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Bandsaw Fence

A couple of months ago, on another forum, a writer asked about bandsaw fences–what folks used, were commercial ones any good, did others make their own? Etc.

Well, 20-25 years ago I made up one out of plywood that was good enough to get into Fine Woodworking. Since then — 7 years ago? — I’ve made a new one that’s slightly improved.

Bandsaw fence from 8020 extrusions

This fence is made from 8020® aluminum extrusions. If you don’t know about 8020, you should check them out.

The fence rides on two 1″sq rails, gliding along on UHMW-PE (Ultra High Molecular Weight Polyethylene) “bearings”. It’s 4″ tall and the length of the table plus a little bit.

Front of fence showing the UHMW-PE glides and fence lock and fence stop

The fence glide(bearing) has a turn knob for locking the fence in place. On the right is a smaller glide that I use as a stop. It’s especially handy when I need to make very small adjustments in the fence-to-blade distance using shim stock, or if I need to move the fence and then return to the previous setting. The main glide is 4″ long to match the width of the fence. It has two bolts going into the fence that can be loosened to allow adjustment for “Drift” (the tendancy of the blade to track/cut away from the desired cutting path).

Between the glide & fence is a wood shim to fill the space from the rail to the table top.

The far end of the fence has a lockdown too to prevent it from flexing out of alignment.

Far end of fence showing locking nut

One of the things I like about this fence is the ability to bolt auxiliary fences to the main fence. This next picture shows a simple fence that allows me to bring down the blade guides when I  cut thin narrow stock. (I know, the pic shows the blade arm up high….)

simple aux fence bolted to the main fence

I have several auxiliary fences that are very simple in nature. Because they bolt to the fence, I don’t have to mess with clamps to hold them in place.

Cutting the legs on the light boxes

Cutting the legs on the light boxes

Here I’m using a stop to limit my length of cut.

Next pic shows the back bracing. I needed to shim the braces slightly to get the fence to sit perpendicular to the table.

backend of fence showing bracing

backend of fence showing bracing

This fence wasn’t cheap to make. With labor included, I probably spent $500 to build it — not too cost effective I suppose.  Excluding my labor, then we get the price down to around $150. The UHMW glides were the most expensive parts.

Now, here’s what I want to build when I get a little (a LOT) of extra money:

CNC Framework built from 8020 extrusions

All I need is some programing skills and knowledge about Servos/stepper motors.

The 8020.net site has “8020 Stuff”, a series of booklets that show a variety of projects made by users.

OK, this is cheating — again — but here’s a video of a totally cool 18th century French writing desk that’s at the J Paul Getty Museum in LA.

Where’s my saw? where’s my wood? Where’s my skill?!

http://www.getty.edu/art/exhibitions/paris_lifeluxury/video_frenchtable.html

Several weeks ago I watched a video from “The Wood Whisperer”. It’s a podcast on woodworking by Marc  Spagnuolo.  His podcasts  contain good information for beginners & intermediate woodworkers, but for an old goat like me who “knows it all”,  Marc’s postcasts are interesting but not that informative — Remember, I already know it all. ;-)

But then he made his video on making a cross cut sled for the table saw. Its. Really. Good. I. Learned. Things.  (link below) Most informative for me was how he squared it to the blade and a cool way for safely cutting multiple small parts.

The Wood Whisperer’s cross cut sled video

Anyway, give it a look. If you’ve never used a cross cut sled, you should. It’s a lot better than the standard miter guage. I have about seven of them, each doing different duty.

The only thing I would add is a pair of hold down clamps to keep your wood from moving.

Toggle Clamp

DeStaco brand Toggle Clamp

A while back, I complained about the quill stop on my Rockwell drill press.
Well, this time it’s an incredibly poorly machined fence.

I borrowed a Shop Fox brand Hollow Chisel Mortising machine from a friend. This is not a high end tool. But still, one would think the mfr could to a little better job.

Shop Fox Bench top mortiser

the company's image

This is the company’s image. Notice how nice and level that white fence is. (admittedly, the white fence is hard to see on a white background.)

Here’s what my friend’s fence looks like:

Shop Fox Mortiser fence

Not nearly as straight as the other pic

Now the reason this fence isn’t straight is because the two flats machined on the rear support/adjustment rod aren’t machined perpendicular to each other.

my square shows how off these flats are

So, when you tighten down the lock knob, it twists out of square.

Now, I will say that I didn’t have any problems with the whacky fence. It’s just that such poor machining gives one an idea of the attention to detail these “fine Chinese” tools are held to.

I have a set of Shop Fox roller supports that failed because of the puny spot welds meant to hold the rollers to the stand. (height adjustment knob failed too.)

Needless to say, I would never again buy a Shop Fox tool, nor recommend them.

