First post and lathe mounting

This topic has 16 replies, 8 voices, and was last updated 24 May 2012 at 13:35 by Ian S C.

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21 May 2012 at 14:08 #91316
GaryM
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@garym
Hi everyone,

I've just bought my first lathe (a SIEG SC2 from Axminster) and intend having a go at a simple oscillating engine like the one on "Steve's workshop" site.

What I would like to ask is how accurately does it need to be mounted on the workbench. I've read about using a DTI to check alignment but is this over the top for the quality of the machine. I am thinking of bolting it to a sheet of 18mm ply. If it needs an adjustable mounting on each foot I would have to drill out the threaded hole that is there already (which I am reluctant to do) or alternatively bolt a flat bar to each foot and then have adjustment on the ends of the bars.

Any thoughts?

Thanks for any help.

Gary Marland
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21 May 2012 at 14:08 #6159
GaryM
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@garym
21 May 2012 at 16:32 #91333
Ketan Swali
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@ketanswali79440
Strip, clean, adjust, lubricate, and basic alignment is not over the top for this machine. The issues are always with assembly – good, bad, ugly, Friday afternoon….etc., regardless of who you buy from, and regardless of what anyone else says. But, please do not give it the label "this quality of machine" which implies some kind of negative (even though it is from a competitor ). If you cant do the basics in preparing the machine, ask someone who knows how to.

Do not bolt it down to anything. there should be a tray and rubber feet. Use them. Let the lathe settle in the environment it is going to be used. "Real precision/near precision" alignement of the tailstock should be considered after a few months.

Readers of this thread, may or may not agree, but this is my opinion. Good luck with making some swarf!.

Ketan at ARC.
21 May 2012 at 17:13 #91337
Andyf
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@andyf
The "to bolt down or not?" question frequently comes up on the Yahoo 7×12 minilathe forum. The majority subscribe to Ketan's view. To quote from a recent post from a member there:

"Strength varies as the square of the scaling factor. Weight varies as the cube. So while our little 7x lathes are ten times smaller than a big machine, and are therefore only 1/1000 as heavy, they are 10 times more rigid. Those who wear both a belt & suspenders as well as relying on a few safety pins will enjoy bolting their 7x machines to a carefully trued & level surface. I find the rubber feet ample."

Some cut shallow depressions in the bench to locate the rubber feet. Others are mindful that lathes are a little top-heavy and add spreaders to the bed casting, moving the rubber feet to to the spreader ends, to stop any tendency of the lathe to tip over. No doubt some do both.

Andy
21 May 2012 at 17:44 #91340
Richard Parsons
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@richardparsons61721
I will agree with much of what Ketan has written. I regard all machines be they new or second hand as requiring ‘Commissioning’. That is dismantling (to a certain level) cleaning, fixing anything that is not too good and rebuilding with great care setting things up as you go.

On a lathe the size of the 7X12 is light and to my mind flimsy, so I would hunt out a nice bit of OLD (yes old) RSJ get it surfaced and bolt the lathe to that (with suitable adjusters in the mountings. You will have two problems with that as you will have to get the RSJ level before you mount up the lathe. You then level the lathe on the level RSJ. Remember with a ‘V’ bed lathe it the tops of the ‘V’s may be very crudly machined as they carry no load. I always level on the cross slide. This can also be doggy.

I will admit I missed something inside a new 6” lathe. It later got mixes up with the cross slide power feed and jammed it. What I missed was a pink paper for a pestilence powder (or the 7^th curse of Dr Fu Manchu on all round eyed foreign devils or even, dare I say, an advert for a local Pale Pink Peppermint Parlour in Pongping).

Finaly the first things I would make are two test/truing bars. Mine are very thick. Yours would need to have about 5/8” (16 MM) shafts and 1” (25.4MM) spools. My spools were stuck on with loktite. Will post pictures of them both ASAP

Edited By Richard Parsons on 21/05/2012 17:48:12
21 May 2012 at 22:51 #91370
GaryM
Participant
@garym
Thanks for all the advice guys.

Ketan: a little explanation. I first decided which lathe to buy just before the end of last year with the intention of buying it sometime in the new year when the weather warmed up a bit. The choice came down to the Axminster one and your Super C3 with the balance tipping in favour of ARC. I was considering whether to pay the extra to have it prepared by ARC or have a go myself. Anyway, just after Christmas, the 2012 Axminster catalogue dropped on the mat and I was shocked to find the price had gone up by 25% (£120). I quickly checked their web site and it was still £510 so I checked the ARC web site and you were out of stock. I thus made the quick decision to buy one from Axminster and have a go at the preparation myself (admittedly using your guide). This preparation and the fact that I built a new bench to sit it on and re-organised the garage as a workshop explain why I still haven't actually turned anything yet. I did come along to the Harrogate show with a shopping list compiled from the ARC catalogue only to find you had just brought machines to the show. If that was you on the ARC stand you might remember me asking if you had another stand somewhere else in the hall. Promise to order something soon.

