New lathe arrived today : The ongoing saga

[Michael GilliganParticipant @michaelgilligan61133]

To me; it looks like the Bush [303] has slipped in the Casting [301] … to the extent of moving past the Grubscrew [302].

Question: Has the Grubscrew now been 'tightened' into empty space … sufficiently for the end of the Bush to jam against it ?

MichaelG.

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Edit: Link to John's clip fom the manual; for easy reference.

 

Edited By Michael Gilligan on 22/10/2015 22:24:22

[Brian JohnParticipant @brianjohn93961]

This grubscrew onto the bushing arrangement has never worked well. It started giving me problems in the first few days of receiving the lathe. For a start, there was nothing for the grubscrew to grip on and you can see where the screw has been tearing at the bush. Acting on advice from the company, I drilled a dimple in the bushing so the screw could get a better grip but it is still not great. I might give the company a call later today and see what they have to say about it.

The grubscrew is not tightened into empty space. I left the bush and hand wheel out like that so that everybody could see the parts. When it is all tightened up there is nothing to see….and it doesn't work !

Edited By Brian John on 22/10/2015 22:57:57

[AjohnwParticipant @ajohnw51620]

It sounds to me Brian that you will have to check that all of the parts that make up the dog clutch still fit together and in the holes they fit in. Parts 324, 322, 310 and 311. Could be that you may need to clean up the the edges of some of them with a file. If the lead screw wont go back in when they are all aligned that is probably the problem. Also things may have happened around the lever that engages the dog clutch. Strip it all and put them back one at a time. For instance 324 might not be engaging with 322 any more.

John

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Edited By John W1 on 22/10/2015 23:04:16

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 22/10/2015 22:55:41:

The grubscrew is not tightened into empty space. I left the bush and hand wheel out like that so that everybody could see the parts. When it is all tightened up there is nothing to see….and it doesn't work !

.

Sorry, Brian … that was not mentioned, and I hadn't guessed.

MichaelG.

[HopperParticipant @hopper]

Posted by Brian John on 22/10/2015 22:55:41:

This grubscrew onto the bushing arrangement has never worked well. It started giving me problems in the first few days of receiving the lathe. For a start, there was nothing for the grubscrew to grip on and you can see where the screw has been tearing at the bush.

The tearing at the bush may be a result of those plates under the carriage being a bit on the tight side. Possibly too from swarf getting into the unwipered/un covered slideways and jamming things up a bit tight.

Also, hard to tell from the pic but the dimple in the bushing looks like it could use being a little deeper and larger diameter to match the grub screw. Can you take the bushing off and drill the dimple out in your new drill press? Also, spin the grub screw in the lathe and file/turn a bit of a point on it to fit the dimple. Use a bit of shim wrapped aroiund the screw to avoid the chuck jaws damaging the thread.

[Brian JohnParticipant @brianjohn93961]

John : but I have already taken out the whole clutch assembly (321 and everything attached to it) and disconnected the 322 from 311 and the problem remains. I thought it was the clutch too at first but it is not.

Hopper : okay, I will try drilling out the dimple a bit. I may also have to get underneath and loosen the carriage but if it will screw one way then surely it should screw the other way ?

.

Edited By Brian John on 23/10/2015 05:36:01

[Brian JohnParticipant @brianjohn93961]

A bigger dimple has helped a lot. The screw is 4.5mm so I tried a 4.5mm dimple but this did not result in a good fit. I redrilled it with a 5mm drill and this seems better. I have not turned the end of the screw at this stage. I would like to have a few spares on hand before I attempt that ! There is a bit of a gap between the hand wheel and the casting so the dimple must not be exactly in the correct spot. I tried the bushing inserted the other way but the gap was even wider which does not make mush sense !

The lead screw is still a bit stiff but it does turn. I will give the lead screw a good clean and oil. Tomorrow I may turn the lathe over and adjust the gib screws and jacking screws under the carriage although the carriage is so sensitive to adjustment I am reluctant to touch it. It gave me a lot of problems last time ; either too loose or too stiff.

NOTE : I would like to order a spare bushing and try drilling and tapping it for the grub screw. I think that would be even better….not tapping all the way through, about 3/4 of the way. I have a lathe so I suppose I could make one out of steel but I do not get a good finish on steel.

