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Headstock lock frozen
Posted: Sun Feb 24, 2013 6:25 pm
by donalexander
This afternoon the handle that locks the headstock to the way tubes froze on my machine. Some judicious convincing with a dead blow mallet didn't help matters and I'm wondering now if it may have made matters worse.

Fortunately for me the lock froze in an unlocked position. I have removed the motor and bottom housing and I have taken the headstock off the way tubes. It is clear that the front wedge lock has frozen to the screw that passes through the headstock.

I've sprayed it with penetrating oil and am preparing to mix a special batch of oil that supposedly outperforms what's available in the market place (I didn't believe in Evaporust either so maybe I'll be wrong twice in one week).
Anyway, i have carefully (and successfully) driven the roll pin out of the headstock lock (part 72) but I can't budge the lock off the shaft.

Any suggestions to remove the big winged lock? I figure if I can get it off, I can turn the aft wedge lock in enough to be able to remove the whole assembly. If I can't get the head stock lock off, my only choice is to cut the rod in half to remove everything.
The machine was made sometime in the mid to late 80's (serial no. 020889 and reading the list of numbers I see more than one possible year). It was build as a 510 and I upgraded it to a 520 after I bought it last year, from the original owner. My best guess was the unit had seen 10-20 hours of use (50 max). The owner said it had been stored most of the time. What little use it had seen was a bit scary - a nice "scar" on the fence, and not one adjustment in the set up was even close to square or true. I'm not sure what the stains on the tables (and the band saw) were but they came out with the right cleaner. I'm guessing he may have abused the machine (over torqued the locks, etc.). I've used it lightly for about six months after cleaning it from top to bottom, lubricating it, upgrading to the 520 fence system, and doing a thorough set up.
I'd had no problems until this afternoon. I was switching from the drum sander to sawing and I noticed the headstock was a bit stiff sliding on the way tubes. The lock had turned normally several times earlier today. The stiffness should have been a red flag but I chalked it up to the crappy condition of the tubes when I got the machine (not a basket case but some rust on the bench tubes and "gunk" on the way tubes). Everything shines now and is kept waxed - so it shouldn't have been a problem. Anyway, when I went to lock the headstock, the lock wouldn't turn.
So - any ideas how to either unfreeze the front wedge or remove the locking wing now that the roll pin is out? Either one will put me one step closer to having a working Mark V.
Posted: Sun Feb 24, 2013 7:49 pm
by charlese
donalexander wrote:This afternoon the handle that locks the headstock to the way tubes froze on my machine. Some judicious convincing with a dead blow mallet didn't help matters and I'm wondering now if it may have made matters worse.

Fortunately for me the lock froze in an unlocked position. I have removed the motor and bottom housing and I have taken the headstock off the way tubes. It is clear that the front wedge lock has frozen to the screw that passes through the headstock.

I've sprayed it with penetrating oil and am preparing to mix a special batch of oil that supposedly outperforms what's available in the market place (I didn't believe in Evaporust either so maybe I'll be wrong twice in one week).
Anyway, i have carefully (and successfully) driven the roll pin out of the headstock lock (part 72) but I can't budge the lock off the shaft.

