I, Sir, am a huge fan of your work.... Learning new tricks from you is literally priceless.... From a Machinist in Amman Jordan....

Hi Adam, don't worry about concave facing cuts, lathes as I understand it are designed to do exactly that, the more precise the machine, the tighter the surface tolerance, but it will still be measurable. It was explained to me, many many years ago, as a way of ensuring matting parts abutt around the periphery, which has loads of advantages to the matting faces of two convex surfaces only being in contact at the centre. Hope the ops gone okay, cheers.

Really neat to see the inspection on the parts. It is always interesting verifying what we think we are doing with a machine.

"A little too much to take... I'll split that into two cuts"!!! Never have I heard Abom say such a statement.

I like vids like this. I feel like i learned something, and you are great at explaining things Adam. I always look forward to new content...

These are the little things that books don't tell you about when you don't apprentice. Thank you Adam for your content over the years I've been watching. It's helped me in my career as an HVAC tech to understand how metals react to stresses, how (measurably) metals change size when heated or cooled, and how some large machinery still has custom parts for them.

That chuck stop kit looks pretty nice. I hope you and Abby are doing well. You have my thoughts and prayers for a quick recovery.

Something about that cleaning service coming through when you turn it is just so satisfying

Thanks for the video Adam, hope you're recovery is going well... Cheers from Australia mate... 👍

I look forward to each and every upload, and I’m not even a machinist, but love learning his stuff. More so because of adam’s presentation style.

Thank's for sharing. Love the inspection part. May you have a speedy recovery. God Bless.

I keep learning from your video's. Cross slide wear , I must check my Lathe for that. Thanks Abom.

Nice easy to use chuck stop. Again you made my Saturday, thanks Adam.

I was worried about it being square, but Adam addresses all of my concerns every time. smart dude

Cheers Adam, Great learning moment with knowing your machine and its little tells on what might be happening! Cheers Troy

Nice to see you Adam!

Hey, Adam its 9.30 in the evening over here and youve rounded another Saturday off nicely for me and my wife. Ive got the phones on and she is laughing at me smiling at your great presentation, she even wants to listen to find out why Ive got to listen every Saturday so intensley. All the best matey from accross the pond. Regards Stuart

Your finish is always just awesome. Very interesting tool thanks for sharing.

Wow, lots of great information in this episode! I'm looking forward to the next video!

good quick demonstration of chuck stop/ check stand productivity, that table is awesome!

.. aaaaaaannnnnnddddddd my Saturday is complete! Adam, your Saturday night videos are the high point of my week!

Nice tool and seemed to work well. Basically a softjaw set up without a specific diameter cut into the jaws. I like it.

Love the short blue chips. Perfect.

Love that starrett test indicator!!

Invaluable information! Great video. Hope that your recovery is going as you want it to. Many thanks.

A lathe should always face slightly concave, even a brand new lathe (because perfection isn't possible, it's either concave or convex), so that if you want a truly flat surface, the concave face sits on its outer rim on a surface grinder chuck. A convex face will sit like a rocking chair. This is what Dr. Georg Schlesinger says in his book ''Testing Machine Tools''. How concave is another question, I think it's in the book. The concavity shown here seems excessive though, and is cased by wear. Pressure on the Near side of the left dovetail surface (also the inner saddle surface), due to cutting forces while facing (and turning), causes this wear. Btw, look at those chips going in and then coming out from under the cross-slide cover at 19:48!!

Really liked this video and the way you walked through measuring all your parts. I am a process development chemist by training and have to take data from multiple experiments to determine what is happening overall. Look forward to seeing the rest of your table build. Based on this video this will be one of the most accurate and precisely built shop tables out there. Thanks

Okay, it's 5:30pm, there are over 80 comments at this time and nobody has said it yet, so I guess it's up to me. "The chuck stops here." It's a dirty job, but somebody had to do it.

got to use these the other day. i tapped all the peices like on a mill and every part cam out within .0002 love the things

Excellent as always

Love this kind of stuff. I made a fairly comfortable living at my chosen trade and have only a few regrets but I do wish I had gotten more into the machining part of the business.

Inspection jop is the most important in this video thanks for sharing.

