Planer/T advice requested

[devonwoody]

My P/T SIP has behaved perfectly up to now but today I am getting a snipe using the planer. It is producing the snipe on the last one inch of planing the edge of timber. I have not experienced this before and I feel that my technique has not altered. ( I am not holding down the last end on pass over the cutter)

Any advice appreciated. .

 

[Steve Maskery]

Hi DW,
Tony has a few ideas on how to minimise it, look at his recent thread.

However, FWIW, here's my take on snipe.

Love and marriage, horse and carriage, spaghetti and bolognese, P/Ts and snipe.

A P/T has two rollers which press the timber down onto the bed. These are sprung, if they weren't, you would have zero tolerance as to the thickness of board presented. As long as they both keep the timber pressed down, you won't get snipe.

The problem arises when the weight of the board hanging out of the machine is more than ONE of the rollers can handle. The weight pulls the board down, thereby forcing the other end (no longer supported by the infeed roller, and heavy enough to flex the sprung outfeed roller) up into the blade. The only way to prevent it is to support the wood so it doesn't fall at all as it comes out (or goes in, of course).

Does this help?

Cheers
Steve

 

[thomaskennedy]

The SIP you say...

Tony has a SIP one and *claims* :wink: that he has eliminated his snipe by using the little brackets on the thicknessing bed...

Look at his post

thats for the thicknesser of course :roll: as i have just re-read your post its the planer that your getting snipe with .... as for the jointer you could leave the extra few inches and cut off after planing...

But thats not very practicle...

Someone will be along with a more practicle solution :roll:

Ta

Tom

 

[Noel]

Dev, I think it's quite difficult to get snipe using a jointer, it's either technique or the timber. Or a very slight possibility of a badly seated outfeed.

Noel

 

[Noel]

Dev said " ( I am not holding down the last end on pass over the cutter)" Looks like, or at least I hope, he's talking jointer....

Noel

 

[Aragorn]

We talking thicknesser or surface planer here?
If the latter, then my bet would be that the outfeed table has budged a bit and needs resetting.

 

[Steve Maskery]

Ah yes, not for the first time in my life I've got the wrong end og the stick.

Yes, indeed, eithe r you outfeed table has dropped, or your blades have moved up (much less likely but possible if you have had a kickback.

The outfeed table should be fractionally lower that TDC of the blade (the surface is like ploughed field, and the ridges, not the bottoms of the furrows, must be level with the outfeed table). Too high and the timber will not ride onto it without hitting it and being lifted up, too low and it will fall onto it until the infeed table runs out when it will drop with a sickening 0.5mm thud. Snipe.

It's very difficult to eliminate thicknessing snipe if you machine big stuff, but it should be fairly easy to eliminate planing snipe.

Cheers
Steve

 

[devonwoody]

Top table snipe

Yes I did have a kickback yesterday.


So has soon as the storm has passed over, it looks like a have a setup session coming on again.

Let you know the outcome, although it looks like my new project is going to be 3mm narrower

 

[Pete W]

it looks like my new project is going to be 3mm narrower

3mm? Why, that's almost invisible :wink:.

 

[devonwoody]

it looks like my new project is going to be 3mm narrower

3mm? Why, that's almost invisible :wink:.

Yeah but I had already reduced 2mm earlier.

 

[Gill]

Talking of small dimensions, I've been thinking about using a sled to carry some small, thin pieces of timber through my thicknesser. I'm worried that they might not survive the journey unaided.

Has anyone ever made such a sled? Does anyone have ideas as to how one could be made?

Gill

 

[Chris Knight]

Gill,

I have used a piece of MDF with a couple of small bits of double sided tape to hold the wood being planed. The only problem is that double side tape can stick like the dickens and there is a danger of wrecking the wood getting it loose from the carrier.

I have seen but not used, sleds that have a very thin fence fore and aft of the prices being planed. As long as these were glued rather than screwed, they are probably fine - could perhaps use tape to stick the fences for speed too. If there were a danger of the piece buckling under the planer blades, then I would be inclined to stick fences alongside the wood so that the feed rollers did not put all their pressure on the wood to be planed.

 

[gidon]

Gill
I've used a sled to carry <3mm thick pieces of wood through my thicknesser. Just a piece of contiboard the rough dimensions of the thicknesser table with a lip / stop screwed underneath at the back. And then just let the pieces pass through. I have put small (length) pieces through like this too and I've not had a problem.
How small pieces do you need to pass through?
Cheers
Gidon

 

[beech1948]

Gill,

I have used a couiple of devices for thinner pieces.
1) down to about 6 mm I have used a piece of ply with stops glued and screwed on. The screws obviously being countersunk to be 3 mm below the finished surface...so you need to be very careful about tightening the screws...slow but sure is what counts. I mainly use this on wood which could break up when thicknessed below 8 mm..eg curly grain etc etc.

2) I have used a ply sled with glued on stops a front rear and if necessary the sides. Don't need to be all the way round but need to be about 2/3 of the length. A good approach is to use tape for the trailing stop to allow later adjustment. I have gone down to 3mm this way. Again try to be slow but sure taking very slight passes eg. 0.5 mm or less

There is some danger of pieces breaking up, they can sound explosive in your thicknesser but it does not happen very often. More sound than damage, so you might need to prepare and try a second piece. Good luck

alan

 

[devonwoody]

Had a rough time this morning setting up the planer
I've had to reduce the projection of the blade from blade holders down it wouldn't have anything to do with the old settings.

I've been machining up that sycamore Tony advised looks like its a bit tough and blunting the planer/thicknesser blades.

 

[AndyG]

I'm building a new bed and sled setup for my thicknesser. Motivated by some rather iffy in and out feed tables.
Hopefully the end result will be a long bed that will reduce snipe and allow a sled to be used on warped timber that needs flattening. I'm very happy with my thicknesser, but I get very fussy when it comes to wood being flat, so I'm hoping this setup will help.
I'll post some photos of the rig soon, so you can see if the solution might help you.

 

[Anonymous]

The SIP you say...

Tony has a SIP one and *claims* :wink: that he has eliminated his snipe by using the little brackets on the thicknessing bed...



Tom

Claims?? Whadya mean claims???/

I provided photographic evidence didn't I? :lol: :lol:

 

[Charley]

The SIP you say...

Tony has a SIP one and *claims* :wink: that he has eliminated his snipe by using the little brackets on the thicknessing bed...



Tom

Claims?? Whadya mean claims???/

I provided photographic evidence didn't I? :lol: :lol:

Ah but it could be a cunning photoshop trick :-$ :lol: That's why we need WIP pictures :wink:

 

[Alf]

Ah but it could be a cunning photoshop trick :-$ :lol:

He might even have <gasp> hand planed it... :shock:

 

[Charley]

Ah but it could be a cunning photoshop trick :-$ :lol:

He might even have <gasp> hand planed it... :shock:

Never thought of that :shock: Umm Tony I think we need some more prove :-k Instead of just photos is there any chance you can video it? :lol: