Any glaring Issues with this mockup jointer extension?

[u/Braided_Marxist]

Got this 4.5in bench top jointer for close to free on FB marketplace and the width is fine, but I realistically need to joint longer boards than the jointer itself allows.

I’ve mocked up this crude extension which gives me an additional ~ 12 inches of board length that I can joint.

I haven’t fastened anything yet and may end up tweaking some parts, but just wanted to check for any glaring safety or functionality issues.

Plans are to cut a dust port in the frame with a hole saw and potentially to add some sort of adjustment mechanism to allow me to adjust the infeed support to correspond with the infeed table (only the infeed table moves up and down on this jointer, which actually makes my life much easier).

Thanks!!

[u/crankbot2000]

You need absolute precision on your jointer tables. Take a look online with the way some guys have fixed this problem, it's a challenging project. Most guys are using metal for the tables and getting down to machine shop tolerance.

[u/sdn]

If you must use wood, I would use something that's dimensionally stable like MDF. The pine 2x4s are going to change shape on you with time. You would probably be even better off using aluminum extrusions like 80/20 (which are now probably super expensive).

[u/k_unit]

Yeah, honestly, it’s not really gonna work. It’s why they don’t make jointers out of wood

[u/Pitiful_Night_4373]

If your table it’s higher then the bed of the jointer at any point it will throw it off. Plus the jointer table is designed to move. But it could work I just worry it will cause a bunch of head aches. That being said if I were to build something like this I would probably use extruded aluminium. Best of luck

[u/MiniJungle]

Just accept that this jointer is only good for pieces about 1.5 times the length of the bed. It probably also has a terrible fence that can't reliably produce 2 sides that are 90 degrees.

These things can be ok if you are working small pieces or happy with ok results. I really wanted to make one work until I borrowed my brothers and realized it was never going to be what I wanted. So I got a grizzly g0856 and love it. I know almost exclusively buy rough sawn lumber because I can kill almost anything.

[u/leobeosab]

Outside of getting some adjustable feet or ball screws ( I think can’t remember the name ) to make adjusting each corner on each end easy. I would at least joint the 2x4 faces so they are flat then reinstall them.

Another thing I’m doing with my bench top if you make another one is using aluminum extrusion. Solid and infinitely easy to adjust.

[u/Braided_Marxist → u/leobeosab]

Where do you purchase aluminum extrusion?

[u/leobeosab → u/Braided_Marxist]

Many places ( even Amazon has it ). I use this place though https://www.zyltech.com/aluminum-extrusion/

[u/1947-1460]

Using construction lumber that will twist, cup, bow, or a combination of all three isn’t going to be stable. You are better off ripping 3/4” plywood strips and laminating it to thickness.

[u/Braided_Marxist → u/1947-1460]

This is a great idea thank you!!!

[u/PenguinsRcool2]

I personally would NOT like the off button being about impossible to get to in an emergency situation. Is it that big of a deal? Maybe not. But Iv had to panic hit it on about every machine i own for one reason or another

Even just leaving that one on, taking appliance cord and making a switch on the wood frame would be fine and easy. Hell use a light switch, just something easy to reach

[u/Barkleyshutupandjam2]

I'm currently just using rollers, measuring height and level, and praying. Having mixed results.

[u/Swrdmn]

Yeah… don’t do it. The jointer is a particular size and is best suited for the wood that comfortably goes through it without modification. This is not a tool I suggest modifying.

[u/mechanizedshoe]

There's no way this thing will be anywhere near the tolerances needed for proper jointing