Thread: edge jointing long boards on short-bed jointer

Even a short bed shouldn't have problems with 1400 long. It might be technique, but it also might be the tables not parallel to each other or the knives not being level with the outfeed table so I'd be checking those first.

It's probably technique... and maybe the fence.

I'm confident the machine is setup up reasonably well, because I spent a loooong time getting the tables to be co-planar, setting the knives to the right height height, and cleaning everything up when I got the machine. Very fiddly work, with straight edge and feeler gauges, going back and forth to get it decent. It behaves better than I imagined it could for face jointing and planning.

But... the fence is a piece of junk. Extruded aluminium on a janky sliding housing that surely has some play and flex, even under light pressure. And the face of the fence has a bow in it too. Dips about 1mm in centre from top to bottom. This would not be helping.

As for technique, I've been treating it more or less the same as face jointing. Very light pressure down and into fence on infeed side, pushing forward from the back of the board, then continue in the same way from the outfeed side once the first 150mm has passed over cutter head. I believe that's theoretically the right approach. I admit that I haven't mastered it though. Feels awkward, and the transitions from hand-to-hand I move the board through is not very smooth.

I'll keep working on it. Maybe with some practice I'll get it.

Originally Posted by rogerwilco

Very light pressure down and into fence on infeed side, pushing forward from the back of the board, then continue in the same way from the outfeed side once the first 150mm has passed over cutter head.

Firm pressure down on the front of the board, pushing from the front. Basically you want to keep the downward pressure over the machine tables around the cutter area; the tables are your reference surfaces, you need to make sure the timber has good contact with them.

If/when lockdown ends I could probably come past if you want some pointers.

Elan’s advice is good. The only thing I would add is that you may want to check your setup... I had the same sort of problem one day, and was very confused as I’d not had it before and am a bit ocd about setting up tools. When it became obvious that there was a problem that just wouldn’t respond to technique adjustments, I grumpily went back to basics, and started by checking out feed height against cutter head with a steel rule. Surprise surprise- it was way too low- somehow, It had been banged or knocked in ‘normal workshop use’, and my assumed perfect setting...wasn’t. Outfeed/cutter height is the critical relationship for these machines.

Originally Posted by elanjacobs

Firm pressure down on the front of the board, pushing from the front. Basically you want to keep the downward pressure over the machine tables around the cutter area; the tables are your reference surfaces, you need to make sure the timber has good contact with them.

If/when lockdown ends I could probably come past if you want some pointers.

Of course, that makes complete sense. I'll give it a whirl.
And thanks for the generous offer - I may well take you up on that!

Originally Posted by jpdv

Elan’s advice is good. The only thing I would add is that you may want to check your setup... I had the same sort of problem one day, and was very confused as I’d not had it before and am a bit ocd about setting up tools. When it became obvious that there was a problem that just wouldn’t respond to technique adjustments, I grumpily went back to basics, and started by checking out feed height against cutter head with a steel rule. Surprise surprise- it was way too low- somehow, It had been banged or knocked in ‘normal workshop use’, and my assumed perfect setting...wasn’t. Outfeed/cutter height is the critical relationship for these machines.

This is good advice too!
I just grumpily went down there and checked the setup, and to my surprise, walked away happy!
infeed/outfeed are still co-planar. I didn't get the gauges out this time, by I'm eyeballing with a straight edge hanging over the whole length of the infeed and it looks good. From memory it got it to within a few 10 thousands when I set it up. I have the infeed set about 1mm under outfeed for light passes.
Checked the cutter height too. It hasn't changed. I used the method where you put a stick on the outfeed table, spin the cutter and measure the travel from top dead-centre. I checked all 3 blades, back, front and centre. All positioned within 1-2 mm from 10mm.
Knives are sharp.

Must be technique!

The key is all the downward pressure on the out feed table nice and close to the cutter head - not the in-feed table.

Look along the edge to be jointed, crown should be UP, so concave edge against the table, if the bend ismore than the machine is set to cut off, take a bit from each end first, sometimes holding the middle section off the cutters to get a bit off the back end helps. Then take a bit more off each end until the edge is looking better, then usually I will take a bigger bite and lower the infeed table and this last cut is where it’s important to maintain pressure on the outfeed side of the head,all the way along.
It’s Really not that much different than if you were planing it by hand, start from the high parts and work down, except it’s upside down and you’re moving the timber,and not the plane.

Can confirm: it was technique.

I just jointed some 1800 long boards of the same stock over the weekend. Results were bang on. Straight edges with no gaps under the straightedge after one or two light passes.

I dunno why I thought edge jointing would be any different to face jointing in terms of technique. Well, yes I do… I think I was overemphasising the importance of lateral pressure to get an edge that is 90 degrees to the face. Turns out lateral pressure is less important than consistent downward pressure on the outfeed side (which I knew to be true from face jointing).

Thanks for the tips everyone.

Do you have any extension tables for your combo?

Originally Posted by Greg Q

Do you have any extension tables for your combo?

Nah, thought about it, but my assumption is that it will be near impossible to get an extension table to be coplanar with the infeed table, given that my floors are uneven, and my machine is on a rolling base and gets put away after each session.

No kidding, it took the best part of an entire day to get the tables and cutters ON THE MACHINE setup correctly in relation to each other. I can't imagine tryna do the same with a ball bearing table or rollers or whatever. Sure, probably doesn't need to be deadnuts... maybe I'll have a go if I need to joint anything super big.

For the most part though, I only store 2.4m boards ('cause that's the capacity of my vertical storage) and break down to oversized rough parts before I put through the jointer. I'll have a go at a 2.4m board... If I can joint that with reasonable accuracy (unlikely?), then I can't imagine needing extensions.

I was thinking of the clip-on extension tables like Felder sells. Ruwi make one for under $200, available at Craftsmen Hardware in Boronia, but I don’t know if it is robust enough for an extension that has to be coplanar with something heavy on it.

I had to make some extensions for my spindle moulder last week. It wasn’t trivial, but it works. A much shorter extension can add say 400 or 500mm to each end and be self supporting. Anyway, I find them handy, but I do some wacky things like jointing 4 m boards on my rig.

I think it would be incredible difficult to align the extension tables.

Another technique I have used is with track saw, check out - Login • Instagram

For one example of how it is done

Its actually pretty easy to align extensions if you design them properly. And by that I mean slavishly copy the expensive ones. But there is metal work involved which does have its own accuracy requirements. Everything I made for extensions was done with a grinder and a file and a hand drill and is hardly pretty, but the built-in adjustment
S make zeroing in dead simple.