Increasing Machine Tool Height for Improved Ergonomics

[JellyParticipant @jelly]

Inspired by this video by Clough42, I started thinking about this problem again.

At 6'4" and a bit, I am just a bit too tall for almost every machine tool I've ever run to be ergonomic, ideally my own machines would be between 4" and 8" higher, but the relative instability and massive weight of the machines has deterred me from using riser feet for risk of them toppling as I haven't bolted my machines down.

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The way I see it, the options are:

• Riser feet and bolts,
• Concrete plinth, possibly with grout and bolts, which would be the "proper" way,
• Tall stabilising legs bolted to the machine and leveled with shims.
• A fabricated riser block which bolts to the machine base and has a skirt which bolts down to the floor, allowing the holes to be drilled after positioning the machine.

Initial I was thinking the feet option is probably the most practical one, but would still involve drilling 4 precisely positioned holes, epoxying in studs, then manouvering the machine over the bolts way up in the air.

I may of course be being too risk averse, but 8" is quite a lot of additional height in terms of negatively effecting stability, and I'm pretty sure any reduction in back and neck pain would be outweighed by the effects of even a small crush injury.

It did then occur that the feet could bolt to the machine and have a fabricated skirt or tab which bolts to the floor outside the machine's footprint allowing me to drill holes and insert anchors after the fact, which might be more practical.

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To other tall machinists: Are the ergonomic benefits worth the effort involved in raising your machines to a comfortable height?

[JellyParticipant @jelly]

[FulmenParticipant @fulmen]

I raised my lathe 4 or 6" by bolting a H-beam to the legs. It's not bolted down, so it was a simple fix. The foot brake is a bit high, but I don't have to hunch down while working anymore. Well worth the effort IMHO.

[DC31kParticipant @dc31k]

Posted by Jelly on 09/04/2023 16:46:25:

…epoxying in studs…

Female threaded glue-in anchors are available.

Use a tube with an inward lip welded on the bottom and a large washer on the bolt or stud. That will allow adjustment so you do not need to be over fussy with the holes.

Make a cap with a rim for the top with a female thread in it to attach the machine. If you doubt the ability of gravity to hold everything in place, bolt cap to tube sideways.

[Anonymous]

Posted by Jelly on 09/04/2023 16:46:25:.

…the options are:

Dig a hole in front of each machine tool?

Andrew

[Frank GorseParticipant @frankgorse]

I’m about the same height as you Jelly and I know I couldn’t work with machines at ‘standard’ heights.Apart from the effect on your back it’s harder to see what’s happening,another thing that doesn’t improve with age.

My miller stands on 6” of concrete,another one that I had was raised by 8”. My lathe is on a purpose made stand so I’ve no idea how that compares to the manufacturer’s one except that it’s a lot higher.

My advice would be to cast a concrete slab,slightly bigger all round than the base, with bolts cast in. It’s not that much work and once it’s done it’s done.

[Frank GorseParticipant @frankgorse]

I tried digging a hole in front of the machine Andrew but it just filled up with swarf.

[duncan webster 1Participant @duncanwebster1]

I stood my Chipmaster on solid concrete blocks laid on their sides to gain 150mm in height. The floor is pretty good so I didn't bother with grout, but if floor not so good I'd use some

Edited By duncan webster on 09/04/2023 18:10:34

[JAParticipant @ja]

If I dug a hole as Andrew suggests it would fill with water. At present I have a dry workshop but there is a river 50m away and the water table is always high.

However I am only 1.70m tall so I will just continue machining.

JA (who is having a metric April)

[Peter G. ShawParticipant @peterg-shaw75338]

What is a "standard height"? When I set up my present workshop, some 25 years ago, I started with the basic idea of setting the vice jaws level with my elbow. That then fixed the main bench height, and since the lathe/drilling machine bench was to be adjacent to the main bench, I made the machine bench surface the same as the main bench. That might have been a mistake, but I didn't fancy different heights.

Now, I have Ankylosing Spondilitis and I was shocked some years ago when my GP casually informed me that as a result of that disease I was now 5ft 5" as that meant I had lost 3" off my erstwhile maximum height. Since then, I suspect I've gone down a bit more. Which means that I now have to use a 5" "step up", to get me to a comfortable height to use the lathe.

In addition, following on from an idea in either ME/MEW, I've extended my bench mounted vertical drill by 4". I now have to use an old caravan step when using it for any length of time. Plus, I've added a set of mounting posts for the lathe something similar to Tubal Cain's suggestion in one of his books.

So, rather than increasing Machine Tool height, I actually need to reduce them, and indeed, my milling machine, a Sieg X2 clone, is mounted on a trolley whose worktop is quite a few inches below the other two workbench tops.

It's horses for courses, and perhaps we should, if possible, custom build our workshops individually to suit our individual heights.

Cheers,

Peter G. Shaw

[BufferParticipant @buffer]

I have done what Duncan has done. I jacked my harrison up with a toe jack and put it on 4 breeze blocks. It has made a huge difference and it's minimal effort, it took about 15 minutes.

[Niels AbildgaardParticipant @nielsabildgaard33719]

I  adjust my lathes so that centerline of crosslide spindle is at elbow heigth.

Edited By Niels Abildgaard on 09/04/2023 20:00:09

[BazyleParticipant @bazyle]

Is there an engineer in the house? If you are worried about it toppling bolt it to 4x4s or maybe railway sleepers extending forward and backward as far as makes you feel comfortable.

