Skip to main content

Laser cutting 1/8" plywood on a Full Spectrum laser cutter

So it turns out that there is actually a very big difference between cutting the various types of 1/8" hobby plywood! I had no idea.

I bought my plywood from National Balsa. They offer three types of 1/8" hobby plywood:

1. Lite ply, which is very light but not too strong. Apparently it is made from poplar. Very flexible. I haven't tried to cut it, but would imagine that it cuts easily.

2. Regular, 3-ply plywood which is called birch, but seems to clearly be not as refined as 6-ply. Much stronger than Lite ply, but a bit heavier too. Cuts really well! Less reflective, fewer layers which means less resin to melt.

3. 6-ply birch plywood. This is actual birch. Very reflective, strong and solid. Tough to cut! 6 ply's mean lots of resin to melt.

They also offer both 1/16" and 1/32" birch ply.


So, the other day when I was laser cutting my frames, I was able to easily cut through the first two sheets. Then on the third sheet, the laser was incredibly bright and flames were shooting off of the plywood! Yikes!

Turns out that that third sheet was actually the 6-ply birch plywood. I had ordered both regular 3-ply non-birch and 6-ply birch. My initial idea was that I would use the regular to do the test-hull, and then the good stuff (6-ply birch) to do the real boat. Now I'm convinced that the best way to go is with just the regular stuff.

I laser cut the regular 1/8" 3-ply on our Full Spectrum 90 watt laser at 60% speed and 45% power with one pass. It cuts very well and just barely releases the parts. There is little scorching and the cuts are vertical.

When I cut the birch however, I had to do many test runs. Turned out that the best setting to cut it was at 50% and 100% power with one pass. Multiple passes only scorched the wood even more. Even at the 50/100/1 setting, the cut was still very burned and had a noticeable angle to it. Yet it was the cleanest of all the test cuts I did. At this point, I'm not sure how to cleanly cut the 6-ply stuff.

My guess is that the birch is a much more reflective and harder surface than the regular stuff. I got similar reactions when I cut the 1/16" and the 1/32" sheets too which are only 3-ply, although due to cutting faster, and the thinner material, the scorching wasn't too bad. I'll continue to use birch when I need thin sheets, but at 1/8" I'll only use "regular" plywood.


Popular posts from this blog

IOM Sailboat Stand

I made an IOM boat stand! The plans are from David Jensen in Bellevue, WA, USA. I found the plans through someone else's blog here , and a model sailboat club from Australia here . It was pretty straightforward to build. My only contribution to the design is that I laser cut the cradle out of 1/8" Lite Ply. I made eight copies, and then epoxy laminated two sets of four each. Turned out really well. If you wish to laser cut your own set, here is my DWG file . You'll have to have your own laser cutter, or send the job to a laser cutting company like National Balsa . Here are the original plans , and here are the original plans for just the cradle . Thanks to David Jensen!! Note that in the picture below, my boat is not finished! Yikes. You can't see it in this image, but there's a small chuck of self-stick foam behind the bulb to protect the bulb. I'll eventually incorporate some Velcro or a strap of some sort to hold the bulb in place so

IOM Rig Box (IOM Sail Box) plans

So all the cool IOM kids seem to have nice wooden boxes to store their rigs in. This might be my next quick project then, so that I can pretend to be cool too. :-P The rig box images that I've seen online are mostly similar, and would work well, but David Jensen from Bellevue, WA, USA (The same guy who designed a fantastic IOM boat stand I posted about earlier) has a really nice design that he shared on RC Groups . Or if that link doesn't work, the go here and search for " IOM sail box " or " IOM rig box ". It holds three sets of rigs for the A, B, and C rigs. He also has a nifty way to attach his IOM boat stand, with a boat on it, to the rig box. His rig box has wheels attached, so once everything is loaded up he just wheels it to the launch spot. Very nice! There are other sources online. They show different variations of the same type of sail box. Here's a nice looking one . Here's a YouTube video of a really nice one . Wil

A Wooden "Alternative" IOM RC Sailboat

Being forced to stay home due to the Coronavirus quarantine has had a positive impact on my boat building. I still haven't been able to sail my newly completed Vickers V8 IOM, yet have just planked and glassed a wooden Alternative IOM . It only took me eight days. It usually takes a couple weeks. I haven't been motivated to blog about it, but I started planking on 5 April and finished planking last night. Today I sanded and have fiberglassed the outside. The Alternative by Brad Gibson was a challenge to plank due to its up-swept bow and flared sheer near the bow. It turned out okay, but as any builder will tell you, there are goofs all over. One that I only discovered after sanding is a lighter colored plank on the starboard side. It really showed up after fiberglassing as the epoxy brought it out... GAAAAH! How did that get there? The other goofs I'll let you find, but that one is pretty obvious. Here's how it looks so far: Here you can see that mu

IOM Alignment and Measuring Jig (UPDATED)

I need to start to consider how I'll mount the fin and bulb, and get it all straight, so I made a 3D modeled alignment jig: Ian Dundas in Scottland sent me pictures of his setup. I just bought a laser level too! He does amazing work and has been a great help in this project so far. There is also another jig featured on page 14 of the winter 2008 Canadian Radio Yacht Association (CRYA) newsletter that features one. It's by Lawire Neish. Read it here . I took both those designs and made my own version that features sliding cradles for the hull, a fixed waterline sight, proper depth to cradles for the bulb, etc... Most of the parts can be laser cut, and the two end pieces and the base can easily be cut on a tablesaw. It has fixed waterline sights that are 420mm above the top edges of the bulb sliders in the base. The fore and aft cradles can be slid up and down to adjust the waterline of the hull. You'll see that the overall interior length is 1003mm t