Pseudo Jointmatic?

[reible]

The way and table support tubes need clearance(slop) to allow easy movement.

AIUI the joint matic has the ability to raise/lower while cutting. Gorilla hands while doing so is I believe a reason for lead screw attachment failure as much as the material.

Without that ability, I question the reason for it.

The jointmatic will cut with the wood between the router bit and the base. You need to look no farther for the reason the tables get broken. For those of you familiar with the expression of a rock and a hard place will understand.

One of the big plus points of using the machine is to be able to count turns, unless you can figure out a way to duplicate this all you have is vertical router table.

Perhaps one day I will get sometime and do a project so people can see how this works. Don't have time now.

There is no reason one shouldn't or couldn't get most of the features of the system but one needs to decide what features and how much effort they want to put in to the effort. The OPR can duplicate some of them as well as being a really great over head router. It still lacks the easy crank count movement that makes a jointmatic a jointmatic.

Ed

[nuhobby]

Thanks for a very interesting topic! I have a Mk-V-mount OPR and often wondered which parts of the JointMatic I was missing functionally.

[benush26]

Dusty,

Yes, I "was" planning on using the main table for height adjustment. After reading your reply, can I presume that the deflection slop/error is because the material is resting in the edge of the table and not over the trunnion?

I guess I could clamp the router box jig to the main table and then set up the aux table with tubes and a floating table to give a wide enough surface so the pressure would be on the aux table, but that may just trade one set of errors for another, though this time the router may deflect the main table upward as the material passes through, but I would think keeping the bit pushing the material down would be neglible.

JPG,
RE: adjustability
If you mean how,
The micro adjustability would be via the micro adjust collar same as working with dados and such.
If you mean why,
I often find that the bit is just a wee whisker off and or I need the slot a tiny amount wider. One pass, adjust by the thousandths and a second pass.
If you mean something else... Like I'm set in my ways (aka rigid, inflexible and not adjustable.....). I've not a clue how to fix that

Ed,
I had never given a thought to the pressure between the router and the main table. As I give it some thought, I would presume that the bit would break first, though between the table breaking or a sharp bit spinning a 25000 rpm when it breaks, neither is a fun thought!!:eek:

Thanks to everyone for their thoughts and concerns. As soon as I figure out how to reliably secure the legs on my adjustable woodworking bench (which may take more than I can design ), I have a hankering to build some furniture and was looking for a good method for making mortises. The Jointmatic seems an easier way for "me" to accomplish that.

I guess I'll shelve the idea of making something like a Jointmatic, until I really need it.

The diversion away from my current project (the adjustable height bench) was to let me change focus until I can design a reliable leg clamp system (angle iron, wood 4x4s, cam lock, pipe clamp, hole and peg!!!! ARG!!! too many choices and no real clear path). So rather than pick one, I let my mind drift into Make a Jig Land!

Again, thanks for your thoughts. They are all appreciated.

Be well,
Ben

[JPG]

I was questioning the ability to reliably adjust to the 'milli inch' resolution when there is so much slop in the tubes.

[benush26]

I was questioning the ability to reliably adjust to the 'milli inch' resolution when there is so much slop in the tubes.

Hmmm Wouldn't the slop be the same using the adjustment collar whether cutting dado, or a non through cut or raising the table to vary the cut of the horizontal router bit?

I've run through the set up in my head and can't see much difference in the stability between this and any conventional use of the table and it's various height adjustment parameters. I can understand the pressure / torque difference between over the trunnion and edge of the table but am having no luck figuring out where the tube slop would be increased or changed. What am I not seeing? I'm sure it's something simple or basic

Be well,
Ben

[JPG]

Hmmm Wouldn't the slop be the same using the adjustment collar whether cutting dado, or a non through cut or raising the table to vary the cut of the horizontal router bit?

I've run through the set up in my head and can't see much difference in the stability between this and any conventional use of the table and it's various height adjustment parameters. I can understand the pressure / torque difference between over the trunnion and edge of the table but am having no luck figuring out where the tube slop would be increased or changed. What am I not seeing? I'm sure it's something simple or basic

Be well,
Ben

The slop is constant. The slop is greater than 0.001". I question the repeatability of the clamping to be such that the fine adjustment of the collar will not be lost. i.e. the clamping will vary more than 0.001".

Nothing wrong with the approach, but the 'slop' must be considered.

I do not know how 'sloppy' the jointmatic is, but I would expect it to be less than the main table etc..