Hello Adam, have a good recovery. Your quality check reminded me of being careful about my assumptions on how accuarte my machines run :)

WE missed seeing you at the Bash this year.Again it was a BIG success.

Great video as always, informative and motivating as well

Great show Adam. I hope you are feeling well from your surgery. Rich

Love your work adam.. keep going.. thanks..

Adam, great video sure liked your parallels.!.!.!.

Hey Adam, thanks for the video mate. Great content as always buddy! Hope your recovery is going well and your back up and about soon. All the best, Deren from Australia

Dear Adam, I agree with Stephen Deakin, that lathes are set up new to face cut a slight, very slight concavity. This is done by misaligning the headstock relevant to the long axis of the lathe to a very small degree. Trying to adjust this is futile! Best wishes and hopes for a full and speedy recovery from sunny West Cornwall, U.K.

Adam, thanks for the video. If you are up to it, please give us viewers a short update of your surgery & how you are doing. Wishing you well my friend. RJW

Good video Adam Good information in this video. Hope you are resting and healing ok buddy' Praying for you and Abby as she takes care of you. Have a great weekend. God Bless!!!

Enjoyed that Adam thanks for sharing. This reminded me that making a set of chuck stop spiders has been on my to-do list for a while. I was thinking of you on the 19th, so take a moment to remember that 190,000 people are sending you their best wishes ! Regards, UK.

I've used hockey pucks as light duty machine feet, works very well. I used them for a Grizzly G8084, 838 pounds.

Lecture here: Accuracy is how close the measurement is to the real value Precision is how repeatable the measurements are. So, the 0.002" dip to the center off all of the parts shows that the turning operation is precisely the same to within the limits of measurement. The one part coming out at 2.0015" while the other 5x came out at 2.000" shows that there was an imprecision in the setup, with a part coming out inaccurate to 0.0015" Now, this is all rather pedantic, since the tolerances on these parts as required for function are quite a bit looser than +/- 0.002" - they are going to be welded to saw-cut carbon steel tubing after all! So, the spider is a very precise stop for making repeatable parts to close tolerances - thanks for sharing Adam!

Adam you have the best content on youtube! Also you sir are an artist on those machines my hats off to you.

Hope you're doing fine mate !

Really interesting video! Thanks.

Great review! This looks like annother awesome edge tech product!

Nice work Adam, looks like that will be a useful tool. ATB, Robin

Nice product.

Great video hope all is well Adam

Nice!! So much better than a 3/8" plate with a hole in it and a nut welded to it to accept the pad. Interesting!! (as usual)

Hi Adam, I hope you're doing well after your surgery, and you are hopefully at home by now.

On the flat face issue, I don't doubt you could have worn ways, but another factor is how low your cutting speed gets as you approach the center. You only get consistent metal removal with constant cutting speed.

Close enough for me man , AWESOME !! Enjoyed .. Get well soon my friend ..

in my home workshop I usually use soft claws for that type of work or other similar ones with very good results

Not bad at all. My lathe has similar wear. I think most lathes have a small slope built in. Guess its just to keep parts setting flat vs rocking from being high in the center like a top. Thanks for the video Adam. I enjoy seeing new products demonstrated. Thumbs up..

Thanks for the video.

Adam . I do believe when you start cutting with the insert at first is cooler then when it gets to the center it gets hot and it is spans 1 to 2 thousand try to use coolant to cool the insert than to see if there's a difference .

really enjoy your videos, I can watch for hours, kind of strange, but I cant stop! thanks for sharing. roger

Adam good tip.

Nice!!! I have made a miniature chuck stop similar to that for my lathe !

Good thick tables are a real blessing in the shop. This is a beauty bud. Perfectly level is the real bonus for sure. That chuck stop is such a great idea. I wonder what is coming next eh.That is one winning system for sure bud.

In my experience, assuming you have the ways locked (long feed) so the tool won't back out , what is happening is the tool is actually digging in as it gets towards center due to the increased tool pressure from the slow surface footage. Any play in the cross slide ways will allow the tool to lever itself into the part due to the force of the facing cut. A lite finish cut or increased surface footage to reduce tool pressure will usually result in a flatter part. Of course having a lathe with absolutely no play always helps too. Having worked on Old machinery most of my life I always had to be aware of heavy face cuts possibly digging into the workpiece.

