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Default Cheap Linear Bearing Solution

I'm still struggling with my X,Y tables for my H-mortiser. I've tried
full extension drawer guides and they had way too much vertical
slop. I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. Four bushings total inserted into two separate equal
lengths of wood. The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


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On Sep 28, 5:30*pm, GarageWoodworks
wrote:
I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop. * I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. *Four bushings total inserted into two separate equal
lengths of wood. *The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


Give these guys a look. A lot of their stuff is very reasonable.

http://www.technocomponents.com/
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On 9/28/10 4:30 PM, GarageWoodworks wrote:
I'm still struggling with my X,Y tables for my H-mortiser. I've tried
full extension drawer guides and they had way too much vertical
slop. I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. Four bushings total inserted into two separate equal
lengths of wood. The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


I haven't really been following, but the rod/guide description sound a
lot like what's in the arm of my RAS. Those concave guide bearings that
would fit snug on the proper size steel rod are all over the net and
ebay for cheap.

google RADIAL ARM SAW CARRIAGE BEARINGS

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-MIKE-

"Playing is not something I do at night, it's my function in life"
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Default Cheap Linear Bearing Solution

On Sep 28, 5:30*pm, GarageWoodworks
wrote:
I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop. * I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. *Four bushings total inserted into two separate equal
lengths of wood. *The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?



I have tried similar approaches and found it less than ideal.
Mind you, you are not looking for a lot of travel so you might be able
to bang the stuff around so it will work for a bit...but linear
bearings are a breed on their own. The bushings have the wrong aspect
ratio to the rods, even when using two. The slightest bit of skew and
you jam.... and you just need one of them to do that by a couple of
thou.

I quite like Mike's idea.



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Default Cheap Linear Bearing Solution

In article ,
GarageWoodworks wrote:
I'm still struggling with my X,Y tables for my H-mortiser. I've tried
full extension drawer guides and they had way too much vertical
slop. I also looked at under-mount slides today at Woodcraft and
they too had too much slop.


You might want to look at the commercial offerings from Rollon Corp.
www.rollon.com/USA/rollon.htm

I haven't purchased anything from them, but have had discussions with
sales and engineering abut some of their _big_ stuff (multi-ton loads).
I found them _most_ helpful, even when dealing with an application that
was _way_ outside the scope of what they normally deal with. And this
was research _only_ for an admitted one-off project.

Their "mono-rail" has accuracy of +/- 0.1mm in the 'normal' precision units.
+0.000/-0.04mm in the really high-precision ones. lengths for single
sections, up to roughly 4 meters.

lots of other alternatives, too, if you need something telescoping.
Catalog data includes the data to figure out how much play there will be
in your application. Assuming you can build to the precis ion of their
gear.


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Default Cheap Linear Bearing Solution


"GarageWoodworks" wrote in message
...
I'm still struggling with my X,Y tables for my H-mortiser. I've tried
full extension drawer guides and they had way too much vertical
slop. I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. Four bushings total inserted into two separate equal
lengths of wood. The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.




About six years ago I was dealing with the same problem you are having in
making the X, Y tables. My solution was to use KV 1129 center under mount
drawer slides because I was given a couple cases of these slides. Using a
set of slides for each table gave unacceptable vertical and lateral play.
This slide has a carrier holding the ball bearing in position as the two
parts move past each other. Seeing I had so many slides I added a second
carrier to each of the drawer slide, cut the drawer slide shorter and
limited the slide travel to several inches. The result is a short travel
slide supported by ball bearing throughout most of its travel with no
lateral and vertical play.

Saw dust has not been a problem yet.

Works for me.



MGH






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On Tue, 28 Sep 2010 14:30:16 -0700 (PDT), GarageWoodworks
wrote:

I'm still struggling with my X,Y tables for my H-mortiser. I've tried
full extension drawer guides and they had way too much vertical
slop. I also looked at under-mount slides today at Woodcraft and
they too had too much slop.


How were they mounted? Were the X guides in the closed position when
the table was up against the Z gantry? Were the Y guides just a
couple inches open when the table was centered? Most joints won't be
but 2 inches in either direction, so you should have the ball bearing
glide stiffness working -for- you. Weight of the table and part
should keep them pretty much together, too. (Support that stray end
of a long table leg, bed sideboard, or whatever, though.)


