screw cutting on warco 220

[kevin largeParticipant @kevinlarge76611]

I want to cut threads on a warco 220 the chart says Z1-6 for the change gears but I can only see 4 gears on the lathe if Z1 is the top and Z6 is the lead screw where do the other ones go

[kevin largeParticipant @kevinlarge76611]

[JasonBModerator @jasonb]

you usually find Z2 & 3 are on one pin, Z 3 & 4 on another but depending on what ratio you have at the moment may only have one gear on each pin thats why you can only see 4 in total.

J

[Peter G. ShawParticipant @peterg-shaw75338]

Hi Kevin,

Z1 is, as you say, the top, ie mandrel gear. Hence it is always 32 teeth.

Z6 is, again as you say, on the leadscrew and can vary.

Z2/Z3 take the place of the existing gear, assuming your lathe is still set up for surfacing, which mates with Z1.

Z4/Z5 take the place of the surfacing fine feed arrangement, ie the thing with the large disk and the triple grooved wheel.

On the chart you will sometimes see one changewheel covering two Z numbers, eg Z2 & Z3 or Z4 & Z5. What this means is that you will have to add a spacer which may be a smaller changewheel or one of the spacers supplied to take up the spare space.

To adapt the lathe for screwcutting you will have to remove the surfacing fine feed mechanism, including the long T nut with the adjustable screw from the engagement fork. This T nut should be replaced by a short T nut which was supplied with the lathe. Then build up the sequence using the correct changewheels, spacers and spacing changewheels as appropriate. The bronze sleeve on the Z2/Z3 position will also need changing: there should be one with the lathe. You will also need to tighten the caphead screw on the front of the fork.

It's all in the manual even though the translation from the original Bulgarian leaves something to be desired, as does the printing and layout.

Regards,

Peter G. Shaw

[Harold Hall 1Participant @haroldhall1]

Whilst it is not totally applicable to your lathe go to this page and click on the link "see explanatory drawing" (lower right of the page) and this will show what Jason and Peter have explained. The gears are though referenced as A – F rather than 1 – 6

Harold

[kevin largeParticipant @kevinlarge76611]

HI PETER I have a manual on cd but I cant make head nor tail of it

if I understand what your saying I take it when set up the lead screw is engaged all the time ?

ive checked all the bits that came with lathe I cant find a bronze bush or a short t nut what ever that is

do you have any photos of the set up

and do you know the size of the sleeve

[Peter G. ShawParticipant @peterg-shaw75338]

Agreed that it isn't the best of manuals!

When set up for screwcutting, the leadscrew can be disengaged by means of the lever on the front on the headstock, the same lever that engages/disengages the fine feeds for surfacing. So no, it isn't engaged all the time, but it is either surfacing or screwcutting.

Assuming you are set up for surfacing, then if you dismantle the large changewheel and three-step device, you will find a small T-nut on the end. You should have another two of these. Whilst dismantled, you will find a bronze stepped sleeve: this is used purely for that particular position, probably owing to the restricted diameter through the three-step device. The plain sleeve(s) you will need are the same length and internal diameter, but without a step so the external diameter is the same as the larger of the two diameters. I think you need two but at the moment am not sure.

If you dismantle the large disc, you will find a long T nut with a screw and locking nut on one end. For screwcutting this has to be replaced with a short T nut.

From memory, ie it means going into the garage and having a look, and it's too late for that now, you should also have a special 32 teeth changewheel along with nut, sleeve (possibly) and bolt. These are used for left hand screwcutting.

You should also have at least one each of a spacer about the thickness of one change wheel, and one about the thickness of two changewheels.

I'm sorry to say that if you haven't got these, then you are going to be on a hiding to nothing as you will need to source them from somewhere. I'm assuming you bought the lathe s/h, so it might be an idea to go back to the seller and see if they are available.

Good luck.

Peter

[kevin largeParticipant @kevinlarge76611]

Hi peter I do have a full set of change wheels and the reverse gearing don’t seem to have any spacers but shouldn’t be to difficult to make them if you could give me the sizes as go nuts bolts etc I can sort them as well the lathe at present is set up for surface cutting and all works fine on another matter how do you turn the compound slide for cutting angles etc I can’t see any way of turning it
kevin
kevin

[Peter G. ShawParticipant @peterg-shaw75338]

Compound slide.

Slacken the four 10mm hex head bolts, rotate to the required position, and retighten.

Other stuff.

Ok, will do, but it will take some time as I can't do it immediately due to other commitments. Similarly photos.

Peter

[kevin largeParticipant @kevinlarge76611]

No problem many thanks

Kevin

[Chris HembryParticipant @chrishembry84309]

Kevin,

Happy to make a list of items needed, had to make a few extras to cover shortages over the years. Also happy to supply any bits you find you need.

Chris

[kevin largeParticipant @kevinlarge76611]

Many thanks Chris at the moment I have full set of change gears everything for surface cutting and that’s it Peter said I need a couple of spacers and a short t nut and bolt but I don’t know for sure I more than happy to pay you for what I may need and really appreciate the offer as it’s quite difficult to know what you need when you have no idea
regards kevin

[Chris HembryParticipant @chrishembry84309]

I'll knock up a little drawing of all the parts so you can identify those you have, and those you need.

Chris

[Peter G. ShawParticipant @peterg-shaw75338]

Saves me a job. Over to you Chris.

Peter.

[kevin largeParticipant @kevinlarge76611]

Cut my first threads on the lathe today one on some ally bar and one on some rebar on both the threads seam quite rough is not a clean cut the ally cleaned up OK with a wire brush is this normal I did use cutting oil.

 

Edited By kevin large on 30/05/2015 16:15:38

[Peter G. ShawParticipant @peterg-shaw75338]

Kevin,

Screwcutting in the lathe using a single point tool does indeed throw up rough edges. Possibly better if you used free-cutting mild steel rather than rebar. Also, paraffin is better for aluminium than cutting fluid.

If the threads you are cutting are standard sizes, you may be better roughing out on the lathe and finishing off with a die. Otherwise, possibly taking a finishing surfacing cut after thread cutting to remove the bits sticking up. You could then follow up with a final threading run just to get those little bits that have been forced back down into the thread by the finishing cut. Messy, I know.

Another thought. Generally, I do screwcutting with fine, shallow cuts, ie I don't try and chew it out at one go. I don't know if that will help.

Regards,

Peter G.Shaw

[kevin largeParticipant @kevinlarge76611]

Thanks peter I will practice some more

Kevin

[Author]

Posts