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Member postings for Robert Atkinson 2

Here is a list of all the postings Robert Atkinson 2 has made in our forums. Click on a thread name to jump to the thread.

Thread: Unusual GPO hammer?
29/09/2019 22:31:29

I inherited a small hammer from my father in law (an American) that looked similar but the back end was straight with a narrow slit in it. It looked like a claw but almot closed. I discovered that it is intended for holding pnel pins or tacks for the first blow. It's magnetised with one side North pole and the othet South so the pin is helad firmly and centered between the two halves. Similar to this

Robert G8RPI.

Thread: Aero Fuel
29/09/2019 20:04:31

Biggest problem with Methanol is the energy content. Methanol has around half the energy content of petrol so you would have to carry much more than twice the weight for the same range.

Robert G8RPI

Thread: Water in fuel
27/09/2019 20:16:43
Posted by RMA on 27/09/2019 09:35:41:


Nice one! I often wonder what happens to the samples taken from the main tank at my airfield when we have a delivery. I'll ask around, not sure what Avgas would do to the car.

The samples should be put in a waste container and disposed of properly. Eye witness evidence, stains on the ramp and dead grass on parking areas indicate it is often just dumped.

Avgas is leaded and will kill your catalyst / O2 sensors and is illegal for road use as the corret tax has not been paid. Jet A is not good for modern diret injection diesels du to poor lubricity and i likewise illegal for road use.

Robert G8RPI.


Edited By Robert Atkinson 2 on 27/09/2019 20:18:14

26/09/2019 12:43:58

Washing the ethanol out with water is pointless in this context because the washing will leave MORE water in the petrol than before. It seems pointless to me anyway.

Just looked at the ethanil kit £50 for a clear fuel can with a drain tap! And how do you dispose of the petrol contaminated water ethanol mix?

Not all old cars have the issue with modern fuels. When unleaded was starting to be introduced in the mid to late 80's it was a lot cheaper than regular leaded (usual tax incentive to lull us into a false sense of security) I had a 1975 Jensen Healey and used to use unleaded, if the cashier would let me! They could not believe that a 10 year old car was OK on unleaded and often took some persuasion to turn on the pump. The JH had a Lotus 907 2l, a modern design and the one I had was a LHD Californian spec example that was specifically meant to run on unleaded.

Edited By Robert Atkinson 2 on 26/09/2019 12:46:41

25/09/2019 20:12:22

Dave W beat me to it on ethanol affecting tank coatings. As I mentioned earlier it badly affects some light aircraft tanks. It has some odd effects. Materials that are fine with just petrol or just ethanol can be softened by a mixture of the two.

Robert G8RPI.

Thread: Silent compressor problem
25/09/2019 07:16:33

A company I worked for used lots of these and they should not run too hot to hold your hand on. Have you checked the oil level?
If that is OK the next thin to check is the capacitor (or thermal time delay relay if fitted, but most of these except the very small ones used a capacitor)

Robert G8RPI.

Thread: Water in fuel
24/09/2019 13:00:34


Sorry not a chemist but do know something about alcohol in aircraft fuels.
Ethanol in petrol does not attract water, but would rather dissolve in water than fuel so if you add say 2ml of water to a 50ml sample of fuel containing 2% ethanol, shake it and lit it settle there will be 4ml of "water" at the bottom of the container. This is of course 2ml of water and 2ml of ethanol. The ethanol does not attract extra water to the fuel. The test above is an approved method for determining ethanol content in motor gasoline "Mogas" (petrol) before using it in aircraft that are approved for it subject to ethanol limits. Amongst other things ethanol can cause some plastic or GRP fuel tanks to fail.

To get water out of your fuel, add isopropyl alcohol (IPA) This should ideally be 99% pure but 70% or higher is OK. It absorbs water and is miscible with petrol so keeps the water in suspension and allows it to be carried into the engine and discharged through the exhaust at a constant rate that does not affect combustion. Most commercial fuel "dryers" are just IPA.

Robert G8RPI.

Thread: Petrol Gen for 7 1/4 locomotive
15/09/2019 11:50:26

Where are you located Andy?

15/09/2019 11:49:00

What voltage is the Loco motor? If it's 12 or 24V an engine driving a car / lorry alternator would be a better idea than a mains generator and transformer arrangment. A major limitation with mains generators is the need to keep the engine revs constant tto keep the correct frequency, this is not efficent. If using a vehicle alternator the engine can run at it's optimum revs as he AC frequence does not matter as it's turned to DC. This i what the modern "inverter" generators do, they generate "frequency wild" AC, convert to DC and then chop it up into AC at 50 (60) Hz.

If you use a vehicle alternator you could remove the regulator, connect the motor to the alternator output and control power and speed by varying the field of the alternator. Depending on the motor and if it has a governor you might have to provide some throttle control to that too.

Separate enge and alternator gives layout flexibility too.

Robert G8RPI.

Thread: Bench block for small parts - ice hockey puck
15/09/2019 11:34:15

Plenty heavy enough to support a phone.

I do understand the urge to hit a "smart" phone with hammer but don't see why you need a holder to do itdevil

15/09/2019 10:39:57

I thought this was well known, but have found no reference on here so I'll give this tip. Ice hockey pucks are cheap, a handy size and made from hard rubber. They make great bench blocks when hand filing or fitting small parts. Enough friction to stop the work piece moving, but won't damage surfaces (or tools if ou do slip. can be easily drilled, V slot cut or similar to locate parts. Also firm enough for backing up when driving small pins or collars etc. The rubber has filler and is quite "dead" so no bounce.
Put one no the cup of your trolley jack to stop slipping and damage.
They can be bought on ebay or Amazon as well as sporting goods stores. I tend to buy a few when I visit North America to save postage.

