Evaluating Rockwell Surface Grinder?

I've purchased my lathes and milling machines used- but never owned a surface grinder.
There's a Rockwell surface grinder for sale locally, don't really "need" one, but I think it'd be nice to have one (and I'll bet I'd find uses for it).

I know that bearings are critical on these machines, but no idea on how to evaluate them? On lathes I've bought I've checked with an indicator on the spindle- is it the same process here? Other than sliding surfaces, screw backlash, etc which I know how to check- what else is critical to check to have the best chance of not ending up with a boat anchor? Not sure if it is able to be run under power, but it's 115v so there's gotta be a plug somewhere...

Thanks in advance for any suggestions for the Rockwell specifically, and surface grinders in general.

As a guy who owns a surface grinder (not a Rockwell) and uses it a lot, here's my two cents...
The best is if you can plug it in and test it. It should not be overly noisy, and shouldn't heat up beyond perhaps warmish at the spindle housing after running 15-20 minutes. Other than that, you could use an indicator and test spindle runout but mainly I'd be turning it by hand, feeling for any crunchiness, listen for anything, see if I can find any side play by hand, etc.
You could also use an indicator mounted on the spindle to check bed wear. Normally it will be somewhat heavier in the middle, as that's the most used portion of travel. What variance you'd accept is, I suppose up to you and the accuracy of work you'll be doing.

Thanks, I suppose I could deal with five-tenths, even more- for what few applications there are for it in riflesmithing (like grinding recoil lugs).
It's more about flatness for me, than whether it's within a few tenths of desired dimension.

I'm guessing flatness is dictated by the spindle bearings and table wear- and "accuracy" of the dials is in the screws like other machine tools?

Remember, the Rockwell SG does not run on spindle bearings as most do. IT is a bronze bearing, tapered, and adjustable to eliminate most slop that may develop in the bearing. IT's not a high precision machine, but is okay for most stuff. For a starter SG and not sure what one will do for you, its perfect!

Had one. Requires a " special " spindle oil for the bronze bearing. Don't remember the grade, but it's super thin.

Salem Straub is right that only a try-out will tell.
Need to see a ground finish you can accept, The feeds are smooth, the wheel head does not have any twist free play on the column, the spindle not having push or up and down play, a plane bearing may have .001 up and down when cold and the near non when warned up I think that is a plane bearing spindle and they are actually better but take a warm-up time.. pull play, you can set the wheel on a block of wood and then see the free-play in the vertical lead screw.
It is a low-end machine but in decent condition can grind well.

The up and down hand wheel location is inconvenient to reach and crank.
One easy check is to place a precision parallel on the chuck to see it lays dead flat. That tells the long travel will grind a flat part. With a honed chuck top, one can feel/see that the last chuck grinding made a flat grind, you do the at the area of the chuck close to you because that is the least used place on the chuck.

QT Salem [You could also use an indicator mounted on the spindle to check bed wear.] Actually, that kind of check can give a false impression of grinding a flat part, striking an indicator on a precision parallel shimmed to flat gives a better way flatness check.

look under and see no rusted ways..and the condition.

The Rockwell grinders also are a belt driven machine with the head and motor set up on a see-saw type assembly to fine-set height. OEM, they would have had the motor, spindle, and pulley's dynamically balanced, but if those parts are not original to the machine then you'll have to put-up with some chatter from vibration, or find a way around it.

All that said, I think they're a nice machine for a home shop or a simple second-op grinder in a pro shop. The motor/spindle set-up means that vibration balancing aside, you can put any base-mount motor you want on there. I had one that was set-up with a 110v motor, the next owner swapped it with a three phase motor and inverter to run smoother. They also have a neat feature where the column/head can pivot 360 around the base/table so you can grind at angles. They had tool sharpening fixtures available where this feature really came into play, but it could also be helpful when trying to grind up to odd features.

4GSR is right as well that the spindle's are old-school tapered bronze. That means unless the thing is totally trashed, you can adjust for any level of accuracy you need. It'll run hotter at higher pre-loads, but keep the spindle oilers in check and topped off with the right oil and it'll wear in. worst case you can get the bearing surfaces re-ground or lapped, but you'll never have to worry about buying un-obtainable bearings.

The way surfaces are also all flat and square. No dovetails or other weird geometry, so when it wears it's an easy project to re-scrape. It's the kind of machine that might not be the very best, but it'll never end up in the melting pot.

Very much appreciate the input, gentlemen.
This one seems to have been set up for tool grinding, no magnetic chuck. I'll be inspecting next week and we'll see if the stars align...

With not having a chuck ground by the grinder then there is no chance to do the parallel feel test on the chuck for flat grinding ability.

If a 110-volt machine you might take your own wheel and diamond to dress, clamp down a piece of steel and take a grind.

If the seller used the machine he should know something to tell..if he is just a machine flipper that is not so good.

likely a Rockwell did not have industrial use so if well cared for it may not have high mileage.
Some later Rockwells have bearing spindles. The spindle should not feel gritty when you hand spin it, but that alone does not prove a good spindle.

As mentioned, there are two models. The original grinders were labeled "Delta". This model is mounted on two cast iron legs. These I know little about. The later design is mounted on a steel cabinet base and is labeled as "Rockwell Delta". I have that model. It is the same basic design as the earlier model, the differences are that the spindle is mounted on preloaded ball bearings and the table has a flat and a "V". The table ways have a strip of teflon tape which makes are a smooth motion.

Tom