Survey on Sieg 7" lathe - Bazmak

[bazmak]

Just posted on my thread on the sieg lathe concerning the slop between the carriage and the bed.The width of the bed will be fairly accurate and i hope the width of recess in the carriage,which has lots of play.With the saddle firmly located in the V i have a gap of approx 20 thou at the front and 60 thou at the back.If you put a horiz rotation force ACW and CW i have lots of play as the carriage tries to ride up the V.There is no location on the front and back edges
of the bed,
.I am currently playing about to try and improve this problem.So all you sieg lathe owners,please check and comment on this problem.Also please post the following dims and hopefully arrive at a remedy
1-Width of Bed.2- Width of recess in carriage.3-Gap at front and 4-gap at back.I have located the front gib plt to run against the rack,and hope to fit a 1/16" thick
gib plt and screws to the back,for location only.Hoping for lots of responce Regards Barry

 

[goldstar31]

The classic way- call it old fashioned- is to pull a new lathe to bits, cleans it and adjust it -to one's own liking.

From then on, one regularly takes it to bits, cleans and adjusts it- to one's own liking. Sounds like the needle beeing caught in the groove- but that is engineering.

As far as a lot of lathes are concerned- of the cheaper variety they are put together in the shortest possible time and held together with the least possible adjustment. It is is cost accountancy so that you can afford them. If you can hold a wobbling gib with a couple of any old screws- so be it. If you have time- you read John Ruskin on Price. Makes a change from standing on the edge of Friars Crag in the English Lake District and looking at the lake and alternating with look at his statue. It will not make your lathe better but you might realise that 'You are some man's lawful gain'

Usually, there is nothing that is basically wrong with the bits that go together to make something that sort of looks the part- but doesn't.
You might find that someone in an effort to get a profit- which is why people work or whatever, has skimped the machining and left it there instead of scraping in- PROPERLY. You might find that there are two adjustiing screws on a bit of something that passes for a gib but in practice wobbles about like a pea on a drum. Perhaps it could do with putting a peg in the gib to hold it in place and perhaps a couple more adjusting screws. Agan, the gib might be far too thin and could do with a thicker one or the air space being filled with - well, some shim. Nothing more than having a coke and using a pair of scissors to make packing strips. You could even glue them together- with a pennyworth of two part epoxy.

It's often as simple as that. Remember that the factory never wants to see the lathe again but you do.

End of lecture.

Norman

 

[bazmak]

Nice lecture goldstar but all i want is feedback on the gaps to front and rear
of the bed.This will tell me A are all the lathes the same. B Has it caused a problem with anyone else C.Is anyone wanting to do anything about it.
Please will someone with this lathe post the requested measurements
Regards barry

 

[bazmak]

Had to strip down the carriage to adjust the gibs so did the mod anyway.
Seems to have solved the problem.A piece of 1.5 thk brass 8 x 100 was a nice fit to the rear of the carriage and fitted 2 gibb screws.Set to just touch.
The front gibb plt was then pushed to just touch the rack.All locked up
and the problem appears to have been solved .Only time will tell. Still hoping for input as 5 alive used to say Barry

 

[Swifty]

Just be careful Barry, the back of the lathe is just a rough finish, the "V" has to do the location. If the back of the lathe is not spot on parallel to the "V", it might lift it up. Have you put an indicator trailing along the "V" as you wind the saddle along.

Paul.

 

[bazmak]

Not done anything yet other than take out oodles of slop which was allowinthe carriage to ride up.Will see if i have any problems and check everything
when i test the the cross slide feed is square to the main axis.It was a couple of thou out as recall when i first checked out the lathe just after delivery
The rack may not be parallel either as its fixed to the bed casting.At this stage it seems to be an improvement.Regards Barry.

 

[goldstar31]

Lecture maybe- sorry Barry but the problem is endemic. The world is full of people who have bought these lathes and in the words of a cleverer guy than me 'Are asking the same silly questions and getting the same silly answers' This guy is building his own steam locomotive, a world authority on tugs and writes jazz for the saxophone.

Quite simply, you go to Moran- Gadgetbuilder.com and the various fora. I've cross referenced and cross referenced - and am included in the same silly answer brigade. Most owners become disallusioned(sp?) and flog their lathes to another equally confused aspirant.

The number of people that actually re-adjust their lathes etc seem to be counted on the amputated fingers on a fingerless hand.

I only commented because I like your style. It is like that.
Best regards


Norman

 

[bazmak]

I can opnly say that i am very happy with the lathe and enjoy finding problems and sorting them out.This is a problem i have come across which i feel is an easy fix and wondered how many others out there know or dont know of it
Again i will reiterate love the lathe and the mill

 

[///]

Agree with you Baz. Enjoy my lathe immensely.
Captain Jerry's quote in my signature also sums up my position pretty well too.
The hollier than thou elitists can go jump.
I am planning to upgrade very soon, but it will be another Sieg as that is all my finances can allow.

Edit: Sieg, not site. Damned autocorrect!

 

[goldstar31]

As an elitist, I had a basket case of a lathe. It has been run on mahogany dust, it had stripped gears, it was worn out beyond getting spares- Myford had gone to the knacker's yard. It was awful and still looks it- but I doubt few could afford it.

