Member postings for John C

More excellent advice - many thanks!

John

Thanks for all the replies Gents, much appreciated. I will digest the knowledge imparted and think about what to do. At least I now am better informed than an hour ago!

Once again, many thanks for your helpful and knowledgable input.

Best regards,

John

I had a search of the forums, but didn't stumble across anything about this.

I have 240v single phase to 240v 3 phase inverters in my workshop, which is powered from the house supply. Lately, the house RCD has begun tripping, sometimes when first powering a motor from the inverter, sometimes when the machine is running. Only one inverter is powering a motor at any time.

I have read that inverters and RCDs are not good companions. Does anyone have any suggestions to cure the problem of the house RCD tripping? The RCD is about 20 yrs old.

I am considering changing the existing RCD to a type B RCD, or replacing the consumer unit with an isolator and RCBO type, but I am not sure if RCBOs suffer the same problem with inverters.

Many thanks for any info,

Rgds,

John

Working fine for me.

So, the answer from 'the panel' is......jump in, buy some gear and make some swarf!

Another £.01. Toolposts. I have had a number of Dixon style (Chinese made) quick change toolposts but I found the toolholders varied slightly and some needed some 'adjustment' on the grinder. I have since switched to the 'Aloris' (again, Chinese made) style. All the toolholders I have bought, regardless of supplier, fit exactly the same. The downside is a slight reduction in the tool shank thickness that can be used.

John

Hi Alan,

I have tooling from all the suppliers you mention, All of it has ended up fine, although I have had to return a few items for replacement - which has been done quickly and without quibble. I also have tooling from Arc Eurotrade (UK) and CTC tools (Hong Kong). I have some 'high end' kit purchased second (or more) hand from a certain auction site; some good, some not so good.

If you look back through these forums (fora?) you will find many discussions on such tooling, with opinions varying from 'you get what you pay for' through 'not fit for purpose' to 'it's the only way I could get started', with plenty of brickbats about quality control.

If you accept that this kit is made to a price, and that YOU are the quality controller, all will be well. If you expect Rolls Royce accuracy for Trabant prices, you will be disappointed!

It also depends on what you call 'sensible' tolerances. One man's 'perfectly OK' is another man's scrap bin entry.

If you are happy with your lathe, which was made in the same type of factories as the tooling under discussion, then you should be happy with the tooling.

Arc don't exhibit at shows any more, but Chronos, Warco, Chester and RDG do, so you could see what is on offer in the flesh. Depending on where you are you could also visit the premises of tool sellers to get a feel for what is on offer.

I guess if you are building a lunar lander you may need to save up for top end kit - if you are just enjoying yourself in the workshop, my feeling is that the kit from the sellers mentioned above is fine.

Just my £.02 worth. Opinions may vary, etc etc.

John

I had a S7 bed reground by Brian Caddy of Slideway Services, Nuneaton A search on the internet will give details. No connection, but I could not recommend Brain enough. Excellent work, fair price and a very pleasant experience throughout. He will regrind the saddle as well.

Hope that helps,

John

Hi Mark,

I could help you with this. Where are you?

John

Hi Maurice,

Arc Eurotrade list them, under 'precision angle blocks'. But out of stock at present. Sorry, can't post a link from here.

John

Which translates to:

Wire 1 : +ve supply and brown wire from sensor.

Wire 2 -ve supply

Wire 3 Blue wire from sensor

Wire 4 Nothing

Wire 5 Black line from sensor.

I used an 18 v printer power supply for mine.

Rgds,

John

Mike - this should help - I have wired up mine using this diagram.

Rgds,

John

It's a Keats angle plate. Bin it my way if you like!

John

Now you're talking!

Cut. Even if your saw is not fine enough to produce two pieces of 1/4 X 6.1mm from one length of 18mm, you will still have 36mm of 1/4 X (say) 5mm, which will come in more useful for something else than a bunch of brass chips!

John.

From Yorkshire........

And page 5.24 in the online manual states quite clearly Deceleration Time units 0.1 yes nought point one secs. With a default of 10 units, giving 1 second. Just so the OP doesn't get confused. A ten sec default accel and decel time would be quite long.

Gary, I think that the decel units are 0.1 sec - so the default is 1 sec.

John

Vic, my inverter has a 'ramp up/down' setting which determines how fast the spindle gets up to speed, and slows down. It's not braking as such, just the time taken to go from selected speed to zero. Yours would appear to be on page 5-3 of the manual, called decel time (1-10 and 1-12) The default appears to be 1 sec, so it may have been altered. Chapter 4.4 shows how to alter the parameters. Without the unit in front of me, I can't help you on changing the settings, but if you work through the guide 4.4 you should be able to get to Group 1 (Basic parameter), then item 10 (decel) and set the value to 10 (=1second)

There is a section on braking resistors, but you may find that decel solves your problem. If all else fails, you could try a factory reset to get accel and decel to be 1 sec

Rgds,

John

Thanks all!

Neil - do you have a link to Colonel Salmon's work? Google brings up this page and then goes on to fish!

Nick G. I have the diagrams - there are indeed 2 clamps for the headstock, spindle end and rear end. The bolts for the rear are accessed by removing the change gear quadrant. All are good hand tight.

John M - thanks for your story! It reinforces my belief that I am probably looking too hard. I have now less than 0.002mm defection at the spindle nose, but a 25mm steel bar clamped in the chuck shows 0.04mm deflection at about 100mm - which has to be due to bending.

I fully agree that the proof of the pudding etc, so will try some more turning tests later.

Once again, thanks for talking the time to reply.

Regards,

John

As seen in another thread (Boxford Spindle Play) i have been chasing my tail trying to reduce the play I thought I was experiencing in the spindle of my Boxford STS10.

In a flash of inspiration, I moved the indicator from the cross slide to the headstock - and presto - no more play! So the play I was seeing was movement between the headstock and the bed. Clamping an indicator to the bed confirms this - pushing the spindle shows movement between the lathe bed and the headstock.

I have carefully tightened the headstock clamping bolts and the TIR movement is now about 0.004 mm - that's 1-1/2 tenths in old money. I can get this same deflection by leaning almost anywhere on the lathe, and over twice this if i apply a spanner with only moderate force to the headstock mounting bolts.

So my question is how much flex is acceptable, and to those who have set up industrial machinery, did you experience similar movement?

I am just off to read Schlesinger's 'Testing Machine Tools' to seek inspiration, and perhaps sanity too!

many thanks,

John