How on earth do I do this

This topic has 11 replies, 8 voices, and was last updated 15 February 2016 at 16:25 by Sam Longley 1.

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14 February 2016 at 11:43 #8004
Sam Longley 1
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@samlongley1
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14 February 2016 at 11:43 #225308
Sam Longley 1
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@samlongley1
I have just set up my new Warco 250V & the first job that I did a number of times on my Drummond M type taking about 45 minutes seems impossible on my new lathe

I want to make a thrust washer for the rope cutter on my boat. Because the cutter is a bit worn I cannot buy standard ones so for the last 4 years I have made one in Tufnol. This year i am going to try Rg 1000 plastic

The washer has to be 1.5mm th. with little tolerance. In the middle is a hole 30mm diam & a shoulder around this hole of 40 mm diam 5mm thick. Then the outer face is 1.5 mm Th& overall diameter is 100mm. so in section it is "L" shaped.

In the past i have bolted a 12mm th piece of Trespa to the face plate ( Trespa is similat to formica but much thicker)

I then face it up so I have a nice flat surface. I then fix the tufnol 125 diam to the trespa with lots of self tapping screws around the perimeter beyond the 100 mm diam so that the outer edge stops the tufnol flapping off the face & upsetting the thickness.

I face up the centre 50mm or so to 5mm. Then I bore the central 30mm ( it does not matter if I cut the sacrificial trespa). i then I then put a rod through the headstock & bolt a disc of trespa exactly 40mm diam to hold the centre of the tufnol tight to the trespa. I then turn the tufnol to 1.5mm for a diameter a little over 100mm & cut it out. I can get the 1.5mm dead accurate as it is screwed on the outer face & clamped in the middle so it is held tight to the trespa

the first problem with my new lathe is that I cannot face up the 240mm diameter piece of trespa. This is because the travel on the cross slide is 100 mm so one also has to use some additional movement on the topslide which may not be square to the face. If I put the tool on the inner face of the tool holder I cannot wind the tool post right out as it fouls the yellow safety guard. If I put the tool on the outside face of the tool holder I cannot get enough travel on the cross slide to face right to the centre

To make matters worse the carriage has extended parts that stop me getting tight to the face plate as they will not go under it ( Face plate would be better to be smaller)

So how do i face something the full width of the face plate? Do i have to remove the yellow guard- I rather feel like doing that any way. I have had a lathe for years & never needed one yet.I would stil have to use the topslide with the handle facing inwards to get the travel I need

Then I need to be sure I can do all the thicknessing operations with one tool setting to ensure I get 5mm & 1.5mm. The tolerance on hole & shoulder are also finely balanced to fit the cutting discs of the rope cutter

To get the 1.5mm exact I used to take to tool tip to the outside face of the trespa beyond the piece of tufnol then bring it up to the trespa & get the dimension then move the cutter inwards to the area to be cut & wind it in 1.5 mm off the face of the trespa thus leaving a 1.5mm piece of tufnol

But the Warco is severely limited compared to my pre war Drummond. Which may have to be bought back into use before it gets sold

Any ideas how to turn the face of the trespa the full width of the face plate please

Edited By Sam Longley 1 on 14/02/2016 11:44:12

Edited By Sam Longley 1 on 14/02/2016 11:44:59

Edited By Sam Longley 1 on 14/02/2016 11:47:55
14 February 2016 at 12:17 #225318
Tony Pratt 1
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@tonypratt1
A picture might be better? Anyway if you need to remove a guard to help you I would do it & just be careful. A 100 mm cross slide travel wont allow you to face 240mm diameter in one tool setting, do you need to do so if not face the important area & relieve the rest.

Tony
14 February 2016 at 13:06 #225332
MW
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@mw27036
I've removed the guards from both of my machines and replaced it with a magnetic base adjustable splash screen because like you said, they always get in the way and the only time i've needed protection was from scattered debris and bits of oil.

Unfortunately theyre isnt an easy solution to your cross slide movement, it was built that way so only a big modification to this machine could make it go further.

Michael W
14 February 2016 at 13:23 #225338
JasonB
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@jasonb
if the 250 is anything like the 280 you can position the topslide anywhere along teh cross slide so that will cure your reach problem eg slide it away from you and habe the tool on the side of teh toolpost nearest to you.

Most of these range of lathes the chuck gaurd gets in the way when using the faceplate as does the lead screw cover and I think the extra bump on the end of teh motor for the cooling fan that eats into the splash tray can also get in the way.

