'Living with an old Synchro' and other tales from my shed.

[DavidA]

Not really sure where to place this. But if anyone objects I'll move it elsewhere.

As many will know I acquired an old (1982) Denford Viceroy 280 Synchro : 12 speed.

This machine had been in use at the company I worked for at least from the time I arrived there ten years ago and was under the care of an old school machinist who really knew what he was doing. He retired a couple of year back and the person who took over his job really didn't have much of a clue.

So the machine stopped. and then was moved into a storage shed. It sat there unloved until the maintenance chief asked me if I knew anyone who would be interested in buying it.

I offered him a very low price and was most surprised when it was accepted.

It was in a truly sorry state.

It was covered in grot; rusty grot. There were still tools in the tray, along with lots of old cutting oil. Fortunately the cutting fluid helped preserve all the tools that were covered in it. It was the bare metal that had rusted. all the ways were fine.

£50 changed hands for carriage and the lathe was delivered to my drive way. My brother and I spent an interesting day getting it from the gate down to the shed. This involved moving two cars that were long term projects and building a roadway out of breeze blocks to get across an unpaved patch.
But we managed. put it roughly in place and called it enough for the day.

It took days to clean it. But the basic machine was clearly in quite good condition.

The first difficulty as that it was three phase. That little adventure has been covered in the posts on three phase conversion.

Now, there does seem to be a lot of controversy when it comes to using capacitors to make a single to three phase convertor. Some seem to heap derision on the whole idea. But it works. You have to put up with the fact you will never get a true three phase supply as the capacitor(s) give you a 90degree third phase and not the 120 degree that one would really like. Small price to pay.

I set up the motor I bought from our esteemed colleague as a pilot and now have a happily running lathe.
When it's cold,  on first starting up, the power to the shed occasionally trips out as the trip is only16 Amp. This will be addressed in the near future. I did find that adding an extra 6 MFD to the pilot motor on start up seems to cure the tripping out.

When it first arrived the lathe was fitted with DC injection braking. This looked to me like trouble just waiting to manifest itself, so I bypassed it and now have the usual forward reverse and stop buttons; Oh yes, and the sud pump when I re-fit its contactor.

There is always a moment of trepidation when you first start up this kind of system after having 'modified' the circuitry. But the moment comes when you have to press the button and hope that there are no dramatics. And there weren't ; nothing happened.

After much musing over the contactor wiring I found that the contactor relays had no return path. I had broken this when I remover the suds pump contactor. So, inset wire into L1 and try again.  Success!

For about five minute.

I found that pressing the start buttons wasn't working anymore.
It turned out to be a sticky 'stop' push button.  A quick squirt with WD 40 and we were back in business.

So, it lives.  then the series two problems started. More on that later.

A quick question to anyone who has a similar machine.
On the top there is an oil fill plug. But no apparent level glass. Anyone know how you check the oil on the headstock ?
The gearbox has both filler plug and sight glass.

Dave.

[John Rudd]

Interesting story....great to hear a bit about how other folk acquired their machinery and the toil and trouble caused when installing them....sadly I have nothing to offer, everything I have was bought new and installed relatively easy, except for the Ajax mill I bought from ebay, but thats another story....

An esteemed colleague....? Moi?....

[chipenter]

I don't think its a fill plug on the headstock http://www.lathes.co.uk/viceroy/page3.html stands a good chance to be holdeing the cover down .

[awemawson]

Nice to hear the story BUT

 

[DavidA]

Andrew,

Pictures will follow; trust me.

Jeff,

Thanks for the link with it's most excellent picture; wish mine was as clean.

But that black object on the top really is a plastic oil filler plug. it even  has 'oil' printed on it.

The top is held down with four capscrews in the corners.

The other plug I refer to is the one on the gearbox facing down the bed, along with it's related sight glass below it.

Dave.

[Pete.]

If it's anything like mine you fill it up and it leaks down to the proper level

Really though it only needs enough to splash-feed the gears. The headstock bearings are lubed via the grease nipple behind the chuck.

[AdeV]

But that black object on the top really is a plastic oil filler plug. it even  has 'oil' printed on it.

Are you sure it's not an upside down 710 cap?

http://msgboard.snopes.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=73;t=000115;p=0

 

[SwarfnStuff]

Hi All,
 Just my thoughts on reading this post and I'm probably way off. Is it possible that the oil filler plug originally had a dip-stick attached?  As it seems to be toward the front edge it could possibly pass down clear of the spinning bits.
      Doesn't help with knowing the correct level unless it is lurking down among the sludge at the bottom.
  The linked page shows a really nice machine. Jolly good buy on your part David.

John B

[DavidA]

Ade,
That reminds me of the time when the answer to the world's energy problems was 71077345.

(works better on a pocket calculator).

Pete,

I squirted some oil down the hole just as a precaution before running it. Better a splash of oil than no oil at all.  I'm thinking of using black molly CV joint  grease for the bearing. If it can take the loading incurred with car CV joints then it should be ok.

John,

You may be right. But I have just been looking at the manual again and it says, and I quote...

...check the oilsite levels in the headstock, gearbox and the apron and fill to correct levels...

And the accompanying drawing shows pointers to the filler plugs on all three of these places; including both top of headstock and the front of the gearbox.

I'll give Denford a ring later today and see if they can help.

I do need to remove the gearbox top to take up a bit of slack in the spindle bearing assembly. That will provide an opportunity to assess the situation.

Dave.

[DMIOM]

Dave,

have you tried asking on the Denford bulletin board?    http://www.denfordata.com/bb/

Dave M

[DavidA]

Dave,

Funny you should mention that.

I've just joined the Denford forum. And immediately found the (somewhat ambiguous) answer to my problem.

Thanks for mentioning it.

Dave.

[PekkaNF]

Sometimes there is an "oil" cap even when it not used for oil:
* Once I noticed that it was used as an breather, apparently cheaper than small breather.....
* Once it was used as a plug.....same casting for oil and grease lubrication, therefore same parts....

Both cases it was for the ease of procurement and no regard to end user.

Now when I think of it - I have a cap clearly marked as "Oil" on the grinder oven when spindle is grease lubricated....

Pekka

[awemawson]

Well there's always the case where an accidental hole has been drilled in a machine table, and the perpetrator stamps 'OIL' next to it to cover his tracks 

[Pete.]

Sometimes there is an "oil" cap even when it not used for oil:
* Once I noticed that it was used as an breather, apparently cheaper than small breather.....
* Once it was used as a plug.....same casting for oil and grease lubrication, therefore same parts....

Both cases it was for the ease of procurement and no regard to end user.

Now when I think of it - I have a cap clearly marked as "Oil" on the grinder oven when spindle is grease lubricated....

Pekka

Actually Pekka, you're quite right the oil filler cap on the Synchro has a little hole in it and does double as a breather.

[DavidA]

Had one of those annoying experiences today. The kind that only seem to lead from one problem to another.

Here's what happened.

Before Christmas, when I was still working part time, I embarked on making a couple of drive shafts for my nephew's experimental electric car.  They were nothing special, just 1" BMS bars about 18 inch long.

The original intent was to make them at work where the equipment was on hand.  So  I reached the point where I needed an M16 * 2M pitch thread on one end of each bar.  no problem, Piece of cake on a Colchester 2000. This left me with the other ends. The drawing he had given me didn't specify a thread, only that it had to be 20 MM long and less than the diameter of the 1" bar. And yes, am aware that it couldn't have been larger than the bar diameter; before anyone points it out.

I settled on 22MM * 2m pitch. and again, no problem. This left only a couple of internally threaded couplings to be made to fit.

Then we got busy and I didn't have time to finish the job before I retired; for the fifth time. It would have to be done at home. and the only suitable machine was the Denford. Problem was, this machine wasn't running at the time.
Much of Christmas was spent getting the machine going.

Three days ago I settled down to make the couplings. I had noticed that the gears and the banjo for metric threading were in one of the cabinet drawers. So just a matter if swapping the Imperial set over.

I removed the Imperial banjo and it's gears.

Then discovered that although the gears and banjo were there. there was no trunnions on the banjo for the gears to run on.  Much time was spent making up replacements. They fit perfectly. and the assembly was placed in position. Only to find that the banjo securing bolt that came with the imperial set is too short to hold the Metric set.  And it is 3/8" BSW to screw into the gearbox. And I don't have a longer setscrew. Or a 3/8" BSW die.

