Thread: Spanning beam (torsional) lathe stand for a Myford S7

I have a Myford S7 that was acquired several months ago and will need to get a stand made for it.


Space is an issue and so commercially available (off the shelf) stands are out of the question based on my search and I do not want a benchtop. I want a sliding tray below the lathe for quick cleaning.


I have been working on a spanning beam (torsional) lathe stand design that will suite my requirements within my space constraints.


So far it has been just a few design ideas in FreeCAD while I have been away from home but I have come up with what to me seems as a reasonable design, but I may have overlooked some aspects which is why I thought I pick a few brains on this.

Workbench design.JPG


The materials considered in the design are:


- RHS 100 x 50 x 5 mm (mild steel)
- SHS or U section 50 x 50 x 3 mm (mild steel)
- Angle section 50 x 50 x 5 mm (mild steel)
- Other miscellaneous items such as end caps and leveling feet.

Workbench_front and side view.JPG

Workbench_top view.JPG


The stand with lathe on top is slightly tall but me being 6 ft tall it seems to be comfortable enough for my elbow height.


The beam section is to be made of 2 pieces of RHS 100 x 50 mm stitch welded sideward to make a more efficient 200 X 50 mm beam with 50 x 50 angle iron at the ends. I could have sourced some RHS 200 x 100 mm but trying to save 50 mm additional height and 10 kg additional weight goes a long way.

Is the welded beam made of 2 side by side RHS sections a bad idea?

The beam will be bolted down to the stand (I have read that it can be direct welded but a bolted method will provide some room for adjustment) and can be shimmed with washers to counteract any twist in the stand frame it. The stand itself can be leveled using the leveling feet. I also have leveling feet for the lathe that will help remove any final twist in the bed.


Ideally a steel cabinet will live under that stand to make better use of space. Not clearly visible from the image but there is roughly a 25 mm gap on all sides between the cabinet and stand. A chip/swarf tray can be made to rest on top of the cabinet and should be easy to slide out for cleaning.

Workbench design with cabinet.JPG


Now here comes the tricky part, I am no welder and I could have come up with a bolted design but it would take me a lot of cutting, measuring and drilling. Let us not forget that the beam section needs to be welded up anyways. So I am going to have to outsource the welding part and need to find someone to do this for me.


Another concern is searching for usable scrap metal to build the workbench. If I do find scrap steel then I have to consider the time it will take to clean and prep any rust and corroded portions which is time consuming.

New steel prices are fairly steep and not everything is in-stock at all times especially RHS sections. I need to research the options for this.


Alternatively, if I find a shop to build the stand for me then I don't have to worry about much apart from paying one final invoice. Although the quality of work is hard to predict at times especially if they are rushing through jobs and they may not have an apatite for such small projects.


Any suggestions or experiences are welcome.

Hi Kafie,

I did begin to wonder if you were building a Battleship !

You don't need to use 100 mm X 50 mm RHS. The original Myford stand uses two lengths of 30 mm X 30 mm X 5 mm angle iron under the 16 SWG catch tray, across the width of the bed to support the lathe. I can get some measurements of mine for you if you want.

AJ Stock up on Grand Junction Road both fabricate and sell steel, so may be able to help you get it made.

Two thoughts on the design -

• The spanning beam from what I understand from your description is two pieces of RHS.When you bolt the lathe down, the bolts may tend to crush the tube, so you will need to put in some tube or tapped solid to secure the lathe firmly. Given what it is doing, perhaps stand some RHS on edge and attach some angle so you are bolting through the angle flange.
• A cabinet underneath is a good idea, but enclosing that space with some flat sheet metal would give you more storage and stiffen up the frame too.

Have a look at the 'Rack-it' product (https://rack-it.com.au/) available at Bunnings. It is a heavy duty slot and tab systems for storage and benches. I've often remarked that I could not buy the materials for a similar sized bench for what they charge. It may be more cost effective to make a bench from something like that and just have a welded fabrication that bolts to it to attach the lathe (you can always put a bolt through the joints to lock them up if needed)

Michael

@BaronJ
I am sure 30 x 30 x 5 mm angle iron will be stiff enough if I had a sheet metal enclosed cabinet. I was planning on a all angle iron stand but read people suggesting a SHS/RHS stand to avoid flexing in the stand.


@Michael G
Thanks for the fabrication and steel supply shop address, I will request them for a quote.


The lathe sits on these raising blocks made of cast steel that allow leveling through jacking bolts. If needed, I can run the bolts through a couple of pieces of solid bar stock on the underside of the beam section which combined with the raising blocks should evenly distribute the load rather than crushing the beam at the bolting points.

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I already have the cabinet which is full of various tooling and I have no other place to put it which is why I came up with the under stand concept. I agree, a sheet metal enclosed stand would probably be better only if I had additional space.


The Rack-It system is really value for money and I looked at it a few times at Bunnings and ran their Rack-It planner. However it does not have enough height clearance under the beams based on my rough measurements at Bunnings and I wondered how sturdy it would be without a top and without bolting it to the floor. I don’t think raising it up further by means of leveling feet is a good idea.