Andy: Your answer and Ketans seem to confirm that it is rigid enough as it is and that bolting down might make things worse. I'll take this into account and try it just on the feet and see how it goes.

Richard: Thanks for the advice but I think I'll give the RSJ a miss for the time being.

Gary

Edited By Gary Marland on 21/05/2012 22:52:43
22 May 2012 at 09:14 #91380
Ketan Swali
Participant
@ketanswali79440
No problem Gary.

It was probably me you spoke to at Harrogate. There were a lot of people who were disappointed that we did not have an accessories sales counter. I can only apologise, for the reasons given elsewhere in this forum. Still, it was probably the most pleasurable show we have done. It gave us more time to chat with new prospective customers and catch up with old friends and customers.

Ketan at ARC.
22 May 2012 at 13:58 #91398
Ian S C
Participant
@iansc
Gary, just follow Ketan's instructions and you'll be OK, nice wee lathe, did you get the DRO that goes with it? I would not mind one of those as a second lathe, although I would rather have mechanical speed changing, and back gear, but thats just me. Ian S C
22 May 2012 at 16:10 #91401
GaryM
Participant
@garym
Hi Ian,

I didn't get the DRO add-on. I thought I might learn more using it the old fashioned way to start with. I can always buy them later (bit expensive though). I went a bit mad with other accessories though, mainly due to the price increases mentioned in my previous reply. 4-jaw independent chuck, faceplate, vertical slide and quick change tool post.

Just got to get making something now.

Gary
22 May 2012 at 16:20 #91402
Ady1
Participant
@ady1
You can make a simple DRO with a vernier purchased for a tenner on your cross slide

Use a carbide drill to make the holes in the hardened stainless jaws

The best and simplest mod you will ever make

Eliminates many backlash problems, makes screwcutting far easier, accurate to 1-2 hundredths of a millimeter and can be switched from imperial to metric with the push of a button
22 May 2012 at 17:03 #91403
NJH
Participant
@njh
Hi Gary

You say :- I didn't get the DRO add-on. I thought I might learn more using it the old fashioned way to start with.

Good decision – get comfortable with using the machine first then gradually you will come to realise just what your priority is for the bells and whistles. Your choices so far all seem very sensible to me.

Oh – one other essential accessory – a box in which to chuck the bits that go wrong on your projects ( believe me there will be some!) . It has two functions:-

1) Chucking it in there helps release the frustration and

2) That rejected bit will form the basis of some, as yet, unimagined part of a future project !

Good luck!

Norman

Edited By NJH on 22/05/2012 17:04:32
22 May 2012 at 21:49 #91416
GaryM
Participant
@garym
Hi Ady1

Thanks for the idea. Certainly food for thought and a lot cheaper. One of the things that I like about engineers in general is the way they like to come up with alternative ways of doing things. I think I've inherited that gene from my dad. I've just got hold of a pair of stainless steel shelves that were being thrown away at work and am going to use them as a swarf tray instead of the rather small one supplied with the lathe. I'll have a read of your thread later.

Hi Norman

Thanks for your comments. One thing I've started doing since getting interested in model engineering is looking in the skip at work everyday to see if anything useful is being thrown out. Everything becomes a potential resource.

Gary
23 May 2012 at 05:04 #91420
Springbok
Participant
@springbok
There was a thread sometime ago that advocated magnets from dead computer drives to locate the elcheapo vernier with the usual cable going to the DRO box works a treat and no drilling

Bob
23 May 2012 at 13:09 #91436
Ian S C
Participant
@iansc
Gary, you say you had to buy the 4 jaw chuck, it should come with the lathe, along with 2 steadies, and a faceplate, well thats how they are sold this end of the planet. I imagine they are just getting a bit more cash for the lathe, the 4 jaw is the more important of the two.

Helped a mate unpack his new Chinese lathe, and we found two four jaw, and two three jaw chucks, the box hn opened since it left China (not even for customs). My lathe has 8" chucks, and I bought a 6" one and made my own back plate for it.

I kept the library for our now defunct machinery club, and I remember a manual for Sunbeam cars from the 1920s, spare wheel was an optional extra. Ian S C
23 May 2012 at 13:54 #91439
GaryM
Participant
@garym
Ian, as supplied by Axminster in the UK it just comes with a 3-jaw self-centring chuck. Spare wheels are also becoming a rarity on some modern cars.

Gary
23 May 2012 at 15:16 #91445
Ketan Swali
Participant
@ketanswali79440
Ian,

In this part of the world, all mini-lathes are sold only with a three-jaw self centring chuck.Everything else is an optional extra

Ketan at ARC.
24 May 2012 at 13:35 #91485
Ian S C
Participant
@iansc
Thats OK, by the look of it 4 jaw Chinese chucks are a similar price in the UK as they are here in NZ.

As far as spare wheels for cars, having to have one of those space saver ones is bad enough, although it does'nt worry me too much, I get round on a push bike, don't have a car. IAN S C
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