New lathe arrived today : The ongoing saga

[Neil WyattModerator @neilwyatt]

The other useful gadgets for turning near the end are a 'half centre' and reduced centre.

Neil

[Brian JohnParticipant @brianjohn93961]

I will be buying a half centre with my next Arceuro order but what is a reduced centre ? They are not listed on the website.

I spent some time today using my new full size hacksaw to chop up 25mm and 38mm aluminium and also a piece of 31mm brass bar from the scrap yard. It does not take much longer than the jigsaw !

I have reduced the length of the main shaft of the mandrel by 20mm by parting off in the lathe. This time I reduced the speed of the lathe until I found a speed (about 200RPM) where there was no grinding or chatter. The parting off worked well. I am still practising taking cuts off the minor shaft of the mandrel ; it is down to 10mm. I can get a good finish by taking 0.1mm cuts but even a 0.2mm cut will cause marks on the piece. Everything I have read says that I should take a fairly large cut as I get close to the required 6mm and not make the final cut a small one but this is not what I am experiencing.

Edited By Brian John on 07/09/2015 07:48:13

[Brian JohnParticipant @brianjohn93961]

I have just received a reply to my email regards the steadies and other accessories. The German company expressed surprise that the Australian dealers did not stock these items but they have somewhat reluctantly agreed to send them to me. They said the postage costs may be high but they will give me a quote.

I have looked at their catalogue and they have the travelling steady, fixed steady and a 4 jaw chuck (not sure if I need the chuck). There is definitely no face plate so I will be asking them why not ? I am also puzzled at catalogue number 3440700 : ''follow rest MT1'' ? The follow rest or travelling steady is listed as another item ( 3440210) so what is a ''follow rest MT1'' ? It obviously fits in the tailstock but other than that I cannot work out what you do with it !

 

Edited By Brian John on 08/09/2015 12:20:16

[AjohnwParticipant @ajohnw51620]

The best thing to do regarding cuts feed rate and finish is to try all sorts. A lot depends on the play in various parts of the lathe. Some lathes will take very fine cuts and leave a very smooth finish some benefit from very deep cuts for the size of lathe that is being used.

I'd guess that your 0.1mm cuts MAY actually be just smoothing machining marks rather than really taking a cut. 0.2mm may be partly taking out any play and that will tend to leave a bad finish. I would have thought that cuts of the order of 1mm in aluminium should give a decent finish on a lathe of this size – that's 2mm off the dia. I've never used one but would be surprised if they couldn't do that at least with a sharp tool. If I halved that cut on my Boxford I would probably find that I would have to use feed setting that was significantly faster than the finest one it has. Your lathe will probably be happy with finer cuts than 1mm so work down from that to find out. Steels are harder so can take finer cuts for the same cutting forces. It might even benefit from even deeper cuts.

I mentioned off the diameter cuts because metric lathe dials are sometime marked that way where as imperial are usually marked depth of cut.

John

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[Peter HallParticipant @peterhall61789]

I Googled 3440700 on your behalf and it comes up in the catalogue as a revolving centre, not a follow rest.

Pete

[BazyleParticipant @bazyle]

You will need a 4 jaw chuck within the year but should be able to source one locally (to Oz). Not sure about the Morse follow rest but it might be a version of a 'roller box ' (google it). Doubt you need one at the moment.

If the local dealer doesn't have the bits perhaps you could buy 2 of everything and ebay the extras to recuce shipping cost.

Don't worry about the 'hacksaw blade in toolpost' stuff. It is about making a thin blade into a parting tool for small diameters to avoid wasting so much material. I was parting off brass washers a few weeks back and my view was obscured by the tears in my eyes as 2 mm became swarf for every 1mm item. I know, costs peanuts but it gets me every time.

A reduced centre is just a smaller one, eg a big one turned down or a bit of silver steel held in the drill chuck (obviously less accurate) or at a pinch a centre punch held the same.

Faceplate. In this size of lathe don't expect a slotted one like a bigger lathe. It is better to make a steel or alloy disc to fit the nose and drill/tap holes where you need them for studs and bolts.

Still lots of air between the ultimate position of the flywheel and the chuck body. Get used to operating within mm of the jaws.

On hacksaws have you noticed that the junior hacksaw blades are pretty hard. They will often cut tough stuff you don't want to risk blunting a big blade on so I always use them for cutting bolts and suchlike..

Edited By Bazyle on 08/09/2015 13:14:13

[Brian JohnParticipant @brianjohn93961]

John : I can tell you now that this lathe will not take a 1.0mm cut on aluminium. It seems to struggle with 0.3mm but I will experiment more tomorrow.

