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Member postings for Russell Eberhardt

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

Thread: Chemically cleaning brass - gently
21/01/2021 15:26:41
Posted by Kiwi Bloke on 21/01/2021 08:23:59:

Anyone know how to safely remove verdigris?

Yes, clock cleaning fluid which is a mixture of water, ammonia, oleic acid (olive oil will do), and a touch of acetone. Best used in an ultrasonic bath to get into small holes such as pivot holes in clock plates but should work on brass jets.


20/01/2021 08:39:19

If, as Michael suggests, it is copper oxide you could try using household ammonia solution to clean it.


Thread: Cura 4.8
19/01/2021 15:45:00

You could try "repetier-host" which comes with the Slic3r slicer. That's what I started with and I found the combination quite easy to use.


Thread: Fast charging anyone?
19/01/2021 09:24:59

Hmm ...

5 minute charging time for a Tesla S 60 battery will require 720 kW from the supply, not allowing for charging inefficiency. So, if a standard 240 V supply is used, it will need to supply over 3000 A. So how thick will the cables be? A motorway service station might need 10 charging points so it will need a 7 MW supply at peak times!


Thread: dual boot Dell laptop
17/01/2021 09:47:17
Posted by duncan webster on 16/01/2021 14:14:26:

Thanks to SOD and JAS I think I've sorted it (don't let the laptop hear this, it will find another way to bite me!)

laugh They often do!


Thread: Increasing Friction??
16/01/2021 16:11:01

Good solution Chris. I've done the same in the past - just have to be careful that everything is aligned correctly otherwise things can move as you tighten the screw.


Thread: Etching brass
16/01/2021 15:56:29

I've used this for etching a brass clock face with great results:


Master was ink jet printed on overhead projector film. UV exposure was a few minutes in November sunshine in the South of France so perhaps a bit longer in the UK.


Thread: Smallest powerboat ever?
15/12/2020 12:21:52

You might find it interesting to sign up for their weekly briefing:



15/12/2020 10:17:35

3D printed boat only 30 microns long and powered by hydrogen peroxide:


Can anyone beat that?


Thread: Removing bang in self tappers
28/09/2020 11:53:24

I found them easy to remove from vintage cast iron car engine blocks by filing flats on the edges and gripping with a mole wrench to twist them out.


31/08/2020 16:28:08
Posted by Tim Stevens on 31/08/2020 15:34:28:

Sorry, Howard, but fuel with Tetra-ethyl lead was available from the early thirties. The Shell petroleum handbook 1933 says it is used in aeroplanes and US gasoline, and the 1938 edition refers to it as a regular constituent of motor spirit. Such fuel was often called 'Ethyl' as distinct from Benzole (with benzene etc from coal) and Discol (with alcohol from the Distillers Company Ltd.

Yes Pratt's Ethyl fuel became available in early 1930 and the 2.3 litre Talbot 90 was racing reliably with an unheard of 10:1 compression ratio. That enabled them to compete with the Bentleys with their 6 litre engines!


Thread: varifocals
31/08/2020 15:59:36

The only problem I have with varifocals is when working close to something overhear such as when rewiring a ceiling rose. For those occasions I have a pair of prescription reading glasses.


Thread: ultrasonic cleaning fluid ?
18/08/2020 20:49:28

I use this recipe for cleaning clock parts in my ultrasonic bath. It brings brass parts up to a lovely shine.


For general cleaning I just use a little dishwasher rinse aid in water. It is just detergent but doesnt foam.


Thread: Remote Controlled Boat
16/08/2020 09:54:28

Will it detect and give way to small sailing boats?


Thread: Carbon fibre pendulum rod
12/08/2020 11:22:06
Posted by Alan Crawley on 11/08/2020 19:35:38:
I’m beginning to realise my IQ is too low for this conversation!!

Surely not. Sorry if I have assumed too much.

To simplify things; Q is just a measure of how much energy is lost on each cycle of the pendulum and how much energy must be given back to it on each tick of the clock to maintain it. The higher the Q the smaller the energy is needed to keep it going and the less disturbance that it causes to the regularity of the clock.

Hope that helps.


11/08/2020 15:52:47

I did measure the Q factor of my pendulum with all fittings. I can't find my notes just now but I think it came out at about 6000. Easy enough - set it going and count the number of cycles it takes to decay to 37% of it's starting amplitude. Multiply that number by 2 x Pi to get the Q. The most important factor is the air resistance so best to use lead or even uranium for the bob and an aerodynamic shape. I stuck with steel not having uranium to hand!


10/08/2020 19:30:55

The supplier of the pultruded CF tube I used for my regulator quoted -0.1 to -0.3 ppm/C. I used a threaded bottom fitting for the rod for use with a regulator nut at the bottom of the bob. I calculated that making the transition from CF to steel 30mm below the centre of the bob would compensate for 0.2 ppm/C for the rod with a small positive contribution from the suspension.

Seems to work fine.


Thread: Another new member
09/08/2020 11:47:41
Posted by Peter Cook 6 on 09/08/2020 11:13:26:

Thanks. No plans for clockmaking! I have rather too many clocks as it is. In any case clockmaking would involve gear cutting and (after so many years in IT) I am averse to highly repetitive activities. That is what computers are for.

So clock making probably lies on the far side of a timeline that includes CNC - and I have a LOT to learn before I even contemplate that.

Hello and welcome Peter

I was always interested in clocks having taken old alarm clocks apart as a teenager to see how they worked. Most of them went back together and continued working!

In my retirement my wife bought me a Vienna regulator (American) on Ebay and I restored that and was pleased to get it working. Later, on researching my family tree, I discovered that three generations of my ancestors were watch and clock makers so I took the plunge and started clock making as well as repairing clocks for friends. Making gears (more correctly called wheels and pinions) isn't that tedious.

Your new mill is very good for small items and could be converted for CNC. I have an SX2P which I have converted for CNC and find it very useful for crossing out wheels which is more difficult than cutting the teeth.

Have fun.


Thread: Cleaning emergency !
04/08/2020 19:52:13

Replacing the floor covering in a camper van is by no means easy. The flooring is usually laid before the installation of the furniture so everything must be removed including the kitchen sink!

A possible alternative is to use floor paint. This is a useful guide: **LINK**


02/08/2020 21:42:34

Try Googling "Plasticiser migration". I think you're stuffed.

When manufacturing electronic products we used to have to be carefull how they were packaged to prevent the plasticiser from the power cable ruining the plastic case of the unit.


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