Homebrew, open source, repurposed, hacked, software defined, open hardware

Tuesday, 27 November 2012

Final implementation of the OZroll roller shutter battery replacement

Just as an epilogue to the OZroll roller NiMH battery pack replacement with 12V SLA batteries, I thought I'd upload the photos of the final approach taken.

I ultimately decided against DC barrel connectors for the power feed to the OZroll roller shutter controller, as they are

1) ugly
2) supposedly rated at only 3 Amps
3) have only two conductors, making remote up/down button signalling difficult in future
4) flimsy

I opted for 4 pin microphone connectors. They are rated at 10 Amps per pin, are nice and shiny (improving wife acceptance factor), and have a screw collar for positive and secure engagement. I went with white sheathed 6 core cable. One pair carrying 12V DC, one pair carrying Ground, and the remaining pair kept spare for later used in remote signalling of roller shutter up/down commands.

Here is a front and rear view of the connector mounted in a blank wall plate

It turns out that they have 0.2 inch pin spacing, making a breakout board easy with veroboard and terminal blocks:

And here's the breakout board soldered into position:

Labelling is always good, in case you don't remember what you did in 5 years time. See also the jumbo Clipsal wallplate to cover the SLA battery compartment:

And here's the hole in the wall with custom sheet metal glued into position, drilled and tapped for screws to accept the clipsal wall plate (I couldn't find suitable mounting brackets from the electrical supplier).

The drilled out tongue depressors were invaluable in maintaining alignment of the sheet metal while being glued and clamped.

In summary, the nominal 12V, 3.3AHr, SLA batteries I have installed to replace the OZroll NiMH batteries last a few weeks before needing charging again. This charging will be automated in due course. The batteries have very low demands placed on them and should last many years, unlike the OZroll NiMH battery packs, all of which among my six roller shutter controllers have long since died.

IKEA mounting hole dimensions - In case you need to make a custom cabinet

I needed to build kitchen cabinets to fit within a fairly constrained set of dimensions and to match the oven profile at the front.

Why build rather than use a standard module?

There is a saying I first heard from a software developer named Frank Falco: "You can have it done properly, cheaply, or quickly. Pick two!"

The depth of the cabinet needed next to the oven would exceed the standard depth of a cupboard module, plus, the kickboard and profile of the oven needed to be matched, plus, there was plumbing that had to be worked around at the back of the cabinet for the espresso machine drip tray, plus, granite or concrete benchtops need very sturdy framing.

The benchtop would be granite, or cast and polished concrete, and could be made to match the front edge of the oven's range in terms of thickness and depth.

Framing and benchtops aren't too hard to make with routine woodworking tools, but making and finishing flat panel doors and panels can be difficult to do well (I think painting rots the brain), and then you have to select the (often expensive) drawer slides and hinges, and then learn what their mounting requirements are, tool up and do it properly.

I wanted it done properly and cheaply.

So, the solution was to use IKEA doors and drawers, including their mounting hardware in custom enclosures and framing. IKEA hardware also has nice adjustment features, to fine tune alignment.

The only problem was, what were the dimensions of the drawer slides, what was the minimum depth needed for the drawers, what mounting holes were needed, and at what spacing, and what thickness were the doors and drawer fronts?

I couldn't find anything on the net other than references to the standard 32mm European cabinetry system, which appeared to be different to IKEA's mounting hole dimensions.

In the end, I went ahead and bought some bits and pieces from IKEA, hoping for the best, and things worked out.

So, to

1) avoid having to find and decipher my scribbles at some point in the future if I need to do some more cupboards, and

2) help others trying to fit a custom cupboard into somewhere awkward in deciding if IKEA hardware will work in their situation

I have documented what I learnt and put it on the web.

Those planning to build something should glean all that they need to know from the photos. Don't blame me if something doesn't work out for you - IKEA might change things tomorrow, rendering my descriptions obsolete, or I might have made a few typos.

In summary, IKEA uses vertical rows of 32mm spaced 5mm mounting holes, about 26mm from the front face of the cupboard enclosure, and starting 44mm above the bottom surface of the cupboard enclosure. There is a second vertical row 300mm behind the first row, for mounting the drawer slides, also starting 44mm above the bottom surface of the cupboard enclosure.

Inside dimensions of the various cabinets are about 364mm, 464mm, and 564mm, to give overall outside dimensions of about 400mm, 500mm, and 600mm for the modules.

Minimum cabinet depth for drawers is 550mm, if soft closers are not used. Cabinet walls are 18mm thick, and door/drawer faces are 16mm thick, made of MDF in my case.

On to the photos.

First of all, for anyone contemplating construction of cupboards and drawers with IKEA kitchen hardware, there are some critical dimensions that need to be known.

1) Distance from the rear face of the door to the vertical mounting holes. I found 26mm to be a pretty good spacing. The hinges allow some adjustment. It should not be less than 25mm.

2) Distance from the bottom of the door to the hinge mounting holes. 44mm and 76mm (Given the 32mm spacing).

3) Minimum depth needed for an IKEA drawer is about 550mm. A bit more is needed if soft closers are attached to the rear of the drawer slides:

4) Distance to the drawer slide mounting hole. 26mm is about right.

5) The thickness of the drawer/door fronts = 16mm:

Overall, the most critical dimension is the height to the first 5mm mounting hole, from the bottom surface of the cupboard. I settled on 44mm. The vertical row of 32mm spaced holes should be no less than 25mm from the front face of the cupboard enclosure, against which the doors and drawers close. 26mm is better, as it gives you more leeway with door hinge adjustments. 27mm may be OK.

I bought a "CMT Universal Boring Jig" from www.carbatec.com.au to make the 5mm holes easier to drill at 32mm spacing, and because I had a lot of them to do. Nothing stops you doing it manually without a jig if you're careful, or if you only plan to do just enough holes for your specific door hardware.

It just so happened that a reversed pin placed (shown above in the photo as it would fall out due to gravity otherwise) under the jig in a 52mm door hinge hole gave a 44mm spacing for the first hole along the 32mm spaced holes, simplifying setup.

The jig has been designed with 25mm between the front face and the centre of the 32mm holes. I think 26mm works out a bit better with IKEA door hardware.

The boring attachment is then used with a 5mm wood drill.

Once a few 5mm holes have been drilled initially,

the clamp is augmented with the provided pins to ensure ongoing alignment while drilling.

Hmm, so far so good.:

The next step is to mark out the rear set of 32mm spaced mounting holes. These are used for drawer slides and are 300mm back from the front set:

Marked out and ready for the boring jig once more:

Rear set of holes done:

Door and drawer hardware test fitted:

Hmm, so far so good.

Here's a view of the panel. Note the use of dimensional lumbar, random scrap bits of wood, and flooring chipboard.

Here's the opposite panel which has had the same treatment

The top, sides and bottom ready for assembly:

Although the kickboard/base and custom woodwork still need painting, and the benchtop to match the adjacent oven is a work in progress, coffee was needed, so the IKEA door and drawer was fitted, and the espresso machine put into position: 

Whether you are refitting a kitchen, or fitting out your amateur radio operating room or hackerpsace, I hope this has been useful