Well, you certainly helped it a bit, with what you have to work with in your shop. Only other option would be what, re-scraping the saddle V? That doesn't sound like fun at all. For what it's worth, I often have trouble on softer materials to get a decent surface finish too.
Hey Michael, I just noticed that I have the same machine. I´m in the process of cleaning and restoring it at the moment. You can adjust the the clutch of the carriage. There is a big grub screw on the right side of the saddle (pointing towards the tailstock) that you can turn and adjust the clutch. I have the complete saddle and carriage disassembled at the moment and can provide pictures of the inner workings of it all. Let me know if youre interested. Best regards Kevin
Hi Michel. All of our ageing machines benefit from gentle adjustments whilst we chase incremental improvements. You proved the point with your careful study and adjustments. Yes, sometimes it can feel like one step forward two steps back. But in time, you will get there. Well done on what you managed to achieve so far. 👏👏👍😀
Hi Michel, I get similar issues, usually on harder materials (especially unknownium and scrapbinium grades of steel). I need to do some experiments to see how much of a difference locking the compound and cross slide would make, and look at the way the saddle behaves as you have done here. Another one for the list! Thanks for the video
Hi, What is often over looked on older lathes is the head stock bearing . Taper bearing need to be pre load on them and can give rough finish to work been turned. The old method of checking the lift will show this up. Some way of lifting the chuck with a clock reading the lift will tell you. If you can part off with a problem then the head is fine. Steve
If the carriage has a bit of slop and can move on your bed, it csn be badly affected by your feed screw. If the feed screw is slightly bent it will lift the carriage once per revolution of the feed screw (when using auto feed). You could test by stopping the feed screw, then hand turning the crank (on the rack) while at the same time holding the carriage down really hard with your hand or a very heavy weight and taking a light cut. Then you know the turned surface matches your lathe bed/carriage.
I am chasing down pretty much the same thing on my 70 year old, but little used Atlas/Craftsman 12X24 inch lathe. 3 good tools to use are: 1. Work slowly. 2. Employ plenty of patience. 3. Think very hard before you do anything. I enjoy your videos very much!
I had done a simillar repair on my "weld used" 1968 Logan 10" lathe several years ago. It wa a good thing you corrected that movement in the carriage IMHO Michel.
I'd call it a success if you eliminated some of the play and got a better finish even if it was a small amount. On my 1943 South Bend Heavy 10 lathe I was chasing a bad finish also and two things that gave me the most improvement were making a tool holder for a die grinder and lightly grinding the surface of the jaws on 3 and 4 jaw chucks also removing the cross slide and carriage, stoning all surfaces, cleaning and oiling everything then adjusting the gibs. I stopped after that because for the work I do I was satisfied with the finish. Good video
Hi Michel l have an old Raglan 5" lathe made in the 1950/60 the chuck has a bell mouth problem and both the ways are made of flat ground and hardened steel bars both are badly worn. The saddle and the cross slide are badly worn, also the compound slide is worn. It really needs to be stripped down and have the surfaces scraped but l do not have the necessary skills to complete the work, although l do intend to try. Other than these problems the lathe is great. At the end of the day you can only do what you can with what you have to hand, you produce a high level of work with what you have,so keep banging away with it and do what you can, your doing a grand job. Watching this video has given me the necessary drive to undertake the work on my own lathe. Another great video regards Gary
Hmm, that sure is a lot of uneven contact, but not so much wear on the lathe ways, which is good... Having wear in the saddle or the carriage can easily be scraped out, refreshed with rulon/turcite teflon precision strips and voila, you have a full contact and oem specs for geometry of components back in line... The scraped finish will help the pfte glue work better in any case, and the teflon ways will provide even a nice durable surface, as its not just plastic, its bronze impregnated, so its a good bearing material, but it demands cleanliness, as the plastic can get embedded with chips and actively mess up your ways, but again, way wipers, way covers and general cleanliness of the shop takes care of that... But you cant just tighten the lift straps of the saddle to deal with this kind of wear... Its why there is resistance in the travel... The slop didnt come from the clamp, it comes from uneven contact of the V female to the bed way and the