Tucson tortoise: Edit for photos

[noseoil]

OK, better this morning & only worked until it got up to 95, then called it quits. Here's the skinning stuff. Passenger side skin in place from yesterday.


I added a lower part below the AC box, because the roof panel would have been 122", needing two splices. Figured it was easier to just place the bottom panel first, then seam the roof at the top in one spot I could control.


Here's the groove for the 1/8" X 4" backer for the splice in the roof panel. Just used a router & plowed a slot for it to sit in. It's milled into the vent area as that's just where it was easiest to set things up. The roof panel is about 1/2" too narrow to fit at the edges (60 1/2" wide build because the frame is 1/2" too wide). The 60" aluminum won't cover completely either, but I'm not too worried about it. If I have a 1/4" gap at each edge, the aluminum molding will cover the edges with plenty of overlap to spare & the mastic will seal the edge as well.


Full panel in place showing the AC box. I've figured out how I'll mount the AC, let it slide & close for a weatherproof fit. Not time to explain it yet, so I'll wait until I have some pictures showing how it will install be made waterproof.


The hatch spar in place & the top skin glued with a few clamps to hold it until the glue sets up around the staples.


I'm going to slop on some urethane seal up the skins & keep water out of the joints prior to the aluminum skin being applied. An early end to the day today (only 6 hours). Next on the list will be the hatch build. I have most of the stuff to do it & get it made (struts, wiring, latch, ribs cut, etc.), but I'm thinking I'll work on it next weekend. Still need to do a couple more sketches & firm things up in my mind before I start. Making progress! As always, thanks for looking!

[dales133]

Looking realy good mate,what hatch method are you going with?

[noseoil]

Thanks Dale! I'm not sure what it's called. This is a sketch from last year showing the basic build-up in a sectional view, a slice through the area of the hatch support at the wall. The inner edge sticks up 1/2" to form a shoulder. The gasket is squashed down between the side wall edge & the bottom face of the hatch. It will be slightly different than this, but the main elements are going together like this. The 1/4" filler has been replaced by a 1/2" spacer made out of birch plywood, which holds the wall-side strut support as shown.

Is there a name for this type of edge & seal? I don't know what it might be called, but hopefully it will close properly & seal itself well enough. As long as it's durable & works I'll be happy.

[KCStudly]

Looking good there Noseoil. I would leave a good 5/16 to 3/8 inch clearance between the inner wall trim and the edge of the first rib. I only left about 3/16 inch and had to cheat that some, so with a little flex and stack up of things I can make my ribs rub if I don't lift the hatch straight.

[lfhoward]

Nice work today! It is inspiring to see you skinning the trailer, as hopefully I will be at that stage soon. I like that you have a built in air conditioner in the Tortoise. Will you be able to run it from batteries via an inverter, or will it be for electrical hookups only?

[noseoil]

KC, point well taken about the hatch opening. I'll leave a gap of about 3/8" on both sides for clearance, which should be plenty. I don't think I'll have too much twist the way it's going to be built, but better safe than sorry holds up here. Thanks for the tip, duly noted & will shim the sides with 3/8" material when I begin the hatch build next weekend.

The AC unit is a small window shaker (5,000 btu's) and draws about 400 watts when running. I have enough capacity in the inverter (1,000 watts continuous rating) but the battery is the weak link here. 400 watts divided by 12 volts is 33 amps. Add another 10% for the inverter loss and it's now about 36 amps at best. With a 100 amp-hour battery, it means a useful duty cycle of about 50 amps available for power before having to recharge without damage to the battery from sulfation. That being the case, the AC could possibly run for a bit over an hour, but that's just brutal on any battery. It would mean some major duty-cycle stuff happening when the battery is already too hot & pumping out high amounts of current on top of it. Not the direction I want to go.

The circuit for the AC comes from the shore power side of the PD4045 panel, not the inverter side. I have an inlet on the driver's side for this, so it will be either an extension cord & shore power, or a small generator (yuck, noisy & a poo-tinky little beast). Costco had a sale on their Yamaha quiet type last year, I grabbed one which should work very well. It's a 2,000 watt model, so in a pinch, I can run the generator if I need some cooling at odd times.

Realistically, I think it would take two things for a battery powered air conditioning setup in a small camper. A good strong bank of heavy-duty batteries with lots of power available, or a more efficient AC unit that draws about half of what we have available in today's market place. The AC unit itself is still too big for the size needed in a small box. I guess if you had about 400 watts of solar energy available, it might be a good way to go, but that's a lot of panel area on the roof (about 30 square feet & 100# of top-hamper where you don't want it) and all operating at peak potential as well.

The idea after this summer's build is to AVOID THE HEAT at all costs by going north and into higher elevations! Next summer I plan on doing just that when I retire. For now, it's still a weekend ritual of exercise in the excessive heat and masochism through woodwork & wiring..... Who knows, maybe next year we'll start looking for a place that's cooler to live during the summer.

[Rlowell]

Everything is looking great!
Thanks for sharing your build and ideas with the rest of us.

I have just relocated my A/C to the front of my build.. Had to cut the hole, build a platform to sit on and seal the surrounds area. I also added a box to cover the unit what not in use which also gave me some storage space. I will use shore power
exclusively as it is readily available at most site here in Florida.

