Grinder – bolting down puzzle

[gerry maddenParticipant @gerrymadden53711]

I’m just starting to re-build my J&S 540 and have turned my attentions to where in the workshop I should site it. I thought that bolting it down to my concrete base would be a walk in the park but now I get close to doing that and think about the details, its not as straight forward as I thought it would be. So here are the issues:

(1) FRONT HOLES. The front feet holes are easily accessible. They are approx. 17mm diameter and I’d planned to use a piece of 12mm studding or M12 bolt into a ‘rawbolt outer’ fixed in a hole in the concrete floor. The puzzle is this. As you can see in the picture below there is no flat machined seating for the nut. In fact its quite heavily curved especially near the vertical face. Any attempt to tighten directly against this would be a mess so clearly it needs some kind of insert that locates in the 17mm hole and matches the curvature of the casting. But why didn’t the makers just put a spot-face on the casting ? What did industry do here and what have others on the forum done in this situation ?

(2) REAR HOLE  Here the hole in the casting is almost underneath the bevel drive unit. The clearance between this and the bolt hole is about 2″. The thickness of the cast foot is about the same !  So I cant install a bolt or even a piece of studding from the outside. ! It looks like I will have to lower the machine onto a stud projecting from the floor and this wont be easy, at least for me without the luxury of an overhead crane !  So again, what is the normal practice in industry and small workshops

 

I imagine that many might not bother bolting the machine to the floor at all. Afterall, its pretty heavy and clearly isn’t going to go walk-about very fast. But the manufacturer stresses the the importance of solid fixing for the best performance, so this is what I want to do. I have put many hours of work into this machine and don’t want to ‘spoil the shipman for a ha’peth of tar’, at the final hurdle, so to speak. Unfortunately there is NO information in the manufacturers installation instructions on the fine details mentioned above so I look forward to you guidance.

Gerry

[BazyleParticipant @bazyle]

For the rear fixing can you first insert a short stud, then a top hat nut that reaches down to it. I would also be using plastic washers to avoid undue stress on the casting.
Since factory floors were rarely finished to a billiard table surface it was normal practice to bed machines down on a soft sand cement grout to avoid sharp points in the concrete concentrating stress on the casting.

[JasonBModerator @jasonb]

tapered washer would do the job of flattening teh sloping surfaces

[DC31kParticipant @dc31k]

One each of these:

https://www.cutwel.co.uk/m12-spherical-seating-washer-male-1890-series-er-el-1890-12

https://www.cutwel.co.uk/m12-chamfer-top-washer-female-1910-series-er-el-1910-12

As above, use a short piece of studding, then a studding connector nut then another short piece of studding at the back.

Soft sand is used for bricklaying. Sharp sand is used for grout.

I guess you may have seen the manuals available here:

http://www.vintagemachinery.org/mfgindex/detail.aspx?id=10631&tab=3

[DC31k]

On DC31k Said:

 

Soft sand is used for bricklaying. Sharp sand is used for grout.

In this case soft sand should be used so that it flows under the feet to fill the gaps not locking as sharp sand does.

[Chris CrewParticipant @chriscrew66644]

My 540 has never been bolted down, it was not bolted down by the previous owner either and he did some pretty exacting sub-contract work for the aerospace industry. Mine has three adjustable platen feet, about 8″ in diameter, which allows for levelling. The workshop base is about 8″ of concrete over hardcore. I can’t say that I have done anything so demanding as an aero engine component on it but it will grind consistently to within 0.0002″ which is good enough for me!

[not done it yetParticipant @notdoneityet]

Many flat bases were mounted on a thick sheet of felt.  Avoided much of any vibration to the sub-base.

Wedge shaped plastic washers should hold the machine sufficiently securely.

A crow bar is a simple alternative to an overhead crane?

[DiogenesParticipant @diogenes]

What wording do J&S use? ..it doesn’t really look like it was intended to be ‘fixed’ down..

[Earny49Participant @earny49]

Hi
For what it is worth: I owned a 540 awhile ago and faced a similar problem on my slightly uneven garage floor. I also had no overhead lifting gear. My solution was to jack the machine carefully and place wood packing underneath, then jack some more at the opposite side and pack there (I think jacking in three places to avoid too much tilt) until the machine base was about 5 inch off the floor.

The bolt down holes on my machine were about the same size as yours but, as I recall, they were near as dammit to tapping size for M20 so I tapped them putting the tap in from underneath the machine!! It turned out to be a …… of a job as it needed a large tap wrench and / or spanner  to drive the tap <u>upwards </u>and I remember the tap wrench handles fouling on the packings However, I persevered and after a great deal of effort ended up with three tapped holes through the base of the machine. I then obtained some M20 hex set screws about 75mm long and screwed them in from above onto some steel blocks, to take the weight off the packings and then gradually unscrewed each set screw / removed the steel blocks until I finally rested the machine on some aluminum plates about 4 “ dia and 1/2 “ thick using the ends of the M20 screw to finally level the machine.

What a rigmarole I hear you say !!  Well,  it worked for me and the machine sat on those aluminum pads/ set screws for several years until a house move forced the sale of the grinder .

David E

[Mark RandParticipant @markrand96270]

The instructions for my 1400 say:-

Since I had the grinder before I built the shed, I actually made the floor two foot thick at that end, then grouted the grinder on to it. Somewhat overkill! 😀

The rest of the floor’s only 8″ thick…

[David George 1Participant @davidgeorge1]

Being an retired  service engineer of over 50 years  in a toolroom with many of these grinders and none were bolted to the floor. I would just shim them level with square pieces of steel of various thicknesses using a crew bar to lift the machine to slide the shims under till level.

David

[Dave SParticipant @daves59043]

FWIW my 540 isn’t bolted down, or especially levelled.
I plonked it down in the corner and built a booth to contain the mess around it.

https://x.com/SolutionsByDave/status/1519768656485523457

Dont think I’ll get better than that with more effort…

Dave

[Martin KyteParticipant @martinkyte99762]

From the data sheet I would suggest that the holes are treated as jacking points rather than hold down. At 17mm there should be enough room to design a set of jacking screws with an outer Top Hat supporting the base from underneath and a centre screw for adjustment that protrudes through onto either the floor or better still a floor plate. All the adjustment can then be done from the top by holding the top hat and turning the inner stud.
regards Martin

[gerry maddenParticipant @gerrymadden53711]

Thanks chaps, I think you’ve sorted me out.

My mounting instructions don’t mention that the three holes are for levelling jacks as shown document included by Mark R above. If they had, I might have reached the only logical (and with hindsight obvious!) conclusion a bit sooner. 🙂

My floor is pretty level so when the painting is complete I’ll lower it into position and check its level-ness. If it needs anything I’ll add some plates.

Gerry

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