Add supports to centre backrests
Centre seating backrests are not supported, so will need metal supports. I’m trying to find steel box sections that will slide inside each other with very little play:
to: info@cutmy.co.uk
“Hi, I'd like two sections of steel box section, approx 30-50mm with approx 2-3mm wall thickness, where one the smaller section is just small enough to slide inside the larger one, with as little play as possible. Can you recommend something?”
Tall storage units are impossible to build
As designed, we won’t be able to build them inside the box. Redesign so we can build them in two sections and join. Domino joints need space above for clamps etc.
I’ve updated the order of the Domino Joint feature to make it possible to build, but I’m still worried about this... Keep an eye on it...
Swap linear actuators for more powerful F version?
https://www.electric-linear-actuators.com/collections/high-performance-linear-actuator-f-12000n
Investigate new latch
https://www.penn-elcom.com/ultra-slim-slam-latch-l2572
Investigate removing one of the rear solar panels to add space for Starlink dish [yes, and change the other to 165W]
Can we remove one solar panel?
Normally we have 32 panels, 4 MPPT controllers with 8 panels in series on each controller?
I think it’s fine to remove one panel from this… Is that right?
Re: Add Starlink mount
Each Victron Inverter RS Solar only has one MPPT controller, so this won’t work (I thought it had 2 MPPTs). Consider changing to the Multi RS Solar which has 2 MPPTs. Let’s check we can use two:
Check two Multi RS Solar’s can exist on the same DC circuit without interference
Using panels of different size in the same string
When you have solar panels of different types in series, different voltages don’t matter, but the whole series string will use the ampage of the lowest panel... So if we are going to tweak the arrangement to add the starlink dish, we should choose a panel with the same ampage. https://www.sungoldsolar.com/flexible-solar-panel/tf/
Compatible panels (all 540mm wide) are:
SG-TF-S-120W 19.80V 6.07A 1070mm
SG-TF-S-135W 22.30V 6.03A 1200mm
SG-TF-S-150W 24.80V 6.05A 1330mm
SG-TF-S-165W 27.30V 6.05A 1460mm
All the smaller panels have less amps so would ruin the total output. I think the best solution is to have a single 165W panel on the top of the garage, which leaves ~900mm for the Starlink dish. Even the high largest dish is only 575x511mm so we have plenty of space for anything else that needs to point at the sky.
Design drawer attachment recess / fixations
Accuride recommend M4 screws for the slide attachment
Design strike plate
Slide attachment screws: https://www.accu.co.uk/torx-flanged-button-screws/356710-SHBF-M4-8-A2
Slide attachment inserts: https://www.accu.co.uk/self-tapping-inserts/410830-HSTI-M4-A2
Slide to drawer screws: https://www.accu.co.uk/fully-threaded-torx-pan-head-chipboard-screws/651753-SHPCT-4-10-A2
Strike plate, drawer front handle attachment, also latch attachment: https://www.accu.co.uk/fully-threaded-torx-countersunk-chipboard-screws/650950-SHKCT-4-10-A2
Screws for latch: https://www.accu.co.uk/metric-torx-countersunk-screws/474331-SHK-M3-8-V2-A2
Find cheaper threaded inserts
These are perfect, but far too expensive:
https://www.accu.co.uk/self-tapping-inserts/410830-HSTI-M4-A2
Update CAD with standard drawer spacing, and drawer faces
Check what work needs to be done on the chassis
The old chassis needed quite a bit of work to move all the pneumatics and rebuild the battery tray to squeeze in the larger fuel tanks. Looks like the new one will need less work, but probably some. Check if we need Air tanks and Battery trays.
Think more about the ceiling, and how this will be finished
Remember we shortened the bathroom space by at least 100mm… Do we have to lengthen the body?
Confirm which side the hinges should be on the door
Update the CAD and make sure we’re ordering the right model code.
T72192L Sideway door
DT6797R Sideway pass-through
Someone said it might not be legal to have the main door opening with the hinge at the rear (e.g. so it opens the opposite way to a car door). We need to check this.
I think it’s best to have the pass-through door opening so it blocks the toilet door, not the shower (and also entrance) door. This would be the “L” version. I’ve updated the product code.
Add clearance for adhesive to solar CAD
Check standard size Widebird door / pass-through fit and update CAD
Should we change to a 600L American style fridge freezer? [tl/dr: yes]
Options:
https://www.samsung.com/uk/refrigerators/side-by-side/rs8000nc--8-635l-black-rs68a884cb1-eu/
https://www.lg.com/uk/fridge-freezers/american-style-fridge-freezers/gslv91mbac/
380L fridge freezer plus 90L deep freeze
https://www.samsung.com/uk/refrigerators/bottom-mount-freezer/bottom-mount-freezer-with-smartthings-ai-energy-mo-387l-silver-rl38c776asr-eu/
https://www.indelwebastomarine.com/int/products/product/show/bi-92-dual/
Fridge: 273L
Freezer: 114 + 92 = 206L
Energy: 108 + 130 = 238kWh/yr
Price: £790 + £1919 = £2709
✅ Easier to fit into Storage Long
⛔️ Smaller
⛔️ £1300 more expensive
630L fridge freezer
https://www.samsung.com/uk/refrigerators/side-by-side/rs8000nc--8-635l-black-rs68a884cb1-eu/
Fridge: 409L
Freezer: 226L
Energy: 225kWh/yr
Width: 912mm
Price: £1399
✅ Almost double the fridge space
✅ Easier access to deep freeze
✅ £1300 cheaper
✅ Frees up the whole of the under-sofa area for more relaxed electrics layout, and perhaps some extra storage
⛔️ Less storage space in Storage port
⛔️ Will have to remove Storage long ventilation?
