Angle on Mark V Main Table Changes

alan_huf2002 · Post by **alan_huf2002** » Wed Mar 30, 2011 1:14 pm

I acquired an old Mark V (500) that is a great machine. However, I have noticed a problem. Suppose I adjust the height of the table and then lock it down. The angle of the main table changes when I lock it down. Is this normal for teh older 500 tables? If not, any ideas on how to fix it?

Ron309753 · Post by **Ron309753** » Wed Mar 30, 2011 4:39 pm

Alan,

No, it is not normal. I don't know what would be causing the table tilt to change by simply raising or lowering the table in the carriage if the table tilt lock is tight. I would look at the table posts and the pinion gears in the carriage to make sure they aren’t packed with sawdust or damaged in some way. Perhaps someone with more experience can recommend a solution.

Sincerely,

Ron309753

dusty · Post by **dusty** » Wed Mar 30, 2011 4:40 pm

alan_huf2002 wrote:I acquired an old Mark V (500) that is a great machine. However, I have noticed a problem. Suppose I adjust the height of the table and then lock it down. The angle of the main table changes when I lock it down. Is this normal for teh older 500 tables? If not, any ideas on how to fix it?

This is hard (impossible) for me to understand. The depth of cut lock (table height) and the table tilt lock are two entirely different mechanism. In my opinion, there is no earthly way the two are interrelated.

I would push the head stock out of the way to the left and then center the carriage on the way tubes. I would then seat down on my stool in front of the Mark V and simply operate these functions over and over until I understood exactly what is happening.

I suspect that your table tilt lock is somehow impaired and that when you change height the table tilts (sags) on its own.

Please keep us posted on the findings/fix.

JPG · Post by **JPG** » Wed Mar 30, 2011 6:12 pm

I will hazard a guess, but a couple of pix would help us understand just what it is you are experiencing.

I am also going to assume that the table tilt lock is actually working correctly and is not contributing to the observed 'problem'.

If the table mounting tubes are sloppy in the carriage when 'unlocked' the table will tend to wobble left to right thus altering the table angle relative to the floor That wobble will be removed when the table height is locked. Thus the table can move from an unlocked wobbly position to another when locked. This is the reason it is necessary to lock all locks when measuring or changing table alignment.

However I am like Dusty, it is difficult for me to really visualize this problem. In other words all that above is guesswork.

Underdog · Post by **Underdog** » Thu Mar 31, 2011 3:27 pm

I don't have a MarkV (10er here), but I've noticed a similar thing with my older machine. Like the other gentlemen have said, my table does "shift" a bit as it is locked into place after raising or lowering. However, all is fine once locked into place.

Just make sure your true measurements are taken AFTER locking things down.

Stitch · Post by **Stitch** » Thu Mar 31, 2011 3:40 pm

allen-if all the locks were secure when the alignment was performed and then table height is adjusted does it not return to the aligned position when again locked?

Be aware that when any of the locks are released things move to an undetermined position. Alignments are valid only when everything is locked in place.

I believe that the headstock lock may be the only one that can be locked and unlocked without changing alignment characteristics.

JPG · Post by **JPG** » Thu Mar 31, 2011 5:59 pm

Stitch wrote:allen-if all the locks were secure when the alignment was performed and then table height is adjusted does it not return to the aligned position when again locked?

Be aware that when any of the locks are released things move to an undetermined position. Alignments are valid only when everything is locked in place.

I believe that the headstock lock may be the only one that can be locked and unlocked without changing alignment characteristics.

Carriage lock works the same way(identicaly on the M5/500 and similarly on a 505..520). It can cause movement.

charlese · Post by **charlese** » Thu Mar 31, 2011 8:27 pm

Ahh - a wee bit of disagreement. As Nick pointed out in one of the sawdust sessions, the headstock is prone to shift/raise a little when tightened down. I was glad to hear this as I had thought maybe mine was the only one.

I've never noticed a shift in the table, but all dado/groove/tenoning operations must be set with both table and headstock locked.