Peter : looks like their translator got confused in compiling the catalogue !

Bayzle : I will not be finding any 4 jaw chucks to fit this lathe in Australia. I doubt that this lathe is a big seller here. Most people seem to go for the Sieg machines as you can get a 7 X 12 for the same price as this small lathe.

Yes, I agree that the junior hacksaw blades seem to be just as hard as the larger ones.

I went to Hopper's place today (Thank you Peter) and he was able to cut a longer angle tool to get in closer to the dead centre. The Arceuro tools are good high quality steel and if there is a problem in the cutting then the problem is with me

Here is my first finished mandrel. The unthreaded bush is 5.95mm in diameter which may be too small and I am still not happy with the fit. I will cut a few more holes in something tomorrow and check it. Cutting the 6mm thread was surprisingly easy by placing the die holder against the tailstock and forcing it against the shaft while turning the lathe chuck by hand. (NEXT JOB : spindle handle for the lathe !) Cutting a thread on steel is probably more difficult.

NOTE : total length is 100mm, major shaft 60mm long and 15.5mm diameter, minor shaft unthreaded 18mm long and threaded minor shaft is 22mm.

I will be making another one in aluminium and then try to make one from steel too. 

Edited By Brian John on 08/09/2015 14:14:02

 

Edited By Brian John on 08/09/2015 14:19:25

[Ketan SwaliParticipant @ketanswali79440]

Posted by Brian John on 08/09/2015 14:07:13:

Bayzle : I will not be finding any 4 jaw chucks to fit this lathe in Australia. I doubt that this lathe is a big seller here. Most people seem to go for the Sieg machines as you can get a 7 X 12 for the same price as this small lathe.

Brian,

I am not really keeping up to date with this thread. I think your lathe chuck is 80mm. It probably fits onto a spindle flange. Take it off and have a look on the back of the chuck. it will have a recess. This recess is a register. Take a rule and measure its diameter (roughly). In theory, it should be 55mm. Take a picture of the back and post it here. There should be three mounting holes. if so, they should be threaded M6. Provided this all agrees, then your chuck will be a generic Chinese chuck, which you should be able to source easily. Only thing special about it is the oil lubricating nipple on the front. Take a picture of the spindle flange and post it here. There will be three or better – four holes on the flange (or backplate if a backplate is used to mount it onto the spindle).

If only three holes, and provided all of the above is correct, you should be able to get a 80mm three jaw self centering chuck – Chinese generic – with 55mm register, to fit your lathe from all most anywhere. If you have four holes in the spindle flange/backplate, then you will also be able to fit a 80mm four jaw independent chuck – Chinese generic – with 55mm register. Just ask the sellers to check/confirm the measurements.

Generally, Chinese self centering chucks in small size ranges have 3 mounting holes, and four jaw independent chucks have 4 mounting holes.

I am unable to check this thread regularly at present, but I am sure others will be able to advise.

Ketan at ARC.

 

(Edit – I think you meant 3-Jaw self centring, Neil)

 

Edited By Neil Wyatt on 09/09/2015 14:19:51

[AjohnwParticipant @ajohnw51620]

Are you running the lathe in the lower speed range Brian – set by a belt under the end cover? If you are and ran it at around 600 rpm you should be get something like 1/2 the peak torque available from the motor. You should be able to run faster than that at the diameters you are turning down to but might have problems with aluminium melting onto and sticking to the tool's cutting edge.

You also mentioned chatter and vibration when parting off. This usually down to feeding the tool in too slowly / blunt tool, unless it's a Myford, actually the speed the tool is fed in at will have the same sort of effect on those too. Anything that is loose on the lathe will make this problem worse. Even locking the saddle can help.

Clearly parting off tools can be fed in far too quickly so need some sense. One of the problems is that once they have started to chatter it will just continue unless feed is increased until it stops, then it can usually be backed off a touch. Too much of that and it will start chattering again.

John

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[Brian JohnParticipant @brianjohn93961]

Ketan : there are three bolts at at the rear of the lathe chuck. I have tried to undo them today but they would not budge at all. I might have another go tomorrow as I had bigger problems to worry about today.( see below)

John : I am not having problems with parting off now. I have dropped the speed back to about 200 RPM and things seem to go well. The speed can be increased slowly as the diameter gets smaller. I had assumed that parting off was done at the same speed as taking a traversing cut…obviously incorrect !

