I've Googled the group (not exhaustively however) and can't find
any reference to the use of these 'casters' to replace miter slot
bars and was wondering if anyone has ever done this before. Also would
like suggestions for other WW applications (besides work infeed/outfeed
support) for these casters and/or comments or criticisms of my idea for
utilizing them.
Recently came into a bunch (as in lots and lots) of 'ball
casters' or 'ball transfers' or as Woodcraft calls them 'ball
bearing work rollers'. They had obvious WW applications for
large/long work support. . Woodcraft sells a flange model but these
are stud mounted with a threaded bolt out the back. Various styles are
available at McMaster Carr. In the process of utilizing some as an
outfeed support, I noticed that they set into and rolled nicely in the
miter slots of the TS. The photos here
http://photobucket.com/albums/v697/mike72903 show a simple sled that
uses four of the rollers as guides in the slots instead of miter bars.
A box joint jig I designed to utilize the sled is installed on the sled
front. The sled is remarkably stable as long as some downward pressure
is applied while pushing straight forward. There is absolutely no
detectable side to side slop and absolutely zero binding along the
length of the slots. It glides along with no effort even with heavy
pressure. The rollers on one side were mounted in slots so they would
align perfectly with the slot before final tightening. A couple of
already noted disadvantages are: If you push with a twisting,
non-centered or sideways motion without applying enough downward
pressure it can come out of the slots. Also, you lose about an inch of
cutting height because the base of the sled rides above the table top.
That wasn't an issue with the box joint jig because it mounts
vertically on the front and could be lowered or raised to wherever
it's wanted. Next I'm going to make a dual slot cutoff sled using
these rollers. Probably two rows of three or four rollers spaced so
the sled will remain stable if either sled edge runs past the TS edge.
I'll see how that works. And Yes, the finger joint jig is using
metal for the spacer finger. If anyone is interested I'll be happy
to pass along my solution for the "ultimate box joint jig".
Mike in Arkansas wrote:
> I've Googled the group (not exhaustively however) and can't find
> any reference to the use of these 'casters' to replace miter slot
> bars and was wondering if anyone has ever done this before. Also
would
> like suggestions for other WW applications (besides work
infeed/outfeed
> support) for these casters and/or comments or criticisms of my idea
for
> utilizing them.
Well there's one I haven't seen before. :-)
Sounds like it works great, but since those are metal casters on what
is now effectively a cast iron "runway", I'd check every now and then
to make certain they aren't peening the corners of the miter slots out
of shape. I think it might deform the corner slightly, which would
create a slight bump at the top of the table and inside the slot.
I don't know if this would be a problem or not. The more weight on the
casters, and the more use, the more it would be a factor. Since you're
pioneering you might want to keep an eye on it.
Dan
Hi Dan, thanks for the suggestion. I'll watch for it. Before using
the sled, I took a file and went down the corner top of each side of
both slots. Just three or four passes at 45 degrees or so to slightly
bevel and smooth out any dings. Bevels are barely visible but I think
give a better and broader surface for the casters to ride on. Mike
Not exactly sure I follow your logic about creating an index surface.
I only touched the slot corners with the file lightly. More just to
make sure there were not any dings or blemishes to effect the caster
movement than to create a bevel. I can't imagine a moderately used
sled ever causing any noticable wear particularily since there is no
friction. The caster rolls over the top of the slots, it doesn't
slide. Seems counter-intuative to me they would cause more wear than a
tightly fitting metal bar. Perhaps I just dont understand what your
referring to. Mike
It does rolls perfectly. As far as knocking the sled sideways, well
I'm not sure. It does have the two handles to hold it with and as long
as it were held firmly the worse that would happen would be to ruin
your work piece. Having said that, surely it would be more likely to
get knocked out of the slots more than miter bars would. Interesting.
Maybe small blocks on front and back of each edge that would extend
down into the slot but not touch it. That way if something happened to
dislodge the bearings, then the amount of movement would be very
limited. As far as general safety, I don't see it's any worse than the
normal risk associated with working with power tools. If you use the
handles, then certainly your hands are out of the way of the blade.
When I was using it to cut box joints, I was holding the wood to the
face with one hand and the other hand was pushing the sled forward
centered on the sled. That put my hand directly in the path of the
blade, but since the sled passes well over the blade I didn't see a
problem. However, a high enough blade would cut into or through the
sled base and you wouldn't want your hand or what then remained of it
where I was placing it. Guess it's a matter of being careful and
applying some common sense just like any potentially dangerous
situation.
On 4 May 2005 14:34:42 -0700, "Mike in Arkansas" <[email protected]>
wrote:
> Before using
>the sled, I took a file and went down the corner top of each side of
>both slots. Just three or four passes at 45 degrees or so to slightly
>bevel and smooth out any dings. Bevels are barely visible but I think
>give a better and broader surface for the casters to ride on. Mike
that riding on the corner is a no-go for me. the miter slots have 2
machined index surfaces each- the sides of the slot, perpendicular to
the top, parallel to the blade. they have enough area to provide
accuracy for a reasonable lifetime of the machine. now you've gone and
created another index surface, none to accurately, with a lot less
area, and you're riding it with a curved follower to boot.
consider this:
what happens when that surface gets a ding in it?
Probably a lot less force than needed for something that uses the T bolt in
the T slot technique that is gaining popularity.
"Robatoy" <[email protected]> wrote in message
news:[email protected]...
.
> How much force will it take to knock the sled off sideways? Like in a
> jammed situation? Is it safe?
In article <[email protected]>,
"Mike in Arkansas" <[email protected]> wrote:
> http://photobucket.com/albums/v697/mike72903 show a simple sled that
I bet it rolls just perfectly.
How much force will it take to knock the sled off sideways? Like in a
jammed situation? Is it safe?