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A Jubilee for the Jubilee?


Nick Mitchell
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Nick, just wanted to say thanks again for posting all this, I’m learning so much and being inspired to keep on going when things don’t go right, good to see we all get it wrong occasionally, and perhaps more importantly, how to recover from mistakes.

As I recently posted on another forum (not RMWeb) he who never made a mistake never made anything!   :declare:

 

Jim

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After an enforced hiatus due to the annual September frenzy at work, I'm back with Episode 22.

This time I'm tackling the brakes, which (if you're going to fit them) need to be done before the coupling rods get permanently attached.

 

At the beginning of the episode, you'll see me drilling some holes. At the 2mm Association AGM recently, somebody was asking about the small drills I used.

Several of my modelling heroes agreed that "modern drills are rubbish", and decent ones can't be had for love nor money.

After buying and chucking away packets of tiny drills from the likes of Squires Tools for having either no flutes, or no metal between the flutes (the ones I had 10 years ago were fine), and hearing reports of current Microbox drills being made of an inferior material, I am relying on a stash of "old stock" HSS drills with shanks that I picked up from a clearance bin at Warley show a few years ago. Most of these are Swiss, made by Spirec.

By way of testament to their quality - of the sizes I use most (0.3, 0.4mm), I am still using the first one out of the packet!

 

While great for me, this is not much help to the newcomer who wants to buy some decent drills!

I did a bit of googling when I got home, and found that Fohrmann in Germany supply new Spirec drills with 1mm shanks down to 0.2mm or with 2.34mm shanks up to 2.3mm, and also a Microbox-like set from 0.3 - 1.2mm. I don't know if they're the same as my "old" ones, but if I wanted some new tiny drills, I would give them a try.

 

The nearest thing I could find from a UK supplier are made by Tamiya, who call them "pivot drills". The price is similar, but I have no experience of how good they are.

 

Anyway, on with the show...

 

https://youtu.be/heLc_HAu5aM

 

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Hi Nick, I recently bought some 0.2 & 0.3mm bits off eBay, made by Heller of Germany.

 

They come in packs of ten and seem decent quality, I recall the price being reasonable too (less than a tenner including postage).

 

They seem reasonably robust even with my ham fisted handling.

 

The only issues was I had to purchase a better quality pin vice to securely hold the 0.2mm drill bit.

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The only issues was I had to purchase a better quality pin vice to securely hold the 0.2mm drill bit.

 

I have in the past pushed a length of thin wire sleeving over the shaft of a 0.3mm drill bit so that I can grip it in jaws of a worn pin vice.  I have no evidence but suspect that it might have an additional benefit that it provides a bit of lateral give to the drill perhaps preventing snapping it quite so easily by someone as ham-fisted as me.

 

Ian

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Here is the next thrilling instalment... This time I'm looking at castings and making bits in preparation for assembling the cylinder block.

The Black 5 castings I'm using here have just been made available once more from the 2mm Association shop. This time round you can order individual sprues rather than the whole set. 

 

On viewing it back, it seems this video ends rather abruptly. It is really the first half of a much longer piece, but I had to break them up before I went round the twist doing the editing.

Part 24 will be along in a couple of days (I hope! "just" the voice-over to record...) and will pick up the story.

 

https://youtu.be/r5a44c90E-U

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Here is Part 24 where, after a bit more preparation of parts, I move on to assembly of the cylinder block.

 

The eagle-eyed may spot evidence that I brought fitting the brakes forward in the presentation sequence - the blocks and hangers can be glimpsed still attached to the etch fret at one point.

 

Assembly and fitting of the slide-bars will be next.

 

https://youtu.be/DeGO53vLpWI

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I've had a few people comment that it is good to see things go wrong, and then how to put them right again.

I'm glad this is useful, as it makes me feel better about what happens during this episode!

The bent slide-bar incident last time is nothing compared to the break-up of a previously stable relationship between the left and right hand cylinders...

 

Anyway, here is Part 26 - disasters and all - where I make the motion bracket and attach it to the cylinder block and slide bars.

Savour it, because there may be a slightly longer gap between this and the next episode.

 

https://youtu.be/za5iO-XP3UM

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Things are getting exciting here in Part 27 - First I'm soldering on crank-pin cap washers, then move on to soldering up the connecting rods and pivoting them to the cross heads.

