Odd WM18 Issue?

[Martin King 2Participant @martinking2]

[Martin King 2Participant @martinking2]

Hi All,

I have not used my WM18 for a few days after doing some light drilling on a few odd jobs.

Thought that I would spend some time on a part for my linisher project using a water jet cut hole as a rough datum. Set up my co-axial indicator and it took a LOT longer than usual to dial it in and something just did no look right.

Took a step back and suddenly noticed for the first time that the mill column was way off vertical; put an 8" piece of drill rod in the chuck and it was 1/8" out over 6"!

I have NEVER had to move the column in all the time I have had it and do not recall having any catastrophic issue recently!

I loosened the two bolts which were extremely tight and re-adjusted against a good quality square so all is now good; just cannot work out how this happened.

Also I have never noticed the item ringed in the photo, what is it please?

Cheers, Martin

[SillyOldDufferModerator @sillyoldduffer]

Odd, I expect it's been moving due to vibration.

The ringed item is the vertical lock, which is pulled to allow the column to swivel. I've decided swivelling the head on this type of mill is more trouble than it's worth because retramming the head can be a right fiddly job – when the bolts are tightened right at the end, there's an annoying tendency for the tram to shift at the last moment, and the air turns blue. Good example of a cost-cutting measure on a hobby machine. The feature works, but is a horrid time-waster.

Re-tramming, the swivelled DTI shown below gets far better accuracy than a set-square.

The tram is adjusted so the DTI reads as close a possible to zero on both the right and left hand side of the table, when the DTI is turned through 180°. The arm provides a long baseline. Arrangements like this have to be used with care because the slightest slop gives misleading measurements. The picture is posed – in practice I stiffen it up by not using the arm at maximum extension.

Dave

[Martin King 2Participant @martinking2]

Thanks Dave, I will try and do better like you show.

Martin

[HopperParticipant @hopper]

Possibly "green" castings that were not aged before being machined have now stress relieved themselves and bent into their natural shape. Common issue with Chinese machinery where they do not have the acres of space to store hundreds or thousands of castings out in the weather for six to 12 months before machining. Or the time to wait to pocket their profit. Their government could have pulled their factory's licence to manufacture by that time. It can be quite capricious on such matters, so focus in Chinese industry is even more on this quarter's bottom line than in the West.

[Brian WoodParticipant @brianwood45127]

Hello S.O.D. and Martin King,

Since tramming seems to be such a problem, why not try the method I have used for years?.

Mount a lathe faceplate [or catch plate] on the quill nose and pull that down into hard contact with the table. Bolt everything up while maintaining the contact. Job done.

A big advantage is that both axes can be set at the same time and there is no need to peer at dial indicators from the rear.

Regards

Brian

[SillyOldDufferModerator @sillyoldduffer]

Posted by Brian Wood on 25/03/2022 12:41:49:

…

Since tramming seems to be such a problem, why not try the method I have used for years?.

Mount a lathe faceplate [or catch plate] on the quill nose and pull that down into hard contact with the table. Bolt everything up while maintaining the contact. Job done.

…

Good idea. I think Brian told me that before and I forgot.

Dave

[Martin King 2Participant @martinking2]

Brian, What an excellent idea! Many thanks!

Martin

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