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Sunday 20 May 2018

Enclosure for the 3D printer and 3D CNC

As seen a few heating/cooling issues when using ABS as opposed to PLA filaments decided to box up the 3D printer. Will also box up the 3D CNC but that is for sound proof reasons.

The frame is held together with the same 40mm screws the insulation boards are held with. The little wood blocks help with the frame being square.

The access door will probably be on this large side panel with the longer side board on the left. Which I'll cut out. The door I will likely rebate into the foam.
I'll keep one side board longer that the other on top as the board will just butt up to it. And will add the top later.
Looking down inside, important the blocks are NOT hindering the floor etc. As the printer will be just lowered into this once built.

Will add a door on the facing side, space to store the filament (will need an extra box added internally), cooling and cable entrances etc. I use  a Meanwell type 24V 10A PSU to power this so that will probably sit on top, I'll add some ventilation and a small 12/24V fan for the electronics. The top will be another piece of board with access to the filament storage. Maybe top will have a bit of wood on one side as I'll add an emergency ALL STOP button to the top. Internal lights some goose head LED things I have already.  The base is some odd bit of chip board I had in the workshop, cut to fit, frame, some 15mm square section I had and the insulation is 25mm insulation board with aluminum foil backing (cellotex is common brand name). The sheets were attached with some 40mm plaster board screws, as the boards are Aluminium foam backed, the screws hold the boards in place nicely. I had parts of sheets spare so they were applied to this. The dimensions are to fit the printer and bits... was originally a K8200 in case interested.

The jury is out if there is any point painting this as I don't care what it looks like outside.

Once built will have a place on the workshop bench and I expect will be less vulnerable to being used as a dump ground for projects.

I have a part built 3D object scanner and I might see if I can fit it in side. If I do that the insides will be sprayed Matt Black, I have some chalk board paint. Or that will get it's own enclosure too and sit on top of the printer.

The 3D CNC will use  (mocked it up first) 15mm x 25mm wooden frame, covered in 8mm ply (again was in workshop), the door will use a piano hinge I have and one whole side will open. I expect will line the box with sound reduction foam and the printer will sit on 25mm (at least) rubber blocks (cut from old mouse mats and drive shipping pieces)  so that the sound of PCB milling doesn't send one nuts. It is much smaller but will build with a 500mm width base I expect. Internal storage for CNC 'bits', I'll add a vacuum hose and LED light same as 3D printer.

Tuesday 15 May 2018

IOTA 2019

Maybe a QTH for July 2019.

Call would be MD1K

Tuesday 8 May 2018

CNC plotter from DVD

Just played with few old DVD had been given.

Once stripped the guts to the centre frame and stepper drive connected up to Arduino CNC shield.

DONT do what I did and pull off the connection on one of the stepper motors.

Donor DVD, old Woodpecker 3.0.2 board (faulty).

The sharp eyed in the last image might see an HP ESP120 and some bits for a W6PQL SSPA and some R3KO bits I am building for another.

Friday 4 May 2018

A 3 way 1kW switch for < £20?

Ok this I had to see after it had been mentioned to me so I bought one.

just opened it... you have got to be kidding! I used a phone camera and have a problem transferring images but I'll add them soon.

Zero manufacturers markings.

Couple of videos..

I think mounting might be interesting..

I'm a qrp op but there is no way you could put probably 100W though one of these.

I will put it on the analyser and see how it does.

Tuesday 1 May 2018

Binocular torroid transformer winding

Was asked about this so here are a series of photos that hopefully should explain the process. I am sure there might be other (better?) websites and videos out there.

I have deliberately used larger wire than you might normally and used two different colours to make it clearer.

The torroid, doesn't matter what type it is the principals are the same.

I didn't show the stage but sometimes the torroid has small sharp edges. If you are using wire that is effected (you will find out if you are) then the easiest option is to use a circular needle file and make sure the hole edges are rounded (just slightly you do not want to file away the torroid!)
 Turn one. Pass the wire up through one side and back down through the other. That is ONE TURN.
 Pull it tight.
 Repeat for however many turns you need.
 The free wire end
 The other side of the transformer, you can start on the same side or the opposite side, most transformers in PA stages, ATU, the X-Phase eliminator etc prefer them starting on the other side.
 Same process... through one side and back down through the other...

Pull tight... that is ONE TURN
 Repeat as needed.

That's it. In this case a 2T:2T transformer, if you need a different number of turns wind a different number of times.

There are lots of other possible winding options the other frequently seen option is for a bi-filar or tri-filar winding. Simply take the wires and wind two or three of them together FIRST and then wind them through the torroid.

I note a lot of chinese ebay projects seem to use power feed line chokes often using a single winding with these binocular cores.

VSWR bridges sometimes use winding's about the outside of the torroid. You will find examples of these on this blog too.

You might see the winding's also using hardline, coax braid or even solid brass tubes and PCB ends soldered on but the photos above are for the wire version the X-Phase QRM eliminator uses. It has 2t:8t so two tuns on one side and 8 turns on the other. Here is a photo of mine as I fitted it.