I am still getting those marks on the workpiece when I take a cut. It was good yesterday but bad today. I am sure it is the saddle ; there is still some movement in it when I wobble it by hand. I have to lock down the carriage lock and then loosen it 1/8 turn to get anywhere near a good finish. But this works itself loose after a while. I do not think I should have to be adjusting this all the time ?

I suspected that the adjustment screws underneath the carriage need tightening up as I have already done with the top slide and the cross slide. So I unbolted the lathe from rom the workbench (I will leave it like this for now until all problems are sorted) then hung the tailstock end over the side of the bench to access the screws under the carriage : two large 4mm socket caps and four small 2.5mm grub screws. I loosened the large ones and then tightened the smaller ones then tightened the larger ones back up again. I kept fiddling with this for 2 hours but it has not made any difference. I expected to be able to lock the carriage in place with the four small screws and then back them off a bit and tighten the large ones. Nothing much happened at all and I am not sure why ? I am right back to square one fiddling with the carriage lock screw on the top …frustrating !

Any further suggestions would be welcome.

Edited By Brian John on 09/09/2015 09:13:31

Edited By Brian John on 09/09/2015 09:43:42

[JasonBModerator @jasonb]

"I loosened the large ones and then tightened the smaller ones then tightened the larger ones back up again. I kept fiddling with this for 2 hours but it has not made any difference"

Brian, I would say the 4 grub screws are jacking screws and they need to be UNDONE slightly to allow the gap to be closed by the two larger screws.

I would also suggest you try using the power feed, this will eliminate any tendancy for the saddle to lift and fall as you turn teh handle. Worth a try at least to see what difference it makes.

[Brian JohnParticipant @brianjohn93961]

Jason : okay, I will give that a try tomorrow with the grub screws.

I am not keen on using the power feed until I make some sort of carriage stop but I will also give it a try to see if there is any difference..

Edited By Brian John on 09/09/2015 10:34:45

[Russ BParticipant @russb]

There's free postage from Arc at the minute if I recall correctly so no matter how small your order you might as well get it in!

I do like to give them enough of an order to make it worth their while though.

Regards,

Russ

[JasonBModerator @jasonb]

I know Ketan is a nice man but I don't think even he would stretch to free delivery to Brian who is in Australia

Brian, you are likely to do as much if not more damange by running the auto feed carrage into a bed stop as you are overcutting the length of your work. Give it  atry on a bit of scrap, things move quite slowly so you can disengage the feed before the end of teh cut and do the last bit by hand

Edited By JasonB on 09/09/2015 12:01:15

[HopperParticipant @hopper]

Posted by Brian John on 09/09/2015 10:33:54:

Jason : okay, I will give that a try tomorrow with the grub screws.

I am not keen on using the power feed until I make some sort of carriage stop but I will also give it a try to see if there is any difference..

Edited By Brian John on 09/09/2015 10:34:45

+1 on the grub screw theory. If it is so, you would slacken the grub screws right off then do up the clamp bolts finger tight, then screw all the grub screws in until they just touch metal, then just a tad more maybe 1/16 of a turn or less. All by the same amount of course. Then tighten the clamping bolts and test carriage for free sliding movement. If it is tight, repeat the process but nudge the grub screws in a tad further before retightening the clamp bolts.

Brian, a carriage stop is only for manual feed. If you put a clamp type carriage stop on the bed and drive the carriage into it on power feed, you will do damage to the lathe, probably stripping the feed gears. The carriage stop we were looking at on my old Drummond is a different beast altogether. It moves a bar that disengages the change gear drive to the leadscrew, a feature built into the lathe by the manufacturer but not done on today's lathes.

Did you try those new tools we ground up? Any improvement?

Also, if you have trouble getting an MT1 half-centre, you can get a regular MT1 dead centre and we can grind it down into a half centre pretty easily. But that pointed tool we ground up should get you going in the meantime.

Keep on turning!

[Ian S CParticipant @iansc]

Brian,The only place I could find on a quick Google is Minitech, but that's at Brendale just nth of Brisbane, and that's a 1600 Km away, bit far to walk, but might be worth getting in touch, and see if they have 80 mm 4 jaw chucks.

Ian S C

[Brian JohnParticipant @brianjohn93961]

Hopper : of course I understand now. I was not thinking clearly about the carriage stop on auto feed ! I will try the auto feed tomorrow once I get those adjustment screws set correctly. I did not get enough time to compare the new tools with the old ones.

I have to take my wife out tomorrow and then I have to work the next three nights but I will try to squeeze it in somehow ; I really want to get this working correctly.

The gearbox was making a lot of noise this morning so I applied some candle wax to each of the three belts. As soon as I put it on the third belt, the noise stopped. If I had not seen you do that yesterday I would not have thought of it.

