Mark 5 to Mark 7 conversion

damagi · Post by **damagi** » Wed Feb 16, 2011 5:40 pm

Ed in Tampa wrote:I fail to understand why you need teeth on both sides of the posts.
What I do see a need for is for the trunnions to be able to tilt both directions. I think that could be accomplished by cutting down on the trunnion casting to allow the table to tile in either direction.

Putting teeth on both sides means you don't need to tilt both ways. You turn the table around and the existing 90 degree tilt does what you need

JPG · Post by **JPG** » Wed Feb 16, 2011 5:48 pm

Ed in Tampa wrote:I fail to understand why you need teeth on both sides of the posts.
What I do see a need for is for the trunnions to be able to tilt both directions. I think that could be accomplished by cutting down on the trunnion casting to allow the table to tile in either direction.

After you tilt it 'to the left', what are you going to do from the 'bottom' of the table which now faces either 'up' or facing 'in'.

BTW A reversible motor would be nice here!! Or are we assuming a powerpro update as well?

Enabling the trunion to rotate 180 would be difficult with the current(and older) tables. The trunion location is off center(l-r). The Mark VII was symmetrical(l-r) and used the extension table to increase the table width on the right(away from the headstock) side.

EDIT: Y'all do realize that reversing the table also places the 'controls' on the 'back' side.

ddvann79 · Post by **ddvann79** » Wed Feb 16, 2011 6:06 pm

robinson46176 wrote:I don't understand??? Exactly why would the existing tailstock not be unusable on a conversion. ...

Sorry, I meant the headrest. The MK VII would essentially have two bases and base arms. Exactly the kind of thing hitch pins are good for.

robinson46176 · Post by **robinson46176** » Wed Feb 16, 2011 6:35 pm

The old Mark VII goes both ways (table tilt wise I mean

) And... already has a reversible motor.

See I said that they should have started with it.
It also has a rather different table tie bar that drops down in the middle and gains clearance for it by having a dip in the carriage between the way tubes. I "think" that dip in the carriage gives it a little more swing over the carriage in lathe mode. Here is a picture of the table showing the dip in the tie bar.
[ATTACH]11935[/ATTACH]
And here is a picture of my Mark VII where I "think" that you can see the matching dip in the carriage to clear the tie bar. It dips maybe an inch and that is where I think there may be increased swing. I do not know if you can use the universal tool rest on it or not. I suspect not.
[ATTACH]11937[/ATTACH]
Notice that in this picture that the kind of unique fence lock cam is released. When locked it lays flat in the notch in the end of the fence.

Probably more than you wanted to know.

.

JPG · Post by **JPG** » Wed Feb 16, 2011 8:06 pm

robinson46176 wrote:The old Mark VII goes both ways (table tilt wise I mean ) And... already has a reversible motor. See I said that they should have started with it.
It also has a rather different table tie bar that drops down in the middle and gains clearance for it by having a dip in the carriage between the way tubes. I "think" that dip in the carriage gives it a little more swing over the carriage in lathe mode. Here is a picture of the table showing the dip in the tie bar.
[ATTACH]11935[/ATTACH]
And here is a picture of my Mark VII where I "think" that you can see the matching dip in the carriage to clear the tie bar. It dips maybe an inch and that is where I think there may be increased swing. I do not know if you can use the universal tool rest on it or not. I suspect not.
[ATTACH]11937[/ATTACH]
Notice that in this picture that the kind of unique fence lock cam is released. When locked it lays flat in the notch in the end of the fence.

Probably more than you wanted to know.

.

NEVER happen!!!!!!

BTW: Yer talking a (Mark VII - Mark 5/V) to Mark 7 'conversion'!

peterm · Post by **peterm** » Wed Feb 16, 2011 10:27 pm

This interesting discussion reminded me of this Popular Mechanics article from Aug.1967:
http://books.google.com/books?id=rtMDAA ... &q&f=false

I wonder if it could be applied to a Model V with the Power Pro head.

[ATTACH]11942[/ATTACH]

The table would still have to be modified.

JPG · Post by **JPG** » Wed Feb 16, 2011 10:40 pm

prmindartmouth wrote:This interesting discussion reminded me of this Popular Mechanics article from Aug.1967:
http://books.google.com/books?id=rtMDAAAAMBAJ&pg=PA148&source=gbs_toc_r&cad=1#v=onepage&q&f=false

I wonder if it could be applied to a Model V with the Power Pro head.

[ATTACH]11942[/ATTACH]

The table would still have to be modified.

It worked there because the Mark II had table legs like a Model 10(smooth-no rack teeth). Thus reversal was simple.

damagi · Post by **damagi** » Wed Feb 16, 2011 11:57 pm

JPG40504 wrote:It worked there because the Mark II had table legs like a Model 10(smooth-no rack teeth). Thus reversal was simple.

Right. Now, the Mark VII table/carriage will fit on a Mark V set of way tubes and would allow tilting both directions. As for the motor, you could get a Mark VII motor and adapt it, or hack your existing motor to be reversible.

Ed in Tampa · Post by **Ed in Tampa** » Thu Feb 17, 2011 10:37 am

damagi wrote:Putting teeth on both sides means you don't need to tilt both ways. You turn the table around and the existing 90 degree tilt does what you need

I don't know about every table insert by mine don't line up with the arbor (front to back) if the table is turned around.

The real solution is the modification of the trunnion to allow the table to tilt in both directions.

Ed in Tampa · Post by **Ed in Tampa** » Thu Feb 17, 2011 10:47 am

JPG40504 wrote:After you tilt it 'to the left', what are you going to do from the 'bottom' of the table which now faces either 'up' or facing 'in'.

BTW A reversible motor would be nice here!! Or are we assuming a powerpro update as well?

Enabling the trunion to rotate 180 would be difficult with the current(and older) tables. The trunion location is off center(l-r). The Mark VII was symmetrical(l-r) and used the extension table to increase the table width on the right(away from the headstock) side.

EDIT: Y'all do realize that reversing the table also places the 'controls' on the 'back' side.

If you could tilt the table both right and left you wouldn't neccessarily need a reversing motor. You would just change you feed direction. However that would probably limit the width of material you routed and such. So yes a reversing motor would be nice.

When I asked the question I envisioned a Power Pro upgrade to be included in the conversion package.

After thinking about it the cost would probably be so close to the purchase price of the Mark VII it would not be practical.

As I see it you would have to replace the carriage, the maintable support tubes and trunnions, the left end cap, and powerhead and probably some more things I haven't thought of. That would leave you with the original legs, tubes and aux and floating tables. Really not a lot of cost savings.