First world problems is my reason for a custom stand as space is a premium in my setup. I already sold my CNC milling router (took me well over 100 hours) to build/setup and my Sieg SC2 lathe with several accessories (I can’t have 2 lathes) just to make space.

Hi Kafie,

The Myford stand is basically all folded 16 SWG steel sheet with an angle iron frame round the top and another similar frame about halfway down the stand supporting a non removable shelf.

The angle Iron supports are welded across the frame at the top. There is nothing wrong with your design but you don't want to have to use lifting gear to move it, it will be heavy enough when you have the lathe on it. My lathe uses those same Myford mounting blocks and they are fine ! Though I don't particularly like the way they used the threaded studs to both fasten them to the angle iron lathe supports and then through the externally threaded height adjusters with the nuts on top to fasten the lathe down. I had to thin off a spanner in order to adjust those height adjusters.

The Myford lathe has the bed and the feet machined so that they are parallel. Very little movement of the adjusting nuts will cause the lathe bed to twist, in fact its easy to cause the bed to be twisted simply because the adjusting nuts weren't all at the same height when the lathe was fastened down.

Thanks for sharing your experience with the raising blocks.

I also never knew the bed and feet were machined parallel. Interesting but I can see why they would do this.

I did analyze several photos of the original Myford stand and learned somewhat about its construction in terms of the mixed angle iron and sheet metal construction and I am sure it more than suites the Super 7 to support its weight and provide enough stiffness. Unfortunately I can’t get something like that to work in my case as even taking out the intermediate shelf will make that construction weak.

I actually did look online and found density estimates in kg/m for the various SHS and RHS steel and the angle iron used in my design and calculated the weight of the stand to be about 55kg which is not seriously heavy IMO. I will need an extra pair of hands but I can get away without lifting equipment.

Hi Kafie,

55Kg you say ! It takes me all my strength to pick up 20Kg nowadays.

I do understand what you are saying. The prices that are wanted for steel stock is atrocious, luckily I have a friendly scrap yard not too far away.

Regarding materials, there’s often shorts of RHS on FB marketplace locally here. Definitely some big savings to be had over buying new if you can make do with what you can find cheap.

Steve

Thanks for the advice and I have been looking out for RHS scrap on gumtree/facebook lately to get an idea.

I will also explore a few scrap metal yards in the coming week or so to see if I can find something useful.

Modified the design slightly (ditched the idea of having angle iron at the ends of the beam and replaced the legs with 40x40 SHS) after discussing with the person who was helping weld the stand for me.

The stand was done in a day and ready for pickup:

DC473637-E8F8-4802-8C45-CD3D430E11C0.jpg
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Got it home Friday.
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I didn’t want to take any chances with primer/paint that comes from factory on structural steel sections fearing that the Dulux Enamel paint may not adhere to it properly.

Poly paint stripper didn’t do a good job removing the blue coating and spent a few hours sanding the remaining by hand.

AE86A051-E694-4BDE-8447-9CE56F6D8E3A.jpg

Not the best prep work but that blue coating was a pain. I could not find the wire wheel for my angle grinder and Blackwoods (the only place I know for reasonably priced SIT wire wheels) is closed on weekends, else this would have been a simpler task but that meant waiting till next week.

First time i have ever seen Blackwoods and reasonable priced used in the same sentence

Stand looks great, should work really well.

It was $30 for a 6” SIT steel wire wheel for my bench grinder and I don’t look like porcupine after cleaning rust off tools and parts.

A real SIT brass wheel costs $200 ish last I asked them and that is expensive.

Do not confuse this with the brass coated steel wire wheels sold for $30 at the common hardware stores.

And SIT is still made in Italy or EU somewhere.

$3 or 4 for key steel at Blackwoods which is fairly reasonable compared to even buying from ebay sellers.

Just a few examples.

Are you going to box it in and put in a shelf?

I have a feeling you'll be getting some vibration through those long slim legs.

I used 50x50 when I built the stand for my 12x36 and had issues, I even filled the legs with concrete and that didn't help.

IMG_1086.jpg

I guess I will find out it I have vibrations or resonance issues once its all done. If needed I may get additional bracing welded on.

I am not boxing it in and there will be no shelves as it was designed to provide clearance for a metal cabinet with tools inside that I want to isolate from the lathes primary structure.

Edit: Out of curiosity, is the lathe mounted to a spanning beam in your example? How is the lathe bolted/supported on the stand?

Originally Posted by kafie1980

I guess I will find out it I have vibrations or resonance issues once its all done. If needed I may get additional bracing welded on.

I am not boxing it in and there will be no shelves as it was designed to provide clearance for a metal cabinet with tools inside that I want to isolate from the lathes primary structure.

Edit: Out of curiosity, is the lathe mounted to a spanning beam in your example? How is the lathe bolted/supported on the stand?

Nah, not spanning beam, I welded 3 crosspieces of 75x50 at the bolt hole locations and ran bolts through them.