Flattening material...

[harryball]

Can anyone suggest how I can go about flattening 9" wide x 24" blanks? I have a 6" jointer... even an 8 isn't wide enough. Using the planer is not working out, the crook is just copied to the otherside.

ideas?

[fleinbach]

Robert, Use the Shopbot.

I just plained 2" poplar 12" X 12' to make the bar top in my latest theater room. It is the easiest way to flatten a crocked or winding piece of wood.

To get maximum thickness I layed it on the table and placed shims under the high points trying to equaly distribute the imbalance. To hold it in place I used side presure clamping. Next I ran the table surfaceing routine and lowered until I had a flat surface. After that I surfaced the other side with my 20" Jet planer

[paco]

Here something you could enjoy; it's start from David Buchsbaum idea, Mike Richards and I hacked the code (here on the forum sometime ago) then I made another one for "the other axis along grain (Y)" version that I have never posted. I'd like to make it a single master file but haven't yet work on this project...

You can (should) preview it first.

I use 'em anytime I need to rectify and/or plane an wrap piece of wood.




5094 (1.9 k)


5095 (2.0 k)

Merry Christmas!

*<8o)>

[harryball]

This is great! I'm working with purpleheart and the problems is the boards are 1" thick and I need 3/4" thick. They were flat enough until my POS planer started working on them... the more I run it through the worse it gets. Now I have to get them back into flat on one side and try again.

I've still not decided what is wrong with the planer setup. I think the wood is just so hard I can't take enough of a cut to get a good hard bed on the wood, as if the rollers need adjustment (and I can't find any). I can take about 1/64" at a time or the planer slows down and it looks all choppy. I just put on new blades too. I tried some scrap pine with almost a 1/16" cut and it does fine. Only when I cut lightly does it start to twist the cuts.

I noted that the metal bed on the bottom of the planer is a thin sheet of steel that is bowed. When turning the infeed/outfeed tables I have to push down hard on the straight edge to flatten the warp in the steel (I know... you're now thinking "well there's your problem!")

I'm considering one of those new Dewalt 13" planers. Or at least a new Delta... opinions?

Robert

[rhfurniture]

I have a 12" jointer - send it to me

Stuff like that warps as you plane it, You need to take a little off each face flattening as you go. I would take 1.5mm at a time. There will be a tension between the surface of the wood and the centre, and you need to releive it evenly.

R.

[rcnewcomb]

We have one of the Dewalt planers. The blades like to chip if sand is embeded in the wood surface. Other than that it was worked for 18 months with minimal adjustments needed.

rh is correct about purpleheart twisting as it is planed. It also likes to tear out just when the piece is nearly perfect <grrr!>

[paco]

Unless you have a very large planer, you cannot rectify and wrapped board, you need and jointer for this... or a CNC tool!

The bot can be used to up it's bed size to rectify. My Bot is a 48" X 96" rectifier/planer. If I could afford a jointer (both financially and in term of floor space), I wouldn't go with the Bot for what the jointer could handle (time matter).

Planer if for thickness purpose mostly... and smooth surface at a glance.

rh,

Whoohoo! 12"! How many guys does it take to push on the push stickS?!

8-D

[rhfurniture]

If you dont get on with Paco's file, you could try this one - I use it to calibrate veneers and other stuff.
WARNING: I have written it for my benchtop and mm, so test it first. I have annotated where values might need changeing for imp, and you may need to fiddle with the position and size of the text box. You zero off the surface that you put the timber to be planed on, so entered values are final thickness. It is totally experimental, may not work, on your head be it etc etc

Facemill part file

5096 (3.7 k)

[paco]

Here something else that I dig out. It use the Bot as a thickness gage; sort of a CNC sheet good caliper... this was one of my first SB programming experience.




5097 (5.3 k)

As always, get familiar with the code and test it.

[paco]

rh,

where's park.sbp?

[harryball]

o...k... can anyone suggest how to hold down a 9 x 24 board on the bot to surface it :-)

My first idea was nifty double sided guide clamps, clamp to table, place and shim board, clamp board, surface away. Since I don't have those clamps, HD or LW's does not sell them and Rockler is more than an hour one way... I'm looking for plan B.

I was thinking of a vac holddown with weather stripping... let it suck down and see if it's stable and won't move... has anyone attacked the problem that way and maybe has a hint?

EDIT: Since I'm going to be doing so many of these I'm going to make a vac puck to fit the plank. I'll place the gasket about an inch inside the perimeter and use shims to position the wood like I want it and then run the surfacing routine.

Robert

[paco]

Side clamp with scrap and wedges; one or two should be enough. You might have to screw down some. If you're not too aggressive, you shouldn't need a very strong hold.

[rhfurniture]

Paco,
Sorry, I should have noticed that one. Park is my positioning to change material routine. You could change it (the whole of line 24) to JH, but probably best deleted. The whole routine needs to be gone through to set it up for how you work.