Tolerances in woodwork

[Gary_S]

My son and myself have spent hours in my garage/w shop trying to dimension a piece of maple. We think we get a flat surface on the jointer/planer it doesn't rock or roll on the cast iron surface of the table saw. However, putting it through the thicknesser we seem to make rhomboids and struggle to get the thickness even being out sometimes by as much as 2.5mm across the length of the board (1 metre). It is to make a strip of 5mm length to be laminated as a decorative feature on a guitar he is making. Are we being niaive expecting to get metal work precision with woodwork?

 

[Mike Jordan]

You should be able to get a good level of accuracy if the machinery is in good order and properly adjusted. There are however lots of things that can be out of adjustment and cause accuracy to drop to low levels.
Let me suggest a few and doubtless others will be able to suggest more.
On any thickness planer a thinner piece of material can tend to bounce under the cutters and spoil the end few inches before both feed rollers are holding it down, the normal solution is to add a bit of extra length to the timber to allow the snipe to be cut off after machining. Improperly adjusted feed rollers will also cause similar effects.
If the extraction is not good, chippings can become trapped between the timber and machine bed and cause more material to be removed.
I think the best solution for a small section just a metre long would be to cut it on the circular saw and plane to size by hand plane.

 

[RobinBHM]

My son and myself have spent hours in my garage/w shop trying to dimension a piece of maple. We think we get a flat surface on the jointer/planer it doesn't rock or roll on the cast iron surface of the table saw. However, putting it through the thicknesser we seem to make rhomboids and struggle to get the thickness even being out sometimes by as much as 2.5mm across the length of the board (1 metre). It is to make a strip of 5mm length to be laminated as a decorative feature on a guitar he is making. Are we being niaive expecting to get metal work precision with woodwork?

What is the section you are trying to achieve? 5mm x?

Small sections are awkward, if its 5mm x 10mm or similar you would be better planing a piece 10mm thick x say 50mm and ripping off a strip 5mm.

If you are doing a piece of maple to finish say 50mm x 5mm, then you should get the 5mm thickness ok, but the thicknesser wont like trying to machine a piece 50mm high x 5mm wide.

Better to make a piece 60mm wide, surface plane 1 face and 1 edge. Thickness to 5mm, rip on saw to 52mm, then go back to surface planer and plane off the saw marks to get to 50mm.

A thicknesser should be good to about 0,25mm, ignoring the ends of a board. The best accuracy on multiple pieces will mean putting them through in the same spot.

 

[dzj]

2.5mm is a bit too much.
If this happens when planing stock regardless of thickness, it's something to do with the
planer. Try going over the interior with compressed air, for a start.
Some planers don't 'like' working with thin stock.
A youtube search of 'planing thin strips or panels' will give you quite a few suggestions.
HTH

 

[Gary_S]

My son and myself have spent hours in my garage/w shop trying to dimension a piece of maple. We think we get a flat surface on the jointer/planer it doesn't rock or roll on the cast iron surface of the table saw. However, putting it through the thicknesser we seem to make rhomboids and struggle to get the thickness even being out sometimes by as much as 2.5mm across the length of the board (1 metre). It is to make a strip of 5mm length to be laminated as a decorative feature on a guitar he is making. Are we being niaive expecting to get metal work precision with woodwork?

What is the section you are trying to achieve? 5mm x?

Small sections are awkward, if its 5mm x 10mm or similar you would be better planing a piece 10mm thick x say 50mm and ripping off a strip 5mm.

If you are doing a piece of maple to finish say 50mm x 5mm, then you should get the 5mm thickness ok, but the thicknesser wont like trying to machine a piece 50mm high x 5mm wide.

Better to make a piece 60mm wide, surface plane 1 face and 1 edge. Thickness to 5mm, rip on saw to 52mm, then go back to surface planer and plane off the saw marks to get to 50mm.

A thicknesser should be good to about 0,25mm, ignoring the ends of a board. The best accuracy on multiple pieces will mean putting them through in the same spot.

The strip will be 5mm wide and 300mm approx deep it will be the salami in the sandwich.

 

[RobinBHM]

The strip will be 5mm wide and 300mm approx deep it will be the salami in the sandwich

Ah ok, so your timber section is 300 x 5 with a length of 600mm or similar?

The problem you will have is keeping the timber flat, as it will want to curl.

Surface plane 1 face, then put through thicknesser taking a small amount each pass. I would turn the board at every pass so you end up taking an even amount each side. If your machine isnt extracted well, then blow out dust between each pass.

If the board is tapered, either the chips arent clearing or your thicknessing table is moving during the pass.

 

[MikeG.]

Hand plane it, or use a drum sander.....but no way is a thicknesser the right bit of kit for that job.

Another approach would be to laminate it to one of the boards it will eventually be sandwiched between, then, once dry put the combined boards through the thicknesser.

 

[worn thumbs]

I don't quite understand the description of the piece being sought.The thicknessing problem as I understand it is that a piece of maple is varying in thickness by 2.5mm over a length of 1 metre.A well set up thicknesser should have no great problem holding accuracy much better than that and a serious professional machine ought to be good for less than 0.1mm.There could be a number of things needing attention in this instance and it might help to have a photo of the machine.I have in the distant past used a fairly light machine where it was essential to lock the table height as there was a tendency to seesaw as wood was fed in-does this particular machine have any kind of mechanism to hold the table securely?

The use of maple isn't exactly giving the machine an easy time as thin boards are likely to be drier than thicker boards,everything being equal,and dry hard maple is quite demanding.Depth of cut is another factor and with something 5mm thick you have to be cautious even with a cooperative run of grain direction.the fact that you haven't mentioned the wood erupting into a pile of splinters is a good sign in that respect.I also assume from the lack of disintegration being reported that the knives are in good order.

One final point-can you give dimensions of the piece you are trying for LXWXT.