Thank you for taking the time to show us how you replaced the acne screw with a ball screw. I don't own a lathe (yet) but I am building my first mini manual mill machine. I purchased an XY slide table of decent size and weight and as expected the play in the acne screws is beyond tolerable. The 16mm ball screws came in a few weeks ago but I need to mill out some cast material, and cut the top and bottom of the nut as you did. The tips on centering the parts, machining the mechanism to pre-load the ball screw bearings, and the next video on digital control of the axis is inspiring and educational. I will at least record my journey with the acne screw swap, and perhaps be inspired to post it some day. Thanks again for your time and efforts, they are greatly appreciated!

Nice job, reason for watching is I'm going to have to do the same, my lathe is over 100 years old so backlash is significant, cheers have subscribed

A daunting task facing many of us with ageing machinery, I think the larger the machine the more option available until you get to micro lathes that use a more regular triangular thread form. A very soothing accent to go along with it also!

Hello Mr. Foal. Thank you for taking the time to do this video, It is a real service to us especially the novice user. I just changed the nut on my cross slide last week. I was able to find a generic nut with the same thread and pitch but the screw was worn out in the middle where the cross slide is used most. It was very hard to screw the nut on at the beginning of the unused part of the thread and then of course the back lash was back! about 3/4 of a mil. I am a bit disappointed. Your install was enlightening to say the least. Of course I dont have a bearing at the end of the screw. I can buy a new screw, but I would have to cut mine past the gear on a straight part and reattach the new one with an internal thread and connecting stud I guess. Then a small TIG weld all the way around. My lathe is very similar to yours in capacity but much heavier and bigger. It is an Hernault Batignolles (French lathe) from 1948. it weight 1,8 tons. I am eagerly waiting for your upcoming videos on the install of the stepper motors on your lathe. 6061 is a poor choice for the bearing holder and other components on a cast iron machine. with the water from the cooling system it acts like a sacrifiical anode. Lastly, all the cutting that you demonstrated on the other video with CNC like conversion was used with aluminum. Did you test the motors under hard conditions with deep cuts on SS or hi carbon alloys to duplicate the power and performance of your lathe with its original mechanical turning and cutting abilities, finish etc.? Thank you for taking the time to answer.

Brilliant tutorial. Thank you for making this educational video. I feel I could almost do this for my newly acquired lathe.

Very nicely done... I just acquired a 16"Southbend lathe with the taper attachment that is in need of a replacement lead screw as I write this.. Now that I've seen what you've done here, I'm definitely going to explore this option to resolve the backlash and slope in not only this lathe, but to my other Southbends.... Thank you for sharing your upgrade and inspiring me as well as other's I'm sure! Razor!

Thanks for this video ! It inspires me to go forward with a cross slide ballcrew. Crosslide BS is a much more involved project than topslide ballscrew conversion, that I completed without milling the channel or modifying the nut at all. This "corner cutting " approach results in a slightly shorter effective slide distance Also, the conversions yield an amazing increase in "feel" or touch sensitivity. I replaced the crank dial with a larger round disk, fitted with a simple clamping brake.

Great info, your set up of how you held the parts in place was great, that information is useful for holding parts in a Bridgeport mill or a full blown CNC mill.

I made a handle for my cross slide that you might consider. I took aluminum rod and machined it down. Threads on one end and a rounded head at the other end to act as a stop. A sleeve is machined to hold a ball bearing at each end. The shaft is machined to ID of the bearings. The ends of the sleeve are machined to just fit over the bearing OD. Just go in far enough to hold the bearing but leave a lip so they don't slide around inside the sleeve. Slide sleeve over shaft then screw it into your knob in place of your bolt. Use thread lock. It is so smooth and spins like a roulette wheel. It was worth my time.

A problem which might occur is that ball screws easily back drive compared to acme screws. You might find that the cross slide may move when exposed to the tool pressure.

Great job. You have much more guts than me, I'd be way too scared to mill into my lathe cross slide, or any other part of my lathe for that matter. Luckily my lathe is still relatively new, if perhaps a bit cheap, so backlash isn't a huge issue. More projects!

This video was especially interesting, I've been thinking of a ball and screw for one of my machines. Thank You very much. will be watching the other video. The way you found the center of the rear was very smart. Thank You

Nice work. I did similar on my Colchester Bantam as part of conversion to CNC. For those who choose to retain the handwheel, it's worth pointing out that the original leadscrews are usually left handed so the handle will need to be turned the opposite direction but that's a small price to pay! Similar result if you change the Y axis on your milling machine.

Genius, this video answered a question I've pondered on for years. New subscriber for sure..

I just found your channel a couple weeks ago And just wanted to say that I enjoy your video's. I haven't looked at the other comments yet but I say that your deliberate mistake is that you installed a right hand screw instead of the standard left hand.

great modification - will get round to doing a similar mod to mine machine - thanks for posting

You needed to add the relief cuts for the cross slide v groves to get full movement of the cross slide rewards. Nice upgrade btw!!

Just re-watched. Great video Tony and I look forward to more.

