Lathes : Weak-Points

[Michael GilliganParticipant @michaelgilligan61133]

Pultra 1750 & 1770

Whilst in many respects 'near perfect' [for a miniature, plain lathe]:

• I have two cross-slides where the rearmost portion of the TeeSlot has broken out … obviously abuse by some previous owner; but hints of an underlying design weakness.
• Full installation [in the original style] takes up significant space. [Note: same applies to the Levin lathe, which may be seen as a modern equivalent.]

MichaelG.

[Chris Evans 6Participant @chrisevans6]

After 45 years with a 1942 South Bend heavy 10 I needed/wanted ? a bigger lathe. Did a deal with a dealer for a late model Colchester Student 2000. Went to pay him the day before it was due for delivery and he upped the price by £1500 so I walked. I then bought an Excel branded Taiwan built 14"x40" gear head lathe. It ticked all the boxes of things I wanted. Quick change tool post/Newall readout/Pratt Burnerd chucks a faceplate and both steadies.

It will do all I ask of it but has faults all around the saddle/cross slide area. The cross slide is weak and the Vee ways are to narrow for the size of the lathe. I am in the process of making a new beefier cross slide. The other fault is the inability of the saddle to get close to the head stock for faceplate or chuck back plate work. This requires big tool overhang not helped by the narrow cross slide ways.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by speelwerk on 18/02/2016 19:37:45:

Posted by Michael Gilligan on 18/02/2016 16:48:48:

Despite its obvious strengths; a look at the cross-slide and top-slide feedscrew arrangements reveals that this is a light duty lathe. … Flimsy little die-cast nuts, with no adjustment for wear.

MichaelG.

You can buy an updated Dutch version, Niko.

**LINK**

.

Thanks, Niko

Is it from this company ?

… I ask because your link lands me on a rather aggreesive 'cookie acceptance' page.

MichaelG.

[David ColwillParticipant @davidcolwill19261]

Dean Smith & Grace 1330. Nothing that really bothers me except that it requires a team of oxen 8 days to pull the tailstock down the bed. No gripes with the Smart and Brown 1024 either though a 3 morse taper tailstock would be nice.

[speelwerkParticipant @speelwerk]

Posted by Michael Gilligan on 18/02/2016 22:02:37:

Posted by speelwerk on 18/02/2016 19:37:45:

Posted by Michael Gilligan on 18/02/2016 16:48:48:

Despite its obvious strengths; a look at the cross-slide and top-slide feedscrew arrangements reveals that this is a light duty lathe. … Flimsy little die-cast nuts, with no adjustment for wear.

MichaelG.

You can buy an updated Dutch version, Niko.

**LINK**

.

Thanks, Niko

Is it from this company ?

… I ask because your link lands me on a rather aggreesive 'cookie acceptance' page.

MichaelG.

Yes, it is.

Did not know it had rather aggressive cookies, sorry for that. Niko.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by speelwerk on 18/02/2016 22:12:41:

Yes, it is.

Did not know it had rather aggressive cookies, sorry for that. Niko.

.

No problem … Much appreciated.

It may all be innocent, but [written in Dutch], it felt like I would be accepting cookies from all their associates.

MichaelG.

[MWParticipant @mw27036]

Posted by Chris Evans 6 on 18/02/2016 21:24:36:

After 45 years with a 1942 South Bend heavy 10 I needed/wanted ? a bigger lathe. Did a deal with a dealer for a late model Colchester Student 2000. Went to pay him the day before it was due for delivery and he upped the price by £1500 so I walked. I then bought an Excel branded Taiwan built 14"x40" gear head lathe. It ticked all the boxes of things I wanted. Quick change tool post/Newall readout/Pratt Burnerd chucks a faceplate and both steadies.

It will do all I ask of it but has faults all around the saddle/cross slide area. The cross slide is weak and the Vee ways are to narrow for the size of the lathe. I am in the process of making a new beefier cross slide. The other fault is the inability of the saddle to get close to the head stock for faceplate or chuck back plate work. This requires big tool overhang not helped by the narrow cross slide ways.