 

Edited By Brian John on 23/10/2015 05:50:19

Edited By Brian John on 23/10/2015 05:52:22

Edited By Brian John on 23/10/2015 05:52:43

Edited By Brian John on 23/10/2015 05:54:41

Edited By Brian John on 23/10/2015 06:36:45

[JasonBModerator @jasonb]

A new bush would be a good way to hone your turning skills

[Brian JohnParticipant @brianjohn93961]

That is true but I am getting a lousy finish on steel with this lathe. Brass and aluminium are no problem even when using the carbide tools. If I finish with Hopper's HSS tool bits then I can get a mirror finish on brass and aluminium. But I have found working with steel to be a real problem. I tried turning some axles (6.35mm down to 6.00mm) and the result was awful. I think I might have to buy 6mm stainless steel from now on and hope it has been produced accurately so I can use it as is….what are the chances ?

[JasonBModerator @jasonb]

Buy Silver steel (drill rod) or precision ground mild steel (PGMS) for your shafts that should be onsize.

A brass or bronze bush would be OK, the outside of the bush does not have to be a mirror finish so again the finish you are getting on steel will be OK with areamed hole.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 23/10/2015 05:49:17:

NOTE : I would like to order a spare bushing and try drilling and tapping it for the grub screw. I think that would be even better….not tapping all the way through, about 3/4 of the way.

.

Brian,

Please think carefully about what you are proposing ^^^

[both the mechanics of 'doing it', and its utility]

Hopefully, you will realise that the probability of success is very small.

MichaelG.

Edited By Michael Gilligan on 23/10/2015 09:03:14

[Ian S CParticipant @iansc]

Make the bush from bronze, or brass, or you can use a bit of cast iron. Don't use steel for a bearing on a steel shaft, most metals do not like running together.

Is there a way to easily lubricate the bush(and any other similar bushings)? 

Ian S C

Edited By Ian S C on 23/10/2015 09:14:24

[John Stevenson 1Participant @johnstevenson1]

Still think you would be better off taking up knitting……………………………………

[Gas_mantle.Participant @gas_mantle]

Posted by John Stevenson on 23/10/2015 09:15:23:

Still think you would be better off taking up knitting……………………………………

Are remarks like this really necessary ?

[Brian JohnParticipant @brianjohn93961]

John Stevenson : You may be right but I don't like knitting and where I live there is not much call for wool sweaters.

[AjohnwParticipant @ajohnw51620]

If it's stiff you may have got some swarf in the nut. Over tightening the grub screw might distort the bush. If the edges of the clutch parts burr over that would stiffen things up too.

I suppose the best way to locate the bush would be a dowel that just passes through the body of the bush missing it's bore but going as close to that as possible. The same sort of thing is sometimes done with a grub screw in a tapped hole. Easier in some ways as no need for the tolerance dowelled holes need. Drill through stopping short of breaking all of the way through with the bush in place and tap. The existing grub screw could be used to keep it in place as I doubt if it's a very precise fit. A roll pin is another and easire option – designed to be driven into drilled holes so drill all of the way through.

Maybe very loosely knit thin jumpers made up of holes ?

John

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[HopperParticipant @hopper]

Posted by John Stevenson on 23/10/2015 09:15:23:

Still think you would be better off taking up knitting……………………………………

I dunno, I reckon Brian is doing pretty well for an absolute beginner. There are not many hobbies where one would be expected to dismantle, overhaul and repair the complex machinery bought brand new before one had even had a chance to learn the basics of using it. It would be a bit like taking up knitting for a hobby but finding that first you have to make yourself a pair of knitting needles out of some bits of fencing wire sold to you as a knitting kit, then you have to take a bale of fleece and spin it into woolen yarn, before you can get started on the actual knitting.

[HopperParticipant @hopper]

Posted by Brian John on 23/10/2015 05:49:17:

The lead screw is still a bit stiff but it does turn. I will give the lead screw a good clean and oil. Tomorrow I may turn the lathe over and adjust the gib screws and jacking screws under the carriage although the carriage is so sensitive to adjustment I am reluctant to touch it. It gave me a lot of problems last time ; either too loose or too stiff.

Brian the lead screw needs to be a nice smooth to turn fit. It could also be a matter of leadscrew alignment with the nut it engages with in the carriage. Not sure if your lathe has an adjustment there?

