Warp in proofgrade wood products?

proofgrade
warping
qa

#1

This recent post got me thinking more about warping. Since most of us don’t have access to proofgrade products, I’m directing this question to the staff at Glowforge.

Can you provide an estimate of the average amount (and also worst case amount) of warp you are experiencing in proofgrade wood products in your offices? An easy way to measure this is to put a sheet on a flat surface and measure the largest gap that you see.


#2

Wood warp depends on heat and humidity, it isn’t a constant. They could ship something perfectly flat and it could arrive bent like a banana if it travels through a humid environment. Dry it over a radiator and it could bend the other way.


#3

Yes, I understand. I’m wanting to get an idea of what range of warp they are experiencing in one specific environment, i.e., their office environment.


#4

wood is wood its in predictable supplier doesn’t really change the nature of it. Heck leaving it on bare concert can cause you problems leaving it on top of another piece vs blocking can cause you problems using non symmetrical blocking can then cause your problems having it to close to a ac vent or a heat vent more problems


#5

Won’t try to answer per your request. You likely have already seen the unpacking video from @marmak3261. The Proofgrade panels were packed flat together and tightly wrapped to maintain shape. After you unwrap and store???


#6

I’d be interested in at least some ballpark answers, such at warp at some known humidity level or difference in warp among pieces, I’ve spent way too much time in my life sighting down boards or across pieces of ply. (I’d hope starting warp is minimal.)


#7

This, exactly.


#9

Coming from a high humidity area (like they have at Glowforge HQ), and recently having bought some non-Proofgrade birchwood ply that arrived perfectly flat 6 months ago, I can say that…

  1. Storing it flat with weight on top of it keeps it from warping.
  2. Storing it standing on it’s end causes nice sleigh runners to develop.
  3. Leaving a sheet out on the top of the desk for a week or two in an air conditioned environment can cause a couple of mm of warp to form, even in that short a time.

I think we’re just gonna need to watch how we store it.


Need Proofgrade for accurate alignment results?
#10

True enough. I use neodymium magnets to hold 1/8 & 1/4" ply & wood to the bed of my lasers when engraving/cutting. They’re thin enough that the head doesn’t bump into them when it’s traveling over them going to somewhere on the engrave/cut. It generally doesn’t get too warped to get a piece out of one but if I need something that is too big to come out flat on a warped piece I play swap-a-piece to find a good flat one. Store them flat and wrapped is about the best you can do.


#11

Um, folks, I’m not asking how to control warping or what causes warping. I’m asking Glowforge staff to respond to their observations.


#12

Whoop…sorry.:wink:


#13

You can try and prevent warping of course you just need to be aware that sometimes its out of your control. no matter how much you try. I cant use magnets in my laser the vector bed is aluminum. I had hoped it would be stainlelss steel but its not.


#14

If it’s a honeycomb, another trick I’ve seen used is using plastic wall anchors that will fit snugly into the honeycomb with a large washer and a small screw - the screw swells the plastic anchor just enough to provide the friction to keep it from pulling out of the honeycomb when the force of the warp is applied against it. The large washer is so you can reach a honeycomb cell off the edge of the piece.


#15

Great question!!!

Does pre-release guy with ProofGrade mateterials get a shot at this?

I don’t have a granite surface plate like the cool kids, but I do have a massive slate pool table for reference. All the materials were tightly packed. The plywood arrived flat and has remained so. I have kept them stacked and stored primarily on the pool table.

The only piece that warped slightly in the last five days was the sole sheet of 1/8" Maple MDF. Missouri has turned cool and the humidity dropped I have forced air electric heat pump. Sinuses are raw right now as I am adjusting to low humidity.

Will be interesting how the variable surface monitoring works on this without clamping jigs.


#16

With regard to aluminum beds, I suspect you could get away with finding/creating a thin bracket that slots underneath the bed and fixes your wood to it; it wouldn’t have to raise the honeycomb by more than a fraction of an inch, so shouldn’t affect your vert clearance much.


#17

yes, of course!


#18

No worries. I’m in dreamland if I think I can prevent the thread from wandering. :smile:


#19

Yes anything laminated on one side will warp with changes in humidity due to differential expansion making it curl.


#20

I’m betting they don’t absorb much humidity along the shipping path with that level of packing.


#21

It’s laminated on both sides. If memory serves me. will confirm.