Many (most?) people here probably don’t remember the Selective Service Board. My brothers both got numbers from the government that entered them into a lottery for the privilege of serving in the military in Vietnam. One volunteered instead and flew missions over Cambodia, the other had a school deferral because med school was consuming his time, leaving little left over for learning how to shoot M-16s.
The United States hasn’t had compulsory military service since the end of the Vietnam war, relying entirely on its volunteer citizen soldiers in all branches of the military.
It seems somehow fitting I was able to spend this 4th of July holiday weekend making projects on the Glowforge. We have a degree of freedom undreamt of by people before 1776 and our Declaration. Having the ability to purchase, own and use a machine like the GF would have been nothing short of magical. Using it for the projects we’ve seen in the forum would be prohibited in many countries in the world today. We really are very lucky people in a very special time in history despite the doomsayers & gloom we might otherwise succumb to.
So this weekend I played with another draft board, different from the one that made such an impact on my brothers and their generation.
I just got another order of Proofgrade last week. Included in my order I made sure to get 10 sheets of Draftboard along with resupplies for my favorite cherry plywood and more hardwood.
My Draftboard came in less than a week from order and packaged for protection. (All of the materials had the new thin/medium/thick designations on their bar codes.) Nothing damaged, dinged or warped.
Draftboard is an MDF-type of material. Masked like other PG. Being PG, the GFUI will set the appropriate speeds & power for operations so there’s no need for a bunch of materials testing.
Except, I’m looking to potentially replace my test/initial project material of choice - Baltic Birch plywood- with something a bit more reliable in cutting and overall performance. So, how does this Draftboard measure up to BB?
I pulled out a sheet of medium (3mm or 1/8") and a sheet of thick (5mm or 1/4") Draftboard. I dropped my cut calibration template into the GFUI. For the outside of the template I picked auto-cut and the dark engrave setting. The cut boxes were set for 100% and the appropriate speed.
I left the focus setting to the GF PG default (.209" for the thick and .125" for the medium).
Here’s the calibration result before unmasking:
And the back:
If you look closely, you can see that a couple of the boxes appear to be nearly cut through, almost full perforating the masking. In fact when I removed the masking, a couple of the squares popped out.
Unmasked, the final cuts looked like this.
Instead of the initial 40 & 15 IPM speeds (med/thick) it looked like were required to cut through, once the masking was removed and the other cuts freed, the Draftboard cuts cleanly through with no spew at 50/20. In fact both of the next faster speeds are virtually cut through so the true fastest speeds possible are closer to 60/30.
Nice to know, but really with automagic cuts set by the GFUI it’s somewhat academic. But, it looks like the automagic settings are very conservative (at least for my PRU) with the GF showing 30/17 when I tell it to make the automagic cut a manual one instead.
Using manual cuts could allow you to churn through projects faster.
How’s it compare to my old mainstay Baltic Birch? Draftboard is a perfect replacement. The cut calibration sample on the left is BB and Draftboard is on the right.
The masking on the Draftboard makes for very clean cuts, even when slower than needed speeds are required. More than that though, flashback is less severe even accounting for the masking. The BB surface veneer was more easily fried by flashback as can be seen in the photo above.
What’s more, the kerfs are exactly the same - at least within my ability to measure. Cut outs can be fitted perfectly in either the Draftboard or Baltic Birch calibration samples.
Why does this matter? Well, I’ve a library of projects using BB and it looks like Draftboard will just drop right in without needing any tweaking. Does it really matter? Why not just use Baltic Birch for my projects?
Easy - the Draftboard is consistent. Those power & speed settings are unaffected by glue, knots or voids. The last set of BB I got last month had a 50% failure rate on my Codex project where almost all of the part was cut through but not all. And the uncut portions needed to be done by hand or relasered. With complex parts, it wasn’t possible to get the cuts right with my razor knife so relasering with slower speeds was required.
The finish on both is similar but the Draftboard takes paint like MDF. For painted projects it’s a better base than BB and doesn’t require any surface prep after removing the masking.
As for price, the BB cost me almost $6 for a 12x24" sheet and Draftboard was exactly $6 for a 12x20" sheet. The BB requires cutting down to fit into the GF and masking by hand. On a price per square inch basis, BB I was 2 cents and Draftboard 2.5 cents (2.2 with my Founder’s discount). Clearly, considering the time & cost to prep BB results in there being virtually no difference in price.
Unless you need the structural strength of the alternating plies of plywood, Draftboard is a clear winner.
Anyone want a stack of Baltic Birch? 
Using Draftboard just needs a bit more planning.