[Andy StopfordParticipant @andystopford50521]

I used a couple of bits of RSJ laid on their sides under my Harrison – quick and easy. Previously I'd made concrete plinths; if you do this for a lathe, its worth using one each end with a gap in between for your toes.

[Chris MateParticipant @chrismate31303]

Of the good advice I got originally talking to a german machinest was to raise the lathe, so I did the same with the mill and never regret doing that extra work.

[JellyParticipant @jelly]

Posted by Bazyle on 09/04/2023 20:03:10:

Is there an engineer in the house? If you are worried about it toppling bolt it to 4x4s or maybe railway sleepers extending forward and backward as far as makes you feel comfortable.

I had considered that, as it's something I do for safety when strapping machines down or moving them on skates… But adding two 8" tall trip hazards to a long thin workshop isn't really a very practical solution.

[JellyParticipant @jelly]

Posted by Andrew Johnston on 09/04/2023 17:19:38:

Posted by Jelly on 09/04/2023 16:46:25:.

…the options are:

Dig a hole in front of each machine tool?

Andrew

This strikes me as a rather more "agricultural" solution than your normal high standards…

[Neil LickfoldParticipant @neillickfold44316]

As long as it is stable and meets the height you need it at, is all that matters. Many ways to get the same result.

[PeroParticipant @pero]

I am a little taller than average at 6'1" and have used a variety of methods to achieve comfortable working heights for my machine tools.

The smaller bench mounted ones are raised either by raising blocks for individual machines or by raising the whole bench by means of adjustable feet.

For my round column mill ( RF31 ) I constructed a sub frame of 4" by 4" treated pine with a height adjustable foot at each corner. Metal inserts are used to ensure there is no squishing of the soft pine. There are no problems with stability with this set up.

My big lathe ( 2 tonne ) has six adjustable anti-noise anti-vibration feet which add about 4" to the overall height, again with no discernible effect on stability. It has an integral cast iron base so the CG is still quite low.

The big mill ( 1.5 tonne ) is mounted on 4 similar feet and has proven stable so far. I am about to raise the head by means of a 6" riser but, hopefully, do not anticipate any great effect on stability. If there is any issue I will extend the footprint by means of a larger rectangle constructed of heavy angle iron with the feet moved to the corners of this sub base.

Having shrunk by about an inch over the last decade, something I anticipate is likely to continue, The advantage of height adjustability to maintain comfortable working height is not to be underestimated. None of my machines are bolted down but all sit on rubber feet which are adequate to keep them in place.

Conclusion. Select the best method for the machine and your desired height. Operating at the wrong height for any length of time is a pain in the neck ( and back ) and can lead into other health problems,

Pero

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[Kiwi BlokeParticipant @kiwibloke62605]

Excuse a slight detour. Rather than standing, stooped, with aching back, at a machine, I (now) prefer to sit. I'm of average height, but my back still complains. Therefore, I like to mount bench machines on a bench/stand with knee-room below the machine. An office chair with quick-action height adjustment, and on wheels, is added luxury!

[PeroParticipant @pero]

Good thinking Kiwi!

Probably did not give it due consideration as my bench mounted machines are filled to capacity below with no room left for the knees and no floor room for the chair or even a stool.

Seated work is particularly suited when working with small machines when the required operator movement is also small. Not so good for bigger or taller machines.

As in all cases it is about choosing the best outcome for the operator.

Cheers

Pero

[HollowpointParticipant @hollowpoint]

Have you tried cutting your legs down? 😁

Edited By Hollowpoint on 12/04/2023 09:18:31

[Mike PooleParticipant @mikepoole82104]

Once a machine has reached the tipping point then a human will not be able to recover the situation, if you are lucky then escape without injury is a good result. I was thinking that anchoring to a wall or the floor with a cable could constrain the machine from reaching its tipping point rather like the tall furniture restraints recommended these days.

Mike

[KWILParticipant @kwil]

My Bridgeport is bolted to a separate "H" shaped channel section subframe, [ with a double cross bar], legs sideways,. Originally the legs carried wheels on a separate sub assembly and once in its final place, these were replaced by machine mounts for levelling. The original base of the mchine is now some 5 – 6" above the floor level.

The machine also has the wide head riser fitted. All front to back loads on the machine are within the footprint and side loads, even with the 48" table extended are adequately dealt with.

After all this I have air driven drawbar as the top of the head is quite high!!

[JellyParticipant @jelly]

Posted by Mike Poole on 12/04/2023 10:31:00:

Once a machine has reached the tipping point then a human will not be able to recover the situation, if you are lucky then escape without injury is a good result. I was thinking that anchoring to a wall or the floor with a cable could constrain the machine from reaching its tipping point rather like the tall furniture restraints recommended these days.

Mike

Yeah, ultimately if the lathe reached tipping point I'd need to be able to push it with around 8500N of force… meanwhile the average pushing force that you can exert safely is estimated at about 250N, and the world record is around 3000N.

Actually thinking about the forces involved and drawing an imaginary force diagram in my head, I realised that if the riser base was both:

1. wider than the machine base, and
2. not attached to the machine, but instead to the floor.

Then I'm not actually changing the position of the lathe's centre of mass relative to the tipping point, so it wouldn't negatively effect it's stability.

In that vein I have bought some concrete blocks which will form a suitably wide base to jack it up on.

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