Hi,

There are obviously some problems here which are quite difficult to solve without a big re-make but maybe i can help you with the inability to get close enough to the head stock from the table but have you heard of the "gibraltar" style tool post? it might just be the ticket because itll still offer rigidity with significant overhang.

Michael W

[Ady1Participant @ady1]

Myford Drummond M series

Spindle bore is teeny (10mm?)

Only MT1 taper in head/Tailstock

Kinda weird because it's a great hobby machine, very stiff, and would handle a 1 inch bore with ease

[HopperParticipant @hopper]

+1 on the Drummond M type stupid small MT1 in the headstock and tailstock. This on a lathe that will merrily turn a 6" disc of 1" thick steel plate with nice deep cuts.

The other weakpoint, which was par for the course in its day, is the drip feed headstock bearings that let the oil just dribble out the ends of the bearings and fling all over the shop if myriad splash guards are not fitted.

[Bob Brown 1Participant @bobbrown1]

Only a niggle really, when boring on my Boxford AUD metric the need to put something (piece of rag) up the spindle bore to stop swarf getting on the change wheels.

[OuBallieParticipant @ouballie]

Warco BH600G:

As with MichaelT, the tailstock lock keeps coming loose, necessitating the need to squeeze hand between the ways to turn that lump of CI that's pulled up against the bed, locking it.

The Saddle lock that needs 3/4 turns, but modified to 1/4 turn.

The TOTAL lack of getting oil into the Apron gears as well as the power Feed Rod and associated gears at the rear, Subsequently fixed.

The slowest power feed speed, via the Gearbox to Saddle/Cross-slide, is way to fast to get any decent finish.

A fix being sorted.

On the positive side, however, the screw-on chucks are prevented from spinning of by way of two clamps as shown int the photo:

Geoff – Spent the last week in the Workshop

[John Stevenson 1Participant @johnstevenson1]

Got a TOS 14 x 40, a Chinese 14 x 30 and Debs Phantom Bantam.

None have any faults because I have slowly worked through them and modified them all. Isn't that the reason you have a workshop ?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Stevenson on 19/02/2016 11:50:45:

None have any faults because I have slowly worked through them and modified them all. Isn't that the reason you have a workshop ?

.

But … the idea of this thread was to document some of the design defects, so that we mere mortals have some idea of what we're letting ourselves in-for.

MichaelG.

[Clive FosterParticipant @clivefoster55965]

Posted by Jeff Dayman on 18/02/2016 20:43:35:

My 1949 South Bend 9" lathe has tumbler reverse for the leadscrew. The way the threads are handed on the lead and crossfeed screws, if you have the tumbler set to move carriage toward chuck when feed is engaged, the crossfeed screw moves the tool away from centre. If you want to face toward centre you have to set the tumbler reversed, which if the carriage feed is used moves tool away from chuck.

Not a huge problem usually, but when facing large items it is a bit of a pain.

JD

The cross / long feed arrangements are a feature not a bug! Idea is to reduce the risk of inadvertently feeding the tool into the work when swopping between feed directions. Probably not a bad idea for a school lathe. Only right for external work tho'. My Pratt & Whitney Model B is the same and thats a high class toolroom / manual production machine not a school one. I agree that Southbends are remarkably durable. My 9" A had been used enought to wear the feed drive key in the saddle worm down to little more than 1/16" wide but the bed was still in good shape with some, but not excessive, wear and spindle bearings (slotted type) still near perfect.

Late toolroom SouthBend Heavy 10 with D1-4 spindle was capable of excellent work primarily due to seriously over-engineered headstock able to handle much more power than the drive could provide but that was about as much as the relatively lightweight slides could stand. No keep down gib on front of saddle so things can twist and rise if taper turning attatchment not perfectly adjusted, total bitch job to do. Tailstock travel seriously inadequate which was why it had to go after popping the chuck out once too often.

Smart & Brown 1024 VSL. As standard you need to change the intermediate gear stud on the banjo as well as the gears when switching between metric and imperial threading. Which means removing the banjo too. All too much faff so I bolted the 127 gear to the standard roller bearing intermediate so now I only need to change one gear. Nit picking time. Oil tank is a total bear to fill, but only needs doing every 2 or 3 years. Change-over knob rather than separate levers for cross and long feed selection can be overlooked giving surprise feed wrong way. Bed is a little too close to chip tray so cleaning out is harder than perhaps it need be. Single tooth dog clutch in gearbox drivce train as per Holbrook, Pratt & Whitney and Hardinge would be nice as would a spindle drive clutch but now you are talking deliberate manufactures specification decisions.