I'd leave the outer diameter of your backing piece unskimmed as your tufnol part won't be in contact with it so just skim 200mm dia.
14 February 2016 at 13:56 #225345
Ajohnw
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@ajohnw51620
The travel on the cross slide is 115mm according to the spec. They always seem to be a bit mean in this area compared with the swing.

Less the hole in the centre the effectve diameter of the work for the part that needs to be faced is 210mm so it should be possible to face that in one go if the toolpost is set up for it.

A suitable tool and toolpost setting should also allow the od to be turned.

If the motor housing limits saddle travel and that causes problems more tool overhand should help.

If you need a touch more cross slide travel you might find that there is a stop which screws into the end of the leadscrew but be careful.

It struck me on a similar lathe that if the lead screw was extended and stand off was made for the dial and handle flattened over the top so that it could pass under the cross slide these problems disappear. I haven't looked at it in detail but it could be possible to get an extra couple of inches of cross slide travel in an outward direction on some also curing the other strange one that can crop up going inwards when the compound slide and tool holder are in certain positions. It would have costed them peanuts to do this from new – many many lathes use this technique including earlier chinese ones. If it already has a stand off it could be made longer.

John

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14 February 2016 at 17:54 #225378
Sam Longley 1
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@samlongley1
Posted by Michael Walters on 14/02/2016 13:06:25:

I've removed the guards from both of my machines and replaced it with a magnetic base adjustable splash screen because like you said, they always get in the way

Michael W

I have had to do the same & it has made things a little easier but with only a 100-110 mm cross slide travel it make the operation quite awkward. Plus after i set up the face plate I could not find the pattern I had made on my Drummond for the hole & shoulders ( the drummond dials being a little worn meant I made a pattern to use to take the cutters up to). Changing from chuck to face plate & back again is a real pain after the simple screw on the headstock of the Drummond.

I am finding the metric dial increments a bit confusing so have ended up using a dial on a magnetic stand. I wanted to get 2.5mm of travel but when I turned the dial on the travel 10 units of 2.5mm( taking up back lash & coming back ) I found it did not give me a true 2.5mm. it was more like 8 divisions than 10. The increments on the crosslide are not full increments either but ( from memory) 0.4mm per division. I must be doing something really wrong

On my Drummond the 4 way tool post fitted into T slots mounted anywhere on the cross slide. On the Warco it is limited to a single point by a stud & a hole in the top slide

I really have to get used to the different way of working the lathe & understanding how to do the things differently

Edited By Sam Longley 1 on 14/02/2016 17:55:49
14 February 2016 at 21:13 #225396
Bazyle
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@bazyle
Is it imperial pretending to be metric?
15 February 2016 at 00:03 #225410
Howard Lewis
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@howardlewis46836
Um, could be.

I have a mini lathe, where the Cross and Topsldes have 20tpi feedscrews, but the leadscrew seems to be 1.5mm pitch.

Have been told that one manufacturer does this, and supplies at least two UK importers, so this might be a third.

Try using a DTI to measure the travel for one complete rotation of the handle, after taking out the backlash. That should show the pitch of the feedscrews.

At least this should tell you the travel per division on the scale, in whichever unit you want to work

Howard
15 February 2016 at 10:41 #225447
Ian S C
Participant
@iansc
I think the Chinese see the USA as the target market, so imperial lead screws, and a metric option on the dials for UK and Europe. Get rid of the silly bit of plastic guard, you'll have to bypass the micro switch.

Now you see why people say buy the biggest you can afford/got room for, there is all ways a job that comes along that is just too big.

Ian S C
15 February 2016 at 12:13 #225462
MW
Participant
@mw27036
"there is all ways a job that comes along that is just too big."

I cant say its happened to my lathe (yet, 26mm thru bore) but never a truer word spoken.

Michael W

Edited By Michael Walters on 15/02/2016 12:15:22
15 February 2016 at 16:25 #225501
Sam Longley 1
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@samlongley1
Well I have done it & my rope cutter for my boat works perfectly. (Sailing being my first hobby.)

It took me nearly 1.5 days to make one bush & 2.5 hours to make the second. Now it is a piece of cake. Like a lot of things it is probably the setup & jigs & working out how to do it that take the time. .

I can imagine that some models take years to make but having made one the second would be completed in half the time – But who would want 2 the same ?
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