Galley - a work in progress

 The galley end of the trailer is very definitely still a work in progress.  There are a number of tasks still to be completed before it's really functional, but you can get an idea of the basic shape.

The 45 liter Iceco was a great addition.  One of the keys for me is that it runs on 24 volts, which means it doesn't need the voltage stepped down (or worse- run thru the inverter).   You can also see the Propex heater installed on the lower left wall.  Like the stove above it, it's awaiting hookup - I need the bottle mount to arrive so I can mount it and the regulator outside, and then will plumb it to the two units.  Eventually, there will be a water jug in the propane bay, and some drawers in the leftover space between the two sides.

Both the fridge and Camp Chef stove sit in finger-jointed box frames made from 1/2¨ Baltic birch, and cut on the CNC.  I learned making the first one (which fit the Iceco too tightly) that when CNC'ing interlocking fingers, you do need to leave a little clearance between them.  So making the pins .98¨ and the gaps 1.02¨ worked out just right.  They're glued up with Titebond II, and finished with a few coats of Total Boat water based varnish.  I cannot say enough good things about Total Boat products.  They are not cheap, but you definitely get your money's worth.  Easy to work with, dries quick, and great support.  I've finished a boat, and this camper with their product, and I absolutely love it.  And no, they don't comp me.

The back wall is still a work 'in study'.  I decided that the right half would be used for electricity related 'stuff', like switches, fuses, meters, etc, and the left side will eventually turn into storage for kitchen gear.  I'll put some sort of doors over the electrical bay so that it doesn't spoil the view.

An earlier shot of the right hand bay.  I'll pull the fridge and get a 'final' shot, but at the moment - here it is.  
Widget ID starting from the top right -
Epever 20A MPPT charger.  I tried to balance cost/performance.  This can handle the current 200 watts of solar, plus another set if I were to choose to add them later.  
Victron IP67 5A charger - will be connected to the shore power side of the transfer switch.

Fuses and wiring
12v buck supply - to step down 24v to 12vdc for lights,  the heater, fan, etc.  40A should power everything with more than a little room to spare.

Here's the Propex all vented in, and the 2500W inverter.  I got the inverter when I was planning around a 5000BTU room air conditioner, and needed AC power.  Now that I have an AC unit that will run on 24vdc, this is gross overkill, and I'll probably sell it and replace with something about half the size.  The biggest thing I anticipate needing AC for is a small Instapot.  It draws more power than the fridge does when in idle state.  

What isn't shown here is the battery pack - 16 50Ah LiFePo4 cells wired series parallel to provide 24 volts 100Ah of usable power.  I'll add that to the walkaround.

 That about wraps up the galley at the moment.  As you can see in a couple of pics, this is a work in progress.  I still don't know what all the nooks and crannies will be used for, but we'll figure it out as we go.  

Soft launch!!!

 

It's done - or at least somewhat usable...  It's been almost exactly one year since my wife and I first talked about the idea of a teardrop (since the motorhome was a non-starter).  I spent a month or so researching, watching youtube videos of manufactured trailers, people's video blogs, youtube channels, personal blogs, and Tony's book, ¨Building a Teardrop Trailer¨.  And by October, I'd decided that I could build what I wanted, instead of buying it.  There are a lot of cool trailers out there on the market, and I didn't build because they weren't available, but rather because they didn't tick all the boxes - or mostly, ticked too many!

When it was all said and done, I wanted:

• A queen sized bed
• Simple storage
• Heat
• AC
• Fan
• Stove
• Fridge
• No plumbing

What you see here is the 'soft launch' - mostly done, but still a lot of cosmetic touches to finish up, a lot of seam sealing, and a few things left like hooking up the AC, hooking up the propane system for heat and stove, and some more cosmetic touches.  

The really important stuff - it tows well, the mattress is comfortable, it breathes, and I think it shined up pretty well.  I have to admit I took a step back when I pulled off all the blue and really got to look at it.  

I'll do a couple of additional posts over the next few weeks, including the always questionable 'cost sheet'. 

Utility box version 2.0

 As mentioned in an earlier post, I had originally intended to use a small (5000 BTU) window AC to cool

the trailer.  This would have been fine - it would have been more than enough air to keep the trailer cool even in an Iowa cornfield, but it was a bit bulky and would have required more than a little creative ductwork.  And it would have necessitated what I came to realize was a truly ugly box.  As I was debating myself on the merits of this design, I came across another ad for the Zero Breeze Mk II, which was designed for cooling a camper, tent or similar.  It's small, very lightweight (about the size of an old canister vacuum, and best of all - it runs on 24vDC.  That in itself improves the working efficiency by 15-20% (no need to convert battery to AC).  Yep, ordered one and received it in about 10 days.  Perfect.

With that in mind, I took a fresh look at 'the box'.  I'd never liked the big black box, but it seemed a logical choice due to the space requirements.  I decided to design one that followed the lines of the trailer, and was a bit smaller.  After carefully measuring the Zero Breeze size, and made the box large enough to hold it and maybe a screen porch.  The new box size also means that I can drop the bike rack a few inches lower, which will improve driving - getting them down out more out of the air flow.  I was mostly able to use 'scrap' plywood panels to build it.  The floor is dominoed together from two pieces of 3/4 BB, and the sides are 1/2¨ BB with oak stringers.  I added blocking in the center and along the edges for a little extra surface area. 

