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Member postings for Oily Rag

Here is a list of all the postings Oily Rag has made in our forums. Click on a thread name to jump to the thread.

Thread: Etching brass
15/01/2021 20:00:04

Martin C,

Just viewed the toob vid on laser system - I like the distressed look shown at the end of the video. Could be the way to go - I have access to a laser cutter (cuts up to 2" thick steel plate so might be difficult to turn the gas down)

An authentic patina look always wins over a 'just out the showroom' look.

Martin S

15/01/2021 19:16:16

Rob, Martin & Stuart,

Thanks for your replies. There is another option that I have heard about and think it may be worth consideration, which is to make a metal loaded resin mould of the face of the plates and stamp new plates with a flypress. I was talking to a close friend who worked at Abbey Sheet metals and he was telling me they used this method to do prototype car panels from original hand rolled panels or CNC milled wooden dies digitised off the clay model. He said they were good for 50 off, so sounds durable. Food for thought!

It is the painting that concerns me as much as anything though - the originals, at nearly 80 years old, look amazing where they have not been damaged, the paint must have been exceptionally durable (probably a true enamel!)

Thanks again,

Martin

Thread: My compact workshop
15/01/2021 16:35:57

Compact!? But, but, I can see the floor! Room for some more machinery there me thinks.

Seriously, nice tidy shop with some excellent work on display there - well done. And a good use of shelving - I always like to have good shelving - not too deep so things get hidden and far better a storage area for tools than 10 year old tins of 1/4 full dried up paint.

Martin

Thread: Etching brass
15/01/2021 16:21:50

I have been reading through the archives concerning photoetching brass and thought it appropriate to raise the questions I have using this thread. Apologies if I am OOO (Out of Order!)

I have been asked about making several nameplates for a vintage tractor. The originals were all brass based, and I have detailed photocopies of the original plates. I have looked at all the archive posts about brass etching but there are a couple of questions that I am hoping the great and good on here can advise me on.

1. - 2 Plates carry stamped alphanumerics for such things as gear ratios and serial numbers. I am assuming that these need to be blanked out in any photoresistive mask. They have, in most cases, transferred in the photocopies with either 'fuzzy edges', shadows, and greyscale. We intend to re-stamp these as the original.

2. - The 'highlights' on the plates are in varying colours. One is red lettering for the manufacturer name with a black background with the lettering in the base material. Another has the lettering in a deep maroon on a bare (brass) background. I believe the original plates were stamped, the highlighting was probably paint applied by (probably) a roller, or via a masking process.

3. I read in the archives that 'Dianne' recommended using printers 'lith' paper - has anyone found a supplier?

4. Others talk of 'press and peel blue' and that Maplins was a source, since Maplin went to the wall is there another source other than the 'hold your breath' fleabay (I don't want to be dealing with china! via the East Midlands)

5. My HP deskjet is a printer/scanner/photocopier/telephone/calculator/radio (OK, I lied about the last 3 facilities on it!) I take it the photocopier element is not related to the laser copiers (someone mentioned photocopiers/laserjets use the same technology??) What's the score?

Thanks in advance of any responses to my questions.

Martin

Thread: Socket/thread sizes
14/01/2021 22:44:04

I think Bill has hit the bolt on the head with his point about modern sockets are more likely to be 'wall drivers' rather than 'corner drivers'. This development led to the 'Metrinch' type of socket when manufacturers realised they could reduce stock levels by offering a product which favoured both Imperial and Metric sizes. That, added to the continuing reluctance of the Americans, and a fair few Brits, to abandon inch sizing!

Martin

Thread: Boring bar size ?
14/01/2021 22:09:54

Jeff,

Just noticed your reply that these are Keihin TA09's, from memory these are 'flat sliders' and you stated ...

"the carbs work very well as a standard setup ".....

Well, yes they do, but they can work even better by some other modifications. Changes to the spray bar and separating out the secondary air feeds from out of the bell mouths will give far better performance. The spray bar mods require the reshaping of the main jet well, and the secondary air feed mods improve the mass air flow capability through the carb, probably by as much as the boring out, if not more (just under 15% for boring, empirically around 18% to 20% for bell mouth changes). These are easy mods which can be performed on the lathe whilst set up to bore out the main airway.

Just as a reminder are these 'pumper' carbs?

Martin

Thread: Standards of Electrical Wiring
14/01/2021 16:40:44

Reminds me of the roadside 'cafe' (tent!) I came across in Vietnam. They had a bottled gas cooker, a table and 3 chairs, and a luxurious Coca Cola refrigerator full of chilled water bottles and local fizzy drinks. I wandered around the back of the 'cafe' to check where the electricity for the fridge was coming from as I could not hear a 'Genny' running. I followed a cable about 30 yards to an electric pylon where the bare ends of the cable were twisted around the power lines!

Amazing that the excess cable length hasn't been 'salvaged' yet.