⛔️ Will have to relocate Ubco battery trays to under sofa?
Let’s see if we can fit all this in a redesign of Storage port and make a final decision when that’s done.
Result: OK it fits great. Ubco batteries / ventilation doesn’t need to be relocated!
Can we squeeze in a roof hatch above the bed now we have to remove one solar panel to make room for the Starlink? [tl/dr: no]
KCT roof watch is 710mm wide… One solar panel is 540 wide, so we would have to increase the total length of the solar assembly (e.g. the truck length) by at least 170… Probably more like 200 to leave room for the hatch to open. This is not the end of the world because the new wheel base is 350mm longer…
The solar panels stick up by 30mm, the KCT hatch by 83mm, so 53mm extra height. I think the extra height is the killer for this idea.
Add better products for solar panel mounts to Coda
Check that Multi RS Solar works with new panels
Re: SG-TF-S-135W solar panel
Re: Multi RS Solar (Dual MPPT)
Panel datasheet: https://www.dropbox.com/scl/fi/j65wv14xd2qhx9l7h3fps/SG-TF-S-135W.pdf?rlkey=ifywh90fui6wiu00h9y4rtmwb&dl=0
Victron Datasheet: https://www.dropbox.com/scl/fi/bjwy0yv6hr3nffuy6ox50/Datasheet-Multi-RS-Solar-Dual-Tracker-EN.pdf?rlkey=wphm4ytx1yfif6yij84a2as9t&dl=0
We will have two Multi RS Solars, which each have two MPPT controllers. We will have 31 panels, arranged in three 8S strings and one 7S. In normal operation:
MPPT1: 1P8S
MPPT2: 1P8S
MPPT3: 1P8S
MPPT4: 1P7S
If one Multi RS Solar fails, we can double up the strings:
MPPT1: 2P8S
MPPT2: 2P7S*
* This string will have 7S and 8S in parallel… I don’t think this will be a problem, alternatively we can bypass that panel and have 2P7S.
Voltage
Victron max voltage: 450V
Victron startup voltage: 120V
Panel open-circuit voltage(Voc): 26.2V
8S: 209.6V ✅
7S: 183.4V ✅
Current
Victron max operational PV input current limit: 13A
Victron max PV short circuit current: 16A
Panel short-circuit current(Isc): 6.42A
Panel current at Pmax(Imp): 6.06A
We’re only planning on running strings without parallel, so 1P:
1P Isc: 6.42A ✅
1P Imp: 6.06A ✅
If we need to reconfigure to run two strings in parallel:
2P Isc: 12.84A ✅
2P Imp: 12.12A ✅
Power
Victron max PV conversion power: 3kW per tracker
Panel max power(Pmax): 135w
8S1P: 1080w ✅
8S2P: 2160w ✅
Check two Multi RS Solar’s can exist on the same DC circuit without interference
They can’t both charge at the same time, but I hope we can turn the charging function off on one of them?
Email Victron to ask.
Should we switch to 230Ah cells? [tl/dr: no]
Changing to 230Ah cells would allow us to fit 3 banks of batteries in each container by only increasing the width by 34mm, which would still fit ok under the bed. This would increase from 62kwh to 71kwh… Also give better redundancy if one bank breaks…
Here’s the calculations: https://docs.google.com/spreadsheets/d/1HDJCCxPe_vTsHyQq1_YgeWvUuhZnUDaTOOCOOjih4Tk/edit?usp=sharing
However, 6 battery banks instead of 4 means 6 BMSs, 6 isolation switches, more fuses, wires etc etc. Also the TEXU400 busbar panel only has 4 battery connections, so going to 6 wouldn’t be as neat. I think this is a significant downside. We already have plenty of battery at 62kwh. Let’s cancel this idea.
Think about extractor fan for kitchen if we change to portable cooktops
Maybe just open the window?
Decide on product range and technology for grey water pipes, fittings, valves etc. Add to CAD and Notion.
