This is my 2x72 inch tilting belt grinder.
It can run in either vertical or horizontal mode. You'll notice when I tilt it,
the table does not tilt with it. Speaking of the table, it can be adjusted
vertically without affecting its angle. That way you're able to wear out the whole surface
of the belt evenly when it's in horizontal mode. Until now I've just had two tables for
it: there's this one which is welded solid, fixed at 90 degrees, and I also have this
one that's 45 degrees, also welded solid. So I like these tables, simply because
they are dead reliable. When you have it welded solid like that, you can't knock
it out of square. If I do that to it, it is still square, and the same thing
with this one. So these have their place, but they're not ideal because what
if I need a 28.7 degree angle? So, in this video I'm going to be making one that
has a hinge across here, so it can be adjusted. Here you can see why it's nice to have
two fixed tables. When I need to switch from grinding at 90 degrees to grinding
at 45 degrees, I can just swap them. So the hinge is gonna lay right across
here. To make more room for that, I'm going to notch this out like so. Okay, now we're ready to make the hinge
itself. For that I'm going to use a piece of DOM. This is a 4 inch long piece, 1 inch
outside diameter, 1/2 inch inside diameter. And if you're not familiar with what DOM is,
that stands for "drawn over mandrel". It's just a type of really precise seamless tubing, and
you can get it with a thick wall obviously. A bolt will go right through that, and the table
is going to tilt around that bolt. There's one thing I want to do before I weld this on,
and that is to cap the end of the tube here. I chamfered all of these edges so I'll
be able to fill that in with weld, and then grind it all flush so it'll look
like one piece. Holding this in place was a very clumsy operation but it worked.
A small magnet would have been better. So there's supposed to be a 3/8 inch
offset from this surface to the front of this bar. So I just clamped
the DOM directly to the table, and then I'll use a piece of 3/8 flat bar
to offset this the correct amount. Here I'm just making sure the post and the DOM are
perpendicular before welding them together. So you'll notice I've positioned
the hinge as close to the belt as possible. It's actually so close that
it hits at the same time as the table holder hits down here. You want this
hinge as close to the belt as possible, simply because you want the support directly
under the spot where there's load here. So next up I'm going to start working on a square
frame that will go under the table — the table will be welded on top of it. This frame will
include the outer two pieces of the hinge, and also a locking mechanism
to lock the angle of the table. So these are the two side plates for what
I'm going to call the "table frame". This hole and this hole are going to be 1/2
inch, and then there's this curved slot here which will be 3/8 inch. I'm
going to pilot drill all of these, because the position of this hole
relative to this slot is pretty important. So when you're pilot drilling, you want to
choose the size of drill bit based on the size of the little flat spot across the end
of the larger drill. You don't want to use a bit bigger than that or you're gonna wear out
the edges of the larger drill bit unevenly. Okay so I got in a hurry and put too much
downforce on it and broke the bit. Now you see I'm holding the handle a little
closer to the center so I'm not able to put as much downforce on it, and that
should keep you from breaking more bits. Got all the pilot holes drilled, now I'm moving
up to the 1/2 inch bit for these two holes. And 3/8 inch for the four holes that
I'm able to drill in the slot. Pilot drilling also allows you to drill
two holes right together like this, without a risk of the second
one drifting into the first one. Now we can check the accuracy of this. That
should be 1-9/16 between them, or 1.5625. 1.561, about 0.003 off. Again within about 0.0015, and again about 0.0035 off.
All of them are within 0.005. So I should be able to stick the
hacksaw blade right through here and cut down on either side
of that broke off drill bit. I'm gonna clamp on this block to guide the file, so I don't accidentally make
the end of the slot square. To be sure I have the slot cleared out enough,
I can just take a caliper and go around here, making sure it's at least 2-7/16 everywhere.
Then I can also go along the inside, making sure it's no more than
1-9/16. That's all finished. If you're anything like me this
camera angle makes you want to duck. Okay now to complete this frame
I'm going to use these 3/16 x 3/4 flat bars — one in the back
and one in the front. Like that. I've chamfered all these edges so I have a
spot to fill with weld. I have everything sitting nice and flat on the table. This bolt
is tightened, and I've just laid this piece in between here and gotten it lined up with
the end. So it's all ready to weld in place. So that's just nice and snug, so it's not
too hard to turn and yet it's not loose, which is perfect. We need to finish the
locking mechanism here. So for that I'm going to grind a little piece out of this.