Gloom and despondency descends upon the shed.

'Stuff this Metric' says I.  'Enough already'.

I could cut the thread on the lathe, but this means putting the Imperial set back on. And if I am going to do that I may as well go the whole hog and re thread the bar Imperial.

So, I turned off the Metric thread, machined up a couple of tubular 1" O/D pieces to fit and welded then in place. Turned of the excess weld and am now back to where I was a week ago.

Tomorrow they get turned down to 15/16" and 11 TPI BSF.

Should have done that in the first place.

You can guess which way I am (probably) going to vote in the upcoming European referendum.

Dave.

[DavidA]

Woe, woe and thrice woe.

Just as I am getting the hang of this machine I noticed that the lead screw has around half a mm endfloat.

So now I will have to get into the gear box to take it up.

Oh yes, and while I was looking at the ancillary tools that came with it I fount that the face plate doesn't have any cam - loc pins (or retaining screws) in it.

Spoiled my whole day; that one.

Dave.

[awemawson]

.... and the pictures ......


 


Now if it's a drive shaft does one end not need to be left hand threaded ?

[DMIOM]

......Oh yes, and while I was looking at the ancillary tools that came with it I fount that the face plate doesn't have any cam - loc pins (or retaining screws) in it. ......

Dave,

Just in case you don't know, be careful when getting new pins - whilst the visible part is standardised, the threaded portion isn't - so the pins may have metric or imperial threads; and on another forum, I seem to recall John Stevenson saying at one time he had five different pin fittings!

Dave (IOM)

[Jonny]

[quote
Now if it's a drive shaft does one end not need to be left hand threaded ?
[/quote]

Kick a man when he is down 

Lead screw play wont affect accuracy going in one direction only, some are free to move.

Commiserations on having to faff about with change wheels.

Quite dear them cam lock studs, have bought Chinese D1-4 complete backing plates for less than the studs alone, worth considering.

[DavidA]

Andrew,

Pictures are coming......eventually.

The drive shaft was machined to the customers (my nephew) design.  There were a number of things that were wrong with it, and I pointed them all out to him. But he said it would be ok. So be it.

Jonny,

Yes, the lead screw will work as it is. But I don't like the idea of the shaft moving around like that. Needs fixing.

However, it will have to cut a few more threads as it is.

The only change wheels I have to contend with is the set that changes Imperial to Metric. And on the 280 Synchro you simply change the complete banjo unit. Quite easy once the thing is set up.  The gearbox then takes care of all the available pitches.

There are 72 Metric threads and 48 Imperial threads available. Who could ask for more ?

Dave,

Thanks for reminding me about the studs.

Dave.

[Pete.]

On the metric Synchro there should be a stack of five gears on a bolt under the end cover. Six gears in total (five on the bolt and one on the banjo) stamped A-G and you choose the right gear according to the threading chart.

[DavidA]

Pete.

My Synchro is Imperial.

I did have one of those 'so that's how it works' moments today while looking at the gear train.

As I mentioned, the machine has 48 Imperial pitch choices.   From 4 tpi to 28 tpi and then another range to cover the rest.
I just worked out how it does this.  On the banjo there is a sliding gear. it normally gives a straight through 1:1 drive to the gearbox.
If you slide this 'quad gear' out into it's other position it changes the the ratio to 8:1 . So all the lower tpi are multiplied by 8 to give 32 tpi to 224 tpi. Neat!

I just wish it had a clutch reversing system. Save all the stop - start on the motor. But I suppose you can't have everything on one machine.

Dave.

Typo edit

[Pete.]

I knew it was imperial I just didn't realise the imperial machine does without the swappable gears. It would be great to get some photos of the drivetrain and screwcutting chart I can't find a single example despite extensive searching.

[awemawson]

.... ah photos .... now there's a good idea .... Dave 

 

[DavidA]

Even as you read this I am trying to get my camera (Fuji Finepix S3000) running so that I can use it'sMacro facility to get some pictures.

This camera has something of an unreliability  history, and I don't altogether trust it.

I do have a variety of other cameras, but non that will let me get really close.

Dave.