Thread: Myford ML10 main screw skating
14/01/2021 16:26:54

That looks to me like a spur gear with a slight helix angle to mate closely to the leadscrew (picture posted by Rob). A cheaper way of mating what is a 'worm' (leadscrew) with a right angle driven system, than producing a wormwheel. The gear can be cut in the normal way by a hob or simply by a B&S type form cutter by angling the component by the value of the lead angle.

The apron gears on my Raglan are formed this way which mates with the power feed worm wheel, meanwhile the rack and pinion for the hand drive of the saddle is a normal 'zero offset' spur gear as the rack's lead is equal to the pitch.

So, in conclusion I think Bob's problem is that the gear has been 'over engaged' in the past and the root of the leadscrew thread has worn the tips of the pinion gears. Maybe the original pinion gears were straight cut, which on a closer look at his photograph there is a suggestion this is the case) - in which case the wear will be more concentrated as the pinion gear flanks will be single 'point' loaded rather than having a slightly lower stress level with a 'lead angle' pinion gear matching the appropriate lead angle of the leadscrew.

Martin

Thread: Making go kart parts
13/01/2021 11:17:29

Michael,

No Probs! I like photos to be clear and well defined - that was taken by my main camera (Apple iPhone!)

The cable operated calliper is a simple 'ramp' system with adjustment by way of the central bolt which acts as the pivot point. The actuating lever can be reversed for either left or right hand 'pull' - simple, efficient and practical.

13/01/2021 10:35:13

For a Go Kart I think you will need something more substantial than a bicycle disc brake. If you used a go kart specific brake system like those made and sold by 'Air Heart' you can fit a single disc onto the rear axle rather than have the added weight of hub mounted brakes.

Air Heart produced both mechanical cable operated callipers and hydraulic master/slave systems.

Here is a photo of the rear brake on my Classic Racer from 1966 - a genuine fitment at the time. Quite capable to haul the bike down from 'flat out' to 10mph on the IoM!

img_0521.jpg

Disc mounted on Gold Star 'Crinkle' hub

img_0525.jpg

Disc carrier and hub

img_0526.jpg

The Air Heart calliper with cable operation.

Thread: Interest in pictures of models
12/01/2021 22:15:20

My mum stopped me looking at pictures of models when I was 14!

Thread: Boring bar size ?
12/01/2021 22:12:49

Invest in a solid carbide boring bar with either a ground cutting edge as part of the tool or a carbide tool which accepts a TAT. I use several of these for jobs as you describe.

If you are opening out the throat are you doing other modifications to the carb as well? For instance - one area where the Amal carb can be improved is the slow run jet can be moved from its position in the underside of the fuel bowl facing to the bottom of the fuel bowl itself. There is an angled drilling for the fuel fed to the jet which can be tapped 2 BA to allow the slow run jet to be repositioned. Sinking the jet under fuel improves the transient signal when the jet comes 'on stream'.

Other carbs, such as Keihin can also be modified in ways to improve their transient responses.

Thread: Nitrogen as an Energy Store ...
12/01/2021 01:04:04

There is a paper written by for the US Marine Corps by MIT which looks at mobile power generation for expeditionary USMC operations. The list of parameter requirements goes through usual military concerns, for example low infra red emissions, low noise, lightweight and portable, efficiency and multi fuel capability.

The paper examines conventional ICE both gasoline and diesel fuelled, gas turbines, Wankel rotaries, compounds, etc, The most interesting was a engine described as a 'chemical engine' and this was fuelled by HTP (High Test Peroxide) and any available hydrocarbon could also be introduced as a power booster.

Basically Hydrogen Peroxide is introduced to Potassium Permangate which acts as a 'disassociation' catalyst splitting the Hydrogen Peroxide into steam and oxygen.

Martin

Thread: Ford Quadricycle Engine
12/01/2021 00:45:41

Brian,

"my main worry is the strength of the spark ...."

If you do have problems with the strength of the spark you can utilise a 'sustainer' coil - best example I can give of this system is the Metro 6R4 rally car of 1987 - it causes a lot of people to scratch their heads trying to understand how it works.

Due to the odd firing order of 135 - 45 - 45 - 135...... the 6R4 had a secondary full size coil attached in parallel to the 'working' coil, the weird point is that the second coil had the HT chimney blanked off, this secondary coil acted as a reserve for the short duration firing intervals.

As for using a CDI system the problem I fore see is the extreme high voltage coupled with an extremely short time duration of the spark. An induction or Hall Effect system gives a lower HT spike but a much longer time duration and low speed engines with low compression and low grade fuel much prefer a long spark duration. The Ruhmkorff coil effectively was what nowadays is a MSD type ignition system (MSD = Multi Spark Device). The MSD being a CDI with multiple sequenced sparking to overcome the short time duration of the CDI spark. MSD's are popular with alcohol fuelled engines due to the poor vapourisation of alcohols.

Martin

Thread: Wallaby crankshaft
11/01/2021 16:09:15

Equivalents for AISI 1144 are BS44SMn28, BS44SMnPb28, and BS226M44. In more understandable EN numbers the nearest equivalent is EN8M, close but not exactly the same!