Ian : there are quite a few 80mm 4 jaw chucks on ebay but first I have to get those nuts off to have close look at the back of it as described above. First job is to get this carriage tightened up then I will worry about the lathe chuck.

Edited By Brian John on 09/09/2015 14:53:03

Edited By Brian John on 09/09/2015 14:53:30

[Brian JohnParticipant @brianjohn93961]

Today, I spent the whole afternoon adjusting the carriage. I moved the carriage down to the tailstock end and made the necessary adjustments. It was easier to do it there with the end of the lathe hanging over the side of the workbench. I removed all play and tightened things up but when I moved the carriage towards the headstock where most of the work is done it locked up ie. the adjustment was too tight at this part of the lathe. So I had to get underneath again to make the adjustments with the carriage closer to the headstock. I do not think that is good news : it should be the same from one end to the other ?

I made three attempts and eventually I got everything tightened up with no movement when I try to wiggle the carriage by hand. But it has not helped. I am still getting a terrible finish ; it is worse today than yesterday. I had a look at what I made a few days ago : I was getting a perfect mirror finish then. I also tried the autofeed but this was no better. I tried various tools RH, LH and carbide tips but the problem is not the cutting tool. I am not sure what I can try next. I think I have exhausted all possibilities but I may have overlooked something.

[Neil WyattModerator @neilwyatt]

In time you will learn what works and what doesn't. To speed this process up, have a notebook and write down a note of what works and what doesn't.

Neil

[Chris DentonParticipant @chrisdenton53037]

You need to use the powerfeed when making. Adjustments to compare things etc

[Brian JohnParticipant @brianjohn93961]

UPDATE : there is still play in the carriage. I was sure I had removed all the play ; it is a tricky thing to get right. I will have another go at adjusting underneath it tomorrow as I have to work tonight.

Edited By Brian John on 10/09/2015 09:30:13

[AjohnwParticipant @ajohnw51620]

Have you checked that the cross and compound slides haven't slackened off Brian? The manual on the lathe suggests checking these rather regularly. I'll also add that while you might want an oil free life it's needed on lathe slides. You can probably buy slideway oil off ebay. Just a smear is needed. When adjusting slides it's best to remove the lead screws and adjust for a little friction when they are pushed by hand WITH the oil on them. It can be done via the handles but it's easy to over tighten and wear out the lead screw nuts more quickly than they should. One problem with slides is that often there are no oiling points so the best way to apply it is to remove the slide.

Tools may be blunt now. You could sharpen them again with an oil stone buy running the tool on it's cutting edge side along it. Notice the word oil again – it will improve the cutting action. A light oil is best. Grade 400 wet and dry paper should do a decent job too – oil or soapy water on it, Just make sure it's on something flat.

Tools generally don't cut very well if above centre. Best way to check is to face something off on the lathe – just in case the bed is bent. If you look carefully when it cuts to the centre you will see if it's above or below centre. A few thou under is best.

I hesitate to mention the last thing that can cause problems – loose head stock bearings. You really shouldn't be having that problem yet and the manual gives no clues as to how to check and adjust them. It's very easy for people to mess this up and wreck the bearings very quickly.

John

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[Ian S CParticipant @iansc]

Are the nuts on the chuck ordinary hexagonal, or are the socket head bolts, if the former, at least start with a ring spanner, you can put a bit more weight on it without it slipping(saves the knuckles).

Ian S C

[Brian JohnParticipant @brianjohn93961]

The nuts are hexagonal but I will worry about that later.

The tools are okay. I tried the LH cutting tool which has hardly been used at all and it still gives the same bad result.

There is no play in the top or cross slide. I know it is the carriage as I can feel it wobble when I wiggle it ; I can see it move slightly. What I do not understand is why it is happening. The whole thing was locked down very tightly and I had trouble loosening the nuts to make adjustments yesterday.

Anyway, I am awake now so I will have another go at removing the play in the carriage. I am hoping that practice makes perfect. I am glad I did not buy a 40KG lathe ! I would hate to have to be doing this all the time to a much heavier machine.

UPDATE : I have tightened things up to the point where the lead screw is a bit stiff to wind but I am still getting the same bad finish ; there is no improvement at all. I was sure that the problem was movement in the carriage but now I have no idea. Time to think for 24 hours before doing anything else !

Edited By Brian John on 11/09/2015 07:30:00

[Brian JohnParticipant @brianjohn93961]

Further information : the problem is much worse on auto feed. This is not what I expected. Does this tell anybody anything ?

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