Cutting A Slot in 3/4" Ply?

[Tarheel]

I am currently working the "Utility Cart" featured in the latest issue of Shopnotes.

In the plan, are two slots (one at each end of the top) that serve as handles to roll around the cart. I am looking for the best way to cut these slots in the 3/4" ply top. (The slots are 1" wide and about 4" long - as I recall.) I can use a 1"forstner bit to cut each end, but I don't trust my jig saw to get a nice clean/straight cut between the holes. If I had a template I could just use by plunge base router and a top bearing template bit......but first I need to cut a template!!!

I have encountered similar problems when cutting slots for jigs etc, and haven't as yet found a simple method.

Any advice sure would be appreciated.

Thanks in Advance,

Wayne

[JR]

Making a template may not be as hard as you'd think.

Use MDF. 3/4" is best, but 1/2" will do. Cut the slots in the MDF using the forstner bits and your suspect jig saw. Make sure you don't cut outside the pattern's lines. Now work the slot using a surform, rasps, and files. Once it's done to your satisfaction, you can dive in with your top-bearing straight bit.

The MDF works very easily. You can shape it pretty much at will. If you mess it up you're out only a few cents of unimportant MDF, not some prize figured hardwood.

I used this technique on this project for the curved side braces, the handles on the removable tray, and the wheels. http://www.bt3central.com/showthread.php?t=22177

HTH,
JR

[jackellis]

Before I had a scroll saw and a band saw, I used a jig saw to cut out a few wide slots and the hand hold on a push shoe with acceptable results. On the push show, I could have cleaned things up but didn't bother.

You could also run the edge of the jigsaw against a straight edge to keep the lines reasonably straight and then finish up with a flush trim bit. Not easy, but for straight cuts it's an alternative to using a router and it's certainly better than freehand.

[Thom2]

I made a router board for this type of thing, drill your two holes, then lay the router board across the tangents and rout straight lines.

router board is nothing more than a piece of 1/4"x8"ish for the base, glued to a piece of straight 3/4"x2'ish for the guide bar. Chuck a 1/2" straight bit and zip the edge off the base with the router .... quick cheap and easy ... and handy for a LOT of things

[LCHIEN]

I am currently working the "Utility Cart" featured in the latest issue of Shopnotes.

In the plan, are two slots (one at each end of the top) that serve as handles to roll around the cart. I am looking for the best way to cut these slots in the 3/4" ply top. (The slots are 1" wide and about 4" long - as I recall.) I can use a 1"forstner bit to cut each end, but I don't trust my jig saw to get a nice clean/straight cut between the holes. If I had a template I could just use by plunge base router and a top bearing template bit......but first I need to cut a template!!!

I have encountered similar problems when cutting slots for jigs etc, and haven't as yet found a simple method.

Any advice sure would be appreciated.

Thanks in Advance,

Wayne

This template is simple to make with a table saw or miter saw and scrap wood. No need for drilling and or jigsawing or any lining up of guides or freehanding of lines. It is also a true template, after you make it, you can make a whole series of handle cutouts exactly the same with just the template and a router.

Heres how I make a template to cut simple handholds.
You need: some 1x2 or 1x 4 material for the template.
fixed base Router with 6" diameter base and 3/4" (or 1" if you wish) dia. straight bit

Now normally I would make a rectangular jig and use a template guide bushing but I don't see any bushings being as big as 3/4". So instead I'm going to make a template for the router base to go inside of.

Lets assume a 1" x 4" opening and a 3/4" bit (giving 3/8" radius to the corners instead of 1/2" like you had).
So the router has to travel 1/4" x 3-1/4".
Then you need to make the template opening 1/4" wider and 3-1/4" longer than the router base diameter. for an opening of 6-1/4" x 9-1/4"

So cut 2 ea stiles 1x4 x 6-1/4" long.
Cut 2 ea rails 1x4 x 16-1/4"

Now we didn't trim the width of thd 1x4 which is nominally 3-1/2" wide, so the outside dimension or even alignment is not important. The opening needs to be exactly 6-1/4" x 9-1/4"

Put the two rails horizontally in front of you with 6-1/4" between them.
Put the two stiles vertically between them. make sure everything is square 90° and glue and clamp them in place with a 6-1/4" x 9-1/4" opening framed. Double check the size once you've glued and clamped.

Once this is glued up and cured, you can run the router base inside this opening as a guide. Lower the bit in 1/8 or maybe 3/16th increments after each pass - you want to run the router clockwise around the opening.
Being a fixed base router you may have to start the router with one edge lifted (but keep it inside the template) and tip it in each time you start a pass. Works great.

You may want to draw some centering lines on the jig, maybe also some lines showing the extent of the final handhold area.

You'll want to clamp this to your workpiece and clamp both to the table. Using 1x4 instead of 1x2 will give you more area to clamp to. You may need to have some supporting pieces the same thickness as the workpiece under the sides of the guide jig. Make sure its all clamped securely in place before you start routing. You can never have too many clamps.

[Black wallnut]

Do you have a router edge guide? You could also do a plunge cut on your router table with stop blocks spaced on the fence.

[ejs1097]

I made a router board for this type of thing, drill your two holes, then lay the router board across the tangents and rout straight lines.

router board is nothing more than a piece of 1/4"x8"ish for the base, glued to a piece of straight 3/4"x2'ish for the guide bar. Chuck a 1/2" straight bit and zip the edge off the base with the router .... quick cheap and easy ... and handy for a LOT of things

This is the quickest way to get the job done.

Jig saws very in quality and not knowing what you have, even using a straightedge might not create desired results. Some of mine wouldn't make a 90degree cut to save it's life (face to edge).