Is anyone else champing at the bit to go camping? Just way to humid here to get out.

Rod

[S. Heisley]

It may be hot where you are; but, count your blessings that it isn't raining as well.
Keep going. You're doing a fine job. Getting any work done when it is hot is admirable.

[Rlowell]

Did you mention rain?
We have rain and humidity and lots of mosquitoes in this area. There are times that I wish I could move back to the dry climate of my youth.
We are setting new records for rain fall this year with my area reaching well over 15 inches just for this month so far.

I am so looking forward to camping season this year.

Rod

[noseoil]

Started on the hatch build this morning. I'm using people's advice about gaps & the correct fit. Made some shims to hold things in place to "float" the pieces in place as I go. Basically, I used 1/2" ply shims at the sides, a .030" shim at the bottom on the deck & a .375" shim at the top to simulate the hinge. Just some blue tape to keep things in place. I had cut the ribs out last year when I made the sides & I've had them under some bricks to keep them (somewhat) flat where I had them stacked. Here's the shim setup, top, sides & bottom. The gap at the sides will be 3/8" because I'll cover the screw heads in the sides with some 1/8" skins so the hatch looks properly finished when it's in place.


Once I had the sides clamped, I marked & trimmed the ends of the two outer ribs, to keep them with about a 1/32" gap above the 1/2" plywood build-out on the inside of the panels. The plywood sticks up 1/2" past the sides and forms a rabbet joint on the inside edge of the side panels, to keep any water out if it gets past the gaskets. Just clamped the 3/4" plywood sides to the outside & used a straight-edge to make sure there was a gap all the way around the 1/2" it will sit in, once the hatch is set in place & hung on the hinge.


Here's the amount of gap at the spacer. Not a lot, as you can see, but it's even all the way around & will let the gaskets compress to this amount with the hatch closed. The bottom edge gasket will compress .10" and along the sides it will compress about 1/16" more or less. I'm using a 5/8" X .040 thick hollow type of gasket material. Still need to order it to double check things before final assembly. In this picture, the outer rib is still clamped to the outside face of the wall to check the gap.


After that, it's assembly time for the parts. I'm doing a "dry fit" on this one, because there are a lot of different things happening in the hatch the way it's designed. I have some sub-assemblies to locate & install before I can glue it up for a final installation & do the skinning (latch mechanism & handle, hand grips/bumpers, light fixtures, "T" nuts for the strut mount & handle, paper towel holder, etc). For now I'm just pre-drilling the parts & using dry wall screws to hold it all in place as I add the things it needs. The bumpers/hand grips are just some bathroom type grab rails. I'm using 2 of the 12" grab rails, about 7" above the edge of the hatch & 6" in from the outer edges.


Here's some more blocking being held in place temporarily. I started at the bottom & then worked my way to the top.


I stopped because I ran out of screws this afternoon & because, yes, you guessed it, it's getting too hot to work again..... Time to run out for a few more screws. Thanks for looking. tim

[Sheddie]

Hi Tim looking good
Point to ponder! The ribs you have look very much like the ribs on my one. I have had some issues with a bit of movement on it. It was really floppy with just the outer skin on our first trip. With the inner skin added it has stiffened up really solid, but it has pulled in with a bit too much curve, which has made it sit away from the seals in the centre of the curve when shut. One day I will have a go at sorting it as it really bugs me.

[noseoil]

Thanks for the input Frank. I will have an outer skin of 1/8" (3mm) baltic birch plywood glued & stapled, which is under the aluminum skin (.040 or about 1mm) to support things. The inner skin, more of the 1/8" plywood, will be screwed in place from the bottom for later access to wiring & stuff, if there's a problem which shows up after a while. The frames are 2 1/4" wide (about 57mm), so I'm thinking they should be strong enough to support the loads involved when skinning & lifting the hatch. I plan on skinning the outer layer with the hatch in place & shimmed so it can't move around. If it tries to spring open or change shape on me, I should see it right away. Still thinking about that one though.

Strange that adding another layer of skin actually pulled the hatch into a tighter radius on your hatch. Have to think about that one a bit to try to figure out what I need to do to keep things in place when I wrap the skin over the frame & glue it down.

Did you glue things completely or use screws to hold the inner layer in place? Was the hatch installed when the inner skin was set or was it on the bench?

[Sheddie]

The outer skin was glued on with it on the bench, and braces screwed to the frames to hold the shape. The braces were left on for several days to give the glue plenty of time to cure. It was after we had been camping with it a few times before I fitted the inner skin. It was holding its shape not too bad but trying to flatten out a bit. Also with just the outer skin it was quite floppy, it would twist sideways when shutting it.
The hatch was in place when I fitted the inner skin and just screwed on. It was amazing how much it stiffened it up, and it is only a 3mm plastic sheet. It's as solid as a brick out house now. It is quite likely that the weight of the hatch sitting up on its struts may have caused the end to sag a bit as I installed the inner causing it to pull in a bit, and it only takes a few mm to make a big difference. Also it may have been sitting open for a few days before I got it done. I am thinking of refitting the inner with the outer end of the hatch propped up and see if that sorts it.

[noseoil]

Hmmmm...

[Sheddie]

Your frames are deeper than mine. I think I was 40mm.