2017 Christmas Challenge

Can I just post a message reminding forum members know this is a real, if informal, competition.

I think it might be time to draw a line under the photoshopped entries in the hope we get some real ones.

Oh all right then, I'm making a real pair using 4 different materials.

Each candle-stick will have at least 9 parts and this innocent looking assembly is 4 of them.  Five more to go.

If I have enough time before close of play, I'll be adding another 3 or 4 parts to the finished candlestick.

The cat is in the dog-house. It found a pile of half finished bits on my dining table and broke one.

Dave

Edited By SillyOldDuffer on 06/11/2017 17:36:49

As we are Model Engineers, I made a brace of model candlesticks...

Progress on the Mark IV Duffer Candlestick (Made in England - Patent Applied For).

Dave

Is the cat forgiven yet?

Hi, well I've made a start, but I might miss the deadline.

Might get them finished though, design stage took a lot of humming and harring and work keeps getting in the way.

Regards Nick.

I've hit problems with the Duffer's Turbo self-levelling Draught Proof candlestick and may not finish off fully to expectations.

First, the cat's contribution:

This is my return for feeding the vile creature. Luckily I was able to hide the damage.

Here's the pile of bits ready for assembly:

The spring carrier keeps the flame at the same height as the candle burns. The candle sits inside a glass chimney and is fed with air through the base to reduce the chance of being blown out. Hot air is supposed to spin the fan. Sadly I've run into big trouble balancing the fan : much harder than I thought so I'm back to the drawing board.

In Fusion 360 the design looks like this:

In practice:

And with the fan supports in place:

So far I've not managed to balance a fan on top for more than a few seconds let alone have it spin. I may pretend that the spike on top is a lightning conductor and hope that no-one questions it!

Merry Christmas

Dave

Edited By SillyOldDuffer on 09/11/2017 12:57:43

Dave

Gently punch a depression into the underside of the fan blades using a broad head centre punch or similar, it will sit easier on the lightning conductor then.

Sit the blade over a plate with a small hole in when you punch the depression so it only causes local movement of the fan metal.

That may well then also show up where the blades are heavy, by them dipping to one side when mounted on the lightning conductor.

Stems are brass, tops and bottoms ally. I used the gear I put together to mill helical gears for the stems. First I turned a 2.5 degree (5 inclusive) taper using the taper turning attachment.

Then set up a gear train with a lead of about 3 inches.

I reduced the taper to 1.5 degrees and set up the milling spindle to follow the taper and used direct indexing to mill 4 helical facets.

The curves on the ally top and bottom were done with a hand graver.

The top is held on with a screw and the bottom with Araldite.

Of course, I could have made the pair with opposite helices, but that wouldn't fulfill the brief

That was fun

Rod

Hi Dave, I agree with David Standing 1, your pivot point must be above the fan, otherwise unless it is already spinning it will topple.

Regards Nick.

Wasted a couple of hours experimenting with fans taking into account David's advice. The original design in 0.6mm thick Aluminium sheet is too heavy at nearly 3g. Kitchen foil is too floppy. A very thin foil fan spins well but it wins no prizes for appearance and suffers from severe over-heating!

Most annoying I don't I have any thicker Aluminium Foil. A bit of old pie dish would do the job, but there's none in my recycling bin. It seems I have crashed in flames!

I like Rod's elegant solution and the way he made it.

Dave

PS post crossed with Nick.  Agreed.

Edited By SillyOldDuffer on 09/11/2017 17:29:42

Dave

Oh dear, I'm struggling to find something positive to say about the SOD Mk II fan, crap would be accurate, 'foiled again' would be the humorous reply!

A 3 gm fan is fine, you just need a candle ten times the size of your existing one to propel it .

Back to the (virtual) drawing board

Hi, yes, Rod's look good. Well! I have finished one of mine, although it needs a bit of polishing around the edges and I still don't know if I'll get them both done in time. However here's a cold run of my first one, first photo is with a small pillar candle.

Next photo is with a Tealight type.

The last one is of a large pillar candle, which by a shear fluke in design, can be held by inverting the candlestick and using what was originally designed to be the base, the candlestick can be tilted over nearly as much as a double-decker bus, before it starts to topple, with this big candle in it.

Regards Nick.

Edited By Nicholas Farr on 09/11/2017 22:53:14

If I hadn't been buggering about with my dummy rifle cartridges, I might have got some candlesticks made!

Bet that made your eyes water! I thought they were purely decorative...

Dave

This is starting to get interesting!

Neil

Lol, I walked into that, didn't I? (so to speak )

Never post when you've had half a bottle of Rioja

I did have a conversation in the gun shop about it yesterday and the subject of butt plugs came up, but that's another line of conversation we had probably better leave right there!

Don't you start! Just go back to your glue sniffing

So Neil, when is the winner going to be announced?

It shouldn't take you long to judge the entries