Next trick was to skin the box and wrap it.  I first wrapped the top and front with 1/8th¨ BB, cutting strips around the knuckle rather than trying to bend the plywood in a radius it really wouldn't have been happy with.  I then 'doped' it with penetrating epoxy. For the next step, I started to bend the diamond plate just by leaning on it, which worked somewhat, but I was concerned about having it spring back and whacking me in the face.  I chose a more time honored technique - screwing it down to the top, adding holes every 4 inches along each stringer, and bending it around the curve as I went.   

I used some of my collection of canoe straps to pull it snug, and worked around the curve to get it to conform.   Many more Kregs screws to hold the top in place (because I had lots of those and not many stainless countersunk #8s.  I'll go back and replace the Kregs screws with the #8 stainless and stuff a little sealant into each hole as I install them.  

The end panels will be covered in the left over scraps from doing the sides, and the Seaflo hatches will get added as soon as the ends go on.  The seams will get wrapped with aluminum over sealant over tape later this week, and the whole thing sealed into the body with butyl, trim and mechanical fasteners.  

So now I have this great box and will wrap up the install this week.  And here's the humor for me - I had
really not contemplated how much sheer volume is consumed by 4" ductwork!  With three ducts emerging from the Zero Breeze, two into the cabin for cold air and return air, and an exhaust vent, they occupy a *lot* of real estate.  It's not glamorous, but they got handled and still left enough room for tools.  Also, the Zero Breeze has a set of slots on the bottom that conveniently fit a 1/4¨ carriage bolt, so that will get locked down too.   

Expect one more post on the AC and tongue box.  It's still a work in progress, but I am down to the last bits in prep for a 12 August shakedown run!

A bunch of little (and not so little) things

 It's been a couple of weeks since I did a 'real' update.  It's not that I haven't been working on the trailer, but rather because most of it hasn't been blog/photo worthy.  Except that I forget that some of the things are big milestone items.  Over the past 3 weeks, I've been struggling with 'the hatch'.  It has been bit my own nightmare in the making, so when I realized that the hatch I built just was not going to work, I have consigned it to fuel for the Solo stove and started over.  The new design is much more along the lines of the 'standard' with heavier multi-component side rails and lateral stringers.  I should have a post on it next week.  I'm also making headway on getting the battery pack assembled and wired, and on getting the shore power/transfer switch installed and wired.  

So to keep things moving and allow me time to think about hatch mechanics, I have now:

• Installed the doors
  
  There are _tons_ of good videos on door installation.  I've gone thru a couple of rolls of butyl tape getting them in place.  Sticky stuff!  For reference, I went with the Challenger doors.  Less expensive, and OK for quality, but I don't have a good frame of comparison.  They were being purchased by Lippert at the time I ordered the doors, and delivery was 10 weeks.

• Installed the MaxxFan
  
  I made a (correctable) mistake doing the final cut on the roof. Fortunately, it was cosmetic only and never to be seen by anyone.  For guidance, when cutting the top, it's adviseable to drill all 4 corners, and then draw lines between the holes - and maybe even paint tape to protect the paint from the saw.  It's easy to get an aluminm chip between the skin and the base of the saw.  Once you get the rough cut with a jigsaw, it's easy to make one final pass with the trim router and a flush cut bit to trim the hole back to the 14" frame dimensions.  Butyl tape to seal the fan into place and carefully tighten down the screws.

• 
  Installed the Propex heater (well physically anyway)
  This is an(other) install that has morphed a bit as physical reality met initial visualization!  I cannot overstate the complexity added by air ducts...  They do not simply mold into space- you have to account for bends, interference and inflexibility.  As you can see from the picture, I have an interference between the corner of the inverter and the hot air duct. That would last perhaps one trip before it rubs thru.  I'll print a cradle  for the duct that should protect it from abrasion.  I also raised, and offset the heater by an inch or two from the original mounting to give a little better bend radius for the ducts.  This isn't a big deal, and where the lines pass thru the floor will get centered/sealed as well.  

• Designed/printed registers for the AC ducts
  This was a relatively simple task.  Visualizing designs in CAD has become a lot simpler for me, and it's cut trial and error down to a couple of iterations.  In this case, I initially tried to make the blades too fancy, which resulted in a less than stellar print.  Second  try I also angled the blades to give a little direction to the airflow.  It's a little time consuming, but with a decent printer, not too challenging.

• Tossed out the plan to use a big ugly black metal box for the tongue box and gone with a svelte hand designed and cut one, mostly using scraps.  And it's looking good (so far)
  The profile of the box parallels the front of the trailer, and mimics the curve.  I'd convinced myself it would be too much work, but in hindsight - I'm an idiot:)  
  The hatches came in last night, and I'll cut the end caps to mount the hatches.  
  