There is a bit trick to adjusting that type of carriage gib set up, if it is like the pic below:

The two screws with the hexagonal locknuts on them will push the strips away from the lathe bed when the locknuts are loosened and the grub screws are screwed in. These are called jacking screws.

The three socket head cap screws (allen head bolts to most of us) pull the strip toward the lathe bed. These are the clamping screws.

The trick (well one of them) is this: Loosen the the two locknuts and back out the two jacking screws. Then loosen the three Allen head bolts and back them out a few turns.

Now, tighten down the centre Allen head clamping bolt until the strip is firmly against the bed. Then screw in the two jacking grub screws until they just touch the metal of the carriage. Then back off the centre clamping bolt a quarter of a turn or so. Then screw the two jacking grub screws in about 1/8 of a turn or so. Then tigten up the centre clamping Allen head bolt again. This should set the plate a tiny distance from the lathe bed way. Check with a feeler gauge that you have about .001" (about .025mm) gap between the strip and the way at each end of the strip. If one end is higher/lower than the other, use tiny adjustments of the jacking screws to get it even. When you have the right gap at each end, nip up the centre clamping Allen bolt a tad more and nip up the two hex locknuts on the jacking screws, while holding the screws to stop them rotating.

When you have done this with both the plates, you should be able to slide the carriage up and down the well-oiled ways quite freely, if all is clean of swarf etc. It will have a little bit of slack due to the one thou gap under the plates.

To close up this gap, use the two end Allen head clamping bolts on each plate to just pull the plate down that half a thou or so at each end until perceptible shake is gone but the carriage still slides freely with barely perceptible drag. Don't overtighten them. If you cant get rid of the gaps at the ends, you may have to repeat the procedure with a little less gap when you set the jacking screws.

It would be best to remove the leadscrew or its nut from the carriage so you can manually slide the carriage up and down the fulll lenght of the ways by pushing it and feel by hand if there are tight or loose spots etc. This also lets you know the plates are set right, and if the carriage gets tight agian after installing the leadscrew and nut then you know the problem is in the leadscrew/nut alignment.

[AjohnwParticipant @ajohnw51620]

Posted by Hopper on 23/10/2015 13:18:08:

Posted by Brian John on 23/10/2015 05:49:17:

The lead screw is still a bit stiff but it does turn. I will give the lead screw a good clean and oil. Tomorrow I may turn the lathe over and adjust the gib screws and jacking screws under the carriage although the carriage is so sensitive to adjustment I am reluctant to touch it. It gave me a lot of problems last time ; either too loose or too stiff.

It would be best to remove the leadscrew or its nut from the carriage so you can manually slide the carriage up and down the fulll lenght of the ways by pushing it and feel by hand if there are tight or loose spots etc. This also lets you know the plates are set right, and if the carriage gets tight agian after installing the leadscrew and nut then you know the problem is in the leadscrew/nut alignment.

Just as it's best to do that with the other slides too. Fed up of repeating that.

John

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[Michael GilliganParticipant @michaelgilligan61133]

Posted by John W1 on 23/10/2015 11:39:42:

I suppose the best way to locate the bush would be a dowel

.

Interesting, John …. That's what I originally thought the manufacturer had done, until Neil corrected my mis-interpretation of the drawing. [see 26-September posts]

MichaelG.

Edited By Michael Gilligan on 23/10/2015 17:25:09

[AjohnwParticipant @ajohnw51620]

Posted by Michael Gilligan on 23/10/2015 17:22:10:

Posted by John W1 on 23/10/2015 11:39:42:

I suppose the best way to locate the bush would be a dowel

.

Interesting, John …. That's what I originally thought the manufacturer had done, until Neil corrected my mis-interpretation of the drawing. [see 26-September posts]

MichaelG.

Edited By Michael Gilligan on 23/10/2015 17:25:09

A roll pin would be a lot easier. A TDO I worked near started using them instead of dowels in the 80's. Big, plastic moulding tools producing thin wall containers for batteries. The hammered another down the centre and this was reckoned to be a as good as press fit dowelling. The splits in them were arranged at circa 180 degrees

John

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[Brian JohnParticipant @brianjohn93961]

One thing I did discover last time I adjusted the carriage is that a perfect adjustment at the end of the rails will be too tight in the middle so this time I will make the adjustment when the carriage is close to the chuck. I doubt I will ever be turning anything lengthy in this lathe.

