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• [P] Castor Wheels and Reducing Tees

  kelvinA • an hour ago • 0 comments

  The first thing that arrived were the 100mm wheels, which curiously seemed to have an expander that ranged from 30.7mm to 35.0mm before the expander itself hit the large washer. The test tubing I still had from SecSavr Sublime [gd0036] was a 36.2mm inner diameter. This expander couldn't be for 33mm tubing as the internal diameter of those should be around 27mm.

  I called Scaffolding Supplies and we organised a video call and everything was as expected after some troubleshooting, using an 8mm allen key to tighten the fitting, but it's not ideal as only the top of the expander continues to expand past 35mm. Thus, I plan to get a thick washer (or stack a bunch of normal ones) and put it between the large washer and that little grey wedge part you should be able to see peeking through the black expander.

  The next part is the reducing tee that I found cheaper on ebay. I asked which type of reducing tee they sold and they replied that they can do both and I just need to message them about it, so I did that and wrote a note when in the checkout.
  

  Other than saving money, the reason I got them was to find out how far the 42mm tube goes into the fitting. As you can see, the 42mm tube would be stopped by the 34mm tube beforehand.

  I believe it's this diagram of the normal 101 short tee (and similar clamps) because the drawings include the slightly embossed internal rings, but only applied a hash to one of the views (and even then, the U part of the circle wouldn't be hashed if one was to take a cross section). Thus I was thinking that the ring highlighted was a wall that stopped the tube. Below is the hashing I would expect from the left view:

• [M] Updated Sketch

  kelvinA • 09/12/2026 at 14:51 • 0 comments

  Most recently, I've added the 100mm wheel to the sketch:

  Before this, I simplified the design by replacing the Three Way Outlet with a Combination Socket:

  This eliminates the need of a 34mm beam on each end of the bed, as well as a few short 42mm tubes.

• [R] Castor Wheels

  kelvinA • 09/01/2026 at 09:12 • 0 comments

  The whole project kinda got put on ice when I realised that almost all my other furniture has castor wheels, which makes them barely an inconvenience to move. My set of drawers is the only thing that doesn't and even minor adjustments are a struggle. The server cabinets I bought didn't come with them and I very quickly decided to buy and install them, so it's likely in my best interest to integrate them into the bed frame design.

  After quite a bit of searching and comparing websites, this one was the lowest cost for 4 wheels, priced at £40 inclusive of VAT and shipping. Whilst being the cheapest, they also have the highest per-wheel loading capacity of 100kg, where the lowest I've seen are 70kg. I've never applied the brakes on any wheeled furniture so I will just get 4 plain wheels.

  Scaffolding Supplies LTD offers free shipping over £100 excl VAT, so in theory I can split the key clamps order between The Metal Store and them to get free shipping at both and save £12 in delivery fees for these wheels.

  Notable Mention

  Looking at reviews and the description, this one was designed to simplify the installation down to tightening a single allen key grubscrew, for a convenience fee. Thus I assume that, for the first type, the wheel has to be unscrewed, then the expander has to be screwed into the tube, and finally the wheel rescrewed.

• [T][E1] Switch to 7 ft (213.4 cm) mattress?

  kelvinA • 06/26/2026 at 10:51 • 1 comment

  Staring at the price of the Sevenlife 18 latex mattress in the checkout window, I decided to hone in my Google-Fu to further uncover any additional information and options. The first thing I found was an Amazon listing, and while the vast majority of reviews were positive, there was one 1-star review (from almost 6 years ago) that stood out:

  My whole justification for such a £600 mattress was that it would outlast other options. A 10-year warranty is meaningless if it's financially infeasible to make a claim.

  Understanding that the main issue is overseas shipping of a large and heavy item, I tried a few searches in both metric and imperial measurements and found a company called Purelybeds selling mattresses in 1/2 ft increments up to 7.5 feet (228.6 cm):

  Because I'd have some spare slats from the headboards, in theory, I could spend about £10 on a staple gun to staple the extra 2 - 3 slats for their longest option.

  I continued to look for "7 ft" and longer mattresses and found Bed Cloud, a company that makes mattresses in 1/4 ft increments up to 7 feet at prices much closer to those found on Amazon:

  The first one I clicked on was the one with the grid pattern because I liked the look, and it just so happened to be their 18cm soft/medium offering which is very comparable to the Sevenlife 18 with the main difference being open-coil vs latex.Since the monitor is being mounted on the frame instead of standing on a pane of glass on-top of the mattress, I believe the non-localised nature of open-coil shouldn't be an issue.

  Looking through the others shows a trend that higher-cost mattresses are firmer. I was able to find reviews on Amazon and, like the Sevenlife, most of them are positive. One gave a 4-star because it was softer than they'd like, which sounds good for me since I feel that "medium" mattresses are too hard.

  It took a bit of effort to rework the frame to use a Three Way Outlet instead of a Three Way Through to be able to shave off the 7 cm I needed, in part due to Fusion sketch solving issues I had to track down and resolve. There is a minimum 100mm tube cutting length, so that's why there's a vertical 75mm and horizontal 50mm tube instead of them being shorter. 

  The price of the frame increases by around £12, now £549, but the mattress savings can entirely pay for a new monitor and still have hundreds of pounds left over.