  
  
  
  
  
• One [more] thing I didn't account for very well - the ductwork takes up a *lot* of space!  It'll all work, but I think the kibble bag may wind up staying in the car!  The box is big enough to add a few tools, but the ductwork does limit some utility.  It looks a lot sharper than the big metal box!  

Printed material

One of the most frustrating parts of a build are the little odds and ends that are required - adapters, plugs, grommets, vents, and other weird little widgets made of plastic and filling those 'specific purpose' needs.  The pursui t of which involves finding that none of the local suppliers have anything close, searching the net, finding something sort-of close, ordering it, waiting days for it to arrive, during which time your project is on hold, and then finally getting it and learning it... doesn't fit.  

I'm fortunate to have both the 3D printers, and some reasonable beginner CAD design skills to be able to visualize many of these, design a prototype, and then print it.  Sometimes it works, sometimes it takes a couple of attempts to get it right.  But with an hour of my time, and a couple of hours to print it, and I can quickly validate my assumptions, the part fit, tweak it a bit if needed, and it's ready to use.  

One example of this is the new ZeroBreeze Mk II air conditioner.  The Zero Breeze box contains the necessary ducts and fittings for the AC end, but nothing for the end of the duct.  Since my AC will be mounted in the tongue box, and piped back into the trailer body, I really didn't want the outlet to be a 4'' diameter piece of white plastic tube poking into the trailer!  It took me about 30 minutes to draw out in FreeCAD, 8 hours to print the prototype, 10 minutes to make changes to the louvers and outer chamfer, tweak the thickness, and then a second iteration to print (5 hours) a production quality version.  One feature of this version is that the louvers are angled 10 degrees to aim the air away from our heads while sleeping. 

There are a bunch of items that I've done the same for - from a pad for the bottle jack to fit over the 2¨frame tubes, to end caps for the rails, to collars for cable routing, and wire-way covers for burying wire in the walls.  I've included most of them in 3D prints for Teardrop build.  Feel free to copy, or if you see something you need, I will be happy to sell them as well.  I'm also available for design/prototype and custom print work.

I need to print two more - one for the return air, and a hot exhaust for the bottom of the box.  The one going out the bottom will have a little longer snout, and will have a 'lid' to clamp in a piece of screen to keep critters and insects out.

Slow week

 At certain points in a build, progress comes down to courage as much as it does knowledge or determination.  Knowing what needs to be done, and generally how to do it still requires the courage to make i,rreversible cuts, decisions about placement, drilling holes in walls, etc, etc.  

I've let several of those things slide until now - I have multiple tasks, each of which require the courage to make happen.  

First, up front.  I was probably overly ambitious with the headboard design.  It came out just fine, but in the process, I buried several things in the background - all of which now need attention before I can seal it up.  I finally got the hinges for the headboard doors, and installed them.  Check.

I cut (and re-cut) and varnished the dividers that sit between the storage and utility bays in the headboard, cut and varnished the back wall of the bays, and sort of figured out what goes where in terms of power, ducts and connections in general.  Pics on the front end next week.  So it's now ready to seal up which should happen this weekend.

The other end of this project is the hatch.  I've left it for last just because it's, well, the hatch.  Several design elements were left to figure out as I went along, and now things like gasketing, final end caps and so on are coming back to haunt me.  

The good news is that the skeleton is screwed and glued, and it's reasonably square.  Outer skin will go on tomorrow (glue and staples, and then I will work on end caps and attaching the hurricane hinge.  

Other tasks for the weekend:  

• Sand and varnish the cabin sole (floor)
• Mount the heater and route ductwork to vents
• Cut roof skin, seal and install MaxxFan
• Continue work on corner trim

More pictures next week - promise.

Agile Development

Especially for those in the IT world, the term ¨Agile¨ is usually met with both joy and trepidation.  Done well, it's one of the best things that has every happened to project management, software development, and well, almost anything.  However, it's rarely done 'well', and we'll leave it at that since this is a family show.

This project is possibly the most agile project I've ever done.  Everything about it has been an iterative design.  Almost nothing is exactly as I originally sketched it out, and design goals have shifted as I learned new things.  There are also things like the A/C system I mentioned in an earlier post that drove a major change in the front end, and the ripple from *that* change has kept on giving all the way to the back of the trailer.  In some ways I wish I'd waited to order the inverter - I originally bought with the expectation that I could run the house AC unit on battery for a couple of hours a night and recharge either via solar or plug-in.  Since the new AC runs on 24vdc, I now have a 2500 watt inverter to run the Instant Pot, and to charge laptops.  Just a little overkill, I think.  But it's bought, paid for and too long out of the box to return, so I'll bolt it in anyway.

The board above will get screwed in to the back of the bay.  The batteries will mount on the floor, taking most of the clear space at the bottom.  What's not shown here (future post) is circuit protection, AC switching, the master switch, etc.  That's all going up above the counter where they can be accessed without performing contortionist routines.  And I still have to balance and assemble the battery pack and BMS - not hard, but somewhat tedious and it does require a certain amount of care to avoid arc welding with your fingers.  At the end of the day, I'll have 100aH 24volts of LiFePo4 battery stuffed behind the wall to power all the creature comforts.