other flat carriage way surface too is horribly uneven, which doesnt have anything with side to side movement, but offers shit support of the cross slide into the bed ways and probably allows for slight rocking motion of the carriage, as the other side is likely also worn on the tip, making it convex, which can only be mitigated so much by the clamps... They have to have some oil clearance, and if the carriage ways are convex, there will be some rocking during travel and load... I would first check the contact pattern with blue dye, just to ascertain the level of convexity on both sides of the carriage... I would take it off, check it with a straight edge and so on and do some mild scraping to check the things before fully scraping the carriage out and replacing the removed material with aforementioned turcite bearing material... Only then can you consider the clamps as possible source of problems, as your carriage obviously has other much more glaring issues which cant be resolved without some gentle touch of a carbide blade... Everything else just induces wear on the bed ways from increased pressure and ``point`` contact with the worn area, lubricant notwithstanding... Its very likely why your surface ``feels wavy`` - the convexity, which will act as a point contact with the bed, a point around which the carriage wobbles and produces wavy finish... The fact that the taper widen out near the chuck indicates that your tool is on center, and as the carriage ``climbs`` up the less worn area on the bed ways, it gently rocks backward, lifting the tool off the center ever so slightly, thus reducing the depth of the cut... I would experiment with lowering the tool slightly below the center, 0.01mm would be enough, and running the same cut again, if im right, the cut should taper narrower towards the chuck, as the tool will be brought onto center there and will cut slightly deeper... Which will kinda mess with you, if you hoped that this was a good improvement, as it is likely just the effect of the tool height being set right on, and if the taper reverses, it just proves that the carriage is convex, if that isnt apparent from the shim checking... Dont get me wrong, im not shitting on you here, i just love old iron and want to point out any thing that i can to help any machine user with minimizing the wear on the machine and utilize the machine to its fullest capacity... Im no master in the field, but i did learn a lot, and from what i see in the video, i was compelled to offer the advice above... All the best and kindest regards!
Well you have an improvement. I have noticed over time that with carbide especially, taking a very light cut this happens, when taking a heavier cut it does not happen. Take care Rusty.
Good work Rusti. I agree with Andrew's comment below (gentle adjustments on ageing machines). Oh, those elusive microns we chase. If only I could catch them LOL. Cheers, Aaron.
Hi Michel, Enjoyed the investigative detective work...quite an effort to keep a lathe running right..epically an old one. There just like us as we age...Lol ATB.....
Hi Michel, I noticed the carriage doesnt seem to sit solidly on the ways. I might be wrong of course, but to check I'd take off the apron, blue up the ways and have a look at the contact pattern under the carriage. It might be riding on a small patch in the middle so it can rock, which would cause your problems.
I was thinking much the same as you. It does look like there is a hump or high spot in the middle area of the saddle vees. Hi-spot blue would witness any such defects and indicate where any scraping should be carried out to remove the rocking points.
Hi Michel, tracking down errors in lathe ways and the carriage is notoriously difficult. Watching RU-vid I learnt that hardened bed ways means most of the wear ends up in the corresponding inverted V ways in the carriage. Cheers
Hi Michel, I would say that is a big improvement and I would make a guess that the error would be ok for most of your jobs. Getting to the bottom of the clutch slipping out would also be a great advancement. Enjoyed your step by step analysis of the problem, great video!! Good luck from Spain!!
Hi Michel ☺, these kind of problems can drive you mad, between headstock alignment, and all the variables in the carriage to bed , and cross slide wear it's realy amazing that the lathe has so little run out, but I know the slight taper ,and finish to a cut are troublesome. But as we see here the adjustment to the carriage caused the taper to change direction, so I think your looking in the right area, perhaps a shim in that rear hold down plate would stop the carriage lifting up, and tilting away from the the front way, therefore iliminating a taper cut ?. I think we viewers will be watching whith interest to see where the problem lyes, as I think they will be fellow sufferes out here whith a similar problem. Thanks for another interesting video mate, stay safe, best wishe's to you and your's, Stuart UK.
