Lathework for Beginners

[JasonBModerator @jasonb]

I find the 1.5mm blades do wander if the end is ground at an angle particularly the mor eyou have sticking out so just grind mine straight. Wider and much deeper HSS blade that fits my toolpost holder is far more stiffer so can be angled if needed.

[Bob McParticipant @bobmc91481]

Ha…! this is uncanny….!

Re: my post 20.09.2018

in the latest issue (ME 4596) Graham Sadlers article series on "Lathes and more for beginners" actually says that some of the cheaper toolholders do not hold the blade properly giving no clearance either side and are best avoided..

As a famous person once or twice said… "I don't believe it ! " the makers of these bladeholders must surely know that they are making something destined to cause problems…for the sake of setting over the milling machine a degree or two when cutting the blade holder profile… it might work …but its not right… and I noticed I got a better finish on the sides of the work when the blade was set correctly and is a delight to work with.

Manufacturers in the Eastern countries making many of these tools very rarely puts its name on its products, I may be old fashioned but I do remember reading many years ago not to buy anything where the manufacturer was not confident in putting his name on what he has produced, I am minded to send it back to the supplier.

Bob.

[Neil WyattModerator @neilwyatt]

Posted by Bob Mc on 21/09/2018 21:24:29:

Ha…! this is uncanny….!

Re: my post 20.09.2018

in the latest issue (ME 4596) Graham Sadlers article series on "Lathes and more for beginners" actually says that some of the cheaper toolholders do not hold the blade properly giving no clearance either side and are best avoided..

As a famous person once or twice said… "I don't believe it ! " the makers of these bladeholders must surely know that they are making something destined to cause problems…for the sake of setting over the milling machine a degree or two when cutting the blade holder profile… it might work …but its not right… and I noticed I got a better finish on the sides of the work when the blade was set correctly and is a delight to work with.

Manufacturers in the Eastern countries making many of these tools very rarely puts its name on its products, I may be old fashioned but I do remember reading many years ago not to buy anything where the manufacturer was not confident in putting his name on what he has produced, I am minded to send it back to the supplier.

Bob.

 

 

Most of these toolholders are designed to work with parallel sided blades. Rather than Graham's tool being badly designed, I think it was supplied with the wrong blade, presumably the same supplier for yours too.

I have two bought parting toolholders with vertical slots and one I made myself, all of which are used with parallel blades and work very well, thank you.

It's a myth that parallel parting blades will jam – but they must be held vertically.

Neil

Edit: home made holder for parallel blade:

Edited By Neil Wyatt on 21/09/2018 21:53:50

Edited By Neil Wyatt on 21/09/2018 21:54:53

[Ron LadenParticipant @ronladen17547]

Posted by Bob Mc on 20/09/2018 13:14:40:

I'm glad someone mentioned parting problems again, I have had many problems with this myself and although I can part with reasonable results I can't say I have had an easy time, in the end I purchased a new smaller width hss blade with holder from a well known supplier, this is a 1/16 inch blade which I thought would make the cuts easier.

I was disappointed again, the problem in the end is the blade holder supplied,..I looked at the one I had previously as well and I assumed they would both have been made so that fitting it in a normal toolpost set squarely would give the correct clearance angles at the sides of the blade, to my amazement I found that the holders are not made with an angled side face but are just at 90 deg so that there is no clearance at one side of the blade and double the clearance at the other; this causes the tool to move over and dig in to one side.

I made a new toolholder so that there would be clearance either side of the blade…the results were very satisfying.. has anyone come across this before…? or is this obvious to the more experienced.. I am only too willing to learn..

Bob.

Bob, I received my 8mm parting tool holder and 1.6mm blades yesterday, like yours the blade face on the holder is square. There is not a problem though as the blades supplied with mine are parallel sided with no angles. The cutting end of the blade is ground as a reverse taper. Did some parting this morning and it cut and parted fine. Did you check with the supplier to see if they had supplied you the wrong blades for the holder..?

Ron

[Bob McParticipant @bobmc91481]

Hi Ron, thanks for your message..

I have looked at the suppliers website but they don't actually give any information about the blade or holder other than give its overall dimensions, I suppose I should contact them and ask but I have now made a fitting for my toolpost which puts it in the right orientation and I don't hold much hope out for getting a meaningful response from the supplier as I contacted them previously about another purchase and received an unhelpful reply.

I have to say that with the setup I have now, I am pleased with the way it produces a nice shiny face on both sides of the work rather than the previous flat face setup which produced rough faces and has no chatter with the metal coming off in nice curls…and it just sounds right, and I have ground the blade in the normal way with a flat edge and with the tool fitted to the topslide, no need for rear toolpost or any fancy grinding ….anyway thanks again for your reply to my post.

..Bob..

[JasonBModerator @jasonb]

If you do want to holed a tapered blade in a flat sided holder then a thin piece of fuse wire or a strand of flex against the bottom edge of the blade will have it standing upright so you get equal clearance both sides.

[Neil WyattModerator @neilwyatt]

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

[JasonBModerator @jasonb]

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

[Ron LadenParticipant @ronladen17547]

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

[not done it yetParticipant @notdoneityet]

Posted by Ron Laden on 28/09/2018 08:59:51:

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

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

[Ron LadenParticipant @ronladen17547]

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

[JasonBModerator @jasonb]

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

[Ron LadenParticipant @ronladen17547]

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

[Anonymous]

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

[Ron LadenParticipant @ronladen17547]

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

Ron

[Ron LadenParticipant @ronladen17547]

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

[Ian S CParticipant @iansc]

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

[Neil WyattModerator @neilwyatt]

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

[JasonBModerator @jasonb]

Posted by Ron Laden on 29/09/2018 10:33:54:

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.

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.

[Ron LadenParticipant @ronladen17547]

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

[Ron LadenParticipant @ronladen17547]

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

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 28/09/2018 12:34:27:

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

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.

[JasonBModerator @jasonb]

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.

[Ron LadenParticipant @ronladen17547]

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..?

[Russell EberhardtParticipant @russelleberhardt48058]

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

[Author]

Posts