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

[tony.latham]

Your build is still catching my eyeballs. First it was the CNC router, then it was the white Tacoma (a bit of a joke there), and now the vacuum bagging. I've got a vacuum pump on my wood lathe for running a vacuum chuck –how'd you do the air connection into your homemade vacuum bag???? Maybe I'll git to Googlin'.

And yeah, 30ºF? I haven't seen it above freezing for over a month. I think it was +14º this morning.

Tony

[capnTelescope]

Terry,
I considered calling my next-door neighbor in. He owes me. Now that I've done it once, I've got the method down pretty good. I'll give him the hard work & take the light end.

If you're doing vacuum hold-down and vacuforming, you're more than halfway to bagging. I wanna do both of those. I got started when I wanted to re-veneer a piece of furniture, and mechanical clamping was a total fail. Try it, you'll like it.

[capnTelescope]

Tony, try deciphering this.



veneerSupplies.com is an excellent source for info.

[KCStudly]

13 deg F on commute into work this AM.

Shop temp was 32 -37 F last night. I got 2 hrs work in.

Capt, your vacuum bag setup is the most comprehensive I have seen here.

Is the pond liner just duct taped together, or did you glue it with contact/rubber adhesive?

[capnTelescope]

Hi, KC

Capt, your vacuum bag setup is the most comprehensive I have seen here.

(edit) Thank you, KC. I'm forgetting my manners. (/edit)
I had most of this made up for the veneer repair I mentioned earlier. It did such a superior job there that it was an obvious method for this job.

Is the pond liner just duct taped together, or did you glue it with contact/rubber adhesive?

Neither. Or both. They sell a tape for for that. It's two-sided, 3" wide, and made of just the right stuff for this material. It's supposed to hold water, so I figured it it would work for vacuum, too. All told, it was about half the price of the bag material that veneerSupplies sells.

I get to pull out the glue-up today and see how well it went. Fingers crossed.

[capnTelescope]

Seeing how much the vac bag stretched around the framing boards yesterday, it seemed to me that there was a big chance that the frame pieces could get pulled away from where they are supposed to be. I got to thinking about what I should do, and a lightbulb went on. I'm going to insulate the walls with rigid foam anyway, so why not go ahead, cut it out, and put it in place temporarily? I'll end up with a fairly flat surface that won't be prone to pulling things the wrong way. So off to HD to get 2 4x8x3/4 sheets of insulating foam rated at R5. I wasn't looking forward to measuring and cutting all those pieces, and said to myself, "Self, I wish I had a CNC machine to do that. Oh! wait! I do!" Which leads us into today's video.

Working off my framing layer, I sent a DXF to CamBam, imported it and added a few necessary lines. Next thing I knew, I had G-code to rout out the insulation pieces. Voila! Wah-lah! Walla! Since the foam is nice and soft, I turned up the feedrate to 400 IPM and took the whole cut depth in one swell foop. I now have a shop full of foamy router dust and two sets of wall insulation pieces. I'll have to get out the leaf blower later.



Not much left of the insulation sheet afterwards:



I turned off CamBam's cutting sequence optimization for this tape, and it has an awful lot of short moves and up/down monkey motion. Humbug. And I thought the optimization modes were kinda goofy. They are, just less so. Since I'm only making 2 sets of parts, it's not worth any more effort.

After I pulled my wall out of the vac bag this morning, I confirmed my fears. The baseboard had moved about half an inch the wrong way, away from the plywood edge:

Photo coming tomorrow.

If it had moved toward the edge, no problem, just more wood to rout off. But the baseboard is an important locating surface, so this won't do at all. Luckily, the fix is easy. I'll just glue a 1/2" thick strip of wood to the bottom of the baseboard before I put this wall up on the router, and when it's all together, no one but us girls will ever know.

On this fourth round trip in/out of the bag, I also realized that having the floor of the vac bag higher than the surface I'm assembling on causes me to have to lift the wall into the bag, and stuff moves around. The second wall should go much better by having the work level with the floor of the bag.

I noticed that the insulation was ever so slightly thicker than the framing lumber. That will have to be addressed before I glue on the interior wall. Anyone have a smart fix for this problem? It's only about 1/32".

[KCStudly]

My minimal frame work was assembled (biscuits and glue) before edge gluing the insulation to same. A long board and sand paper gets the foam flush, with some detail work using a smaller hand sanding block to dress the areas of GG (they are harder and need special attention, lest you gouge the blue/pink board). Then vacuum bagged the panels.

When aligning the panels to the wall I used a few pneumatic staples along the baseboard and around the door frame to hold alignment; these got covered later by trim. I used scraps of foam in place of my windows and my doors in the doorways to keep the bag from collapsing in these areas and prevent twist/warp from the bag pulling in on itself.

Shop vac is much better for cleaning up after foam. Leaf blower will just move it around.

[capnTelescope]

KC, I'm sure glad you're paying attention here. I got boards. I got sandpaper. I got sticky stuff to put sandpaper on boards. I even got some elbow grease. Thank you!

I think I'll do this outside the shop.

I'll need the leaf blower to get the fluffies out where the shop vac can get them. I do this from time to time. Too much detail work with just the shop vac. It's OK, I'm an engineer, I know what I'm doing. (Where's that line from? It was a movie. I think it was originally "psychiatrist")

Today I had to take care of some work-ish stuff that keeps getting in the way of play. Tomorrow too. So nothing got done today or manyana.

BTW everyone, the video link in the last post is fixed. Treat yourself to a funny cat video (or whatever) after you see it. You'll have earned it.

[capnTelescope]

After 2 days of other stuff getting in my way, I was back on the build today, and finally got my wall out of the vac bag.