I find that any relatively light lathe needs a little help to keep the carriage or compound seated properly on the ways or feed screws. Makes a difference on accuracy, or on the minute chatter and vibrations that may occur on finishing cuts . For the forward v-way, it can be as simple as pushing down on the carriage over the v-way . ....also gives you a "feel" of how the cutter is doing . On an Atlas type of lathe, pulling back slightly on the toolpost or the carriage can have the same effect . It also occurred to me when I saw you, Rusti was having continued problems with your rear-mounted cutoff that possibly your carriage may be erratically lifting or chattering slightly on the front controlling v-way as the cutting load varies -- and due to the reduced downward load on the front "controlling" way . Just a thought -- cutoff tools can be sneaky on any lighter lathe .
Hi Michel, do a comparison; that cut was made with the power feed, do another with the threading lead screw and see if there are different results. Cheers
As for the variance in the turned diameter of the part. have you confirmed that your head stock alignment is spot on? Because if the headstock is not aligned it will give the same effect. The ways will be worn in an older machine, and most of the wear happens up near the chuck, worn ways will give you the same results ie: diameter increase corresponding to the wear areas.
I'm curious about a couple of things. When you take measurements with the dial indicator, will you see any deflection if you rotate the part but don't move the carriage? Put another way, I'm wondering if the waviness you're seeing will only appear in the axial direction, or if there's also a radial component to it? If the hump twists around the part like a cork screw instead of just being a series of thicker and thinner sections, each running in separate rings around the part, then this particular problem may be caused by something else. The chuck could be bellmouthed, or have some other problem? I'd be curious to see what a test part looks like if you turn it between centers. Unless something else is seriously wrong, and causing the carriage to be supported by the gear that rolls along the rack, that doesn't seem like it would be a likely source of the problem. One thing that happens on older lathes is that the bottom of the carriage wears unevenly. Ex: It may have worn enough toward the ends that there's a hump in the middle, and it could be rocking back and forth on the hump. (Or not.?) Anyway, thank you for another excellent video!
A great improvement but now I suspect a slight twist in your bed is your problem. If you want an excellent finish try using your tangential tool left to right as a final pass taking only 30 or 50 microns (1 or 2 thou) but don't alter the angle to do this from normal turning.
Michel, like Randy said, as carbide inserts wear they leave crappy finish that tend to show themselves in different ways. Even with finishing inserts, cuts of less than 0.010” don’t go well. As for the waviness, you’re gonna have to tackle every moving part individually to reduce lift. So if you want to measure you saddle play, make sure everything else is tight. Process of elimination. I had similar issues 2 years ago.but since then my lathe is very precise. Let me know if I can help further. Gilles
Time 07:55. Haha. It's the demonstration- /show- devil! Do You remember Bill Gates showing what Windows looks like, and he got a big blue error screen? Check that clutch, or the stuff locking the clutch lever. I hope the lead screw has its thread... Regard how the force moving the carriage is applied. Regard "the arm of force" creating a torque that wants to twist the carriage. There must be a play between the V grove and the carriage. Then moving right or left will make the carriage "dance twist". Here the mini mill carrying a 5 inch, 12 kg, rotating table carrying a 5 inch 3 jaw has jamed in the Y direction..... Lubrication is likely needed....
@@Rustinox I'll be looking for Your next video. The mill is cured. The heavy load of some 20 kilo combined with too little oil left made it protest, behave like a donkey sitting on its bum..
The taper you now have is indicative of a lack of tail support. It may be that with tail support the taper will go away, providing your bed isn't twisted. The waviness you are experiencing in the finish might occur due to a feed rate that is too high for finishing or a tool tip that is too narrow (not a large enough radius) for the given feed rate. Consider that a shear tool used for finishing has a very large radius to provide a very smooth finish. Of course it still could be carriage movement. You could try a shear tool and measure to see if the undulations in the finish are larger and farther apart. The material you're using can also have a great effect on the finish. Some of the low grade bolts found here in the US as well as some mild low carbon steels provide terrible finishes no matter what you do. That material is usually stringy when turned and will show areas that appear to be torn away from the parent material. A shear tool is especially helpful on those steels to get a decent finish. Bed wear raises and lowers the tool as it traverses the lathe bed and can result in variations in diameter dependent upon the extent of the bed wear.