In a break with recent tradition, nothing goes wrong in this episode... I hope that doesn't disappoint too many people!

 

https://youtu.be/O55BTCeCbiM

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Excellent series Nick.

 

From my collection of tools used for MERG kits, I have a pair of ceramic tipped tweezers. These are non conducting (both electrically and thermally), so I find them very useful for the sort of work you are doing here.

 

Howard.

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Part 14 is here, in which the wheels are prepared by fitting the crank-pins and balance weights, and de-burring the spokes.

[...]

 

Although I made a special playlist in my YouTube account, adding the videos as you're releasing them, I started to watch from the beginning just a couple of days ago. I cannot thank you enough for your effort, Nick - it's unbelievable how much I learned after going through only half of them...

 

Just a quick question: nearly in all my chassis builds I fitted the counterweights to the wheels by soldering them to the spokes; only once I tried with cyanoacrylate but the bond failed miserably. Is it a particular reason for which you used epoxy and not solder?

 

Regards,

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I can't speak for Nick, Valentin, but for me it's time.  I use epoxy because it allows me to adjust the position of the balance weight and get it to sit just right - minimising any gap between it and the wheel tyre and also ensuring it is over the right spokes.  I've lost track of the number of times I offer up the balance weight to the wheel, think I know just wear it should go with reference to the pictures, put it in place and then look at the references picture again and realise it's in the wrong place after all.  The fact that we are rarely using a wheel with the right number of spokes (just a reality and certainly no criticism of those spending their valuable modelling time producing them for us) makes this correct choice slightly harder as well! 

 

Also I solder my crankpins to the wheel centre and I suppose too much heat through the wheel risks the bond between wheel centre and tyre.

 

Simon

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Just as a heads up for anyone else taking as much inspiration and guidance from this series as me, Trespa offer sample sheets for free from their website. Given that I keep scorching the MDF work board I've been using so far, I was really pleased to see that. Sheets of 300mm square are £10 on ebay, but free is always better and hopefully will be more than big enough for these purposes.

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Just as a heads up for anyone else taking as much inspiration and guidance from this series as me, Trespa offer sample sheets for free from their website. Given that I keep scorching the MDF work board I've been using so far, I was really pleased to see that. Sheets of 300mm square are £10 on ebay, but free is always better and hopefully will be more than big enough for these purposes.

Thanks for the heads up William, a free sample has got to be worth a try

I use a piece of tufnol I got from Eileens which has stood up to years of abuse and is still perfectly flat - if a little battle scared.

 

post-1074-0-48344400-1543842992_thumb.jpg

 

Jerry

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Just as a heads up for anyone else taking as much inspiration and guidance from this series as me, Trespa offer sample sheets for free from their website. Given that I keep scorching the MDF work board I've been using so far, I was really pleased to see that. Sheets of 300mm square are £10 on ebay, but free is always better and hopefully will be more than big enough for these purposes.

 

I've ordered two samples last night; I remember seeing on their website they are 9 x 9 and 4 mm thick; they don't say though what 9 x 9 is (I doubt they're mm or m, hopefully they are inches but I am afraid they are cm...

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Following a heads up from Graham at our last group meeting I purchased one of these .  Mine is slightly different in that the top part is a mirror image.  They're made from the same silicoln material as baking trays and are intended for those repairing mobile phones etc.  So far I've found it excellent as the little compartments give you somewhere to put small parts and the blue colour makes it easier to spot bits that you have dropped or have otherwise gone AWOL.  The material's resilience means it's no use for cutting on, but I use a piece of thick brass or a zinc sheet for that anyway. There will be a mention in the next 2MM SA Newsletter.

 

Jim

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Just a quick question: nearly in all my chassis builds I fitted the counterweights to the wheels by soldering them to the spokes; only once I tried with cyanoacrylate but the bond failed miserably. Is it a particular reason for which you used epoxy and not solder?

 

Hi Valentin - sorry it has taken me so long to get back to you.

The simple reason is that on the first kit I built, the instructions said to do it that way. It worked, and I've never even thought about doing it differently!

Now that your question has made me think about it, I agree 100% with everything Simon said, and I still wouldn't do it differently.

Nick.

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I've always attached balance weights (copper shim on my case) with epoxy, filling in the area between the spokes and behind the weights. Main reason for me was to give a good area of adhesion for them.

 

Jim

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