CNC Build: The Bed and Breakfast at 4 years and 40,000 miles

[capnTelescope]

boy did I feel stupid

I'm past the point of feeling stupid and wondering if I'm losing (lost) it.

Everything's going to be OK (EGBOK). This time.

Still waiting for my nail puller. In the meantime, I cut lumber for the starboard wall framing. It's ready to glue & vac. Except the left wall, which needs the nail puller, is sitting on sawhorses on top of a plywood sheet on top of the vac bag.


I made an "engineering" change that required cutting a piece off of the port wall top framing.

Titebond II is strong stuff. It pulled of the top lamination of the marine ply and some bits of the second.

This is on the top framing where the aft bulkhead meets it. I want to continue the top frame from here with 3/4 ply for dimensional accuracy & stability and to maintain consistent width. This is getting into hatch territory, which i'm sure makes most builders nervous. Me, too. Plus it gives me something else to cut on the CNC.

[capnTelescope]

The Nail Hunter arrived:


So I can quit whining about that. It worked fine, the nails came out, and I'm on to gluing on the cabin interior wall.

My neighbor came over to see what all the noise was about, just in time to help. Got the wall assembly off of the sawhorses on the plywood on the vac bag, and the sawhorses, and the ply, and a partridge in a pear tree.

We glued the interior oak veneer ply to the wall assembly, and got it into the vac bag. Started pulling down a vacuum. At about 15 inches vacuum I asked, "What's that cracking noise?" Turns out that a couple of corner supports I'd slipped between the ply sheets moved, and the 2 ply corners on the roof edge drooped right on down to the outer ply.

From right to left: suction hose, wiring bundle, follow that up to where the wiring disappears inside, and there's the collapsed corner. The square-ish wart left of the wire bundle is the support block that deserted its post.

Even more amazing, the ply within the door frame was sucked all the way down to the outside wall:

I didn't think the foam filler piece would be needed. Hah! Fooled me. Let's see you do that with your puny clamp collections! Bwa-ha-ha-ha!

Unless the wall comes out of the bag terribly deformed, it is ready for CNC cutting to begin. Stay tuned!

[KCStudly]

I would worry about the area around the door where the ply may have flexed up in order to bend down into the doorway. That part may have lifted (?) where it was bent over the door opening. That was why I filled the voids with dead foam.

Also, I'll say it again, build and glue the frame together first, then pin the ply to it at key locations to keep things from shifting around, then put it into the bag.

Hope it works out okay and you are able to save it.

[capnTelescope]

Hope it works out okay and you are able to save it.

Me too!

After I let the pressure bleed off, the top side looked like it relaxed, so probably it's OK. I'll get it out of the bag this afternoon and see for sure. I'm making this up as I go along, so some things aren't going to go exactly as planned.

"Experience is what you get when you didn't get what you wanted."

[GuitarPhotog]

"Experience is what you get when you didn't get what you wanted."

One of my favorite sayings because I seldom get what I want, so I have lots of experience

<Chas>

[capnTelescope]

I don't know if anyone else was as anxious as I was to see how it turned out. Alright no one was as interested as me, but close? OK, here's the news. I'm declaring 95% or better success, but not 100%. This wall goes on to the CNC. We'll CNC 'n see.

Here it is, fresh out of the bag:

This gives you a look at the wood grain for the interior wall. It's going to look good when stained and varnished. From here, we go to the router, where the interior skin, framing, and outer skin get cut to "exact" size. (fingers crossed)

The interior ply was cracked inside the door frame.

You can see it, sort of, in the middle of the photo. It looks to me like most, if not all, will be cut away for the door opening. The door frame will hide whatever is left. Disaster avoided.

There is a slight bulge along the bottom edge under the door.

That fence slat is straighter than it looks. Not saying much. The bulge will be covered up by the mattress, but might affect mounting the door.

All in all, success! Thanks for reading.

[capnTelescope]

Router dust flew today. Well some flew, a lot got packed into the same place it came from and had to be dug out.

In my last post I pointed out the bulge below the door opening. Well, it was more than that. I got the wall assembly up on saw horses and ... The whole dam' wall was bent, so it was drooping up instead of down in the middle.

I moved the wall from the garage to the shop.

That would have been enough for one day right there.

I wrestled the wall up on the router table, clamped the corners and measured the bow. 11/32nds before any cuts.

My theory is that the inside ply got sucked in while the glue was wet, and expanded back after the glue dried.

I took 2 laps around the door.