  [Sep 1] 

  I got the mattress maybe a month ago and the advertised "medium-soft" is indeed as firm as I can go. Furthermore, I was confused why "it feels so firm!... yet I don't want it any softer!", so that Dunelm technology was on point. I remember that the first night or two had my back feeling like it was being realigned in real time. 

  While the mattress isn't made with pocket springs, deformation is much more localised than comparison videos had me believe. The only drawback is there are 2 metal wires that run down the length, approximately +/- 15cm from the centre. That's kind of the only telltale sign it's not fabricated like my old Latex Edge 2000. 

  Would I appreciate another 15cm? Yes, primarily for lying on my stomach. Is that 15cm worth hundreds of pounds? Certainly not.

• [P] KROKWOOD 120 x 220 cm Slats

  kelvinA • 06/25/2026 at 17:48 • 0 comments

  The main reason why I bought this ahead of time was because of the discrepancies I saw between the listing and my CAD model. For example, the listing title said there are 22 slats but the image has 23.

  I opened the box -- which stated it was 19kg by the way -- and as I expected, they have used some rather nice looking wood for bed slats. They've even filleted the faces that come in contact with the bed. I feel it's a little bit of a shame that, for most buyers, wood this good is literally stuffed under their mattress.

  The first slat is the only one that's stapled 4 times on each side. The remaining are only stapled twice and I believe the reason is so that it can be packed in the box.

  The hole is 4.2mm and I measured 12mm from this edge to the centre. It was 13mm on the other side and the slat was 1199mm, so I'm going to assume the holes are 1175mm +/- 1mm.

  I unpacked them all and measured 2086 - 2087mm from front to back. I counted 22 slats. Assuming a nominal 45mm slat, I've used 52.2mm as the spacing distance in Autodesk Fusion.

  Due to such measurements, I've been able to streamline the design and make a BOM list:

  I'm going to use 6 mounting points for the wooden roof since the tubing is closer to the edge and they're not weighed down by a mattress. I'm also going to try and see if plastic end-caps can be used as feet. For the weight, I have used 16kg as claimed on the listing.

• [R] Starting the project

  kelvinA • 06/16/2026 at 16:32 • 0 comments

  A little over a week ago, I realised that I can't get any projects done -- in part because there's no space in my bedroom. This is entirely down to a poor use of space, mainly because of a "Latex Edge 2000" mattress on a divan base I believe my mother got cheaply from a charity store. 

  The floorplan is approximately 2.5 x 4 metres, so this 1.5 x 2m bed already eats quite a bit into that. Additionally, there are two 0.8 x 0.8 metre server cabinets I got very cheaply in 2019. The plan was that one was a 3D printing cabinet, and the other was going to be a 3D printer called the SecSavr Space (which eventually morphed into #SecSavr Sublime [gd0036]). I'm currently considering using this to store a barrel which will be used as an enclosure for #SlimeSaver [gd0105].

  Initial Mattress Search

  Back to the mattress, I don't think those 2000 springs are to the edge like the name implies because the edges of it have all sloped to an approx 45 degree incline. I'm already taller than 1.9m and the slopes further reduce the sleep-able area. The longest mattress size I could find was 220cm, which is the diagonal length of a UK Double and confirmed to be suitable. One of the first I found was a pocket-sprung mattress from vidaXL:

  Wondering about the width of this mattress, I asked Gemini what the ideal minimum width would be and it suggested the length from elbow to elbow when my hands were behind my head. I measured half this length, which was 55cm. Thus 110cm wide would be the ideal minimum. For a few nights, I slept with only 100cm of the mattress available and it was sufficient, but any less would certainly impair movement.

  Another solution seems to come from The White Stone in Italy, where a medium-firm mattress can be had in a range of widths. A 100cm was £170, 115 was £215, 90 was £225 and 120/135/150 were £250. I also considered buying four or eight £40 cot mattresses to make a 120 x 240cm bed in 15 and 30cm thicknesses respectively, which is made from some kind of fiber.

  I've sampled a memory foam mattress in the past and my opinion was that it was a brick. In my search, I was surprised how many options are "medium-firm" or greater, so statistically, I probably tried a mattress that wasn't advertised as "soft". I've also tried a waterbed and airbed, and like air above the other two. Thus, I've come to the conclusion that I like a mattress with springiness.

  Frame Search

  I also had to keep in mind that I needed something for this mattress to go on, in part because I feel like any chair is a compromise compared to a bed; therefore I sit on my bed. My portable monitor (see #Teti [gd0022]) is on a tablet stand, which itself is on a glass cutting board so that it doesn't topple over. The drawback is that I have to tilt my head slightly to the side so that my legs can be straight, which I've found to be the least strenuous position.

  Sitting on the bed means that there needs to be a backrest, thus I searched with that in mind. I soon found that vidaXL sells a variety of 220cm wooden frames, and I liked the one below:

  What would be even more ideal, however, is a bed frame that has a headboard on both sides so that I have the flexibility to change seating positions. The frame looked otherwise symmetrical, so an idea I had was to buy 2 frames and combine them to form:

  As they sell a frame without the headboard, I could compare prices. The bare frame is £45 and a single headboard is £97, meaning the headboard alone doubles the price. This strategy further doubles the price. I found that they seem to sell the headboard separately, but with the unusual discrepancy that it's 106cm wide instead of 105.5cm:

  However, by this time, I had also found that there are two listings on Amazon that, combined, amount to 230 reviews at approximately...

  Read more »

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