Adam, about a year ago you chucked a cantilever bar and made a 10" long cut. With undercut between the 2 ends. Difference in diameters was about 0.0005", as I remember. So you were happy headstock was parallel to ways. Now the diff is 0.0025 in 1.5" perpendicular. Mr. King told me same thing....cross slide not perpendicular to headstock and ways, but he told me to leave part in chuck and run indicator from edge to center. BUT that was not your intent. Thank you and my best.

Hey Adam,if you face with the insert having more of a positive angle to part instead of square or a bit negative,the insert should push crosslide against dovetail,as opposed to wanting to pull away from the dovetail with a negative angle on insert,hope I worded that correctly.

Nice tools

really clever idea that adam

The one you knocked in will be bigger, I bet if you tried a piece of feeler gauge (0.03mm or whatever the Roman equivalent is!) between the part and the parallel you’d have a gap before knocking it in. The jaws will be spreading out at the furthest point from the chuck face, especially since the part it only about halfway in the jaws. When making soft jaws at work we always taper them back toward the chuck (larger diameter on the chuck side) so it pulls the part back to the shoulder on the jaws

Those could be pretty handy. That metal stock is good looking. Ooh,... shiny metal... Hope it's going well with you. Thanks.

I was told that the concave facing cuts that a lathe produces is done intentionally. The lathe is manufactured to produce this slight concave cut so that the work pieces can be stacked without having them fall over. Now of course if the face is perfectly perpendicular, the stacking of pieces would not be a problem. But, if the face were to be even a little bit convex, this would be a problem. So they leaned to the side of caution and made the cross slide cut just a little bit concave. It would be interesting to test other lathes to see what kind of facing cuts they produce to either confirm this to be true, or confirm that this is false. Great videos Mr. Booth, always enjoy watching them.

Man, that's going to be one hell of a stout table you're building.

Actually, I think you would want a lathe to face slightly concave (thicker at the OD of the workpiece and slightly lower in the center). That way a disk will lay flat on a surface rather than spin and rock if the face was convex. And if a lathe faces convex and you need a piece to lay flat, one fix would be to machine a slight depression leaving a land of material at the OD.

Glad to see you up and about. Hope you are healing well. As always I love your vids, always thought provoking. I think the measuring is irrelevant if you don't first make sure the part is mounted parallel to the spindle axis. And to be repeatable you need to tap the parts in, so they are fully seated. Given the hollow in the middle of your parts the pressure of those taps will be concentrated on the three contact points where the part perimeter crosses the spider legs. Those parallels will get chewed up pretty quick, unless they are very hard. If they are hard then the part will suffer. I would prefer to use the entire face of the chuck as the reference, so the full perimeter of the part contacts the chuck, evenly all way round. Frankly I don't see any benefit to the "spider", and this concentration of forces at the limited points of contact seems a problem for long term consistency (esp if the parallels accumulate little dings). I know you can polish out a few thou with scotch brite, so any testing like this should probably skip that step. Unless your forearm is fully calibrated you are introducing some amount of variation, small though it may be. Champhering is good, knock off the sharp edges, as a second op (do all the facing with one tool, then remount each part for the champher step). Keep up the great work, and hope you feel top notch soon!

Preplanned vids, viewer appreciation.

That may work faster than a custom holding fixture I use on one part I make, do about 10 to 15 per order. Gonna check into it. When I make multiple parts like you made in the video, another measurement I take is measure the thickness around the outside in four places. You gonna have a table that you can toss your shaper, lathe, mill and other items on at the same time when you need some quick temporary room in your shop. It should handle your house too if you need some temp yard space. Can't wait to see what you are going to put on it. I know for sure, you will never break it.

If you only turn down 1 1/2” down to 3”, you have a nice edge to set the legs on. I hope you are feeling ok, and the opration went well. Get better soon Mr Abom!

Try taking the same facing cut with the carriage stop locked. The carriage might be moving away from the chuck due to the tool force. The tool cutting force is probably greater toward the center because the surface speed is lower. Love your channel.

One limitation comes to mind. If you can't tap the work back after tightening the jaws you can't compensate for wear in the slides allowing the jaws to tilt and move the part away from the true face of the chuck. So this relies on using a very good/new chuck.

