SM205 mini mill backlash

[andrew lynerParticipant @andrewlyner71257]

I have been chasing some annoying backlash on the x axis (in particular). There is an annoying snatch at times and there is about one turn of the wheel to take up the backlash.

I took off the table and looked at the D shaped brass(?) nuts. The Y axis nut is well jammed into the apron(?) but the X axis nut has about 0.6mm slop in it. (See attachment).

I was proposing to use a brass shim to eliminate / reduce the slop. Any reason why not? I can't see how that nut can have become loose as there are no signs of damage on it. The previous owner was presumably making do with how it came from the factory.

I have moaned about the creaky nature of this forum software. It really is pre-historic. For no apparent reason it has rotated the image and. of course. the way of actually getting an image to sit here is particularly arcane. None of the other fura I use are quite so archaic – but last time I suggested improvements (e.g. a LIKE button), existing members jumped on me.

Drag and Drop is not a new-fangled idea these days.

[andrew lynerParticipant @andrewlyner71257]

Screw Nut on x axis is loose

[Dave HalfordParticipant @davehalford22513]

Posted by andrew lyner on 01/10/2021 15:23:21:

I was proposing to use a brass shim to eliminate / reduce the slop. Any reason why not? I can't see how that nut can have become loose as there are no signs of damage on it. The previous owner was presumably making do with how it came from the factory.

but last time I suggested improvements (e.g. a LIKE button), existing members jumped on me.

Drag and Drop is not a new-fangled idea these days.

The nut should be firm.

Some recollections may vary, I thought most were positive.

[John HinkleyParticipant @johnhinkley26699]

Andrew,

There's got to be more to your problem than 0.6mm end float in the nut to account for a whole turn of the wheel to take up the backlash. I would be looking at least a combination of worn leadscrew/nut combo and/or leadscrew axial location. I'm unfamiliar with your particular mill, but that much backlash should have a glaringly obvious solution, somewhere, if only one knows where to look.

As for the forum software – there was a rumour some months ago that it was going to be changed – not necessarily better, but different – to bring it into alignment with other forums in the MyTimeMedia family. The addition of a like button inevitably means a dislike one, too. A whole new can of worms and ample opportunity to sling mud, of which there's been too much of late in my opinion .

Most of us on here are of a mature age, shall we say, and have got used to its foibles and take our photos in landscape mode or manipulate them in photo editing software before uploading to an album to circumvent the rotation issue.

Good luck in your backlash hunt.

John

[not done it yetParticipant @notdoneityet]

Most of us on here are of a mature age, shall we say, and have got used to its foibles and take our photos in landscape mode or manipulate them in photo editing software before uploading to an album to circumvent the rotation issue.

A simple ploy might be to take pics in both portrait and landscape, load both into the album, use the one that provides the correct orientation – and delete the other?

Works for me, thus avoiding messing around (for a much longer time period) with photo-editing – which may (or may not) work!

[Anonymous]

Posted by John Hinkley on 01/10/2021 15:48:10:

The addition of a like button inevitably means a dislike one, too.

I don't see why. I know of at least one forum that has only a like-button.

[Anonymous]

Posted by not done it yet on 01/10/2021 18:42:34:

A simple ploy might be to take pics in both portrait and landscape, load both into the album, use the one that provides the correct orientation – and delete the other?

'old on! None of this common sense around 'ere if you don't mind. Where d'you think you are?

[andrew lynerParticipant @andrewlyner71257]

"There's got to be more to your problem than 0.6mm end float in the nut to account for a whole turn of the wheel to take up the backlash."

One mm is 1.5 turns iirc so that 0.6mm talks directly to the drive.

This afternoon, I took a 1.5mm copper strip and beat it out to around '.6mm and cut out a D shaped washer / shim. With a bit of persuasion, I got it down in the slot with the nut and it's pretty rigidly home. That seems to have taken care of the backlash for the moment. Time will tell if the copper will creep; it was work hardened after the final annealing and bashing sequence and there is no deliberate movement in there (not any more there isn't). As no one has suggested a possible problem I will leave it in there and see how it goes.

Like / dislike / informative / skeptica / glooml etc etc buttons are all available choices and the designer should consult with users and tell 'em what he's going to do.

The need to have an album for your images is crazy; that (in the same way that the lack of a like) leads to more effort and confusion. The software was clearly designed a long time ago and many of its features show it. Strange that members are pleased to accept useful new machine technology but are shy of making use of good innovations in the IT direction.

There are so many helpful and knowledgeable members on the forum that I don't let it bother me too much.

"Old??" I wonder what the average age of members is. I am up there with most of you. I suspect – but I did start using computers some while before Personal Computing was available so I refuse to le IIT intimidate me when I need to use it and I do appreciate applications that are done properly.

Already, I have found places in this thread which would have suited a 'like' but not a full reply.

 

Edited By andrew lyner on 01/10/2021 20:20:42

[John HinkleyParticipant @johnhinkley26699]

Andrew,

As I said in my reply, I'm not familiar with your mill, but now we know that the leadscrew has such a fine pitch, that would correspond to the perceived backlash. I was erroneously assuming the the screw was of the order of 2 or 3mm thread pitch.

I can only apologise for the divergence my comments on the forum software have brought. I hope you get some positive input to help you solve the problem, but in the meantime, your shimming seems to have provided a solution, albeit a temporary one.

John

 

Edited By John Hinkley on 01/10/2021 21:21:22

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