Author Topic: Magnetic table for grinding machine?  (Read 928 times)

Offline PekkaNF

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Magnetic table for grinding machine?
« on: October 15, 2016, 10:44:07 AM »
I have normal size universal grinder and trying to lean how to use it.

Noticed that magnetic chuck would be a nice idea.

I think that relatively small and lightweigh would do. However, never havin had or even used one, desided to use some time to get my act together before shelling out some money to buy a random one.

* Do old ones wear out or break under normal use?
* Is small (I don't see myself grinding really big parts) fine or do I shoot myself on foot?
* New ones seem to be mostly permanent magnetic type, but some used ones seem to be often electromagnetic type.

Little time ago I saw one old surface grinder for sale, it had almost full table size electromagnet chuck...for 400. It was huge......

So....what should I know?

Pekka

Online sparky961

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Re: Magnetic table for grinding machine?
« Reply #1 on: October 15, 2016, 11:03:03 AM »
Caveat: My surface grinding knowledge is limited, however:

Nice, accurate grinding of long parts is difficult with hand feeding and no coolant.  BUT you can always use more "table space" for setups and additional in-situ measuring.  Go with the vice that provides the most area while still being practical.

I'm not sure about the magnetic on/off elements, but the table surface should be relatively easy (in fact, almost certainly necessary upon installation), to true up with the grinder itself.  I'd suggest that it not be the first thing you try to grind though.  As long as it's flat enough to hold a part well, forget about how parallel it is to the axes and just try surfacing a few smaller parts first, maybe in a small grinding vice.  Then once you get a feel for the machine, go at getting the vice flat/parallel.  If, as you improve your skills, you find that you didn't do it as well as you thought, just do it again.  Take off the absolutely minimum required to get a true surface.  If there's a spot that's really bad and you need to go really deep to clean it up, think about whether you can live with just avoiding that area.  It will be fine if it's out of the way.

I've only used the permanent magnet type, which I think work very well for small machines.  One benefit is that your work doesn't get launched if you have a power failure.

As I'm sure you know, but I'll remind you, YouTube is your friend.  Suburban Tool has a couple of surface grinding videos with nice little tidbits of knowledge thrown in there.

One more thing: DUST!  Obvious, but I wouldn't even try to put it in my living space or near other nice tools without really good dust collection, or perhaps coolant controls it well enough - though no fist hand experience with coolant.

I'd love to get one myself, but do have access to one at work.  Unfortunately it does not get treated like the precision machine tool it is supposed to be.

Offline appletree

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Re: Magnetic table for grinding machine?
« Reply #2 on: October 15, 2016, 12:01:21 PM »
I was always taught to dress the wheel each use and not switch off until that days work was done. not sure how important it really is but it sounds good in theory.

Offline PekkaNF

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Re: Magnetic table for grinding machine?
« Reply #3 on: October 15, 2016, 02:57:16 PM »
Thank you. I really have no experience all advice is greatly appreciated.

I checked the 2.5" SPI sine rule. It rocks 0,02 mm and the beam dips 0,01 mm on the middle on the other side. I should be able to better than that?

I have been watching those Suburban tool videos and really like his style. Not sure if he always offers the "best" way, but surely it's never the worst. I noticed that he has got some flak on rags and some other safety related stuff. But if has all his digits and both eyes left at that age - it has to coun for something!

I haven't really used it yet, but I have checked the spindle best I can, checked the motor (megger, grounding, rotation direction and stuff) and cleaned up the table ways and generally checked that the lube pump works.

I have to build a light partion and welding drapes around it, I have gramped garage and don't want dust everywhere. I had a suction fan for it, but it was way too big and gave it away. I'm looking for a smaller one.

I still have some items left, like building a self/partition on the side of the grinder. Need some self space for the grinder accessories. Might as well build narow self unit from floor to ceiling that has back of it covered with MGO plate (magnesium oxide wall board). Needs a little consideration, because I want to keep the wasted space as small as possibe, but really don't like to get stuff way too close to machine.

On the front of I was thinkking of using some PVC welding curtains. The grinder is tucked as close to as possible to garage door and there is only storage space. Lathe and milling machine are at the other end of the garage.

Anyway, I need to try it out to see in how big mess I am.

Pekka

Offline krv3000

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Re: Magnetic table for grinding machine?
« Reply #4 on: October 15, 2016, 04:38:46 PM »
hi PekkaNF its you lucky day  I do a lot of grinding  as part of my job so I will deal with the important stuff first NEVER levee the grinder running once you have dun you bit of grinding always switch it of  yes I no people will say that they don't but when the wheel is up to full speed it can look as if the wheel is not spinning so you cum a long with a peace of cloth to wipe the table dawn next mint your hand is court up in the wheel grinding wheels at that speed don't cut they burn so its harder to get treatment at A&E right that's the boring bit over there is sum good books out there on the youse of grinders next bit the table eclipse recommend having the table Servest every so often and the good working life of a table is 15 years after witch they recommend a replacement table the tables at work is Servest on a yearly bases be carful if you is grinding the table level the modern ones ant a problem the older ones  that youse brass as a in fill in the segments on the table if you have the wrong stone on IE one that's soft the stone will not cut the brass but will cut the steel so you end up with a wavy table    right the grinding of small components set then to a angel on the table with plates ether side of the component  always grind in the opeset way IE if you remove the component that you is grinding don't put it back on the table the same way turn it rawnd    hope this helps

Offline gerritv

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Re: Magnetic table for grinding machine?
« Reply #5 on: October 15, 2016, 11:07:04 PM »
You should take a look at the Deckel S1 Universal manual, it has lots of set ups for collecting dust at the source.
I am going through a similar process with my Cincinnatti Universal from 1915

Offline PekkaNF

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Re: Magnetic table for grinding machine?
« Reply #6 on: October 16, 2016, 04:15:07 AM »
krv3000 - thank you very much. I appreciate your response.

I bought the manual CD from someone who name reminds me of Marry Popkins and the word is that she is somehow related to Sir John , Earl of Bligeport & Sudspumpwater. MBE etcetera etcetera.

The manual is good at showing purpose of several mystery parts I got with the machine. It is not however a manual (schoolbook) for compelete novice like me. Least I got to use some time metal lathe at the school, but the whole secodaty school did not have a surface grinder.

Pekka

Offline gerritv

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Re: Magnetic table for grinding machine?
« Reply #7 on: October 16, 2016, 07:11:30 AM »
https://archive.org/details/textbookadvance04smitgoog has considerable information on grinding. From 1915 but the theory is the same.

Gerrit