Welcome to leevalley.com. Based on your location, it looks like you're visiting from the United States. Switch regions to browse relevant content and shop in U.S. currency.
I own a popular 13" wide thickness planer and a too-narrow 6" jointer. You can't find cheap smaller and narrower benchtop thickness planers on the market, but you can find a variety of expensive larger and wider jointers. To be able to occasionally joint wider blanks, I designed and built this planer jointing fixture that allows me to joint blanks as wide as my thickness planer can accept.
This fixture, or sled, is not rocket science to build, and only readily available parts and hardware are required. The main objective is building it perfectly flat and as light as possible. Since it’s short to meet my current needs, I'm planning to make a longer model if my projects get bigger.
This image has not been loaded. To print the images, close the print view and scroll to the bottom of the article. Once all of the images have loaded, select the print option again.
It calls for two aluminum T-tracks that can accept 1/4" hex nuts (I had square ones on hand) and two matching flat-head bolts (often called stove bolts), the latter being imperative for height clearance through the planer. Unless you expect to joint very short blanks, your T-tracks can be shorter than the bed itself.
Next, gather three hardwood scraps, as shown, one almost as long as your planer width capacity and the others less than half that width.
If you take a closer look, you will notice that each hardwood part has one slightly bevelled edge (±5°). Those angles will increase downward pressure, as you will discover later.
The bed should be made out of straight and flat man-made boards, such as high-quality hardwood plywood, presswood, or better, MDF (medium-density fiberboard). The single lower part of the bed should be sized to fit loosely between the side guide rails of your planer, while the three upper strips should total that previously mentioned width, including the T-tracks, as shown, which must be level with or below the top surface.
For now, with the T-tracks used only as spacers, glue the three upper bed parts onto the single and flatter lower base. To get the expected perfectly flat sled, I believe the table saw top is the flattest and widest surface in a woodworker's shop to clamp it to. Take the precaution of spreading paper or plastic film on your table saw, just in case glue gets on it. You won't regret it! A quick, easy and effective way to clamp such a large, flat assembly is to drop weight on it, mine being 12 one-gallon jars filled with dry sand, each weighting about 18 lb, which are quite handy in a woodshop.
Meanwhile, mark the center of one face of the two shorter hardwood blocks, then punch and drill a through-hole for your 1/4" flat-head bolts. Then dig a deep and matching countersink in each part, having in mind saving your planer knives!
To finalize what I call adjustable sliding jaws, get the sharpest screws you can find (think drywall) so they will easily poke through end grain to securely grab your stock while it travels through your planer. Add as many as you feel comfortable with (Image left).
Now it's time to drill through-pilot holes for those sharp jaw pins. To ensure downward pressure toward the bed of the fixture, make sure your hardwood block bevelled edge is sitting on your work surface, preferably the drill-press table (Image right).
Now, grab the remaining single fixed jaw, and drill and deeply countersink through-holes (again, think planer knives) for wood screws that will secure it onto the base. When done, head to your bench vise and drive your scary-sharp screws into predrilled pilot holes, as shown, making sure their tips protrude, but not too much.
Because it’s such a large glued-up surface area, let the glue dry overnight under weight to get the expected perfectly flat bed, as shown. The flatter it is, the better the jointing results you will get.
Fasten the fixed jaw on one end of the base using glue and woodscrews. As mentioned, T-tracks don't have to reach both sled ends. And if you're planning to joint shorter blanks, I suggest you refer to your thickness planer owner's manual to find out the recommendations for jointing short pieces.
Immediately remove any squeezed-out glue, which would undoubtedly prevent your stock from sitting flat on the bed. I like to use a plastic straw as a scoop to collect most of it, followed by a damp cloth. It's much easier to do it now than later when dried out!
The two adjustable pivoting sliding jaws will hold down and secure square and most irregular-shape blanks, as long as you make sure most of the screw tips poke into both ends of your blanks. To ensure those two jaws won't move or spin while being fed through your thickness planer, make sure they are securely tightened and/or feed the sled fixed jaw first.
Before the fixture is put to work, consider applying paste wax under the sled, or better, two or more slippery tape strips such as Lee Valley's low-friction tape (25U0401).
Set your blank to be jointed on the bed, press it downward against the jaws, and perhaps use a clamp to deeply drive the pins into the end grain. You don't want it to shift while travelling through the machine! You should always use both sliding jaws to get maximum holding power.
You can also build the fixture using three T-tracks as well as three sliding jaws to feel more comfortable, if necessary. Finally, remember that several light passes will produce better results than a few heavy cuts.
Since either end of the sled can be fed through the planer first, make sure you drop and secure your blanks onto the bed properly. Have in mind that each knife may lift the wood grain while travelling through the planer and therefore produce awful tear-outs, particularly on cathedral grain. For tear-out-free results, observe each face and edge, and lay it down on the bed so the side grain direction will be downward toward the outfeed side of the machine, which I believe most planer owners know about.
Happy woodworking!
Cut List
Base
Parts
Number
Length
Width
Thickness
Material
Notes
Bottom
1
38"
12"
5/8"
Presswood
Very stable material
Top Outer Base
2
38"
3"
1/2"
MDF
Flat & stable material
Top Center Base
1
38"
4-1/2"
1/2"
MDF
Jaws
Parts
Number
Length
Width
Thickness
Material
Notes
Fixed
1
11"
3/4"
1/2"
Hardwood
Sliding
2
4"
1"
1/2"
Hardwood
Hardware / Others
Parts
Number
Length
Width
Thickness
Material
Notes
T-Tracks
2
36"
3/4"
3/8"
Aluminum
+ Screws
Drywall Screws
8
1-1/4"
Very sharp tip
Drywall Screws
10
1"
#8 Flat-head wood screws
5
1-1/2"
1/4"-20 Flat-head bolts
2
3/4"
1/4"-20 Hex or square nuts
2
Countersink bit
Wood glue
Serge Duclos started woodworking in 1972 after purchasing his first house. He soon found it was a way to relax from the stress related to his job as a human resources professional. Since retiring in 2004, Serge continues to enjoy his pastime and to update his bilingual woodworking blog http://atelierdubricoleur.wordpress.com with his projects, as well as his tips and techniques.
