Member postings for Stub Mandrel

I'll look out for it. I have asked elsewhere if anyone knows much about the original of Peter Chadwick's A-Frame engine - I found pictures on the NMES website, but no real info

 

Could Peter be persuaded to write something on his engine and its history?

 

Neil

 

Mark, the one I'm interested in was in the background of Peter's lubricator article, not the famed 'non-dead centre engine'.

I do much teh same thing as Bruce when planning a model. It works for wooden boats and even Daleks (but I haven't built that yet...)

 

On thing that's  hany about excel is you can tell it to display dimensions twice, once formatted as fractions - I usually choose 32nds or 64ths. It makes it easy to spot dimensions which conveniently scale to stock size. But don't mix exact dimensions and rounded ones or you get cumulative errors. I try to make unmachined sizes stock sizes and adjust the machined dimesions to fit. Saves a lot of extra machining.

 

Neil

Email the seller with a couple of sensible questions, even if you think you can guess the answers. The tone of their reply is a good guide.

 

Yopu can't avoid being ripped off completely though - I bought a used mini-lathe  motor for £40 from the back of ME. The elderly seller sounded a real gent on the phone. The armature had two blown coils... you can't trust the old people of today!

 

 

 

Neil

For what it's worth I came by some EN24T and it made nice springy collets OK with no treatment but getting a nice surface finish on the external taper was hard. I would like to try EN8 as I understand it machines more easily.

 

Neil

I have trouble finding citric acid, so I use W5 limescale remover, from either Lidl or Aldi. It is ready mixed,works wonders, is 'irritant' rather than 'toxic' and contains 'corrosion inhibitors' which suggests it's less likely than most to create rust if splashed. Does smell a bit odd though.

 

I bought a 1 1/2" SOBA milling vice from one of the 'usual suspects'. the jaws were about 3 degrees off true and the left had screw thread stripped under modest pressure. In the end I found another screw that fitted and milled the jaws straight.

 

I bought a much bigger no-name vice from Proops for £20 and its excellent...

 

Neil

I had some really useful feedback on the canalside crane at Fradley, so I've started making a 1:12 model. First a pic of the crane, then some bits;

 

 

 Main pillar:

 

Gear wheels, winding drum and brake drum:

 

 

 

Parts assembled on to the winding drum:

 

Tracey Tools advertise in ME regularly (or did) and have keen prices.

 

Neil

 

 We used to do that to make igniters for - well let's say if you did what we did down the quarry as kids now, they'd put you in Guantanamo Bay...

 

On the topic of the EU, did you hear they will be demolishing Brighton Pavilion because of the EU ban on minarets?

 

Neil

 

 

Hi Marcus

 

Hope it doesn't feel like I'm following you around...

 

If roller bearings don't solve your parting troubles - parting is such sweet sorrow

 

Try this - a t-slotted table from continuous cast meehanite (from College Engineering)  and simple toolpost from the same (fixed by two 6mm screws into a double-hole t-nut). A competitor for Tubal Cain's 'Gibraltar' toolpost.

 

Neil

 

Hi again Marcus,

 

Model Engineer Vol. 197 No.4277, 7 July 2006 has an article describing how to fit roller bearings. Shame the archive only goes back to 4290! Modesty forbids me naming the author...

 

Neil

Hey Roy,
I've had electronics as a hobby since I was old enough to wield a soldering iron (about 10).
Books - better than the web, you can read them in the bath.
Two good books for starters are the Maplin Electronics Handbook by Michael Tooley and (for more detail, but costly) The Art of Electronics by Horowitz and Hill. But I learnt most of my stuff from reading datasheets - these days easily available from supplier websites. Sadly in  2010 there are fewer example circuits than there used to be in the 70's (the old 555 and 741 datasheets were an Alladin's cave of ideas).
 
Variable Power supply
I have NEVER had one of these until I made a simple one a year ago +/- 5 and 12V, plus 4-16 variable.
You can get REGULATED plug in power supplies that give a range of voltages, and a simple REGULATED 5V supply will do for most things, both quite cheap.

Multimeter
My main multimeter cost my dad about £60 - in the 70s, an Eagle, one of two he never used as he had an AVO. I still have it (and about six others), but I use a £10 digital one from Machine Mart 99% of the time (and its just as accurate and more precise).

Breadboard
Worth having, but a box of jump wires will cost rather more and is essential. You will rapidly get some veroboard and a soldering iron (18watt Antex or slightly bigger Weller - I prefer the former) if you want anything permanent.


Oscilloscope - worth having, if only for entertainment value
I got my 50MHz two-channel Hameg off Ebay for about £40 - keep bidding, but don't go too high. It took me two weeks but in the end I got what I wanted. Replaced a Heathkit one my Dad made in teh stone age.
Eseential if you want to tackle microprocessors.
I wont argue with MPLAB for PICs, but I use AVRs with Atmel AVR Studi 4.00a and WinAVR - also free (moral - look for the freebies!)
 
I have an STK500 development kit, this is not essential but something like that for AVR or Picstart(?) for PIC is a massive help.

nice to have
Function generator ~£100 - £1000
Frequency/period counter ~£150 - £1000.

I would consider making these; I have it isn't too hard to do once you get into the field, especailly if you use a custom chip and don't expect too much. But even the most basic will help you solve problems faster.

Schematic/PCB capture
Download Eagle demo version - the size of PCB is limited to about 3" by 4" and the learning curve is steep, but it's free for non-commercial use from their website. There is a link from the Farnell website (they bought Eagle).