I mentioned how my baseboard moved in an earlier post, and promised a picture:

The edge of the board should be on the pencil line, which is 1/2" from the edge of the ply. It moved over a 1/4" past the pencil line, which is where I will be cutting later on the CNC. I will glue in a strip of wood so I can make a true cut on the baseboard. That edge will one day rest on the floor ply, and must be right or the 2 walls will be cocked relative to each other. I didn't expect everything to go perfectly, and this is an easy fix.

Here's the wall fresh out of the vac bag.


The breather mesh left an impression on my insulating foam.

I'm using the breather mesh sold by veneerSupplies.com. It helps get all the air out of the vac bag by providing a path to the suction port. The surfaces you see here were smooth going in. Frankly my dear, I don't give a tinker's hoot, but others, especially foamie builders, be warned.

I was going to set up the saw horses and sand down the too-thick foam, but the skies threatened rain, so I set up the saw horses in the garage and worked on the wiring in this wall. Of course, it didn't rain. I am running the wiring inside the walls rather than inside along the bottom of the wall or inside the roof. So I'm running wires now, and hooking things up later. I need to be pretty sure what electric goodies I want now. I also need some way to know what wire is what. I have 7 colors of wire to choose from, so a lot of combinations. I'm using twisted pairs/triples. usually a ground (black) and another color. Not just black/red. Here's where my automotive experience comes in handy. Here's some pix of how it turned out:




Photobombed by the TV:



Twisting the wire pairs was a thing in itself. Wire comes off the spool all curly and tangle-ly:


First, do whatever you can to straighten the wire:


Hook up your (wire) pair to your slowest variable speed drill:

For emergency stop, pull the clamp straight up and off.

Make sure the wires are separated and not tangled. Tighten the clamp just enough to get the drill going slowly. Take one wire in each hand and hold them apart. As the drill turns, you will feel the wires wanting to turn in your hands. This is a good thing, to be encouraged. Allow the wires to twist naturally in your hands as the drill turns. Expect some tangles as you get to the end. Pull the clamp, and you're done. You now have a twisted wire pair that's about the same length as the untwisted wires, and it stays twisted and doesn't unravel. An assistant to start/stop the drill on command would be a big help. It's a low-skill job that doesn't require a lot of training.

Some wires do have to go in the ceiling space, such as fan, dome light, etc. To get there without exposing the wiring, you gotta go through the wall framing. Not yet! We still got some cuttin' to do on the CNC. I pondered this problem for some time. Here's how I think it's going to work: Drill a hole thru the framing, edgewise. Thread a string thru the hole & tie it securely to the wire.


Leave the extra wire inside the wall and start the end into the hole.


So far, so good. I've done it up to here. According to theory, you finish assembling the wall & CNC it. Cross your fingers. Fish the string out of the hole & pull out the wire.


We'll see how this goes. There's plenty of opportunity for Murphy's Law to take effect.

[GuitarPhotog]

Nice! I made lots of twisted-pair, three, four and five wire harnesses just that way. I bought twisted pair for my trailer because it's easier to find here abouts.

<Chas>

[capnTelescope]

A little progress yesterday. The rain I was worried about on Friday came early Saturday Morning. Then the sun came out. Temp in the 60's. Nice.

First I sanded down my wall foam to pretty close to flush.


Peel


Need to take off this much:


Apply elbow grease. Rinse-repeat. Worked up a sweat.

I also glued on the repair strip for my base board and added some more meat on one side of the door opening.


Remember the nails I shot to keep things from moving around, only they didn't? Now I can't get them out, and some are real close to where the router is going to go. I don't have a proper nail puller, and the wire cutters don't work very good. If it weren't for this little issue, I'd be ready to glue on the interior wall. I did some quick online research, and settled on the Nail Hunter. It's the younger brother of the Nail Jack. Rockler had the Jack, but not the Hunter. Woodcraft had neither. But I did find it on Amazon. So, progress on the left wall is stopped, waiting for my new tool to get thru the Xmas rush of mail. Oh, well. It's cheaper than replacing a ruined router bit.

Someone once said that the chief cause of problems is solutions. Amen. (Soapbox) And when government comes up with a solution... (/soapbox)

Wow! Vista just crashed to a BSOD in the middle of this post, and I thought all that above was lost. But it's still there! Pretty darn good BB software we have on the forum!

I'm quitting while I'm ahead. I think I'll start on the right wall while I'm waiting for the Nail Hunter.

Merry Christmas to all.

[capnTelescope]

Pop quiz! What's wrong with this picture? (Full credit.)


Or, if you prefer, What's the significant difference between that picture and this one? (Less credit.) Hint: it isn't exactly the clamps.


I'm so sure everyone's on pins and needles wanting to know the answer. I'm starting work on the starboard wall, since I can't go on with the port side until I get nails pulled. After the vac bag shift I suffered the first time, I decided to glue & clamp like the rest of the world and avoid repairs. I should be so lucky. I was on my way to the house to get the camera when it dawned on me: I had the two end pieces bass-ackwards. I was well on my way to making another port side wall!

Luckily, the glue hadn't set up and it was an easy fix. Everything came out OK.

I'm taking the rest of the day off. Merry Christmas!

[KCStudly]

It's going to happen. I tell you (essentially) what they told me, "the difference between a craftsman and a hack is how well one hides their mistakes!"

Looks good from my house.

[capnTelescope]

They tell me you're supposed to do it perfectly or paint it red so it doesn't show. That's the general idea here. Slop on the glue now and cut it perfectly on the CNC. Two left walls would be hard to paint red so no one notices.

[GuitarPhotog]

My shop houses the "Fiddle, Diddle, and Finagle" wood works. The motto is "Saw to shape, File to fit, and Paint to cover"

But, I've built two left sides before, boy did I feel stupid, mine wasn't so recoverable as I had cut dados for the shelves in one side

<Chas>