As an old man, I pulled it down to pieces and had the bed professionally reground- to BETTER than original. The clapped out saddle is Turcited as is done to--- the better lathes. I handscraped every worn bit of slides and made and pegged gibs- better than original. The stripped gears were made on the mill drill - and there was a lot!

It now has an inventory of accessories- bought or home made that is longer than when the firm issued the catalogue.

If an octogenarian I am now 84- can do this and who was never an engineer- perhaps there is every reason to feel somewhat elitist.

With failing strength and so on, I'm wanting to go CNC or something. Perhaps it will happen. Keeps me from being chased up the aisle by a raging father with a shotgun!

Cheers

N

 

[bazmak]

There you go,the enjoyment is doing things you like whether it is refurbing a clapped out quality lathe or a cheap chinese.Hope your still doing it at 94 Barry

 

[goldstar31]

Thank you for your good wishes. Another thing- in case you missed it- I'm a grumpy old git.
I got a phone call prior to Christmas. Another grumpy old git. A Goldstar who was, like me, just a boy when we met up in 1949. Just 19, he was the best Spitfire mender EVER. The last of his Spits is still airworthy and now in Canada. We sort of owe our lives to each other. I'm still here- his other little Proctors with their worn out Gypsy engines always worked- when others did not! Life was cheap- but not to him!

I expect another Goldstar will drop a card in. He was the best man in my section then . He was only a telegraph boy on a motor bike before we met up in 1948. He never forgot that he weighed about 100 pounds then- he couldn't eat the swill we got. I got him another shilling a day to buy something edible.

It all taught one thing- to try to help each other.

Enjoy your hobby but learn to accept funny old grumpy gits who have seen- well- a lot.

Norman

 

[MCRIPPPer]

you dont need a gib on the back of the lathe ways like that. if the bottom gibs are adjusted snug the V will do the work of keeping you square. a common mod is to make new tapered gibs with tapered holders. it works wonders and will greatly increase your machining capacity in the way of depth of cut and feed ability.

 

[bazmak]

As you say you should not need a gib at the back.However there was play when the carriage was twisted as the it rode up the V.The gib was just touching at the front and back and has cured the problem.The reason for this thread is to get input from other owners of the same lathe and see if they have a problem

 

[MCRIPPPer]

i own a 7x12 lathe and have done the tapered gib mod. after making new gibs you will not need the back gib and you will have no rotation of the carriage. you will be so glad once you do because it not only fixes the carriage rotation issue, but it makes the carriage more rigid in all directions. you will actually be able to bore holes to size and turn reasonable amounts of material off. i also put tapered roller bearings (trailer/ car wheel bearings) in the spindle which helped greatly with rigidity and surface finish. another good mod is to buy the littlemachineshop 16" bed upgrade, and use a milling machine to locate the holes for the rack and leadscrew blocks.

 

[bazmak]

Hi macripper,i have the 16" bed and i am thinking of doing the the taper gibs to the front as you cant adjust the front gib withou stripping down the carriage,as you say the back gibs are not as important and can be adjusted without stripping the carriage.The new gib plt works well and does not cause any problems,also i may be able to use it to nudge over carriage a couple of thou to square up the cross slide

 

[MCRIPPPer]

you should not use the extra gib you made to adjust for square. that wont work. you need to machine the dovetails again if you want to make the cross slide perfectly square to the carriage movement.

build new tapered gibs for front and back.

 

[goldstar31]

Actually, there is NO reason why a saddle cannot be modified to skew it further into alignment provided that rigidity( whatever that translates to on a cheap Chinese affair) is maintained.

I was going through the specifications of the old Pools lathes and noted that mine- a Pools Major had totally different gibs and a mechanical power feed to anything described in Lathes Co Uk site. Again, I had access to a Murad Antarctica when I put it on a tug boat to go down to Queen Maud Land. It was similar to the Bormilathe( which most have never heard of) but a variant is Jack Radfords Elevating heads in his excellent book- which no one will have ever read. People are missing a helluva lot when people simply become disenchanted.

I can cock mine over on the Myford -because I can go off the rear shear.
It may be only fine milled but go off it, you can. In this day and age, superb plastics are the norm as bearing surfaces. The days when a scraper with his sleeves deep in black cast iron and wearing spectacles made out of thick Newcastle Brown Ale bottles are past. Don't get me wrong- I can scrape but I usually spend my scraping to removing mould on my villa walls in Spain! It is worth more and my wife gives me a beer!

 

[bazmak]

I understand that the rear gib plt should in theory not be necesarry,however
it has sorted out my problem,even though it is only just touching.I also think
that it can be used to skew over the carriage (say a couple of thou) to help square up the carriage,not good practice but will help.Only time will tell

 

[goldstar31]

Ah, Barry, you should get Connolly's Machine Tool Reconditioning. Great book, it is big , thick and comprehensive. If a leg falls off the bed or the car has a puncture you can use it as a spare leg or stand. Again, if you are insomniac, it is the finest way of going to sleep if your are not a Kiwi.

Oh, and in case you are wondering, it does tell you how to make a silk purse out of a sows ear.

It doesn't tell readers how to make sufficient money to get a better lathe- but one cannot expect miracles.
These, I believe, came out of the East. There is a book on that as well but I missed them- the first time round.

Anyway, Merry Christmas to all our readers and the ones who cannot, I apologise for not photographing -when I was there.

Cheers

Norman