That will be welded onto the DOM right here, and a bolt will go through this slot to lock it in
place. So you'll be able to rotate this and lock it at any point. So this mechanism will be very
similar to the main tilt hinge on the grinder. Here you can see how it's actually going to work: you have a bolt that's welded in place,
so that slot rotates around the bolt. Now we're ready to weld that little
tab on, so I'm starting by getting the table set to exactly 90 degrees
and locking that securely in place. Now I install a 1-1/2 inch long 3/8 bolt
through the tab, put two washers on it, and that gets installed through the
slot. Then another washer on the outside, and a nut. This all gets pushed up to the
very end of the slot and tightened in place. And that's ready to be welded
together. Now it's worth taking some time at this point to make
sure you got everything right, and double check that it's square. And I'm just
gonna weld it here and here, not along the sides. I'm welding only top and
bottom and not along the sides, because welding the side could warp the
thing sideways, and that'll interfere with how it locks. Just welding the
top and bottom will be plenty strong. Now the bolt is trapped in there,
but that's fine. We're going to weld it in place so it doesn't turn
when you're trying to lock it. You have to kind of maneuver
the table frame into place. Okay, we're almost done. All I need to do is weld
the table surface on and make a locking handle. But before I cover this up with the table, I want
to show you some of the close clearances in here, just to show you why this was kind
of an interesting design challenge. You probably saw my previous video where I made
this new table holder. I had to do that mostly for this table. Notice the shape of the table
holder tube — it's straight across the top and then angled 45 degrees. This angle had to be
there to make enough room here for the table, but this had to be straight to
make enough room for the hinge. This side of the frame had to be far enough over
that it would clear this corner and this bolt, which coincidentally is the same distance
over that this side had to be to make room for this piece to extend past the side of
the table tube to hold the locking mechanism. The back of the table tube, and
this edge of the table frame, and the back of the DOM, and the top of
the table frame all need to be in line, so that this can get as close to the belt
as possible, but yet this still clears. And then also when you tilt
this back to vertical — (voiceover Jer): Okay Jer that's enough rambling,
people are here to see you build the table! You're right. I like the size of my old 45 degree table pretty
well, I just want it a little longer this way. So we just need to square up the edges on this, and also cut this side to a 45 degree
angle. Ugh it's hard to draw on that! I was out of coarse grits for the belt grinder, so this took a lot of grinding with a hand
grinder and fine belts on the belt grinder. I tilted the grinder to 90 degrees and removed
the belt. And now I have this set 45 degrees. I'm gonna slide it in until it almost hits.
Here's my finished table — I'm gonna put that on here and slide it up until it touches the
platen. Then I'll mark that on the bottom. I've got my mark here that tells
me where to position this this way, and I drew two marks, equidistant from the
sides, so I can center this side to side. So this is just going to be tacked in place
— just maybe six tack welds around it. That's all that's going to hold the table
surface on. There's two reasons for that: the main reason is if you weld it
solid, it will warp the table surface, and I want to make sure that
the table surface stays flat. I did the same thing on this 45
degree table — these supports are welded solidly onto the bar but then
the table surface is just tack welded on to those. So the table is dead
flat and that's been working great. Also I put quite a bit of time into this
whole adjustment system and I don't want to lose this if I damage the table,
so if it's just held by a few tack welds I can just cut those tacks
off and replace the table surface. So I just finished welding this and I can
hold my hand on it. So I think that's a pretty good sign, it probably hasn't
warped too much because it's not hot. So that's dropped down as low as it can go, and you can just see a sliver of
light. It just barely goes low enough. So one thing I want to check before I take
this apart and paint it is if it travels far enough. If it goes clear to 90 degrees
and if it goes clear to 45 degrees or if it stops short. If it stops short, I'm gonna have
to file out the end of the slot a little bit. Okay, that's good, we have just
a little bit of over travel. It actually goes past 90. And now I'll check
the 45 degree with the precision protractor. I would say that is pretty much
dead on 45, so, good enough! That's good enough, but I really wish it had
a little bit of over travel on both ends. In hindsight, I should have drilled the two 3/8 holes
on the ends of the slot a little further out. I will have a set of plans available for this and
I'll make sure to include that tip in the plans. This lock nut is just there to keep the
bolt from moving around; it's not tightened. I was fully planning to make a locking handle for
this, that would be the same design as these. But it occurred to me that I can't put that on
— I won't be able to thread it on because it'll hit the bottom of the table. And I could
make a shorter version of this, but well these are honestly already a little short as they
are. So I'm gonna stick with using a wrench on this. You could totally make a little handle
if you wanted, but this is how I'm gonna do it. And now, finally I'm able to set up that
28.7 degree angle that I never needed! Thanks for watching! By the way I will
have PDF plans available for this table, and I already have plans available for
pretty much everything else on this grinder, so check the description for links to that.
