Milling table regrind

[CarlParticipant @carl48656]

Hello all,

I am thinking of getting the surface of my new old machines table re ground as it's been standing for about 30 years, size is 26 by 9 inches. Any idea of costs to be expected or recommendations ? I'm near Bury St Edmunds.

thanks

[CarlParticipant @carl48656]

[David George 1Participant @davidgeorge1]

Hi Carl What machine is it from, is there any bad damage to the face or sides or T slots as it may be possible to repair or sort out defects and diggings before you have it ground. You also have to check wear of the dovetails etc. or do you want to have them reground as well.

David

[Peter G. ShawParticipant @peterg-shaw75338]

Seven years ago I had my minimill table reground by Brain Caddy/Slideway Services. It oast £80 for the regrind + £15 return p&p and £8.39 to send to them by a firm I will never use again. (Because it's so long ago I won't give the carrier's name as they may well have upped their game since then.)

My table is 18 in x 4 1/4 in and was very badly bowed.

HTH

Peter G. Shaw

ps I don't know if it's any better as I'm still faffing about slowly, very slowly, improving the complete machine!

[CarlParticipant @carl48656]

Thanks for the info.

Its a Hayes Diemaster and all the Horizontal surfaces suffered in storage, condensation i suspect. There are a couple of tool marks but still to be cleaned up, its the table surface that will need attention first

Carl.

[john carruthersParticipant @johncarruthers46255]

Any engine recon firms near you?
Our local firm shut down after trading for three generations. Very little they couldn't do 'for a drink' – probably why they closed? :-/

[HopperParticipant @hopper]

Yes, any engine recon shop with a Blanchard-type grinder could probably give it a lick for you.

[HopperParticipant @hopper]

Yes, any engine recon shop with a Blanchard-type cylinder head grinder could probably give it a lick for you.

[Ian S CParticipant @iansc]

I read a thread on the Pro Boards Model Engineering site of a bloke that ground the table of his vertical milling machine by holding a cup wheel in the machines spindle, and grinding it in situ, he seemed happy with it.

Ian S C

[Pete RimmerParticipant @peterimmer30576]

Grinding a mill table can often do more harm than good. A bit of surface pitting won't hurt once you've stoned the surface rust off but milling or grinding it can easily make a banana of what once was a straight table.

[Tony Pratt 1Participant @tonypratt1]

Posted by Pete Rimmer on 06/07/2018 18:05:43:

Grinding a mill table can often do more harm than good. A bit of surface pitting won't hurt once you've stoned the surface rust off but milling or grinding it can easily make a banana of what once was a straight table.

Is this from personal experience?

Tony

[Pete RimmerParticipant @peterimmer30576]

Posted by Tony Pratt 1 on 06/07/2018 18:53:03:

Posted by Pete Rimmer on 06/07/2018 18:05:43:

Grinding a mill table can often do more harm than good. A bit of surface pitting won't hurt once you've stoned the surface rust off but milling or grinding it can easily make a banana of what once was a straight table.

Is this from personal experience?

Tony

Hell no – I learned it s part of the scraping and rebuilding class.

[Mark RandParticipant @markrand96270]

I would add that there will be no benefit from grinding/milling the top of the table unless the ways are also reground/scraped flat. The ways are what control the accuracy of the mill, not the top of the table. Verify the condition of all the sliding surfaces before bothering with the cosmetic stuff.

Edited By Mark Rand on 06/07/2018 21:41:36

[MuzzerParticipant @muzzer]

My tables on my milling machines got a nasty case of surface rust from being outside over winter while the workshop was built around them. But it takes a lot of water and time to make serious ingress and I recovered them without undue grief using WD40, green scouring pads and a power sander (with hook and loop which holds the scouring pads very nicely). There remains some visual evidence if you look closely but as pointed out, once stoned flat, there's no lasting damage to the function and certainly no benefit in grinding.

After 30 years, it might be a different matter. A very light skim may be necessary if it's in a real state. What's the alternative – scrapping it? But if it's been sitting that long then it's not been getting any wear so there is an upside to it!

Murray

[PeteParticipant @pete41194]

Anyone using a cup grinding wheel, flycutter etc powered by the mills spindle while trying to correct any faults in the tables surface simply hasn't thought through how the machine functions. For one part to move within another there HAS to be some clearance. A 1" or 25 mm shaft will not fit within a 1" or 25 mm hole no matter how straight and accurately made they are or how perfect the surface finish is on both parts. Even a brand new top of the line mill will have a few thou of clearance. It has to or the table couldn't move. And once that table does move past it's balance point enough, it's own weight is going to lower the heavy end and raise the lighter end until that clearance is taken up. It's easy enough to check for anyone who doesn't believe the above facts with an indicator. A normal vertical mill can not accurately resurface it's own table. Planers, bed mills, high precision surface or slideway grinders have a fully supported table and very accurately aligned table ways for this exact reason. And because there's a multiplcation factor involved even an extremely good 2 thou clearance would get multiplied to more than that at the tables surface so you'd be cutting the tables face in a bow shape. An older mill with some or a lot of wear the problem would be even larger.

Going by the quote I got to regrind my 9" x 32" table by a very experienced grinding shop who also did this type of work from time to time I'd expect the costs would be in the 150 – 250 quid range.

[Pete RimmerParticipant @peterimmer30576]

Posted by Pete on 09/07/2018 13:06:11:

Even a brand new top of the line mill will have a few thou of clearance. It has to or the table couldn't move.

A few tenths, but not a few thou. You wouldn't even start scraping a few thou of wear unless you had no choice at all, you'd mill or grind it first then scrape it once you were closer than a thou or even half.

[Mark RandParticipant @markrand96270]

Posted by Pete Rimmer on 09/07/2018 17:47:56:

Posted by Pete on 09/07/2018 13:06:11:

Even a brand new top of the line mill will have a few thou of clearance. It has to or the table couldn't move.

 

A few tenths, but not a few thou. You wouldn't even start scraping a few thou of wear unless you had no choice at all, you'd mill or grind it first then scrape it once you were closer than a thou or even half.

 

Possibly… I scraped ten thou from the top and the bottom of my 10"x48" milling machine table. That's over a pound of cast iron. Most of that was distortion, only three thou was wear.

 

I would repeat that the top of the table is cosmetic, it's the ways that control the accuracy.

 

Second pass on the table. Half a thou at that point. Note the swarf:-

 

 

 

Edited By Mark Rand on 09/07/2018 23:53:52

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