I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. Four bushings total inserted into two separate equal
lengths of wood. The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


If you use old-technology, go with sintered bronze bushings and grease
or oil them, not the rods.

If you use linear motion bearings, you won't have slop and they'll
have seals around them. They're not cheap, though.

CNC routers usually use 5/8", but for the shorter tables, you could
probably get by with 7/16 or 1/2".


--
You can't wait for inspiration. You have to go after it with a club.
--Jack London
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On Sep 28, 7:57*pm, "MGH" wrote:
"GarageWoodworks" wrote in message

...

I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop. * I also looked at under-mount slides today at Woodcraft and
they too had too much slop.


I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. *Four bushings total inserted into two separate equal
lengths of wood. *The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


About six years ago I was dealing with the same problem you are having in
making the X, Y tables. *My solution was to use KV 1129 center under mount
drawer slides because I was given a couple cases of these slides. *Using a
set of slides for each table gave unacceptable vertical and lateral play.
This slide has a carrier holding the ball bearing in position as the two
parts move past each other. Seeing I had so many slides I added a second
carrier to each of the drawer slide, cut the drawer slide shorter and
limited the slide travel to several inches. *The result is a short travel
slide supported by ball bearing throughout most of its travel with no
lateral and vertical play.

Saw dust has not been a problem yet.

Works for me.

MGH


Got any more? :^P
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On Tue, 28 Sep 2010 15:21:23 -0700 (PDT), Robatoy
wrote:

On Sep 28, 5:30*pm, GarageWoodworks
wrote:
I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop. * I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. *Four bushings total inserted into two separate equal
lengths of wood. *The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?



I have tried similar approaches and found it less than ideal.
Mind you, you are not looking for a lot of travel so you might be able
to bang the stuff around so it will work for a bit...but linear
bearings are a breed on their own. The bushings have the wrong aspect
ratio to the rods, even when using two. The slightest bit of skew and
you jam.... and you just need one of them to do that by a couple of
thou.

I quite like Mike's idea.


Instead of guide bushings, consider linear plain bearings. Ones made
from Teflon are not very expensive (3/4" for $5-10). They are long
relative to shaft diameter so they avoid the jamming problem mostly.

They don't need lube and can handle high loads as long as you are
moving them relatively slowly and can tolerate more friction than you
would get with linear ball bearings (which can be quite pricey).

For a bit more money you can get self aligning versions which are a
lot more forgiving when mounting....

As this is a key part of your cool project, you don't want something
you will be constantly cursing..

HTH,

Paul Franklin


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On Tue, 28 Sep 2010 14:53:48 -0700 (PDT), Robatoy
wrote:

On Sep 28, 5:30*pm, GarageWoodworks
wrote:
I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop. * I also looked at under-mount slides today at Woodcraft and
they too had too much slop.

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. *Four bushings total inserted into two separate equal
lengths of wood. *The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


Give these guys a look. A lot of their stuff is very reasonable.

http://www.technocomponents.com/


Yeah, maybe to a guy who Festers a lot. Single rails are cheap at $15
for a 500mm, but the bearing carriage is 15 times that!

Where's the reasonable stuff? I couldn't find it.

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London
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On Sep 28, 8:02*pm, Larry Jaques
wrote:
On Tue, 28 Sep 2010 14:30:16 -0700 (PDT), GarageWoodworks

wrote:
I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop. * I also looked at under-mount slides today at Woodcraft and
they too had too much slop.


How were they mounted? *Were the X guides in the closed position when
the table was up against the Z gantry? *Were the Y guides just a
couple inches open when the table was centered? *Most joints won't be
but 2 inches in either direction, so you should have the ball bearing
glide stiffness working -for- you. *Weight of the table and part
should keep them pretty much together, too. *(Support that stray end
of a long table leg, bed sideboard, or whatever, though.)

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. *Four bushings total inserted into two separate equal
lengths of wood. *The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


If you use old-technology, go with sintered bronze bushings and grease
or oil them, not the rods.

If you use linear motion bearings, you won't have slop and they'll
have seals around them. *They're not cheap, though.

CNC routers usually use 5/8", but for the shorter tables, you could
probably get by with 7/16 or 1/2".

--
You can't wait for inspiration. You have to go after it with a club.
* * * * * * * * * * * * * * * * * * * * * * * * * * * --Jack London


I found a local company that sells sintered plain bearings at $4.50 a
pop. Very reasonable IMHO.

http://www.applied.com/apps/commerce...&mp=FB-1013-16

The rod is $13.50 for 18". i just need to think of a design that uses
the least number of plain bearings. 4/axis might be pushing it.?.

