Engineers Level

[Mark P.Participant @markp]

Hello all,I have just aquired an old 5″ M&W level the base of which has lumps and bumps,and a very slight twist.Does the team think that I will be able to clean it up on the mill using a face cutter to get an acceptable finish? I realise that it would be better to have it surface ground,but if I get it flat fore and aft I can recalibrate it.

Pailo.

[Mark P.Participant @markp]

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Pailo, by how you have described it, I doubt you have much to loose by milling it to something acceptable. To have it reground and scraped by someone other than a volunteer would be likely to cost more than a new level.

 

The thing to think about is, is it is any good as it is, or will you make it any worse. You say that it has a sliight twist in it, which what ever method of machining is used, may unlock stresses and make other twists, unless it is heat treated to remove any stresses that may be present.

 

By milling it as you say it will only be acceptable, and can’t be called “precision”

 

I think the choice will have to be your own. Others may disagree with me of course.

 

Regards Nick.

[Chris TriceParticipant @christrice43267]

If you’ve got adjustment screws either end, and from memory I think the M&W ones might, there’s no reason you can’t true the base and then adjust it to zero again. If you’re unhappy with the surface finish you get, you could also glue a known true surface to the underside like a piece of ground stock or strip of glass and then readjust the zero position. It is still possible to level a surface with an engineers level that is slightly off by constantly turning the level through 90 degree turns. If the bubble stays in the same position, even if off centre, the surface that it’s sitting on is level. Once the surface is known to be level, you can adjust the engineers level to bring the bubble into the centre. You can keep fine tuning it until it’s spot on.

[KWILParticipant @kwil]

I would try lapping the base on a piece of very fine wet & dry (1200 Grade), placed on a sheet of plate glass. That way you will how far it is or is not out of true. I have a large and known accurate diamond lap plate (no not the usual so called diamond plate rubbish) which I have used on larger items.

[chris stephensParticipant @chrisstephens63393]

Hi Pailo,

Go for it, it is no use as it is. Using various grades of wet&dry paper on plate glass is a safer bet than machining it, but do do it in a figure of eight motion and swap end for end often.

The one feature that might not remain accurate is the V in the bottom, but I don’t suppose you will be setting up line shafting too often, so don’t worry about it.

If you have three engineers jacks, you can use them to set a piece of plate glass, or similar, to be perfectly level, as other have said, and then readjust your level. When you do this you will find out how precise your level is. I put a new bubble in my 12″, make your own jokes up and keep them to yourselves, and found that atmospheric dust fall upset the recalibration.

chriStephens

[Mark P.Participant @markp]

Thanks for the replys,ran the mill over it today and a swift lapping session, recalibrated it. Seems good came on bubble easily,maybe not as good as new but now very usable.

Thanks again Pailo.

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