection mirrors for a second attempt the other day, so we'll see how that goes.
As far as the angle gauges, I found a video on making them using some trig functions to calculate the offset of two drilled holes. Why do it? Because the guy then uses worn end mill bits to lay the angle block stock across the vise (vertically) for facing off. Angles, he says, are broken up into degrees, and degrees into minutes and seconds. This method is claimed to be accurate to within minutes.
With that method, you can even carve a stop into the angle block, so that you can reliably place multiple parts in exactly the same position. Good for batches, I think. I never believed I would have much use for geometry or trig, but you can bet I plugged that little formula into a spreadsheet as soon as I figured out how. I'll see if I can get the formula posted up as well.
High-Accuracy Angle Blocks:
Still trying to figure out Imgur... -_-
Oof. Nope. It doesn't want to embed the image. Basically, you can do the same thing he did in that video, or you can use the TAN function (either in your PC's calculator program or in a spreadsheet) to get the same result. I created a spreadsheet for it because it's faster and easier to just enter the numbers there.
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Post by Guylo Ren on Jan 4, 2022 13:31:18 GMT -5
ππ» Anything Joe Pie says to do as a machinist,you do!He really is an ΓΌber-pro,Joe's setup & execution are second to none,way above any level I'll ever achieve... what an engineer,& teacher!Genius.ππ»
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Post by Weaver on Jan 4, 2022 13:43:54 GMT -5
Agreed! He's got Divergent Thinking, which is rare to find these days; especially in any professional environment. It's the reason I felt compelled to mention him here. The guy is a beast in the shop, and everything I want to emulate.
People get hung up on the method and end up forgetting that it's the result that matters. My $0.02 on the issue.
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. Thought this would make a good general discussion thread about aluminum turning. The only two sources I'm reasonably familiar with are Amazon and McMaster, so if you guys have better sources for tooling do tell!
Hey, that Frankenstein of a tool setup worked well for the most part! Only complaint I had was parting, but I feel like that's a scary operation no matter what with hobby machines. 
