In the thread above about knurling tools it slightly diverged into machine capacity for a few comments (mine included), but as I do not want to hi-jack the thread further, I thought it was more appropriate to give it a thread of its own. I hope I put it in the right location, if not perhaps admin can move it.
Personally I got a bit surprised to understand that a small Unimat/MJ-189 is thought to only be useful for the softer metals but not steel, and then only in small dimensions. That is not my experience and perhaps not knowing that I have overloaded my small machine. But let´s take a look at what I have made on that machine so far.
My MJ-189:

First an example of a large turning, the aluminium disc at the back is 90 mm in diameter - as large as is possible to fit onto the spindle. Runs true and used for thin work turning where the job is stuck to the face using double-stick tape.

The second example is the foot for my version of GHT´s Universal Pillar Tool which is in fact a one-piece 70 mm diameter mild steel part - which was just about possible to fit into the 4-jaw.

It machined beautifully but took a long time to do as the diameter was larger than possible to run free over the x-slide. I first had to machine it down so the saddle/X-slide could pass.
All fitments to the arms of the UPT is done on the MJ-189 like the stem for chucks for example ...

... and with a fitted chuck ...

None of these items have posed any problems other than if I became over-enthusiastic with too fast feeds or too big cuts which normally resulted in broken drive belts - I have used a lot of those belts

Quite early I found a need for a knurling tool and quickly found the scissor type ...

... the one I pointed to in my earlier comment on knurling. This tool has served me very well so far, but is now becoming a bit loose in the arms making them want to separate from the center line. With that tool I have made the following items from EN3-type steel.

Diameter from 25 mm at the top to 15 mm at the bottom. Also some brass knobs from semi-hard brass came out nice and was put on the boring bar holder I made for the MJ-189.

This holder is square at the bottom which is more rigid than the standard rectangular holder. The bar holes in the holder are drilled with the drill in the spindel and pushed forward with the saddle to get the holes exactly on centerline. 8 and 10 mm in diameter and a sleeve for the 6 mm bar (in the hole closest).
So from my point of view, the little Unimat/MJ-189 is quite a capable machine not limited only to the softer metals, but must of course be handled according to size!
So have I overdone it?

BR
/Peter