Member postings for john feeney

Hi Taf,

About 20 years ago I built a cnc milling machine. I used a Chester`s 626 column. I used an SKC resin. The basic procedure is to mount the column above the base and inject the resin into the gap.

1. Clean both surfaces, if possible machine one flat and square

2 Drill 4 small holes in the column and tap M6 for jacking screws

3 Place the column on the base, screw the jacking screws down to leave a gap of about 12mm.

4 Replace the holding screws, adjust the jacking to get the column vertical in both planes.

5 Coat the underside of the column with mould release agent.

6 Apply sufficient resin to overfill the, replace the column and check that alignment is OK. Nip the hold screws to

hold column in place.

7 Remove excess resin.

For more information Google " SKC resin, scroll down to "Coatings for Joint Faces - Buttkerit "

This gives much more information. Buttererit supply the resin ( Based in Manchester)

I wrote an article on this in Model Engineers Workshop ~ 2000? but have lost my copy and can`t find it in

the MEW index.

It looks more complicated than it is to do. This method is used by major machine tool makers.

John Feeney

My Dad was a machine tool fitter for many years, he used a small block of hard felt( as used in piano hammers) for applying `blue` to the surface plate.

It was about 10mm thick, 20/25 mm wide and about 40mm long. I still have such a piece in my "scraping box" although have not done much in the last 10 years.

He worked in the Manchester/Stockport area ( mainly for Craven Machine Tools) where there was a distinct pattern of the finishing scraping, quite different from the "Halifax" pattern.

John Feeney

Hi "Tug"

Most of the engines with the` high performance` bearing set up are of 2.5cc capacity and used for class F2C team racing. I think they are of Russian and Ukraine design and manufacture. They are not generally available, although Profi engines are, where price is around $800.

My engines( 1.5cc capacity) where designed in about 1980 and originally used a `machined from solid` crankcase. I eventually found an investment foundry who would make castings from `home made wax` dies. (see album photo`s) The top one is the crankcase, the next one is for the soluble wax core, the third one shows the front and rear housing dies. The final one shows a crankcase wax pattern before the core is dissolved, it`s a previous version.

I have tried most of the bearing arrangements but not all at once.Currently I clamp the front bearing onto the shaft with the prop.driver. I have run it up 18000/20000 rpm with no problems, power is about 0.3 bhp.

There is a lot more involved in these types of engines and I havn`t kept up with their design and manufacture over the last 10 years or so. Mine are basically 1980`s vintage using steel cylinders and cast iron pistons.

For most model engineers making an I. C engine the Nalon Viper is a good step up from the side port `Mills` type engine

Another one is the Sugden Special, I think plans are available but not sure if the cast aluminium crankcase is available.

John Feeney

Hi John MC

That`s pretty well how all high performance engines are made although the circlip is often replaced by a threaded locking ring.

John Feeney

Hi,

This is not a problem in practice. For the engines I make I bore the bearing housing about 0.001" under size, this for bearing of 19 or 22 mm outside diameter. These engines run at 16000 to 20000 rpm. There are other ways that have been used such as fitting a steel sleeve into the aluminium crankcase but even in very high performance engines the direct fitting into the aluminium is usual. There are many other aspects regarding fits in small engines which run at high speed and use only the oil in the fuel for lubrication.

John Feeney

Hi,

I have built one of these and have the drawings somewhere, and yes it`s designed by Richard Green.

The drawing are at least 30 years so not sure how well they would copy. I found the most frustrating part was the inlet pipework. Let me know if I can be of assistance.

Regards,

John Feeney

Hi Graham,

As said by Jason 6082 T6 is of higher tensile strength than 6061. In all other properties they are virtually identical. In terms of performance the Nalon Viper was not of such performance that would need any kind of so called "high strength.

Regards<

John

Hi Graham,

I,ve made many similar I.C engines and used 6082 T6. It,s readily available. If you let me know the sizes I have many kilo"s of assorted section and cut what you need.

Regards,

John Feeney

Hi David,

I made one of these over 20 years ago, I used 303 stainless steel. The information is in a Strictly I C magazine.

I have all of these and will have a look for it over the weekend.

John Feeney

Hi Bob,

I have a 540 and a user manual. By dwell control lever do you mean the one that controls the table traverse speed? Further in the manual this seems to be called the table throttle valve and is listed as Item 15 E under section 15 " valve block and fittings"

I think J & S still exist ? The manual says to quote code number, description and serial number of the machine.

Hope this helps.

John Feeney

Hi Mark,

I have 3 new (unused) D1-4 cams. Bought them 10 ? years ago( from Colchester ?) but never used. please let me know if you are interested ?

Regards,

John Feeney

Thank you John & Joe,

Thanks for the information. I`ll look into selecting a motor and a power supply. For my application I will often need to run for up to 30 mins so cooling may be a problem along with bearing life. Joe, in your set up how do you clamp the motors?, in all the small out runner motors ( IOO watts) I have used the outer case rotates along with the shaft. Perhaps I`m missing some thing simple !

John

Hello Joe,

I have a Stettler 64-110 internal grinding machine. It has an internal spindle driven by a high frequency motor.Unfortunately this motor is beyond repair ( speed range was from 6000 to 24000). I have thought of using a "model" motor, probably a water cooled inrunnner. All these motors use an electronic speed control (ESC) and are generally low voltage and high current from a battery. What power supply system do you use ? is it battery or mains.

I have looked for mains supplied power supplies for electro plating, say 10V/ 50 Amp but quite expensive. Also how do you control the speed of the motor. ( I have flown model aircraft where the speed is controlled by the size of Prop. used)

The machine also has an air spindle which runs at 96000 rpm and can grind bores down to 0.8mm diameter. Don`t think I`ll be using it very often!

Regards

John Feeney

Hi,

Contact Anglo-Swiss Tools, David Samways.

John Feeney

Hi

Correction Much less trouble !

Hi,

Bentonite is used to make moulding sand. Some cat litter is bentonite but of poor quality. Other clay minerals are also used for cat liter, eg sepiolite but this not suitable for use in moulding sand. That said it is not easy to blend sand and bentonite " at home"

I`d suggest buy the moulding sand,it`ll be much trouble.

John Feeney

HI Martin,

The `old boy` you referred to is Clen Tomlinson. As well as the deltic he has built most of a quarter scale napier sabre engine (24 cylinder sleeve valve). I was also going to build one but looked too complicated for me !

There is some information on this on the web site of the `Bay area model engineering site` (San Francisco USA)

I keep in touch but he does not spend as much time on model engines as he is building a house.

John Feeney

Hi John,

That`s great news,thanks for your response. Have sent PM

John

Hi Niels,

Yes, by all means- let`s hope I can find a drawing. If so! I can make parts( wheels ?) on my cnc milling machine if you can produce the CAM data. You would be welcome to a set if you want to build this loco.

Hi Robin,

I had a holiday in the I O M in June and went from Douglas to Port Erin on the I O M railway which gave the idea of building a model. A friend told me that there was a supplier but I could find them. I saw the by Bill Tabiner ad. but it had been sold- which resultedin this inquiry

John Feeney

Hi All,

Hoping to build this loco. I believe drawings and casting were available from Ashdown Models but they have ceased to trade. Did any other company take over their range? If not is there any access to the drawings.

If any forum member has a set of drawings that could be copied I would pay for them and any associated costs. Would there be any copyright issues with this?

John Feeney