@@Rustinox Try raising or lowering the back side of the bed slightly at the tailstock end and see if it makes for less taper. Cast iron, like all materials, is flexible and the bed can be twisted causing taper.
its a great video. And in my opinion (amateur), there is not much that can be done here, besides to regrind the lathe bed. It looks like a very common problem on old and used lathes, just simple bed wear in an area in front of the chuck. One thing also that should maybe be considered, is a headstock (spindle) alignment. In your place, i would try to put in the good test bar in the chuck and try to measure then to see. That can also be a source of a taper. Anyways good job and effort....
The greater fault seems to be a high spot under the saddle vees rather than the bed itself. Scraping out any high spots under the saddle would go a long way to correcting any 'rocking' of the saddle.
@@Rustinox then i would agree that you should check underside of the saddle... Oh and one more thing just pop on my mind. Maybe you should check your lathe alignment, could it be that you have diagonal twist in lathe bed, so that could also be soource of rocking in saddle...
Rustinox, have you printed and scraped your saddle to your ways? My Jet lathe had .003” of rock in the saddle when I got it. Looking from overhead, normal operators position, it would be the 2 o’clock and 7 o’clock lifting and falling. I scraped the saddle to match the ways and it has no more rock, and the carriage now glides easily across the ways. I also had to scrape the bottom of the compound slide flat as it rocked in and out of the cut as well. Simply putting a dial indicator on your tool and prying up and down on various things can expose a lot about your lathe!
Hi Michel. Good work on the maintenance. I did notice unless it was the video , that you were running the lathe RPM quite slowly. Have you tried at a higher speed as i get better cuts at a higher speed. I have sent you a new sticker as those early ones are fading due to me printing myself. The new ones I have had made. Regards. Steve.
That's really strange, and discouraging. I think your problem lies in the wear of the V ways on the saddle. I would take the carriage apart and turn the saddle upside down and examine the way surfaces. Maybe you have a piece of swarf or a burr that is causing this misalignment. If you have a large enough surface plate (who does?) you could measure the V ways for wear down the length of it. You may need to mill the ways flat to solve this one.
I have the same issue, I initially suspected a bent leadscrew but on measuring the bend it's not as much as I initially suspected. I think it's a combination of the very slight bend and the lack of rigidity causing very small movement of the cutting tip. Still haven't fixed it 😐
Mr R Unfortunately I can't offer any positive advice. I do question the validity of running the dial indicator up and down the part. If the lathe weeble wabbles down the part when it makes its cut won't it also weeble wobble the dial indicator ? Can you mount the indicator in different locations and possibly see where the weeble wobble is coming from, cross slide, apron etc. Also try it with an unturned piece of stock that you know doesn't have a wave in it. John 🇨🇦
Michel, can you adjust the alignment of your headstock to eliminate the taper? I had a similar issue with my Colchester. I didn't realise that there were adjustment screws between the headstock and the bed. It took a while but I was able to dial out most of the taper when machining parts without tailstock support.
I have the solution make a warm soothing drink watch the sunset and come to terms who cares it’s under a thou and we are in it for the fun life is to short lol
what if... you slotted that rear clamp, and reduced the height slightly to make it adjustable for best clearance? is there another clamp under the front? are there marks on the bottom sides of the V way from carriage sink and wear?
@@Rustinox To be precise, this lathe was made in the USSR. After Armenia gained independence, it no longer produced machine tools. The plant was in the city of Kirovakan. And the model of your lathe is called 16У04П [16U04P]. I have another model of this plant - 16Б05П [16B05P].
For me most of the time high speed steel works better than carbide. Probably because me carbide is cheap offshore stuff. I have some much better quality carbide now and I can't wait to try it. I also find the more I try to figure out the more questions I have. Good one Michel. 🔧⚒🔩
