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View Full Version : Reid #2 Surface Grinder ?s



customcutter
07-22-2012, 09:30 PM
I bought a Reid surface grinder years ago, when I was making custom knives. It replaced a smaller unit that was "manual". The "automatic feed" on the Reid was a welcome addition.

However, I found that when I made "cuts" when the material was less than 1/8" thick that the "head" didn't always feed down properly. Also the closer the head got to the chuck the worse the problem got. I'd be taking off .002 at a time, and all of a sudden the head would drop nearly .010" in the middle of a pass. Once it actually threw the blade off of the chuck.

I tried taking it apart several times and trying to find the problem. I'm thinking the vertical "ways" are slightly worn and as the head drops it is more likely to stick. I had been using a grinding wheel that was worn down to 6.5" from 8". I guess the simple solution would be to replace the grinding wheel? Is this a common problem with surface grinders? Other suggestions?

thanks,
Ken

duckman
07-23-2012, 12:29 AM
Its not a perfect solution but lower the head into position, mount an indicator on the column to the head, zero the indicator, lower the head and then raise the head back up to zero, now it can't drop. Do the math for feet per minute for each wheel size 8" X 3.1416 X RPM (divided X 12) = sfpm , 6.5" X pi X RPM / 12 = sfpm notice that there is a big difference , this why I like using my grinder with a VFD, the proper solution is to find whats allowing the head to drop it only takes as little as .0015" to bind the head and when you start grinding the slight vibration that is there allows the head to drop.

oldtiffie
07-23-2012, 01:05 AM
Ease the vertical (grinding head) dovetail until the head moves down freely - with no "sudden drops - and no "play".

Many surface grinder heads are suspended and rely on the weight of the head and the setting of the dove-tail for smooth and accurate operation.

Same applies to many square column mill milling heads too. My HF-45 mill is prone to it but my Sieg X3/SX mills are not (they are as smooth as glass)

loply
07-23-2012, 08:32 AM
This sort of behaviour can be caused by the gibs being loose or too tight.

I'm assuming the head rides on dovetails and has an adjustable gib of some kind.

If the gib is loose then the head is sitting at an angle relative to the dovetails and so jams up and jumps instead of sliding smoothly, if it's too tight then there's too much friction and the nut/screw will give a bit before a sudden movement occurs.

The general procedure is to pop a DI on the head, loosen the gib up, then crank it up and down measuring the backlash. Increase gib pressure steadily and the backlash will drop, then begin to climb again. You want to set the gibs at the lowest point of backlash.

customcutter
07-23-2012, 08:01 PM
Its not a perfect solution but lower the head into position, mount an indicator on the column to the head, zero the indicator, lower the head and then raise the head back up to zero, now it can't drop. Do the math for feet per minute for each wheel size 8" X 3.1416 X RPM (divided X 12) = sfpm , 6.5" X pi X RPM / 12 = sfpm notice that there is a big difference , this why I like using my grinder with a VFD, the proper solution is to find whats allowing the head to drop it only takes as little as .0015" to bind the head and when you start grinding the slight vibration that is there allows the head to drop.

Duckman: Raising/lowering the head and reading an indicator I guess would work, but a major PITA when removing .020 from a piece of stock .002 at a time. Also having to flip the stock over to avoid warping.

I'm assuming the VFD allows you to "over" speed the motor to make up the lost FPM due to smaller diameter?

The head just drops suddenly during the grinding operation, it's not a matter of the motor vibration due to start up causing it to fall.

thanks,
Ken

customcutter
07-23-2012, 08:09 PM
Ease the vertical (grinding head) dovetail until the head moves down freely - with no "sudden drops - and no "play".

Many surface grinder heads are suspended and rely on the weight of the head and the setting of the dove-tail for smooth and accurate operation.

Same applies to many square column mill milling heads too. My HF-45 mill is prone to it but my Sieg X3/SX mills are not (they are as smooth as glass)

Oldtiffie:

I've never felt any slop or drop in the head. I'm assuming that the machine simply relies on the weight of the head to lower it as the "feed" screw is lowered. I'm pretty sure this machine has square ways, I don't remember them being V shaped or dovetailed. I don't even remember if there is an adjustable gib to "tension" with. I'm just "researching" for the next time I decide to tear into it.

thanks,
Ken

customcutter
07-23-2012, 08:19 PM
This sort of behaviour can be caused by the gibs being loose or too tight.

I'm assuming the head rides on dovetails and has an adjustable gib of some kind.

If the gib is loose then the head is sitting at an angle relative to the dovetails and so jams up and jumps instead of sliding smoothly, if it's too tight then there's too much friction and the nut/screw will give a bit before a sudden movement occurs.

The general procedure is to pop a DI on the head, loosen the gib up, then crank it up and down measuring the backlash. Increase gib pressure steadily and the backlash will drop, then begin to climb again. You want to set the gibs at the lowest point of backlash.

Loply:

Any chance it could be caused by using the "wrong" way oil. I just used some motor oil that was handy (ignorance, years ago, and it's been sitting the last 15 years). I'm not sure if there is any way to tension the gibs, but I'm thinking that there is "wear" in the areas where the head lowers properly, and then when it gets low enough, into the "unworn" area it is "tightening" up. Like I told Oldtiffie, right now I'm doing "research" for when i get ready to tear into it again this fall season when the grass quits growing. I'll definetly(sp) try your recommended procedure.

thanks,
Ken