Hazmat training suit

Beam me up Scotty

I get an e-newsletter from one of my suppliers that seems to have very little to do with what they sell: nuts, bolts, really cool linear motion bearings, etc. I usually toss it after glancing at the articles. But today, they had an article on CFL’s (compact fluorescent lamp) that scared the bejesus out of me!

Let me tell you, you DON’T want to break one of those cute little curly cues.

broken cfl

Smashed to bits! Run for your lives!

So, here’s what you should do to clean up a broken bulb according to the EPA:

1) PANIC! (no not really). Have people & pets leave the room.
2) Air out the room for 5-10 minutes via open window/exterior door.
3) Shut off HVAC.
4) Collect materials needed to clean up broken bulb (Like your spare hazmat suit).

5) Be thorough in collecting broken glass & visible powder. (DON’T SNORT! In fact, don’t even breathe. Don’t use your hands, don’t vacuum.)
6)  Place cleaned up & cleanup materials in a sealable container (TWO zip lock bags.)

7) promptly place all bulb debris & cleanup materials outdoors in a trah container or protected area until they can be “disposed of properly”. (That would mean driving 100 miles to our local toxic waste site.) Avoid leaving any bulb fragments or cleanup materials indoors.
8) FOR SEVERAL HOURS, continue to air out the room with HVAC off. (Don’t want to break one of these in the dead of winter or in August, huh?)

I tell ya, that’s some pretty scary stuff.
To see that I’m not really lying about this, you can check it out yourself at: http://www.epa.gov/cfl/cflcleanup.html

We live in California, where these bulbs are becoming mandatory We also live about 10 miles from a nuclear power plant that rests on several earthquake faults. I might be inclined to move a little closer to the plant so we can read at night from the glow of the radiation rather than have to buy CFLs.  Candles might be a good option too.

Don’t know if this title really says what I want to talk about….

A few weeks ago, I got a job to remove the 1/4″ wood panels from a bunch of cabinet doors and cut a rabbit in the door frames for glass.

Removing the panels was straight forward. the doors are what’s called a “Back Panel” door; meaning the center panel is attached (glued & nailed) to the back of the frame rather than set into a groove cut in the frame. First I drill a hole near one corner of the panel. Then using a flush trim bit and the inside of the door frame as my guide, I rout away the panel from the frame.

The stack of doors after removing back panel

Stack of doors after routing out the center panel

(actually, this picture shows the rabbet too. I forgot to take earlier photos of before & after.)

The next step as a little harder. I needed to cut a rabbet that was 3/8″ wide by 3/8″ deep. Normally, this would be easy too using a rabbeting bit of which I have several. Problem is, I don’t seem to have one that will cut a 3/8″ wide rabbet. Everything else, up to 1/2″ wide, but not 3/8″. So I had to jury-rig a bit & bearing to do the job. (the bearing didn’t quite fit the rabbeting bit’s shaft.)

Rabbeting bit

Once I got things to work (the bearing wouldn’t fall off or run out of round) cutting the rabbet was easy too.

But after routing the rabbet, I needed to square the corners as the bit left them with a 5/8″ radius.

door frame with rabbet for glass

door frame showing the rabbet cut for glass and round corner I need to square

Now, normally, I would use a chisel to square the corners. But I have 17 x 4 = 68 corners to do so chiseling by hand will be a little too slow & costly.

So I made a jig to speed things up.

Corner squaring jig drawing

Computer generated drawing of corner squaring template

Using a computer to lay out the template helps in determining just how deep the template’s corner notch needs to be so the 3/16″ bit doesn’t cut too deep or too shallow into the rabbet.

Now, this set up will also leave a radiused corner but it has gone from 5/8″ to 3/32″. So the glass should fit fine if it’s cut with a little wiggle room.

corner routing jig in place

The corner routing jig clamped in place

corner routed square

corner after routing with 3/16" bit

The end result is a pretty good looking corner, IMHO.

In 1994 I bought a new Powermatic #60 eight inch long bed jointer. Boy, was it nice.  Compared to the little 6″ hobby jointer I had before, this thing was massive AND accurate. I could actually joint wood square & flat.  The only problem with it was in changing and setting the knives. Like most jointers, referencing the knives to the outfeed table was by trial and error — mostly error.

 

Powermatic® Cutterhead endview

Cutterhead showing knives & gibs. ©Powermatic

This image shows the how the knives set into the cutterhead. What’s not showing are the Jack Screws that support, raise, and lower the knives. What’s difficult about setting the knives is that I have to try to reference the sharp edge of each knife to the top of the outfeed table.  I finally bought a magnetic bar that would hold the knives to the level of the table.

 

Woodstock® Magna Set guage

Woodstock® Magna Set Gauge holds knives flush to the outfeed table.

(Unfortunately, this Company’s image shows the gauge sitting cross-ways over the knives.)

