Shopsmith Forums

I got my 1st MKV ripfence with an old MKV I got recently (I've had a MKVII for several years).
my problem is when I want to clamp the fence to the table, I turn the knob with 3- 4 turns of the wrist (not 360 degree turns of the knob) and the front clamp locks; 3-4 more turns to get the back clamp to lock down. When the fence is loose on the the table the back clamp is a full inch away from the table (see pic). Is this normal ? I would think the front and back clamps should lock down somewhat at the same time. I've looked at blowup pics of the fence and it looks the same as mine; no obvious pieces missing or out of place.

any thoughts?

The M5 rip fence 'knob' first tightens the small clamp against the back of the front rail. This draws the front 'foot' of the fence against the front of the r=table rail. This causes the fence to migrate to the correct alignment.

Additional tightening of the 'knob' will draw the rear clamp in towards the back edge of the table.

This takes more than one rotation of the 'knob'.

The rod on yours does not appear to have the double lead screw thread. That would double the amount of rotation required.

" double lead screw thread" ? What is that? How does it work?
My rip fence does have the double thread nut (#222 on SS ripfence exploded diagram).
ARe they the same? Can I adjust it? If so, how?

A 'normal screw thread has one spiral thread. A double lead screw thread has two spiral thread.This increases the distance a 'nut'(or a whatever it is threaded into) travels with one revolution of the screw shaft. A distinguishing detail is there are two thread starts. I know, not very descriptive. Yes it can be adjusted to reduce the 'at rest' clearance of the rear clamp. Just be sure the whole thing operates as described above.

Here is a thread with a lot of info about how the MKV 500 fence should work.

viewtopic.php?t=23391&start=20

Near the end of this thread is a link to video which I posted showing how mine works. It is hosted on Dropbox, and you should not have to sign in to view. Just close the window asking you to sign in or join and the video should be playable.

Thanks for the info and the links.
I compared mine to all your info and I think it's all normal.
br549, I watched your video and you turned the knob several times to lock both clamps.

So, to confirm, are 7-8 turns of the wrist to lock both clamps normal or excessive?

I think it is normal, based on my experience.

However, since each person's amount of turning with each wrist action varies (mine is closer to 10 or 12), I tried counting the actual number of knob revolutions. With the fence starting as loose enough to be easily lifted off of the table, I count between 4 and 4.5 complete turns to tighten both the front and rear clamps.

br549 thanks. I guess that's another reason why I like my MKVII better. Just push the fence into the table and lock the lever down. Done.

I sympathize with you since I like having the Pro Fence system of the Mark V 520, Mark 7 and Mark 4 and only having to flip two levers to lock the fence.
I have not owned a Mark VII, so I have yet to use its fence. You can get rid of some of that turning of the lock handle with the Mark V 500 Rip Fence upgrade. Like the 510/505 fence it uses handle rotation to lock the front lock and a lever to lock the rear lock. Plus, you get a "T" track on the fence top for attachments.