L. H. Sparey Running Centre

[James Jenkins 1Participant @jamesjenkins1]

Hi all,

I am looking at the running centre in L. H. Sparey's book The Amateur's Lathe (pg. 57 in my copy) and contemplating whether this would make a good first middling project. It seems fairly straight forward and would be a very helpful addition to my set up. Couple of questions that maybe you can help with:

1. What do you think of the design?

2. It seems unlikely that the specified Hoffman T.E XBY & S.K.F R7 bearings are going to be available, any suggestions on replacements?

3. Cast steel seems a bit tricky to get hold of too, would silver steel be an acceptable alternative?

Many thanks for your time and look forward to hearing your thoughts.

James

[James Jenkins 1Participant @jamesjenkins1]

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

I has made the L.C Sparey running centre from The amateur's lathe. The design is good and i am very satisfied to use the running centre in many year now.

The house is made of mild steel (no important to be cast iron, hard or high alloy) and the running cone is made of silver steel.

The bearing must be selected to nearest in all dimensions ,also change the dimension in the house and the running cone to fit the bearings.

Light press fit the bearing in the house and hand push fit the running cone into the bearing. Never light press fit the running cone into the bearing due the bearing will stuck!

Fill up grease into the house before the running cone is mounted.

[James Jenkins 1Participant @jamesjenkins1]

Hi Jens,

Thank you that's really helpful. What bearings did you use?

Kind regards,

James

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

The bearing size..

Single row angular contact bearing 12x32x10 SKF 7201BEP

Deep groove ball bearing 10x26x8 SKF 6000

[James Jenkins 1Participant @jamesjenkins1]

Thank you!

[brickyParticipant @bricky]

Hi James, I made two rotating centres from his plans 40years ago and they are still going well today.Why two,at the time I was making clocks and I needed a fast speed for my flycutters which I mounted in a bar between the centres with a pulley on it and driven from a motor mounted behind this got me to over 3000 rev's and the centres stood this easily.

Frank

[RobboParticipant @robbo]

James

Like most of the designs in 'The Amateur's Lathe', Sparey first published this in 'The Model Mechanic' magazine, of which he was Editor. This one was in July 1948.

In the text he said that "As the centre revolves, it may be made of mild steel, but a steel of harder grade is preferable as this will withstand accidental damage much better. A cast steel or silver steel may be used- although the centre is not hardened………."

For those with an interest in such things I have put a copy of the 2-page article in my albums as "Sparey Running Centre"

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Robbo on 22/06/2018 09:44:49:

… For those with an interest in such things I have put a copy of the 2-page article in my albums as "Sparey Running Centre"

.

And I have grabbed a copy for reference, Thank You

… an excellent, concise description of the work.

MichaelG.

[Ian S CParticipant @iansc]

When I first got my lathe, I made a number ( probably a dozen) of running centres of a similar design (I didn't know of Sparey's book), I used what bearings I had, and made the centre from a bit of old car axle. I sold them as suitable for a wood lathe, and made them with #1, and #2 MT. $NZ 25 each twenty five years ago, not too bad for a practice exercise.

Ian S C

[Bob StevensonParticipant @bobstevenson13909]

Sparey is still good for everything but a bit dated now. If you are going to make a live centre take a look at Steve Jordan's video here as his is a more modern take that gives greater facilities, especially on small lathes…

[Michael GilliganParticipant @michaelgilligan61133]

That's neat, Bob

MichaelG.

[Alan JacksonParticipant @alanjackson47790]

Hi James,

If you look at my photos you will see a simple design I made years ago and its still working very well.

Alan

[John MCParticipant @johnmc39344]

Reading this thread makes me feel old! Made a Sparey running centre 40+ years ago when the imperial size bearings were cheap and readily available. I asked if I could make it at work during my apprenticeship, it was considered to be a good grinding exercise, so everything hardened and ground. Made it with a 2 Morse taper to suit the lathe I had at that time, sold with that lathe after about 15 years use, still going strong now.

John

[duncan webster 1Participant @duncanwebster1]

I lost the will to live part way through the You Tube, but the cross between an inside caliper and a DTI looked a useful bit of kit, anyone know it's proper name?

Of the 2 the Sparey design looks the better, the rotating part should be a tight fit in the bearings, the outers can be slip fit. Rather than the press fitted seal you can get shielded bearings

[Bill Davies 2Participant @billdavies2]

The bore gauge looks nice, Duncan. Here is a Mitutoyo version:

**LINK**

Just don't look at the price!

Bill

[duncan webster 1Participant @duncanwebster1]

I'm glad I was sitting down! However, knowing the name I searched on e-bay and found an ad for MEW99 which has an article on how to make one. Another job for the to-do list!

Edited By duncan webster on 22/06/2018 12:35:34

[James Jenkins 1Participant @jamesjenkins1]

Hi all,

I have worked through L. H. Sparey's design and modified it for modern metric bearings. I have used slightly smaller ones than Jens Eirik, to maintain the same proportions as Sparey, but taken up the suggestion of an angular bearing at the front. This will be used on a 1MT lathe, so I didn't want it to become any bigger, already, sadly, some of the lovely proportions of Sparey's 2MT design have been lost.

One ideal I did have since doing the drawing is to put a small hole up the morse taper, so as to be able to knock the shaft out when it needs cleaning (obviously then re-turning the taper).

I would be interested in any thoughts you might have or suggestions.

Kind regards,

James

[James Jenkins 1Participant @jamesjenkins1]

[James Jenkins 1Participant @jamesjenkins1]

I should have said, if anyone would like a .pdf of this design please just let me know.

James

[not done it yetParticipant @notdoneityet]

James,

Metric in this century? I note the mixed units!

[James Jenkins 1Participant @jamesjenkins1]

All my kit is imperial, so it's just more natural for me!

James

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

Posted by not done it yet on 02/11/2018 19:33:57:

James,

Metric in this century? I note the mixed units!

Very fine for newbeginner to learn and use both metric and imperial measure tools.

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

The grease nipple part 6 is not strictly necessary since the grease last very well in the rotating centre tool. The treaded hole where you added grease nipple is to hold the rotating center with the bolt while you are turning 60 degree cone on rotating centre who are new without 60 degree cone or turn the new 60 degree cone if the cone is damaged or worn out after a lot of years use.

Edited By Jens Eirik Skogstad on 02/11/2018 20:59:31

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