On the first lap, I lied to the computer and told it the cutter was an inch in diameter. This generated a tool path that was considerably undersize. I wanted to take a peek thru the groove to see if I was positioned correctly before I cut to size. It looked good, so I told the truth (always the best policy) about the cutter size and got the correct tool path for the second lap.

I got a nice, mostly usable offcut of oak veneer ply.


A little chisel work got me to here.


The bow in the wall is now 7/32nds. Progress!


But the door doesn't fit.


I traced around the door corner, and found I was using (ass-uming) too big of a corner radius.


I went back to the drawing board, fixed the radius, checked the tape and went for the full depth.

Got me another nice offcut. This time it's Marine ply.

Here's a closeup of the cut inside of the door opening.

Top to bottom: 1/4 oak veneer ply, 3/4 poplar, 1/4 marine ply. The final cut took out the poplar and marine layers in one whack.

We're down to 3/32nds!


There's the wires for the door switch. Where's the string?


All is well!


The door fits fine, no gap-osis.


I'll get the video up PDQ.

Thanks for looking!

[tony.latham]

I used those same doors and really like 'em. What I didn't care for, was the bare aluminum trim. I cleaned it up, sprayed it with a self-etching primer, and put a finish coat on it. This pic will give you an idea on how it looks. Too cold out there (+25º) to run out and take a better pic.


TL

[capnTelescope]

The pucker factor was off the charts today, with tool applied to the left wall assembly for the first time. So far, so good!

Here's video of today's festivities, cutting the door opening:



Enjoy!

[capnTelescope]

I used those same doors and really like 'em.

Me, too. Grant does a really nice job on them. These doors earn the CapnTelescope Seal of Approval.

I really like how they look with the paint job you did on the trim piece. I'm going to steal the idea, if you don't mind. Did you use any particular brand of primer?

Now that the wall is on the router table, more CNC stuff will be happening on a regular basis. The second wall should go quite a bit smoother, thanks to Experience.

We went from T-shirt weather this afternoon to 35F now. I went out to the shop a little bit ago & nearly froze.

[tony.latham]

I don't recall the brand of self etching primer. I just grabbed an aerosol can at NAPA, along with silk black. After the self etching stuff dried, I roughed it a bit with a Scotchbrite pad and sprayed the finish coat. It seems to have stuck. Have at it.

TL

[AlgoDan]

I must say watching your videos Brad has me wanting my own CNC, Dang should of asked for one for Christmas lol. Also your videos puts me in the shop kind of feeling...

[capnTelescope]

I must say watching your videos Brad has me wanting my own CNC, Dang should of asked for one for Christmas lol. Also your videos puts me in the shop kind of feeling...

Thank you, AlgoDan. Just sharing the fun and spreading the religion.
Probably gonna be a whole bunch of spouses teed off at me for that.
Now I have to remember to change my tee shirt from day to day.

WARNING! Advice follows:

For those of you getting the itch, there's a few things to think about. First, do you want to build a CNC or do you want to use a CNC? If you want to build from scratch, you're a better man than I am, Gunga Din. Just realize that it's going to take you longer to get started on those pet projects you're dreaming up. Probably a lot longer. If you want to use one, consider a turnkey kit or go with a ready-built. Mine's a kit, and I have no doubt I made the right choice for me.

Size the thing according to what you want to build. If you want to make things out of plywood, you need a 4-foot wide machine. (Sometimes they call me CapnObvious. ) Blah blah blah.

A CNC router is an extremely versatile woodworking machine. You can use it as a thickness planer, a jointer to straighten boards, panel saw, drill holes of any size, and make almost any shape. So you can tell the love of your life you won't need to buy any of those things. Well, almost none.

Plenty more free advice is at http://CNCzone.com. They're the TnTTT of CNC. Go there.

(/advice)

[AlgoDan]

If you don't mind me asking Brad, what is the cost of a kit like yours?

[capnTelescope]

If you don't mind me asking Brad, what is the cost of a kit like yours?

I don't mind. The basic machine is a CNCRouterparts CRP4896 with a base price of $3795. With NEMA34 upgrade, prewired electronics (strongly recommended), cable tracks, dedicated PC, software (CamBam and Mach3), spoil board, router bits, spindle motor, so on and so forth, you need to be able to budget around $5,000 for the whole project as a minimum. YMMV.

The basic CRP machines are open source. You can download the plans and build from scratch. They also sell their proprietary parts for the machine. Think teardrop build, as far as getting all the materials and parts together, and it's a zillion times easier to buy the kit.

CNC Router Parts has earned the CapnTelescope Seal of Approval, but there are other good sources out there. Poke around http://cncZone.com for more/less expensive alternatives.

Good luck with your Finance Committee!