Under the carriage has four grub screws (jacking screws) and two socket head caps ; there are no locking nuts.

There is a small ball bearing type lubricating nipple on the gearbox end of the lead screw. The manual says to grease once per month. What sort of grease ? I am thinking that a ball bearing type nipple such as this is designed for oil and the use of the term ''grease'' is a translating error.

[HopperParticipant @hopper]

The absence of lock nuts could be part of the problem. Things move under vibration on lathes if not locked down.

With four grub screws and two SHC screws, presumably two plus one on each plate, all you can do is try to get the one thou gap at each end of the plate then nip the cap screw down a little bit to take up the slack. It seems like you will end up with the plates always bowed this way. It might be worth looking at doing away with the jacking screws and using brass shim to set the plates in position, then you can tighten down on the cap screws and positively locate the plates. Of course, it would help too if the plates were ground/scraped dead flat.

Grease should be ok to lube the leadscrew bushing if the fitting is a grease nipple and not an oil nipple. Grease nipple has angled end and oil nipple has rounded end, usually. Allied sell a handy little disposable grease gun the sixe of a large Texta pen that is perfect for such things.

A properly fitted grub screw should work just fine on that bushing. It's all I use on the drive pulleys on the 3/4 horsepower motor on the old Drummond and they have never let go yet. It might be a good idea eventually to drill a small oil hole right through the housing and bushing so you can drop a spot of oil in there every time you use it.

[Brian JohnParticipant @brianjohn93961]

It has a rounded end like a ball bearing so it must be an oil nipple.

I spent an hour trying to adjust the carriage but no luck. Either the hand wheel is too tight (which is why I am trying to adjust it) or if the hand wheel feels nice and smooth but then there is wobble in the carriage. By ''wobble'' I mean I can wiggle the carriage when I grab it with both hands. I must have made 20 attempts to get it ''just right'' but no luck at all. I will try again tomorrow when I am not so rushed ; I have to work again tonight.

The adjustment is so sensitive. I am putting the lathe on its end to make the adjustment then laying it flat to test it. I have a feeling it cannot be done this way. I tried it this way last time and could not get it to work so I ended up getting under the lathe while it was laying down ( suspended between two benches). I will have to get under the lathe and make the adjustment while it is in the correct position again…..a real pain !

I forgot to take a picture but there are two socket caps and four grub screws…that is all. I do understand how the jacking screws and the clamping screws work but it is really difficult to set it correctly. Either the hand wheel is too tight or the carriage wobbles.

I was hoping to avoid removing the lead screw but I will do that tomorrow. But surely this does normally not have to be done as part of the carriage adjustment process ?  I already know it is tighter at the tail stock end then in the middle but I am not concerned about that as there is nothing I can do about it and I will never want the carriage to be up that far. I just need it to be set correctly around the middle and close to the chuck and I will be happy with it.

 

 

Edited By Brian John on 24/10/2015 07:30:17

Edited By Brian John on 24/10/2015 07:34:31

Edited By Brian John on 24/10/2015 07:46:32

[James AlfordParticipant @jamesalford67616]

Posted by Brian John on 23/10/2015 23:02:22:

One thing I did discover last time I adjusted the carriage is that a perfect adjustment at the end of the rails will be too tight in the middle so this time I will make the adjustment when the carriage is close to the chuck. I doubt I will ever be turning anything lengthy in this lathe.

I spent an hour trying to adjust the carriage but no luck. Either the hand wheel is too tight (which is why I am trying to adjust it) or if the hand wheel feels nice and smooth but then there is wobble in the carriage. By ''wobble'' I mean I can wiggle the carriage when I grab it with both hands. I must have made 20 attempts to get it ''just right'' but no luck at all.

Brian,

I doubt that it is any consolation, but I found exactly the same when setting up my Flexispeed. The carriage would be either too tight by the chuck or too slack by the tailstock. Similarly, it took me forever to get the adjustment correct; half a gnat's whisker of a turn would make all the difference between slack and tight. I persevered, like you are clearly doing, and eventually got it set………….. only to go out of adjustment again as soon as I used the machine because I forgot to tighten the lock screws.

Good luck.

James.

[Author]

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