There is a solid reason manual lead screws use square threads. On a CNC machine, a ball screw can be used because the driving motor applies a constant torque to the lead screw and holds in in position when movement is not wanted. If you put a ball screw on a manual machine backlash is reduced, but tool pressure can cause the screw to move. You would have to constantly hold the handwheel to keep the screw from turning. Back lash is not a problem, you have a DRO for measurement. Backlash does need to be considered if you have a taper attachment, but I don't think your lathe has one.

Great job mate !! Mine is a new lathe and I hate the backlash !

Thank you very much for this. Very much appreciated.

I was alerted to LH thread screws and I have one on order.

Hi Tony, a new subscriber from Mentor, Ohio USA, here, my lathe is in need of a leadscrew replacement soon, I like your video and will look into replacing my leadscrew with a ballscrew. Thanks. saved your video for reference when that day comes.

Very Nicely Done Only thing i Noticed was that now the direction of feed in is now opposite to original . Not a problem once you get used to it

Reason to watch I m going to convert my conventional lathe in linear cnc production lathe. Thx so much

This was a great video. Very fascinating project. Thanks so much.

Thank you for that helpful video. I will now change my lathe in the same way,

Really enjoyed watching that. Thanks for spending the time to share.

Hello Tony, A really interesting video and a great approach to giving an older machine a new lease of life... Take care. Paul,,

Good video my friend ,stay healthy!

given the cost of these balls screw I think its worth it. Im going to do the same for my Z axis and get rid of the half nut and use an electronic leadscrew.

So enjoyable watching that, thanks Tony!

Very informative video. Thanks for all the details. Wish I had seen your channel long time ago. Defo a new subscriber from a fellow machinist... Greg

@10:20 yes. Don't put too many constraint if not needed. Work becomes more difficult without any benefit.😊😊😊

I have done several cnc conversions and found that although the ball screw is hardened steel, it is possible to mill it with a new carbide cutter, but it will have to be thrown away afterwards as the edge will be very dull if not chipped. Incidentally I am renovating a Lorch lathe from about 1900 and its feed screws are both right handed! This makes it a bit confusing to use and there is a danger of winding into the work rather than away from it especially if it is needed to be moved urgently. The use of ball screws is not a bad idea if LH screws can be sourced. I just checked and they are cheaply available on AliExpress. John

Very much enjoyed watching your video. Thanks for sharing, just subscribed.

Very interesting. Nice work

Brilliant! Being a novice, I must ask: since the pitch of the original screw is different from the new ball screw, if you left the original "handle" in place, the readings on the dial would be inaccurate? I do not have a DRO.

Should have been left-hand thread?

yep, i noticed in the block you did not do the Dove grove so the assembly would hit the back bearing block and stop unless you fixed that.

Thanks!

Thanks for the video. Very informative. Just wondering whether you attached the power drive nut to the ball screw, and if so, how?

Hi great vid very intuitive I have a student I am thinking of converting and I think your mistake was total length of the ball nut was considerably longer than the lead nut and with you putting a bearing block at the back reducing travel

Very good video. We have 12 small lathe in the labs and I think to do it to each of them. But we also have 3/5 axis mill and CNC lathe do help doing it...

Ball screws have the added benefit anti backlash nuts which would remove the backlash alltogether. My question though, would it not be easier to create an anti backlash nut as replacement rather than modifying the lathe saddle?

thanks for that i need to do mine that way.

Could have milled two slots in the back block in line where the bolts are, then place a jack screw under it; indicate the ball screw and lock it into place. Less set up and allowance for adjustment if the cross slide ways ever get wear in it.

Excellent job. Really. I enjoyed hearing you explain all your steps and why you were doing it. Your ability to align the bearing hole was amazing. I found your mistake. You made this modification on your lathe instead of mine. What do I win? Any thoughts to converting the long lead screw? The one that drives the sled right and left? Thanks for sharing. I’m now a subscriber. Paul

The bearing receiver could be made to adjust in x and y so you could dial in the alignment, Yes?

Hi Tony, Great video. I spent many years repairing many different types of machinery. Sometimes you have to think outside the box. Can you please tell me what the make and model is of this lathe?

Spot the mistake?...The ballscrew you ordered is right hand helix whereas the original Acme is left hand helix. Now you have to rotate the index/hand wheel counterclockwise to infeed the cutting tool.

You don't show how you mounted the bracket for the ball screw in the back. I would have drilled and tapped holes when you had the saddle on it's side.

Thank you for sharing.good job

Great mod but did I miss where you bought the new screw/bearing?

Good video. May i ask why you didn't reattach the power cross feed?

Thank you for a very informative video, I have been considering doing this to my 1964 Colchester student and you have convinced me to do it, do you have a link to the parts please, regards Nigel Cox.

nice modification. however .03 backlash on a lathe cross slide means nothing as the cutter is always pushing back on the cutter. but i do understand why you did what you did.

With a ball screw how do you get the self-retention?