Any suggestions to remove the big winged lock? I figure if I can get it off, I can turn the aft wedge lock in enough to be able to remove the whole assembly. If I can't get the head stock lock off, my only choice is to cut the rod in half to remove everything.
The machine was made sometime in the mid to late 80's (serial no. 020889 and reading the list of numbers I see more than one possible year). It was build as a 510 and I upgraded it to a 520 after I bought it last year, from the original owner. My best guess was the unit had seen 10-20 hours of use (50 max). The owner said it had been stored most of the time. What little use it had seen was a bit scary - a nice "scar" on the fence, and not one adjustment in the set up was even close to square or true. I'm not sure what the stains on the tables (and the band saw) were but they came out with the right cleaner. I'm guessing he may have abused the machine (over torqued the locks, etc.). I've used it lightly for about six months after cleaning it from top to bottom, lubricating it, upgrading to the 520 fence system, and doing a thorough set up.
I'd had no problems until this afternoon. I was switching from the drum sander to sawing and I noticed the headstock was a bit stiff sliding on the way tubes. The lock had turned normally several times earlier today. The stiffness should have been a red flag but I chalked it up to the crappy condition of the tubes when I got the machine (not a basket case but some rust on the bench tubes and "gunk" on the way tubes). Everything shines now and is kept waxed - so it shouldn't have been a problem. Anyway, when I went to lock the headstock, the lock wouldn't turn.
So - any ideas how to either unfreeze the front wedge or remove the locking wing now that the roll pin is out? Either one will put me one step closer to having a working Mark V.
O.K. you've got the stripped down headstock off of the way tubes. Although I'm not a premier Mark V repair guy, I've had one apart a couple of times. IMO, first, you need to get that winged handle off of the shaft. It may screw off. Penetrating oil and tapping with a ball pien hammer will help - REMEMBER, I SAID
TAPPING. Once off you need to remove the fastener on the back side. I can't remember what type of fastener is on the back (aft) side of the thru bolt, but you need to take that fastener off.
To make removal easier you should rotate the rear wedge lock toward the center, then slide the rod into the headstock.
Posted: Sun Feb 24, 2013 7:53 pm
by wa2crk
Hi
I think that the serial number is a date code. 020889 corresponds to Feb 08 1989. IIRC the handle is a left hand thread and you should try to turn it to the right to loosen it. If you are talking about the wedge locks inside the headstock those can sometimes freeze because debris and sometimes metal particles from the threads of the softer metal of the wedge can get jammed and cause the wedges to not move. This is generally caused by overtightening the lock handle. As long as you have the motor pan removed try to grab the unthreaded portion of the lock rod with a pair of vice grips and turn the handle off. (to the right)
Bill V
Posted: Sun Feb 24, 2013 9:11 pm
by beeg
When I had this happen to mine. I had to cut the rod. Then I had to order a new one and replace the front side wedge.
Similiar problem.....on a recondition....
Posted: Sun Feb 24, 2013 10:05 pm
by allsas
I had one that started to turn very hard. it seemed like the wedge was seizing the threads on the rod. I got it to ease up with graphite and waxed the threads after it released. But, it was headed down the path to seizing within just a few turns when I was trying to adjust the wedges on the rod.
Better to be cautious with this combination, ?aluminum? and steel rod. I THINK SS recommends graphite.
Posted: Sun Feb 24, 2013 10:05 pm
by donalexander
wa2crk wrote:Hi
I think that the serial number is a date code. 020889 corresponds to Feb 08 1989. IIRC the handle is a left hand thread and you should try to turn it to the right to loosen it. If you are talking about the wedge locks inside the headstock those can sometimes freeze because debris and sometimes metal particles from the threads of the softer metal of the wedge can get jammed and cause the wedges to not move. This is generally caused by overtightening the lock handle. As long as you have the motor pan removed try to grab the unthreaded portion of the lock rod with a pair of vice grips and turn the handle off. (to the right)
Bill V
Bill, The vice grip on the unthreaded portion of the rod combined with charlese's tapping almost worked. I moved the vice grip to the wedge lock, which gave a better and tighter grip, and tapped some more and voila', the parts came free!:D There was no other fastener on the back. I cleaned everything up and never could find a cause for the binding.
Having the machine apart, it looks almost unused - virtually no wear on any of the parts, including the "pork chop". I'm basically ready to reassemble but I lost one of the tinneman nuts in the process (hopefully I can find one locally). As long as its this far apart I'm going to replace the belts before reassembling it.
Posted: Mon Feb 25, 2013 6:53 am
by dusty
donalexander wrote:Bill, The vice grip on the unthreaded portion of the rod combined with charlese's tapping almost worked. I moved the vice grip to the wedge lock, which gave a better and tighter grip, and tapped some more and voila', the parts came free!:D There was no other fastener on the back. I cleaned everything up and never could find a cause for the binding.
Having the machine apart, it looks almost unused - virtually no wear on any of the parts, including the "pork chop". I'm basically ready to reassemble but I lost one of the tinneman nuts in the process (hopefully I can find one locally). As long as its this far apart I'm going to replace the belts before reassembling it.
Any good hardware store has tinneman nuts. Take one with you as a sample because there are many sizes and styles and "they all look alike". Don't buy just one; it is certain that you will need more in the future.
Posted: Mon Feb 25, 2013 10:08 am
by JPG
donalexander wrote:Bill, The vice grip on the unthreaded portion of the rod combined with charlese's tapping almost worked. I moved the vice grip to the wedge lock, which gave a better and tighter grip, and tapped some more and voila', the parts came free!:D There was no other fastener on the back. I cleaned everything up and never could find a cause for the binding.
Having the machine apart, it looks almost unused - virtually no wear on any of the parts, including the "pork chop". I'm basically ready to reassemble but I lost one of the tinneman nuts in the process (hopefully I can find one locally). As long as its this far apart I'm going to replace the belts before reassembling it.
The hole in the quill end does not use one!
P.S. "tinne
rman' nuts/clips are also available at 'good' hardware stores.