The gauge works fine, but you have to try to align the high point of the knife’s arc to a mark on the gauge. Easy enough after you’ve determined where the high point is. But then you start to tighten down the gibs and the cutter head begins to move all over the place.  A simple indexing pin built into the jointerhead and bearing supports would fix all this, but such a design change might cost the jointer makers a couple of bucks.  (My Japanese planer has this feature & I can set those knives in about 10 minutes or less.)

In 2003, I figured I’d had enough and I bought a Terminus® replacement cutterhead. It has knives that are double sided, and are indexed into the cutterhead so there’s never a need to use any jigs or gauges to set the knives.  It only took me eight years to finally remove the old head & put in the new one. (The original Powermatic head had a bearing going out & the Terminus® comes with bearings already mounted in place so I had to do something.

 

Terminus® Arbor Planer

The Teminus® Cutter head (without bearings)

 

The switch over wasn’t nearly as bad/difficult as I imagined.  I just gathered up a few things I thought I might need and set them near by:

 

Tables-are-handy-to-have
It’s nice to have a flat surface.

It turns out, I have misplaced my manual, So went online to find a pdf. It turns out that the only manual I could get from PM is for their newer model 60. But they are close enough in construction that it would work.

First step is to remove the blade guard & the fence Then remove the fence support (manual says to swivel it out of the way, but couldn’t see the point in that).

 

Removing the Jointer fence

Removing the fence (image© Powermatic)

Next step is to lower both the infeed & outfeed tables so the cutter head can be removed by lifting straight up. There are two bolts that hold the bearing housings in place (“B” in image below). One bolt is easy, the other has about 1/2″ clearance between it’s head & the jointer stand. A socket wrench won’t fit, but a box end wrench will. It just takes a little longer to remove — Oh, and having never been touched for 16 years, it needed a little “persuasion.”

 

Powermatic® schematic-removing cutter head

In reality, pulling out the cutterhead is easy. (Image ©Powermatic)

To remove the bearings & housings from the cutterhead, I tried using wood wedges but that didn’t do it. So I went to my shop neighbor who’s an auto mechanic. He used a press to push things apart. And to be honest, it didn’t take much effort. (When I put the bearing housings on the new cutterhead’s bearings, they turned out to be a slip fit.)

The final step in all this is to align the new cutterhead to the outfeed table. With the old head, you level the knives to the table, but the Terminus® knives are indexed to the cutterhead so you can’t align them to anything but the head itself.  Aligning/leveling the cutterhead to the outfeed table isn’t too difficult if you have a dial guage and some shim stock.

using a dial guage to set the heigt of the cutter

Using a dial guage, I set the heigt of the cutter head level with the outfeed table by shiming under the bearing housings

I was able to shim the head to within .002″ front to back. It’s important to have the outfeed table raised and locked in place. And to tighten down the cutterhead after placing shims as needed under the bearing housings. Taking dial readings with bolts loose won’t be accurate.

cutterhead-in-relation-to-table-04

Looking across the head, it's a pretty close fit.

knife-arc-in-relation-to-table-05

The knife looks pretty close to the table. It makes me a little nervous.

This picture shows a few things: the table is still too low. The knives are barely above the surface of the cutterhead. And you can see how the knives are indexed into the head.

Last step is to set the table height equal to the knives:

Outfeed-table-too-low-06

here, the outfeed table is too low

Here, the outfeed table is too low because when I rotate the head, the knives lift the stick off the table. If I were to joint a board with the table set like this, I would get a snipe at the trailing end of the board.

Outfeed-table-properly-set-08

Outfeed table set "just right"

Here, the table is set correctly. The knives do not lift the stick. Furthermore, when I rotate the head, the knives just barely skim the underside of the stick. If the knives didn’t touch the stick at all, the table is too high and will create a convex bow in the bottom of the board being joined. (The infeed and outfeed tables not being parallel to each other can also cause convex or concave joints.

After all my setups, I ran a board over the jointer.

first-joint-10

Joining the first few inches of a board to check for square, smoothness and depth of cut.

What I noticed first off was that the machine was a little quieter and didn’t vibrate as much as before (probably that bad bearing). I also noticed that the cut wasn’t quite as smooth as the old knives after sharpening and honing. Maybe running these knives over a whetstone will help. I checked the depth of the cut (about 1mm) and reset my infeed “depth of cut guage” (about as accurate as a dull #2 pencil). I checked for square and adjusted the fence (using the fine adjustment capabilities of the heel of my hand against the fence adjustment handle — This handle isn’t shown in the fence picture above. I guess it’s been redesigned out).

Checking for square

Checking for square (the clamp is just to hold the square in place while I take the picture)

Shavings from my first cut

Shavings from my first cut

After using the jointer for a couple of weeks, I am pleased overall. There does seem to be a bit of chatter (knife marks as if one of the knives is too high) so I’ll have to look into the cause of that. It may turn out that I will need to hone the knives while in place to be sure they’re all the same height.

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