Just wandering, did you want left hand drive??? That would throw me out of wack😵‍💫🤔

I'm surpriced that you are even able to use the lathe manually. Typically ballscrews are used only in CNC machines because they need holding torque from motor. Normal threads should lock on a place by friction so no cutting force should turn the screw into different position. Ballscrews on the other hand, quite easily turn applied force into rotating motion making it impossible to make straight pieces unless you can mechanically lock the screw in place. Maybe there was enough friction in your system but others planning to do the same should take this into concideration

Great video, I’m planing on changing lead and cross slide to ball bearing, as for the deliberate thing you left behind, I guess it’s the automatic feed gear, having to do with the advance per revolution? Since it doesn’t match up with lead in the other gears in the apron, or relation to spindle? If I hit it please let know. Great video again!

If you use an externally threaded ball nut you will have more clearance. Just make a threaded bracket in place of acme nut.

Changing the direction of the feed would have me unintentionally gouging parts like crazy. Hope you're able to find a LH version of the screw.

Nice work

Hey Tony, First, I would find it strange to have a RH thread vs the standard LH thread for the cross slide. I guess you get used to it but just so used to clock-wise being in vs out. Never looked, I assume they make LH ball-screws but probably at a premium? Second, I suppose you do not use the power cross feed often? I noticed the gear on the standard axis shaft. I supposed I don't use power cross feed all that often. Or you could convert to electronic if really wanted I suppose.

How do you lock the cross slide to arrest any movement during a heavy cut?

do you think a 12x4 ball screw supported with angular contact bearings on both ends will be enough for a 14x40 lathe? thinking of putting the screw under slight tension so its never pushing the cross slide, but rather always pulling on either end bearings. ill have to make some kind of inverting gear system so that my hand wheel still work right. will see.

Superb

Thanks

what holds me from ball screw install on my cross slide is not finding a left-hand screw. i dont have a dro so that means 1 the dial will be inverted and worst of all my hand will also have to learn the wrong way........that may cause a crash or two.

are you tony foale frame chassis manufacture from 70s if so this is steve mainwaring rode one you tz350 chassis owner cigy poole found your video interesting I have gone from manual to CNC haase mill lathe got excel d40 cnc be not needed but be interesting in doing conversion like you done were did you acquire electronics if you don't mind kind regards steve mainwaring

Im sure there are many comments about it. Left-handed shifted to right-handed thread. How does that feel?

Great video thanks. I want to convert to a ballscrew on my milling machine but it will require me to do some turning on the ends of the ballscrew. Do you know if whatever they are made of they could they be turned?

Great video on fitting the new ball screw and nut. I would like to change my acme cross slide screw and nut as well but the pitch is .125” or 8 TPI LH. There are lots of metric size suppliers but does anyone know who sells an 8 TPI ball screw and nut?

I have the same lathe, any chance you have a manual for yours?

Nice conversion video, thanks. The balls and leadscrew almost have the same hardness unlike the original lathe cross feed brass nut setup. Will the ballscrew get backlash in time and how then to reduce the play?

Wonderful project, I see further development will include graduations on the collar, I am interested in knowing the difference in pitch obtained by this modification. Enjoyed, cheers!

Поменялось направление и шаг резьбы , надо менять лимб и заново привыкать крутить в другую сторону

useful info nice job

how can you fix the thread screw? mine is trying to stay in while threading .

Great Vid - thanks Tony :)

Where you bought tha ball screw? My lathe uses a 2 mm pitch screw. Good diy video 👍🙂

How much travel did you lose? Couldn't see from the video, but if you had room, perhaps the cast iron collar would have been better placed on the opposite side of the bearing carrier? Nice work nonetheless.

Thanks for the video. I am considering applying this to my 5913 Clausing that has a worn lead screw, My question is do you still have power feed on the cross slide ? BTW I am a new subscriber. I am impressed by your work.

It looks like you eliminated the power cross feed gear ?

Would like to do this conversion myself. Curious as to where you are getting your ball screws.

What happened to the gear for the carriage

Should be a left hand thread. Deliberate mistake ? Enjoyed the video though. 😊

I have heard that ball screws feel completely different than an Acme screw. The few people I have spoken to have explained that you don't have as much feedback. Eleven months on, what is your opinion?

Nice video Tony, is the power crossfeed no longer in use?

the only "mistake would be the ball screw is right hand where as the original screw would be left hand thread"

Did you find it difficult to get used to direction change

Pretty useless IMO as on a conventional lathe you always come in from one direction. Much more useful is a locking mechanism on all slides, locking any slide not in use will greatly improve any lathe. in fact I found a very well executed locking mechanism on the compound slide of the Colchester Triumph 2000 lathe at work which was a nice surprise.

Trading accuracy for speed is a no go in my opinion.

left or right screw?

Great upgrade there. I always thought the original bronze nuts were 2 piece so you could adjust one of them fore / aft to slightly bind to remove backlash. Was the deliberate mistake not cutting the dovetail into the rear bearing block?

so you have lost auto feed ?

Also watch channel: we can do that better. mini lathe but the guy is incredible, he should design lathes.

Dont know why you milling out that cross slide. It would be easyer to mill that ball screw nut for mm.

hello how about the camshaft design software