Thread: Thicknesser skewing left and right! HELP...

How often, and how recently have you waxed or whatevered the table? Sounds like a friction problem to me.

Consider the following:

• We tend to put material through the centre more than the edges (even though we try to spread it). And of course the centre gets more wear than the outsides by default of wide boards.
• Given the above, it follows that the slipperiness of the centre will be gone before the outsides
• If it's the front edge of the board skewing in towards the centre then that would make sense because the centre has greater friction

Thanks! I use silverglide regularly. Also gave it a good clean and fresh application of silverglide. It's the back edge skewing towards Centre. I also use Centre, but as you say trying to wear it evenly means you want it working perfectly no matter where the board is fed. Any other ideas?

It sounds like something is crowning. I doubt it's the cutterhead/blades and probably not the feed rollers. They tend to be substantial, whereas the bed rollers tend to be more lightweight.

If one is "sagging" in the middle it'd give you symptoms pretty much as you describe... the timber will want to move to the centre, unless you adjust tensions so it'll sit on one end or the other.

So I'd suggest you get a very, very accurate straight edge, lay it on top of your roller(s) and look for even the slightest glimmer of daylight in the middle. Of course, this isn't a definitive test; the middle of the roller(s) may be flexing only under load.

Still it's one possible cause for you to look at...

Do you have a way of determining if the centre has belllied out a little? Lay a short straight across the table?

could this be a design issue -- the feed rollers are ever so slightly grooved so that they tend to automatically center a board?

Thanks. I've spent the least attention on the bed rollers, so I'll look into it. cheers!

Thanks. I don't think so. Only because I've been using it daily for 3 years and this is the first time it's happened.

Is it possible something has gotten onto the feed rollers on one end or the other that is changing the friction coefficient? Maybe you could hit them with a light abrasive or something to make sure they are grippy all the way across.

Just a thought. I've never used a machine of that scale.

Good luck,
Luke

Ive found this to be common among many different thicknessers. It never crossed my mind that it is a 'problem', I just guide the timber through straight. Is the machine overpowering you regardless of how hard u try to keep timber feeding straight?

My first thought would be to reduce infeed roller pressure

One more to consider. Is the cutter body assembly parallel to the table ? I have the 15" Jet unit (with the honking motor mounted on top) and the weight of the motor can cause one side to drop marginally. Also another vote for roller pressure perhaps.

Since we swapped to a Shelix head, our thicknesser has been doing a similar thing; timber wants to twist anti-clockwise as it goes through. I increased the tension on the springs on the infeed roller and I think it's helped a bit.

So is it kind of skewing as a result of the sheer cut you think Elan ?

The spiral pattern in ours hits the timber from right to left and it's getting pushed to the left, so I have to say yes.

Originally Posted by Cam.H

Hi Guys,

My thicknesser is giving me grief! Model is here.

It's skewing the boards on infeed towards the centre of the table. So if I feed a board in on the right hand side it will skew the end of the board to the middle and if I feed it in on the left hand side it will skew the end to the middle.

I have tuned this thicknesser and addressed this issue many times before so can't work out the problem.

What I have done/checked:

Adjusted all rollers, chipbreaker and pressure bar to factory recommendations using a dial indicator. Checked, re checked and triple checked at least a thousand times.....
Adjusted the spring tensioners on the infeed and outfeed rollers

Confirmed the cutterhead is parallel with the table.

Confirmed bed rollers are parallel and set to factory recommendations.

Greased and tightened everything and ensured all moving parts, spring tensioned parts/rollers are all moving freely.

When a board is fed through the centre it's fine.

I can get boards going through the centre and RHS ok, but feeding though the LHS is causing the most trouble.

The infeed roller, chipbreaker, cutterhead, pressure bar and outfeed roller are all in parallel the entire way across the bed, are in good condition and aren't worn in any obvious manner.

No problems with outfeed or with snipe.

I can't 'force' the board to skew away from the centre by means of adjusting tension. I can max it out and achieve the board feeding straight but only on one side at a time.

Any help at all, or if you are or know a wood machinist in Brisbane would be fantastic if you could get in touch. We lost all day Friday, and have a heap of work to get through this week.

Cheers.

The spirals are likely to be causing the skew.

Importantly, what type of finish are you getting? Is the cut an even depth? Are there planer marks?

Regards from Perth

Derek