Ensure they are compatible with grey water tank fittings (that space is limited)
Add trim / spacers to Onshape window CAD
Confirm bus bars still work with 304ah cells
It looks like 304Ah cells are still available from Shenzhen Luyuan with the old style terminals, so probably order them?
https://www.alibaba.com/product-detail/Luyuan-1pcs-EVE-304AH-Automotive-LiFePO4_1600301903451.html
Also, this guy doesn’t like the new EVE terminals: https://www.youtube.com/watch?v=CF8HzPAW94M
Add storage for portable induction hotplates to CAD, remove built-in hob
Research fridges
Re: Fridge RS68A884CB1
There’s lots of new options for A rated fridges… needs some research
The Isotherm BI92 uses 360Wh/day = 130kWh per year, so we can increase overall efficiency by using a larger fridge with 200L freezer space (approx 150kwh/yr).
We will have to redesign “Storage Long” to accommodate the larger fridge, and then the electrical area can be extended to take up the whole of the area under the sofa, or perhaps some storage. Relocate the Ubco batteries to under there too.
HOWEVER, the only larger option is the KENWOOD KSBSXA23
https://www.currys.co.uk/products/kenwood-ksbsxa23-americanstyle-fridge-freezer-inox-10249127.html
This says it is 130kwh/yr, but I suspect this is wrong. All the other American Style fridges are ~225kwh/yr. I think it’s a typeo, and it’s actually 230kw/yr. Also, all the Kenwood fridges on Which get really bad reviews. Cancel this idea.
There’s various other options in the approx 380L size, which all seem to be the same dimensions / approx same efficiency (approx 100kwh/yr).
Here’s several “A” rated fridges, all about the same dimensions:
https://docs.google.com/spreadsheets/d/1SDxiqekbH_FheuuAaMldKOrHQsfbH_t1TBlW3kVaSCs/edit?usp=sharing
Any of these will do just fine. I’ll assume the Bosch but make a final decision later.
Add estimate for window armour plate storage shelf
Add waste plumbing to bathroom sink (including traps and overflow)
Add overflow to kitchen sink waste plumbing
Research how to power a PWM fan with an Atom PWM unit
Looks like https://esphome.io/components/output/ledc.html will work output a 25khz PWM signal with esphome…
Add L-Track to side of box
Design slides, locks, seals for cab bars storage
Add water pipes to conduits
Decide on battery removal tape
Re: Electrics
Add grey water dump plumbing to CAD
Work through pipe sizing calculations
https://www.heatweb.co.uk/w/images/3/31/BIP2177sample.pdf
Remember pressure relief valve on holding tank
Add mains pressure connection that bypasses the tanks / pump?
Remember pressure reducer valve on water fill inlet
Design overflow into shower tray (with exit pipe through floor)
Adjust CAD for box panels including accurate edge interfaces
Plan hob extractor ventilation
Add Starlink mount
If we decide Investigate removing one of the rear solar panels to add space for Starlink dish [yes, and change the other to 165W] is OK, remove one solar panel from the top of the garage, and add starlink dish there.
Tweak ventilation pipes to be angled
Add grilles to all convectors
Rename storage / kitchen
Storage Long → Appliances
Storage Short → Tall storage
Kitchen Long → Kitchen (wide)
Kitchen Short → Kitchen (sink)
???
Add chargers to CAD model (seating)
Work out if this needs to be waterproof - shower seals etc.
Design bathroom shower door
Where does the rear camera go?
I swapped the rear camera on the CAD with the 360 degree Vivotek FE9381-EHV… This will have a better view, but it’s not ideal…
Design toilet air circulation system
Add kitchen long heating to CAD
Add seating heating to CAD
Add toilet heating to CAD
Add bathroom heating to CAD
Add bedroom heating to CAD
Add chargers to CAD model (kitchen short)
Add chargers to CAD model (kitchen long)
Add chargers to CAD model (bedroom)
Design battery frame
Emailed support@overkillsolar.com about BMS cooling requirements
Overkill solar replied: “The BMS will heat up but will not require extensive ventilation, they can be inside the battery box. We have not had any issue with confined BMSs”
Add sand ladders to current design
Research fresh water plumbing
Can we completely remove the inner cappings? They will just get in the way of furniture that needs to go right up to the wall...
Narrow down estimates for alternator wiring
Change crawl-through door so it’s hinged on the RHS (so we have access to the shower door latch if the shower door is latched open).
Decide on drawer latching mechanism
The current idea of having exposed drawer mechanism looks awful. We need faces to the drawers and a better locking mechanism.
Redesign drawer latch CAD
Todo:
Make it symmetrical
Make the cover plate bigger so it screws into the face
Lose the fillet on the outside corners, and don’t have an offset on the drawer
Don’t have it in the middle of the drawer, it should be directly on the inside face
Don’t cut the recess with “in context” editing because it won’t update when config changes
Also fix drawer slides CAD model, needs simplification
Update CAD to use 18mm ply for furniture frames
Add glue and fixation hardware to furniture frame estimate
Add glue and fixation hardware to furniture front estimate
Decide on a standard drawer spacing [tl/dr: 150mm]
See: https://docs.google.com/spreadsheets/d/1h00wqU28yWIK2XiyUNEpeQVpcVhwfItj-e8ixA1E0yw/edit?usp=sharing
Looks like the best is 150mm, which gives us the best options for stacks of 2 euro crates without too much wasted space