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On Tue, 28 Sep 2010 14:30:16 -0700, GarageWoodworks wrote:


I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. Four bushings total inserted into two separate equal lengths
of wood. The wood would support the table (two per axis). If I lube the
crap out of the steel rod do you think this would work? Hope this makes
sense.


That actually sounds like a pretty good solution if there isn't too much
free play.

You can get a T-bar that fits in a T-slot. If the bar was full length I
wonder how that would work?

--
Intelligence is an experiment that failed - G. B. Shaw
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On Tue, 28 Sep 2010 18:13:41 -0700 (PDT), GarageWoodworks
wrote:

On Sep 28, 8:02*pm, Larry Jaques
wrote:
On Tue, 28 Sep 2010 14:30:16 -0700 (PDT), GarageWoodworks

wrote:
I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop. * I also looked at under-mount slides today at Woodcraft and
they too had too much slop.


How were they mounted? *Were the X guides in the closed position when
the table was up against the Z gantry? *Were the Y guides just a
couple inches open when the table was centered? *Most joints won't be
but 2 inches in either direction, so you should have the ball bearing
glide stiffness working -for- you. *Weight of the table and part
should keep them pretty much together, too. *(Support that stray end
of a long table leg, bed sideboard, or whatever, though.)

I am thinking about using 4 steel rods (2 per axis) and using guide
bushings. *Four bushings total inserted into two separate equal
lengths of wood. *The wood would support the table (two per axis).
If I lube the crap out of the steel rod do you think this would work?
Hope this makes sense.


If you use old-technology, go with sintered bronze bushings and grease
or oil them, not the rods.

If you use linear motion bearings, you won't have slop and they'll
have seals around them. *They're not cheap, though.


I found a local company that sells sintered plain bearings at $4.50 a
pop. Very reasonable IMHO.

http://www.applied.com/apps/commerce...&mp=FB-1013-16


Bueno, bwana.


The rod is $13.50 for 18". i just need to think of a design that uses
the least number of plain bearings. 4/axis might be pushing it.?.


Lets see, 4 for each axis, plus a pair of rods for each, comes to $135
plus shipping, which will be heavy.

I still don't see why the ball bearing glides wouldn't work decently.

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London
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On Sep 28, 2:30*pm, GarageWoodworks
wrote:
I'm still struggling with my X,Y tables for my H-mortiser. *I've tried
full extension drawer guides and they had way too much vertical
slop.


Long-extension drawer guides will keep the motion parallel, but
aren't intended for precision positioning (there will be a millimeter
or three 'slop'). A pre-tensioned linear bearing is expensive
(even the circular plastic ferrule gizmos have to be precision-cut,
which is not an easy task in plastic).

Can you add something, like a featherboard, to provide a preload
force on the drawer glide? A hydraulic tensioner would be
ideal, like maybe a spring-assist shock absorber. You'll want
two axes, so two such will be required, along with suitable
slide plates or rollers to engage the moving part.
Some drawer glides engage balls in V-slots, you can use
two of these and apply the load pressure between the two glides.
The stationary 'plate', then, becomes a ZZZ-frame, with parallelogram
type linkage so the glides stay parallel, and the shock to keep
the load force will be anti-diagonal to the linkage.


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On 9/30/2010 4:33 PM, whit3rd wrote:
On Sep 28, 2:30 pm,
wrote:
I'm still struggling with my X,Y tables for my H-mortiser. I've tried
full extension drawer guides and they had way too much vertical
slop.


Long-extension drawer guides will keep the motion parallel, but
aren't intended for precision positioning (there will be a millimeter
or three 'slop'). A pre-tensioned linear bearing is expensive
(even the circular plastic ferrule gizmos have to be precision-cut,
which is not an easy task in plastic).

Can you add something, like a featherboard, to provide a preload
force on the drawer glide? A hydraulic tensioner would be
ideal, like maybe a spring-assist shock absorber. You'll want
two axes, so two such will be required, along with suitable
slide plates or rollers to engage the moving part.
Some drawer glides engage balls in V-slots, you can use
two of these and apply the load pressure between the two glides.
The stationary 'plate', then, becomes a ZZZ-frame, with parallelogram
type linkage so the glides stay parallel, and the shock to keep
the load force will be anti-diagonal to the linkage.


