Member postings for Tim Hooper

Modified Ohlsson and Rice .23

Over the last few weeks I've been using a 1940's O&R 23 sparkie to gain machining experience.

I've turned up a new prop driver (complete with inset magnet) to trigger an electronic ignition unit.

I've milled up some transverse bars to act as beam mounts.

There's a turned aluminium fuel tank to replace the leaking, plastic original.

At the back, I've fabbed up a simple sort of variable carb - connected to a throttle servo.

Hanging off the side is a milled exhaust stub that leads to an expansion chamber (complete with internal baffles)

Yup, it runs. Yup, it flies my Murg vintage model - just. Power is marginal, but that's not the point. It works.

Tim

Believe it or not, I'm employed by Smartwater (now part of Detertech), and I'm actually the bloke who runs the automatic process that manufactures the forensic coded solution for domestic use. How's that for a co-incidence?

It's chief function is as a deterrent. The customer uses the supplied SmartTrace solution (which contains a unique combination of metallic elements in a fluorescent polymer suspension) to mark their belongings with a small dab in a grease free area.  Note there's no fragile synthetic 'DNA' in its formula - it's all based on metallic chemistry, sourced from around the globe.

Included in the kit are a variety of stickers (door, window and anti-tamper) that serve as the initial warning to any would-be thief that the property is marked. The idea is to persuade chummy to bugger off, and is known to be effective.

If an item is stolen/recovered, the police are equipped to shine an ultra violet light on the item, and the applied Smartwater will glow bright yellow. At this point the suspected thief will probably be advised by his legal brief to drop any defence and to confess.

If necessary, a tiny sample can be taken from the Smartwater dab, and our own forensic laboratory will determine the actual registered owner of the item.

Detertech

Tim (whose workshop and tools are daubed with SmartWater......)

Edited By Tim Hooper on 23/04/2023 21:25:14

Tug,

I had a look at your engines - they're all beautiful, and far too nice to be used in anger on any of my toy aeroplanes!

Tim

Again, thank you for the positive feedback, gents!

It just so happens that I have a couple of Starrett red blades in stock, so it looks like the one currently in use will be making the ultimate sacrifice quite shortly.

Tim

Thank you, gents!

Since my initial post, I've ordered a 1.5mm blade to grind down a tad, but I do like the idea of recycling an old hacksaw blade.....

Tim

Hi all!

For my first lathe project, I'm making a new ali cylinder head for a .75cc DC Merlin diesel engine.

I've succeeded in cutting a workable thread so it screws into the crankcase quite happily. The next step is boring out the interior to accept the cylinder liner.

My question regards the subsequent cutting of the external cooling fins, and luckily I have a spare cylinder head to copy. I'm guessing that a thin (1mm) blade is used to remove material, and I'm wondering whether it's safe to take a 'standard' parting blade (3mm wide), and simply grind it down to size?

I understand that some relief on the sides of the blades is necessary.

Just wondered what the accepted method is?

Thanks,

Tim

Again, thank you gents!

Howard, I hear you on the making of tools as a learning process. It's obviously easier and cheaper to buy tools online these days, but that's not the point, is it? I did buckle and buy a knurling tool, but I'm already regretting it!

Ramon, thanks for the engine advice! I'm looking at the 2.5cc Holly Buddy for an eventual project. There are no castings involved. I think the trick would be to treat each separate engine component as a mini project in its own right.

In the meantime, I'm involved in some heavy duty decorating at home, so there won't be much movement in the workshop for a week or two....

Tim

Thanks for the warm welcome, gents!

As a hacker of balsa wood, I'm too aware of my limitations as regards precision. I have to be closer than 1/16", right?

Perhaps I should also mention that I'm a regular columnist in RCM&E magazine, where I'm logging my progress in model engineering as an adjunct to my usual aeromodelling adventures.

I'm also very lucky in that not only do I have a very supportive spouse, but there's also two proper machinists in my local model flying club, who are both being very helpful with advice and scrap material to practice on.

To be continued......

Tim

Hi all,

I've been lurking here for a few weeks, so I guess it's time to say hello!

I'm a time-served aeromodeller, who's heading towards retirement and has decided to take the plunge with some metal abuse.

This isn't an impulse decision; over the last few months I've attended a short course at Shrewsbury College to learn the basic basics of turning and milling, as well as binge-watching YouTube videos from the likes of Blondihacks and Clough42.

A few weeks ago I took the financial plunge and went shopping at Chester Hobby Stores, returning home with a V20 mill (since fitted with a DRO) and an 8x16 DB8 lathe.

There's a also a drawer full of cutters, collets, parallels, etc.

So what's the point? Well, eventually I'd like to produce a working model diesel engine or two (I've downloaded several sets of drawing from the Outerzone), but in the interim I'll attempt to produce replacement parts for my small collection vintage diesels.

So that's the plan! In the meantime, I'll hang around here and pick the brains of the experts, if that's OK.

Tim

Although a long-time aeromodeller, yesterday was my first ever visit to a model engineering exhibition.

My wife and I travelled from Telford, not knowing quite what to expect. We were both very pleasantly surprised at both the size and popularity of the event!

I've just started out in hobby engineering, and was able to collect some well-priced tooling for my new mill from a number of traders, which made the trip worthwhile.

What struck me most of all was the visible enthusiasm of both the exhibitors and traders (all of whom were happy to chat), and of the rest of the visitors too.

Yes, we had to wait a few minutes in the queue to get a cuppa, but so what?

All in all, a very good day!

Tim