Thicknesser drive roller marks

[thomvic]

The thicknesser drive roller on my Kity 635 has suddenly started quite seriously marking the wood on one side only. I know there are pressure springs and a means to adjust them. They seem to be adjusted to minimum pressure anyway. I am reluctant to touch them as the problem arrived suddenly - not gradually increasing so I don't think the problem is there. Does anyone know what might have caused it? A friend says it is probably to do with insufficient blade protrusion from the block but it works fine for surface planing (jointing).
Any help will be appreciated.

Richard

 

[Stormer1940]

How much are you trying to take off in one pass? Is it a small amount? Is it happening if you increase the amount you intend to take off?

 

[thomvic]

You don't actually adjust the cutting depth when using the thicknesser - it is just determined, I think, by the amount of pressure you screw on when you raise the thicknessing table. However, it still marks with just the minimum of pressure - hardly any cut at all. Now that I've had a shower an cleared my head , I think it may be the blade protrusion that is the problem. If the blade is not out of the cutter block enough then it won't cut lower than the drive roller underneath will it? Am I thinking along the right lines or do I still have my turnip head on?

Richard

 

[Jacob]

Could be shaving under the bearing housing causing it to tilt. I've had that with other machines. The remedy being to put a block of wood on the bed, machine switched off, raise it up to lift the rollers and see if you can see and/or poke at the underside of the bearing to dislodge chippings.

 

[custard]

You don't actually adjust the cutting depth when using the thicknesser - it is just determined, I think, by the amount of pressure you screw on when you raise the thicknessing table. However, it still marks with just the minimum of pressure - hardly any cut at all. Now that I've had a shower an cleared my head , I think it may be the blade protrusion that is the problem. If the blade is not out of the cutter block enough then it won't cut lower than the drive roller underneath will it? Am I thinking along the right lines or do I still have my turnip head on?

Richard

That makes sense to me, but you could easily check by pencilling some lines across a board and seeing if a pass through the thicknesser removes them.

 

[Steve Maskery]

Yes, the problem is insufficient blade protrusion.
The infeed roller is serrated and mars the wood when gripping it. The cutter SHOULD then cut away enough to remove those marks. I f it doesn't, the marks remain.

When Planing, there is no serration, so the only thing that matters is the relationship between the knife and the table. In thicknessing, however, the relationship is between the knife, the roller and, therefore, the cutter block.
Your friend is right.
S

 

[thomvic]

Thank you very much gents. I felt sure I would get good advice here - I'll check it out tomorrow and let you know what happens. In the meantime, any further suggestions will be welcome, whether they are the ones that resolve the problem or not, they all add to the knowledge bank.

Richard

 

[Stormer1940]

You don't actually adjust the cutting depth when using the thicknesser - it is just determined, I think, by the amount of pressure you screw on when you raise the thicknessing table. However, it still marks with just the minimum of pressure - hardly any cut at all. Now that I've had a shower an cleared my head , I think it may be the blade protrusion that is the problem. If the blade is not out of the cutter block enough then it won't cut lower than the drive roller underneath will it? Am I thinking along the right lines or do I still have my turnip head on?

Richard

Sorry I meant. Say your timber was 50mm and you wanted it down to 48mm you would crank the table up or down to suit the amount to take off... However if you have taken too much off during the flattening stage and not realised and then put it through to thickness at 48mm then you could end up with the serrated roller pulling the timber through and the planer knives not touching the timber. It was just a thought thats all.

 

[tool613]

Could be shaving under the bearing housing causing it to tilt. I've had that with other machines. The remedy being to put a block of wood on the bed, machine switched off, raise it up to lift the rollers and see if you can see and/or poke at the underside of the bearing to dislodge chippings.

I would have to agree. this is way

The thicknesser drive roller on my Kity 635 has suddenly started quite seriously marking the wood on one side only.

If your running with out dust pick up shaving can pack in under the spring and restrict upward travel of the serrated feed roller.this a common problem because the head through shaving towards that roller. Beside knifes don't tend to slip further into a head all the sudden with out leaving knife marks and bad milling marks. In fact I have never heard of knifes doing anything but slipping further out of the head. . Just saying.

jack
English machines

 

[thomvic]

Thank you gents - problem solved. I did all of the chip and dust clearing as suggested and then started the blades set-up from the beginning. First set the out-feed table to 1mm higher than the blade block. Removed the blades, cleaned the slot, re-placed and re-set the blades and bingo. Everything now ok. Thanks again. You are a veritable mine of information.

Richard