FWIW, if I were to make a jointmatic like jig with one 'leadscrew', I would place the height adjustment force directly over the router axis. That is where the weight and opposing force from the cutter is.

[dusty]

I think we toss this term "slop" around much too freely. Just what is slop and how can it be measured?

I believe that with a standard Shopsmith setup that "slop" is all the direct result of the locks not all being properly secured.

When the five locks are all secure, how does one determine the level of "slop" that remains.

Let me go on record as saying I feel that I have no slop. If I am wrong, tell me how to determine that myself.

FLEX is a different discussion and most of that is eliminated by using the 5' tubes or some version of them to tie the tables together providing a four point (or more) stance.

[dusty]

Dusty,

Yes, I "was" planning on using the main table for height adjustment. After reading your reply, can I presume that the deflection slop/error is because the material is resting in the edge of the table and not over the trunnion?

I guess I could clamp the router box jig to the main table and then set up the aux table with tubes and a floating table to give a wide enough surface so the pressure would be on the aux table, but that may just trade one set of errors for another, though this time the router may deflect the main table upward as the material passes through, but I would think keeping the bit pushing the material down would be neglible.

JPG,
RE: adjustability
If you mean how,
The micro adjustability would be via the micro adjust collar same as working with dados and such.
If you mean why,
I often find that the bit is just a wee whisker off and or I need the slot a tiny amount wider. One pass, adjust by the thousandths and a second pass.
If you mean something else... Like I'm set in my ways (aka rigid, inflexible and not adjustable.....). I've not a clue how to fix that

Ed,
I had never given a thought to the pressure between the router and the main table. As I give it some thought, I would presume that the bit would break first, though between the table breaking or a sharp bit spinning a 25000 rpm when it breaks, neither is a fun thought!!:eek:

Thanks to everyone for their thoughts and concerns. As soon as I figure out how to reliably secure the legs on my adjustable woodworking bench (which may take more than I can design ), I have a hankering to build some furniture and was looking for a good method for making mortises. The Jointmatic seems an easier way for "me" to accomplish that.

I guess I'll shelve the idea of making something like a Jointmatic, until I really need it.

The diversion away from my current project (the adjustable height bench) was to let me change focus until I can design a reliable leg clamp system (angle iron, wood 4x4s, cam lock, pipe clamp, hole and peg!!!! ARG!!! too many choices and no real clear path). So rather than pick one, I let my mind drift into Make a Jig Land!

Again, thanks for your thoughts. They are all appreciated.

Be well,
Ben

Yes. If you apply downward pressure at the edge of the main table (especially the right edge) you can alter table tilt. The table tilt lock is not strong enough to resist that pressure (distance from the trunnion functions as a lever).

If I am doing a job where I can not accept unwanted/unexpected movement of the table, I support the edge with what amounts to an adjustable third table leg.

[JPG]

I think we toss this term "slop" around much too freely. Just what is slop and how can it be measured?

I believe that with a standard Shopsmith setup that "slop" is all the direct result of the locks not all being properly secured.

When the five locks are all secure, how does one determine the level of "slop" that remains.

Let me go on record as saying I feel that I have no slop. If I am wrong, tell me how to determine that myself.

FLEX is a different discussion and most of that is eliminated by using the 5' tubes or some version of them to tie the tables together providing a four point (or more) stance.

Agreed, I tend to use the word often, but it is not necessarily a bad thing. In the context of this thread, clearance is a more accurate term. Things which move(main table mounting posts) must have clearance or they would be jammed in the carriage bores. That small clearance gets reflected at the table as a much larger range of motion.

Also for this thread(pseudo joint matic) where the table is intended to provide vertical adjustment/movement, this clearance and the table positional variation as a result will compromise very fine tuning.

I assume that the vertical repositioning need be done while the cutter is 'cutting' and for that the lock is 'off'.

As clarification again, I only question the ability to adjust vertically repeatably to an accuracy of one thousandth of an inch. For all intents it will work probably satisfactorily for most applications, but not likely as accurate as a jointmatic.

[dusty]

How much "slop" is typical in a Mark V setup? I don't know! But, just for kicks, I would like to know and thought this might be a start at finding out.

I have the dial gauge setting on an extension table where it can measure any movement with respect to pseudo main table legs installed in the carriage. Likewise, if the carriage moves with respect to the extension table, that too will be reflected on the dial indicator.

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