Pratt & Whitney model B 12 x 30. D1-5 spindle fitting is rare, 1 1/4" spindle bore small by modern standards, spindle speed range low but mine is the two speed motor version so it goes up to almost 900 rpm rather than almost 600. Topslide trave grossly inadequate. Star wheel twist clutches for feed selection rather than simple levers, not so bad once you realise that its a true 4 shaft lathe so you drive it a bit different.

Portass S. Oh dear nothing good to say about it. Pools Special. Saddle feed handle turns wrong way which can really confuse you. Tailstock travel too short but at least its not self adjusting. Otherwise pretty good basic machine given its era. Acceptable candidate for updating with dials or economy DRO (ex calliper) system if got cheap.

Clive.

[John BromleyParticipant @johnbromley78794]

Boxford Model A, B and C.

There is no through bore on the tailstock, so ejecting tooling without a tang is a pain.

If I remember I stick an M6 nut up the spout before inserting the tooling, but I don't always remember!

Krusty

[MWParticipant @mw27036]

 

"But … the idea of this thread was to document some of the design defects, so that we mere mortals have some idea of what we're letting ourselves in-for.

MichaelG."

Here, Here!

Who wouldnt want a person to give us the "low down" on what somethings Really like?

[AjohnwParticipant @ajohnw51620]

I keep meaning to make a bit of an extension on my Boxford Bob. Trouble with swarf coming out of the front is it gets in the chuck. The boxfords have tubular extension that goes over the spindle end built into the change wheel cover but sometimes it still gets in.

John

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[Swarf, Mostly!Participant @swarfmostly]

Hi there, all,

I bought my ML7, second hand, in 1970. While I have not been an intensive user, the only problems I have encountered with it have eventually proven to be between the operator's ears!!

Best regards,

Swarf, Mostly!

[Bob Brown 1Participant @bobbrown1]

Swarf, Mostly!

One could suppose the major fault with all machines is the operator, that said we do get to know the limitations.

[Ian PParticipant @ianp]

Posted by Bob Brown 1 on 19/02/2016 10:21:05:

Only a niggle really, when boring on my Boxford AUD metric the need to put something (piece of rag) up the spindle bore to stop swarf getting on the change wheels.

I found a 60mm long bit of PVC tube and after turning the OD down slightly and putting a slit in it, I slid it into the back end of the spindle so allowing only letting the swarf escape on the outside of the change wheel cover. On the rare occasion I need to use the full mandrel bore I just take the extension tube out.

Ian P

[MWParticipant @mw27036]

I'm always the weakest link in the chain myself.

Michael W

[Steven VineParticipant @stevenvine79904]

I can confirm a serious issue with the ML7 cross slide. On a lot of occasions, when I use the controls, my work ends up either undersized or oversized (depending on what I am doing). There is just nothing there to prevent a c**k up. I am appalled that they can let a machine leave the factory in this state

Steve.

[JAParticipant @ja]

Posted by Steven Vine on 19/02/2016 17:10:14:

I can confirm a serious issue with the ML7 cross slide. On a lot of occasions, when I use the controls, my work ends up either undersized or oversized (depending on what I am doing). There is just nothing there to prevent a c**k up. I am appalled that they can let a machine leave the factory in this state

Steve.

Steve

Please could you explain the problem.

While, as explained, I have found the cross slide not very stiff when items are bolted to it I have never had problems with ordinary turning operations.

JA

[AjohnwParticipant @ajohnw51620]

Hands up.

Who on here have used say for instance a Lang Toolroom or a Colchester Student that hasn't had many hours of even light work done on it. Say 2 weeks max and by no way continuous and oiled well each week even if it's not been used.

Anything similar would do. Very top end such as the Lang and middling such as the Student. Or anything in between.

John

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[Chris Evans 6Participant @chrisevans6]

Michael, can you please give me more info on the Gibralta toolpost. Chris.

[Author]

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