Just a suggestion when you are turning the round stock leave flange on one end to keep it from pushing up into the tube.

I'm certain that the cross slide dovetails are worn on mine. It will tighten up on you as you go in. I was a bit disheartened when I discovered that the top half of the cross slide had been milled by someone that had the lathe before me. It would probably take some inlay work to bring it back out to the point where it could be scraped in and have the gib tighten properly. I got my eye on a D-8 Do-All surface grinder. Depending on what I find on it, getting a really flat face may come down to leaving the part a few long and finishing it on the grinder. Gotta get that home first and see what it takes to make it run.

HA! I wonder if you could rig up some air to those feet for your heavy table to a central location and levitate that sucker anywhere you want with air pressure. You would need a pretty tight fit with the floor so the air pressure doesn’t leak out. If it works it should move with finger pressure, LOL. Retracting the center 2 pads (no air) should cut air usage. Three feet (tripod) would be better. Worth trying to amaze your friends.

Check the chuck stop parallel setup on the surface plate, I bet their spot on. Looked looked an OXTOOL video.

The stop works reasonably well, depending on what work you want to do on the lathe. Great view with your Starret indicator. I like Starret equipment. And that .002 out of flat looks to be coming from the lathe. Not a big deal, just remember it is there when you set up, then compensate for it. You're no dummy, so I guess you already knew, but machinist OCD! Had to say something.

#1 do the first facing without the parallels -> more area from the jaws to align the part -> force is closer the the jaws guides #2 with the parallels on the 2nd side, use a torque wrench to tighten your juck -> jaws will allways move the part away from the juck becouse of the play in the jaw guides -> with a torque wrechn you get the same error, but with an higher repeate rate. #3 your lathe is just fine. Its better to have concave parts then convex ones (in my eyes)

great video, get well soon!:-)

The dip to the centre seems very high at over .001" per inch. If the cross slide is out of square,then this could be confirmed by facing from the back which would result in the high point at the centre. My guess is that there will be some adjustment to the squareness.

According to Dr. Schlesinger "Testing machine tools", a finishing late should face within 8 tenth over a foot diameter (hollow only), and a tool room lathe within 6 tenth over a foot diameter (hollow only). So, your machine has wear, indeed. But it is not terrible :-).

It would be interesting to try again with a sharp high speed tool and light cuts to see if low tool pressure makes the problem go away. You could also run your compound forward or rearward to see if the wear is worse at some places on the cross slide.

Nice job to check the run out on the machinery. Surprised you didnt consider the shaper to cut the square to fit the tube as an exersize. Des.

It's possible you're getting a bit of jaw lift as you tighten down the chuck. Would be interesting to see if you can get a feeler gauge under the back after tightnening, or feel the stop for looseness.

Perhaps you could indicate the slides under load to see where the wear is and in what directions. If you could take half the wear out or better with your surface grinder or shaper it would be a big improvement. Once you have the (fixtures?) made up you could do any similar machine, and you could scrape some other day and have much less material to remove. Or that is what I am guessing, anyway :).

Seems that a half thou to a thou wouldn't be much in the grand scheme. Looks like that instrument will be big help for repeate turns.

Adam , hope R&R is going ok . As to the lathe I was always under the impression that they were set up to turn a very slight dish with the cross slide to make sure the part would sit flat on its outer edge ,if it was the other way high in the centre it would wobble , at least that’s what the then local machine builders told me when they scraped in the saddle’s , I think they aimed for 1 thou in 12 inches dia

hope you feel ok.

this table is going to be a beast! Most peope would put a plate on the end of the leg, weld on a nut, and call it good....

Interesting ...just thinking through this and wandering if the runout is due to the increasing load on the tool due to decreasing surface speed as you near the centre. Maybe slow the feed speed ...? Or maybe try same experiment on much larger diameter and check graduation of runout. If it is due to wear on the dove tails then you would expect it to be worse closer in and rectifying that might bugger up outer alignment. Maybe move the tool to the other side of the head stock where you would expect less wear in the dovetails. Love ya efforts bro.

Is it possible to check the parallels that come with the tool on the granite? I'm curious as to the accuracy of the parallels.

see you