Therein above, lies the reason the JDS Multi-Router, is an expensive,
well engineered piece of precision equipment ... and worth the price for
a small production run shop.

--
www.e-woodshop.net
Last update: 4/15/2010
KarlC@ (the obvious)
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On Sep 30, 2:45*pm, Swingman wrote:
On 9/30/2010 4:33 PM, whit3rd wrote:


Long-extension drawer guides will keep the motion parallel, but
aren't intended for precision positioning..... [so] provide a preload
force on the drawer glide ....
[mount the glides to ] a ZZZ-frame, with parallelogram
type linkage so the glides stay parallel, and the shock to keep
the load force will be anti-diagonal to the linkage.


Therein above, lies the reason the JDS Multi-Router, is an expensive,
well engineered piece of precision equipment ... and worth the price


Yeah, but... a home cruftsman can change a plywood plate to
a ZZZ-frame with a Forstner bit and a few quick kerfs...
and I bought the shocks for something similar years back,
they're still in the basement...
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On 9/30/2010 5:08 PM, whit3rd wrote:
On Sep 30, 2:45 pm, wrote:
On 9/30/2010 4:33 PM, whit3rd wrote:


Long-extension drawer guides will keep the motion parallel, but
aren't intended for precision positioning..... [so] provide a preload
force on the drawer glide ....
[mount the glides to ] a ZZZ-frame, with parallelogram
type linkage so the glides stay parallel, and the shock to keep
the load force will be anti-diagonal to the linkage.


Therein above, lies the reason the JDS Multi-Router, is an expensive,
well engineered piece of precision equipment ... and worth the price


Yeah, but... a home cruftsman can change a plywood plate to
a ZZZ-frame with a Forstner bit and a few quick kerfs...
and I bought the shocks for something similar years back,
they're still in the basement...


Yeah, but ... ITMT, I'm using an MR, and yours is still in the basement.

--
www.e-woodshop.net
Last update: 4/15/2010
KarlC@ (the obvious)
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On Sep 30, 6:59*pm, Swingman wrote:
On 9/30/2010 5:08 PM, whit3rd wrote:





On Sep 30, 2:45 pm, *wrote:
On 9/30/2010 4:33 PM, whit3rd wrote:


Long-extension drawer guides will keep the motion parallel, but
aren't intended for precision positioning..... [so] *provide a preload
force on the drawer glide ....
[mount the glides to ] *a ZZZ-frame, with parallelogram
type linkage so the glides stay parallel, and the shock to keep
the load force will be anti-diagonal to the linkage.


Therein above, lies the reason the JDS Multi-Router, is an expensive,
well engineered piece of precision equipment ... and worth the price


Yeah, but... a home cruftsman can change a plywood plate to
a ZZZ-frame with a Forstner bit and a few quick kerfs...
and I bought the shocks for something similar years back,
they're still in the basement...


Yeah, but ... ITMT, I'm using an MR, and yours is still in the basement.

--www.e-woodshop.net
Last update: 4/15/2010
KarlC@ (the obvious)


IMNSHO, the MR is nothing but a grown-up, more precise and robust
Domino.
Before I got my router, the Domino would give me a Semi and the MR the
Full Chub.

g,d&r
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On 9/30/2010 6:09 PM, Robatoy wrote:
On Sep 30, 6:59 pm, wrote:
On 9/30/2010 5:08 PM, whit3rd wrote:



Therein above, lies the reason the JDS Multi-Router, is an expensive,
well engineered piece of precision equipment ... and worth the price


Yeah, but... a home cruftsman can change a plywood plate to
a ZZZ-frame with a Forstner bit and a few quick kerfs...
and I bought the shocks for something similar years back,
they're still in the basement...


Yeah, but ... ITMT, I'm using an MR, and yours is still in the basement.

--www.e-woodshop.net
Last update: 4/15/2010
KarlC@ (the obvious)


IMNSHO, the MR is nothing but a grown-up, more precise and robust
Domino.
Before I got my router, the Domino would give me a Semi and the MR the
Full Chub.

g,d&r


Eatcherheartout ...

Pssst ... Got a cnc for trade?

--
www.e-woodshop.net
Last update: 4/15/2010
KarlC@ (the obvious)
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