Robert G8RPI

Thread: PayPal Warning
13/09/2019 12:24:54

Don't know how to turn it off, my account just gives option to turn it on. If all else fails ask them.

Robert G8RPI.

Thread: Are there any left?
13/09/2019 07:40:46

Close Mick, I'm pretty sure it was Moto Sails not sales.
Used to be shops everywhere, Even the used test equipment dealers have mostly disappeared or gone on line. Johns Radio and M& B radio in Yorkshire, are two examples. Property prices are a big driver I think. Why keep a business making a few tens of thousands a year when you can sell the property for a million or two and retire. That happened to two small car repair garages I used in Dorset Stewart of Reading that was Chiltmead (test equipment again) are still going but have moved out of Reading into what is basically a house in a small village.
It's not just in the UK. Most of the surplus places in "silicon valley" in the bay area of California have closed, A big one Halted Speciality Supplies closed last year. Helmut Singer in Aachen Germany also closed without notice recently. A big issue is that the "stock" can become hazardous waste "WEEE" and you have to pay to dispose of it if you cant sell it
Greenweld in Southampton (still going but new management selling mostly "new" surplus Chinese junk) had a huge batch of D size SAFT Lithium primary cells about 20 years ago for a fraction of the price of a standard D cell . They were just about to expire when they bought them. If expired SAFT could not sell them and would have had to pay for disposal.

My wife want's to know what is going to happen to all my junk when I die.......

Robert G8RPI.

Thread: PayPal Warning
12/09/2019 17:38:57

Of a similar nature I had a very realistic Smishing attempt yesterday (Smishing is phishing by phone SMS).
The SMS purported to be from EE (my phone provider) saying they were unable to process my last invoice payment and providing a link (not that exactly) link.

The giveaways were the and .com in the link and the fact that the origin was a full mobile telephone number. A genuine provider SMS would normally be rom a 4 digit number. And of course the common on that it did not have my name in it.

Reported it to EE and they confirmed it was fraud and that anumber of people had fallen for it.

I don't authorise PayPal to automatically debit my bank account. You have to let them to open a paypal account these days, but can, and I suggest you should, cancel this once the account is set up. You have to transfer funds manually but at least you have control. It's not just fraud, I know someone who sold a vluable item and took the paypal payment out and a couple of weeks later the buyer made a complaint, paypal then took the same amount out of his current accout to put "on hold" while they sorted it out. No warning whatsoever.

Thread: Stuck oil filter
12/09/2019 12:37:13

A particular issue with modern filters is that the can is very thin (presumably to save cost and weight) so will not withstand removal forces. If you can get access, try applying impact force in the unscrewing direction to the rolled bead at the base of the filter. use a punch or blunt cold chisel. It's the strongest part of the filter I've had success with this when all else failed. If going for the punch-through method an old wood chisel is the best tool the flat side distributes the load over a bigger area than a screw driver.

Robert G8RPI.

Thread: How to upset the neighbours!
12/09/2019 07:25:37

Nah, this is how to annoy the neighbours


Not a model engine. I know the offenders.

Thread: To Pin or Not To Pin
11/09/2019 07:33:37

I would dry assemble. drill for a small (1/8" / 3mm) pin and then clean and assemble with loctite retainer (correct fits etc). The pin is only an assembly aid to make sure everything is aligned properly. If you do use a large pin and loctite there will be some load sharing between the two as nothing is completely rigid.

Robert G8RPI.

Thread: Are there any left?
10/09/2019 12:36:45

Thats a few years ago, I still use them for stuff as and when required, I find my goodies at all the vintage rally's I attend, my latest find was a milking bucket with a plaque attached which reads Listers Dursley England.

Martin P

That brings back memories. When I was at college in Bristol in early 80's I had a part time job repairing gaming machines and the Listers Dursley social club was one the sites Always a priority call, they had a habit of smashing the machine to get their payout if we didn't turn up quickly enough.
Back on topic there was Target electronics in Cherry lane at the bottom of Cheltenham road. Lots of surplus and new microtan computers. Further up Cheltenham road was Marshalls component shop.


Thread: Repair required for Milling Knee
07/09/2019 08:47:24

+1 for epoxy and threaded fastteners. Ideal would be low head shoulder type like this

with the shoulder crossing the break.

I'd sort out clamping, and possiblr drilling jig, throughly clean mating surface, uses quality slow cure epoxy and about 40 deg C heat. Leave for a couple of days then dirill threading holes an clearance in small part for standard screw. thread and bolt with standard screws statting ain to places and screwing up before drillin next. On last hole after tapping drill, ideally ream, and counterbore the hole for the shoulder bolt. Clean hole and assemble bolt with permanent anerobicthreadlock / bearing retainer (loctite). The move to the most distant hole, remove screw and drill /ream/counterbore for bolt. untill all done. If the counter bore / head is wider then the dovetail just machin back after allowing 24 hours for loctite to set.

Robert G8RPI.

Thread: Anyone know where I can get hold of 'Gauge Rods'
06/09/2019 08:27:01

For this sort of work a loupe magnifier with scale is a good option. Peak make nice ones and can often be picked up used quite cheaply. Only problen I could see is if you can't get your head close enough with the workpiece in the lathe. A little jig to keep it squae to the work and at the same distance might be useful.

Another option woud be a USB "microscope" camera in a fixed position connected to a cheap laptop or tablet with a scale stuck on the screen calibrated against a couple of slip gauges. There is also measuring oftware available see for a similar application.

Robert G8RPI

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