M300 Cross slide jammed!

[Rannsachair]

You can shim the non-working side of the gib. A shim of a few thou thickness will bring it back within working range.

You might also want to scrape the working face to stop it sticking and allow some oil pockets to retain lubricant.

Thanks @Pete. my concern is that the jib is about 1/2" short of start of the adusting screw with the rear screw fully home, so the adjusters are doing nothing. Looks like I need a jib about 3/4" longer.

 

[Pete.]

Thanks @Pete. my concern is that the jib is about 1/2" short of start of the adusting screw with the rear screw fully home, so the adjusters are doing nothing. Looks like I need a jib about 3/4" longer.

That doesn't make sense. Unless the narrow end has snapped off. Does it look like it was cut or broken?

 

[Rannsachair]

**Language** me that's got some wear

Aye it it does, knew there was wear when I bought it, it was worse than I expected, lucky I have not had to make anything very long on it.

That doesn't make sense. Unless the narrow end has snapped off. Does it look like it was cut or broken?

There is some damage to the face of it, I will stick a post on the M300 forum to check what length the jib should be.

 

[Agroshield]

You can shim the non-working side of the gib. A shim of a few thou thickness will bring it back within working range.

Please see extract from his post below. If there is a gap to the front screw with the rear screw fully home, shimming it will only change the width (and relative position) not the overall length.

Though I Think the issue is, with the jib against the fully screwed in rear adjuster screw, there is this gap to the front screw:

If it is too short, just make one or two new longer adjusting screws so that they reach it and can do their job. That is a lot easier than sourcing a new one and then having to fit it (as in exercise the skills of a fitter) to a worn saddle and cross slide. The old one has lived and worn with all the other parts, so you either have to redo everything or put the existing stuff back together. There is not really a good halfway solution. Every man wants an extra half an inch, but what you have is more than adequate to do its job.

 

[scottmk1]

I think the depth of the pocket in the cross slide will be the limiting factor there.

 

[Brad93]

Aye it it does, knew there was wear when I bought it, it was worse than I expected, lucky I have not had to make anything very long on it.

There is some damage to the face of it, I will stick a post on the M300 forum to check what length the jib should be.

Well it's only the cross slide which won't affect to much. A nice project to scrape in.

 

[Rannsachair]

I think the depth of the pocket in the cross slide will be the limiting factor there.

Thats the problem, think I would need to make a washer with a lug where the gib strip sits and a pin on the lug to push against the jib.

 

[scottmk1]

Probably. I'm not at home right now so cant check the length of the gib but it shouldn't be too much shorter that the cross slide casting

 

[JimmyS]

Mines just over 15 inches long

 

[RichardM]

Until you find a new gib, is it possible to put it in the 4 jaw and drill and tap both ends, then loctite socket head screws into both ends to elongate the gib and get the adjuster screws to have something to work against?

 

[Rannsachair]

Until you find a new gib, is it possible to put it in the 4 jaw and drill and tap both ends, then loctite socket head screws into both ends to elongate the gib and get the adjuster screws to have something to work against?

nice idea, will see how hard it is.

 

[Pete.]

Before you do the above tap the gib in gently and see which end is actually short. No sense packing out the thick end if the thin end is missing a chunk.

 

[daedalusminos]

New gibs are available from 600 group...

Sit down....

£150 + postage + VAT

Edit, it might be £150 inclusive...the gib is supplied over length and obviously needs scraping in

 

[500e]

Seems cheap

3 x 5/16 unf
2 we took out incorrect

 

[Munkul]

For what it is, I'd work out where the gib sits when adjusted right (middle? Nearer one end?) and drill and tap the short end(s) for a dummy bit of metal for the adjuster screws to snug against.
From what I see there, nothing is wrong apart from the gib having a broken off end (it absolutely should not be that short) and possibly it's worn excessively because of that broken surface... But what's done is done, and as long as there are np sharp edges on it, it'll still do a job.
The "proper" way i suppose would be a new gib scraped in.

 

[scottmk1]

Here’s one on eBay

HARRISON M 300 CROSS SLIDE GIB STRIP AND ADJUSTING SCREWS USED | eBay

Find many great new & used options and get the best deals for HARRISON M 300 CROSS SLIDE GIB STRIP AND ADJUSTING SCREWS USED at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

 

[daedalusminos]

There is some damage to the face of it, I will stick a post on the M300 forum to check what length the jib should be.

Standard gib is 390mm, replacement oversize is approx. 440mm.

 

[Rannsachair]

Standard gib is 390mm, replacement oversize is approx. 440mm.

Mine is 325mm long! So 65mm short on narrow end.

 

[Rannsachair]

Here’s one on eBay

HARRISON M 300 CROSS SLIDE GIB STRIP AND ADJUSTING SCREWS USED | eBay

Find many great new & used options and get the best deals for HARRISON M 300 CROSS SLIDE GIB STRIP AND ADJUSTING SCREWS USED at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

Does not post to the Highlands, I have messaged the seller.

 

[pawsnizzy]

Does not post to the Highlands, I have messaged the seller.

Can't one of us bid and send it onto you?