Lathework for Beginners

Anyone interested in an SC4 may want to take a look at Arc Euro's website.

The price has been 'slashed' along with that of mini lathes.

Neil

And while you are there take a look at the Blingtastic latest pimped up mill the SX3.5DZP. I've seen a couple of videos of this mill in action and it looks to have plenty of power and also a 5000rpm spindle that will suit small cutters or those thinking of a CNC conversion.

This and some of the other mills are also available at reduced prices

Edited By JasonB on 27/09/2018 18:38:01

Still havnt got myself a mill just yet, but what I would give to have that SX3.5DZP, looks superb for the model workshop.

Edited By Ron Laden on 28/09/2018 09:01:04

Edited By Ron Laden on 28/09/2018 09:01:58

Exactly £2251 - unless you can twist Ketan’s arm a bit more!

I know £2251 which I havnt got, about a third of that amount will be the cost of the mill when I get one.

Edited By Ron Laden on 28/09/2018 12:32:15

In that case don't hang about, I see Ketan has been knocking more money off all the other mills as well.

Sorry guys but another parting tool question, is a 3.2mm tool just a bit much for a mini-lathe...?

Yesterday I was parting some 2011 which is said to be free cutting but I struggled to stop chatter. I checked everything I could think of, re-sharpened the tool and ground the cutting edge dead square. Checked for backlash but that was as normal which was quite good at 0.15mm. I mounted the tool well back in the holder, checked the tool was vertical and sitting square to the work piece, used WD40 for lubrication. I also tried no end of speeds but although it improved at some speeds I couldnt cure it completely.

I dont know if I,ve missed something but just wondering if a mini-lathe is not quite rigid enough for a 3.2 parting tool. I did some parting with a 1.6mm tool and that was fine, no problems.

Ron

Edited By Ron Laden on 29/09/2018 09:01:08

Feedrate? If you get chatter when machining the solution is often to increase the feedrate, which is the opposite of what most people do.

Andrew

Thanks Andrew, I must admit I didnt try that, will give it a go.

Ron

Well done Andrew, I just tried a higher feed rate and it cured the chatter. I did stall the lathe once but it was a case of balancing the speed with the feed rate and then it was fine.

Many thanks

Ron

It might also help if you can try a narrower tool, say 2 mm, my first parting tool was a bit of broked industrial power hack saw blade about 1.5 mm thick, worked well for many years, and while I now have "proper" HSS tools, the old home made tool is still there. One thing about a narrow tool is you don't waste so much material which can add up as on my first big job, 16 bronze nuts for the radiators on a Lanz Bulldog tractor, from the piece of cast bronze bar I ended up with a 1/4" slice x 2" diametre at the end.

Ian S C

1/8" tools are about the limit for a mini lathe, as Ian suggests a slightly thinner one will be more forgiving.

Andrew's advice on increasing, not reducing, feedrate if you get chatter is the best you will get and cheaper than a rear toolpost

There used to be a video of me putting a 1/8" groove in 2" diameter steel on my mini lathe.

Neil

Edited By Neil Wyatt on 29/09/2018 16:48:43

As you have found with the vari speed lathes you need to have them running fast enough to get the motor in its power band to avoid a stall. Not too much of an issue on smaller diameters but as the work diameter goes up you will be getting a rather fast cutting speed so as Ian and Neil say a thinner tool will reduce the load on the machine so you don't have to wind up the wick so much. And/or go to carbide that can take the faster speed.

Thanks Ian, Neil and Jason.

I have the 1.6mm parting tool plus I will try and find a 2mm blade for the 8mm holder I recently purchased.

Jason, I did find I had to increase the speed with the higher feed rate to get past the lathe wanting to stall, but once I found the balance between the two it worked ok.

Ron

Oh dear, I,m pretty sure that the head stock gears in the low range on my mini-lathe have either lost a tooth or teeth. I was parting off yesterday and all was going fine with no problems when suddenly the lathe started to make a loud clicking sound. I can still use the lathe as high range seems fine but turning the chuck by hand in low range I can feel something is not as it should be. I did stall the lathe a couple of days ago and all seemed fine afterwards but I guess the damage was probably done then and yesterday the tooth/teeth finally gave way.

So it looks like a strip down to replace the gears and was wondering if it would be worth fitting metal gears whilst I,m at it. I have read though that the nylon gears are considered by some to be a safety valve and offer some protection to other parts of the lathe...? Also having to go to the trouble of stripping and removing the head stock do I take the opportunity to change the spindle bearings to taper roller or angular contact...?

Ron

Yes Jason, Arc have some really good pricing on both the lathes and mills at the moment, just bad timing though as I wont be in a position to get a mill until the new year. The machine I am leaning towards is an ARC machine, the Sieg SX2 Plus which I think would be a good start, well at least I hope so. Size wise there is not much to choose between the various machines in a similar price bracket. I am attracted by the 500 watt brushless "output" power, I did look at some smaller lower cost machines but as their size decreases so does the power figures.

I dont know how long the price reductions will last but when the time comes I,m hoping I can get a reasonable deal.

Might be worth giving Ketan a call and see if he will hold one for you on a deposit.

For those who are not on ARC Euro Trade's e-mail list this is the latest list of reductions.

I am getting a few extras for the lathe, I have a fixed centre for the lathe and was wondering if there is a real benefit in having a live centre. I can see that you lose the tip wear that you get on a fixed type but is there other benefits. Also half centres, why half..?

Half centre enables you to get the tool closer to the centre of the work. I don't often use my live centre. Keep the centre well lubricated to prevent wear.

Russell

Or more clearance if threading towards the tail stock at high speed!

I only use a solid centre if the job demands - otherwise a good revolving centre, as rubbish ones defeat the objective. A solid centre is better than a cheap live one - as long as the tailstock is good, of course (minimum quill extension at all times).