Surface grinder improvement

[caliper]

I'm new here and delighted to find such a quantity of quality info. Perhaps someone has some ideas: I have recently acquired a 1953 Reid 6X18 automatic (chain drive) grinder. Took the table & saddle off, cleaned all ways, removed metering units (they were clogged) so lube manually. An indicator on the Pope spindle shows about 3 10ths with hard push. Properly dressed wheel produces much surface chatter (waviness) no matter what the feed speed. I've read of a wheel balancing proceedure involving a couple of aluminum tabs on the spindle but haven't tried that yet. Last thing I want to do is replace the spindle ($2K) so am looking for other ideas first. Thanks in advance.

[kwhizz]

Before Balancing.......Put the wheel on the grinder and side dress both sides from the Label out and then dress the bottom........Now that the wheel is true with the Hub assy, remove and balance....But.....With a 1953 Machine.....Who Knows???

Ken

[RICHARD ZASTROW]

caliper, chain is driving what? I've seen a Reid grinder with v-belts (converted I believe) driving the spindle, but not chains. Is the chain used in the table drive? I'm just being nosey.

Dick Z

[caliper]

The chain (about 1" wide) drives the table. A sprocket is on a shaft which is driven by a V-belt connected to a reversible 3-phase motor in the base of the machine. One thought is that the slight variations in the chain/sprocket interface may produce minute variations in table movement, thus a bad surface. However, the "chatter" I get is consistent regardless of feed speed so I don't think this is the problem, although on second thought as the chain moves across the sprocket the interaction of the chain/sprocket remains proportional to table movement. I'm going to experiment with various wheels to see if this makes any difference. All ideas are appreciated.

[RICHARD ZASTROW]

caliper, It may be the chain is worn or slack. That could produce an irregular feed rate. If the sprocket is worn, same thing. I had a similar device on an Asquith radial drill used to traverse the head on the arm, worked fine. Your application requires far more smooth travel though. How about rack & pinion? Involute tooth engagement should be smoother and steadier than chain/sprocket.

Dick Z

[caliper]

Dick: Wear is certainly a possibility. Also, the insturctions are to "not get the chain too tight" as this may cause the table to jump at the end of each stroke when in automatic mode. I think I can test this by adjusting the chain tension; easy to do as it is attached to the table ends by threaded studs into L brackets. Pull it up snug and run it by hand and see what it does. Parts are available.
Your notion of gearing would certainly be smoother but a big project. The drive shaft is about 6" from the bottom of the table, which is about 4' long. Possible adapting a timing belt and appropriate fittings? The chain rides around its sprocket (which slides on the keyed shaft which is square to the table), then up to wide rollers, then horizontally each way to brackets near the ends of the table.
Another idea is hydraulic motion: probably the best but my knowledge of that is only theoretical. Sounds interesting, though.

Bill

[RICHARD ZASTROW]

Bill, Want another addition to your "ideas from off the wall"? How about a rodless cylinder with the belt on the outside? Secure the cylinder, attach belt to the table to drive it. Would be a fairly easy plumbing job.

Dick Z

[caliper]

Dick: My (very) limited knowledge of hydraulics is showing. I don't get what a "rodless cylinder" is. I think you're talking about something on the outside of the table which is appealing as pulling the table & saddle is a hassle. If you'd be kind enough to elaborate, I'd appreciate it. I'm a patternmaker by trade but spent a bit of time in a machine shop and have a Bridgeport and a couple of pretty good lathes so could make whatever might be needed.

Bill

[RICHARD ZASTROW]

Bill, Google rodless cylinders. Brand names= SMC E-TECH; HOERBIGER; TOLOMATIC; BOCH REXROTH etc. The problem with this idea is it might cost more than replacing your existing machine with a good used one. Also, as previously mentioned above, the problem may be balancing or bearings.

Good Luck and keep us posted.

Dick Z

[toastydeath]

Change to a softer wheel?

[RICHARD ZASTROW]

Bill, toastydeath may have the answer. Could be something as simple as too hard of a wheel. We may have obfuscated the obvious. (I,ve waited since the movie "Gettysburg" to use those terms).

Keep searching out the simplest cause.

Dick Z