It's a fascinating hobby and goes well with model engineering. They were very close in the 50s and 60s when RC fans made their models AND their radio gear!

Neil

 

Well I've made a start!

 

 

Hi Marcus,

 

The Arc Euro Trade website has (or had) a video of my Clakre CL300 (essentially the same lathe) where I'm plunging a 3/16" wide parting tool to cut a groove in 2" EN1A. No chatter and the swarf 'came off with the sound of frying bacon', to coin a phrase.

 

Standard motor, but with the roller bearing headstock mod -  plus carefully adjusted gibs and slides.

 

I have since made a t-slotted cross slide that I use with a one piece tool post, but only this weekend I've been reducing a 1 1/2" bit of high tensile (OK I picked up the wrong stuff from the pile) down to 5/8" at one end. Just 10-15thou cuts and the swarf is coming off in long coils - I managed one over a yard long!

 

One idea I plan to try is a smaller toothed wheel on the end of the motor. Increase motor speed and get more torque for the same speed.

 

One thing I rely on is my digital tacho - not to get the right speed, but I keep an eye on how much the speed drops - shows up a too heavy cut or a blunt tool pretty quickly.

 

 

Regards

 

Neil

the pics were hard work. I think the perspective is too severe for me, I could only get part of all but one picture to work. I wonder if reducing the angle or making the vanaishinjg point much further away would help?

 

Yes we can all do stupid things. I left my Antex soldering iron left switched on all last night. i still have aworkshop, but the element blew and farnell no longer stock CS elements. They are twice the price from other places

 

Neil

I've electrocuted myself enough times to be able to speak with authority on this.

 

We can all make mistakes - I have IEC connectors on several things in my workshop and around the house. But oh no, I'm not stupid enough to get the leads muddled up am I?

 

And its amazing how many people know machinery inside out but really don't get electricity. There really are reasons why plugs are polarised etc. prat ideas like wiring two 13A plugs to a welder are just so dangerous as to be beyond the pale. The screwdriver idea isn't that bad, but even the builder changed tack and went to a safer solution so he knows it wasn't the best way - just a stop gap.

 

Something like this it costs nothing and it is zero effort to make a short comment on safety. I remember someone in one of the mags suggesting wiring capacitors to the mains o make a bridge to test their value - he had unshielded mains floating around, and got shirty when I worte in to point out you could do the same thing in perfect safety by using 12V ac instead of mains.

 

Now I like big bangs as much as the next man, but not when they are someone else's fault. Even if we don't have kids, one day we all die and our wife/daughter/son/mate will come to sort through our stuff, and maybe switch on and try it out. I make a lot of electrical stuff, much using mains in it, and while  I don't hit CE standards, I don't make anthing I would worry about a kid plugging in and switching on. they might break it, but it won't break them.

 

 

Cheers

 

 

Neil

 

 

P.S. Some may know SIDE...

 

Tubal Cain's "Model Engineer's Handbook" has a really good diagram on the spark test. Perhaps David could get permission from Tom Walshaw's widow to publish it in MEW?

 

My understanding is that EN8 is suitable for use without further heat treatment?

 

If you want tough but machinable steel EN24T is the stuff to use (it has been pointed out to me that the 'T' for 'tempered' is vital.

 

I went to metal supermarket today  and all their stock was marked with old EN numbers, except the silver steel and ground flat stock.

 

Neil

Well done Wheeltapper!

 

If I''m not mistaken that''s one of the cheap drill stands from Machine Mart. I bought one to convert to a mini drill stand, and finally gave up on any idea of making something useful out of it.

 

Even the machine vice that came with it (not the one oin your photo) was so nasty I couldn''t even get rid of it at a boot sale for 10p!

 

I didn''t think of a tapping stand, where rigidity and 100% accuracy aren''t needed - I''m sure it will be much better than working by hand. I wonder if I still have the bits?

 

Neil

Well I finally got to the West Brom Metal Supermarket today.

 

Nice guys, very proud of what they stock. Not much passing trade - they said I was the second new customer in a week!

 

They don't advertise in the ME press as they get a lot of 'tyre kickers' and phone enquiries that come to nothing because of the postal costs. They like folk who search them out and call in though, as they say they really want something.

 

They had plenty of bar ends, angle, tube in EN1A, EN24T, aluminium alloy, stainless and silver steel as well as some scarily huge bits of ground flat stock. Also odd stuff like engineering plastics and titanium. They said that toolmakers used to buy up most of theiir odd ends, but they are building up more these days.

 

I got some 3/16" stainless (for boat prop shafts) and got 10 kilos of big offcuts of big EN1A PB (yes they still use the 'real' classification) and 50mm black steel angle. I also got a good deal on nearly a foot of 30mm silversteel. I can now make a Eureka and it's cutters.

 

Buying odd ends it was a case of taking what they had, but compared to buying by mail order I think I got a good deal.

So worth a visit, I say.

 

 

Neil

Blimey - Peter Chadwick's A-Frame engine (Peter are you in here???) bears more than a passing resemblance to my 'Norden' engine. Issue 4371, T&K Lubricator article. Although it appears to be a different size with different slide bar arrangements and flywheel, and a built up table (not cast in one piece), the basic arrangement is the same including the governor under the table.

 

Does anyone know anything about these engines - is it possible Norden's inspiration was an older product.

 

Thanks Neil