Thread: Ford Quadricycle Engine
11/01/2021 15:58:48

Interesting project!

Having seen the original in the Ford Detroit museum I would have thought they would be able to help with the technical details. On your suggestion of using 'lighter fuel' I would sound a note of caution as lighter fuel is mainly Naptha based and has some serious drawbacks for running an IC engine, one of which is serious oil degradation the other being vapourisation characteristics.

From a distant memory of this vehicle I believe the carburettor was a surface evaporation type (see http://earlymotor.com/leon/misc/html/surface.htm) and the ignition was a trembler coil system, sometimes referred to as a Ruhmkorff coil (search Wikipedia for this).

Martin

Thread: The Repair Shop is getting to me...
11/01/2021 15:37:59

Well said Tug,

I do believe it 'de-nerdifies' all crafts people as it opens a window for the general public to see that the skills shown on the programme do have a place in society and that things do not have to be 'chuck and forget' when they come to the end of their life.

I think the respect for people like Steve Fletcher, 'the clocky' and the young carpenter, Will Kirk, amongst the general public has been for the better of all of us 'sheddies'.

My gripe is with Jay who makes out to be the Foreman - wanders around in a nice unblemished leather apron episode after episode and can't hit a nail square on the head, pretty important to do if you are a so called furniture restorer. Having seen his furniture restorations on Money for Nothing they appear to be no more than slapping a coat of paint onto a 1950's bit of Ikea! Also, I see there is a nice Myford in the background but have only seen it used once. The metal worker Dominic Chinea, and bike bloke looks to know his onions as well. Meanwhile the ladies are all excellent craftspeople in their own fields.

It has raised the profile of craftspeople and for that we should all be grateful.

Thread: Oil Blackening and other Oil Issues
09/01/2021 11:02:33

+1 for chemical Gun Bluing - imparts an oxide protective layer which will resist further corrosion.

Thread: Another car
09/01/2021 10:43:15

As John MC has pointed out, the change of bearing shells on the Dart engine at 50,000 miles was a preventative measure against bearing fatigue failure due to crank cavitation issues.

The Bandit/Fury bikes did perform well as road tests of pre-production bikes attested to at the time, but they were plagued by production issues. One major issue was the cylinder head bolt recesses breaking through into the OHC boxes, something like 70% of castings were being rejected due to this after machining. The original Turner designed ETED1 is shown in a picture on page 233 of Hopwood's book "Whatever happened to the British Motorcycle Industry?" It looks like a twin cylinder Tiger Cub. The later Bandit / Fury was a step change for the industry; apart from being a high revving engine (10,000rpm) being competitive with products from Japan, it also featured DOHC, 5 speed gearbox and electric start. There were many ingenious and tantalising designs being developed, a V5 modular engine based around a triple and with twin cylinder offshoots. A single cylinder 480cc 4 Valve OHC engine was also under development by BSA, the one prototype escaped the scrapman and was last seen in a Bandit frame at Silverstone in 1988.

The biggest obstacle to the industry, and this holds true across the whole of British manufacturing was the lack of investment in modern machine tools. At the Meriden closure auction I was struck by the machine tools being 1940's/1950's in fact many were 'war grade' - one Brown & Sharpe 'rocking bed' cam grinder had a hole in the base casting as big as your fist where a piece of shrapnel had hit it from the original Triumph factory bombed out in Priory Street Coventry factory! At Herberts', when I was an apprentice, I worked on a Herbert No. 16 Universal miller dated from 1915 and rejected by the Russian Tsarist Government inspectors as unsuitable (Herberts had a huge Russian contract to supply the Russians with machine tools for their war effort)

Martin

08/01/2021 20:49:53

John,

One of the test bed failures was a spectacular in that the engine disintegrated between the front pair of cylinders and the rear pair of cylinders. On wag suggested welding the remains together to make a V twin. I happened to be walking past the test bed when it had its 'moment' There was an almighty bang and a sheet of flame filled the cell, the tester came out with singed hair and covered in dry powder from the automatic fire extinguisher system. Anyone so caught out by the extinguisher system got called 'Fred the Flour Grader' after the then current Homepride adverts.

The cars failed on test track running due to oil cavitation within the crank drillings which starved the big ends. This generally led to con rods 'escaping'. We did fit sump baffles, and modified the crank oil drillings which cured the cavitation but Daimler blamed our installation rather than accepting that it was their problem.

That said we could design in our own problems as good as anyone though! The Triumph Slant 4 engines with the integral cam carrier - which necessitated angled head bolts was a nightmare for destroying head gaskets until we solved it with the first silicone silk screen printed gaskets and reinforced fire ring closure. Developed jointly (no pun intended) with Coopers Gaskets. The integral cam carrier was demanded by SAAB for their engine as the Slant 4 was a Joint Venture with SAAB. After they took over their own production the first thing they did was get rid of the integral cam carrier and the angled bolts!

Martin

Martin

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