clarke cl500 improvements

[john halfpennyParticipant @johnhalfpenny52803]

There was an article in MEW maybe 10 years ago which described one persons take. I did it slightly differently. The main casting is reversible on the bed, and the barrel bore is plain, so the barrel can also be reversed. You will need to substitute some M10 or M12 left hand thread (easy to get on ebay) to keep rotation of the tailstock handle in the same sense. The barrel clamp is moved to the top by adding a square block to the back of the tailstock housing and drilling a through bore down at the interface. You will need to lightly skim or file the casting flat where the block attaches. If you dismantle your tailstock, it should all be clear. Photos follow.

[john halfpennyParticipant @johnhalfpenny52803]

Pictures show the block for the barrel clamp, and a spare screw which I made for a colleague with the same lathe, but havn't delivered due to lockdown.

john halfpenny on 29/01/2021 09:05:33

Edited By john halfpenny on 29/01/2021 09:07:34

Edited By john halfpenny on 29/01/2021 09:11:13

[Stuart Cox 3Participant @stuartcox3]

Thanks John, that's very helpful! I will give it a go and see how I get on. Just out of curiosity do you find you have less rigidity when the tailstock is at full reach? The only reason I ask is there is obviously more overhang from the base of the tailstock.

Thanks Stuart

[john halfpennyParticipant @johnhalfpenny52803]

Not noticed any change in rigidity – mostly drilling, so no problem. It's a worthwhile mod if you lose some clearance due to a DRO, which you can see in my pics on the tailstock side of the saddle. Also, you may want to adjust the length of the screw to get full barrel travel – I pushed mine up from 35 to 50mm. I recall needing to fiddle with length of the screw to get the barrel zero mark aligned with the mouth of the bore when the barrel is fully reversed – not absolutely necessary, but satisfies my ocd.

[john halfpennyParticipant @johnhalfpenny52803]

Stuart, you will also need to reposition the key which prevents the barrel rotating. Simply drill through the casting to the bore, and make a small hole on the opposite side to suit the key stub. The axial position is not critical, and you can see where I have plugged the hole with a button oiler. A second new oiler lubricates adjacent the handwheel, the originals being now redundant.

[Stuart Cox 3Participant @stuartcox3]

Thanks John. I will probably have some questions when I get time to have a look, hopefully I can call on you if I do?

Many thanks

Stuart

[not done it yetParticipant @notdoneityet]

That mod is OK as long as you don't want the full length of the bed for machining between centres…

It’s all a compromise.

[Stuart Cox 3Participant @stuartcox3]

Posted by not done it yet on 29/01/2021 14:47:52:

That mod is OK as long as you don't want the full length of the bed for machining between centres…

It’s all a compromise.

Its a good point! but for me it's not a forseeable problem.

Thanks NDIY

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