Member postings for Ramon Wilson

Dave I am intending to put my Amadeal bench mounted mlll up for sale this year. It has had little use since purchase, is in fine condition and comes with a lot of kit.

It's buyer collect only (Suffolk) but if you are interested send me a PM and I'll forward full details.

Tug

Ross, You have a PM

The immediate problem, of course, morphed into something different when I discovered that the plastic in question was [to all practical purposes] insoluble.

Yes Michael, I should have said about varying plastics but as you said 'plastic modellers' I thought you were meaning the part was styrene.

Some plastics simply will not glue with anything whilst others adapt to varying solvents/adhesives. Polyethylene springs to mind - far too waxy for any adhesive I'm familiar with.

Epoxy may be better on your part, especially if you can reinforce it with a small pin of some kind but even that won't always be successful.

Good luck with it.

Tug

Michael, as a frequent user of plastic solvents I have found the best 'tool' for applying small amounts of solvent is a fine pointed but full bodied artists paint brush. The brush is held so that the solvent stays in the brush but allows capillary action to draw the small amount required from the brush into the join, i.e. not pointed directly down to the part. It doesn't need to be an expensive brush, the best I've found for shape and longevity are the 'Boldmere' brand from 'The Works' - quite inexpensive for what they are.

Super glue of course is another matter, the thin type will run everywhere if not controlled properly - a paint brush is of no use of course but a simple sewing needle reversed in a holder of some kind - mines in a pin chuck - with the eye of the needle outwards is. I have small slices of aluminium drilled with 3mm holes a few mill deep to act as 'inkwells' for the cyano. The glue is picked up in the eye of the needle and transferred to the part. - if you use the pointed end of a needle the glue runs back up the needle a short way and is impossible to apply. There are of course, commercial, photo etched, equivalent applicators available but a needle works well

Needless to say but be aware of where your fingers are - any solvent will quickly leave a fingerprint impression and the cyano of course even more quickly ensuring that the part becomes an extension of your fingers!

Many years back I bought one of the micro bore applicators - a very small hypodermic needle attached to a thin walled plastic tube reservoir. To use it's stood in a bottle of solvent to allow it to fill before using on the parts. The needle quickly becomes contaminated with residue plastic inside and impossible to remove and it stops working - it still sits in the drawer!

Best - Tug

Hi Richard B,

I rebuilt my double ten for a steam launch a few years back and made separate eccentrics for each end with small grub screws to lock accessed through the eccentric strap for setting. I made them from free cutting mild steel and off set them in a simple fixture held on the face plate to ensure accuracy of throw one to another and squareness to bore. The setting proved simple and easy to do on final set up.

I described this here on the build log on Model engine Maker forum at the time - you may find it useful.

Best - Tug

PS Though I haven't described it I have used the same method to make the eccentrics on the 'Marine Condensing Engine' thread described elsewhere on here to equal success.

Edited By Ramon Wilson on 08/04/2023 10:34:49

The advice above is spot on - its an ABC set up and definitely should not be run in as a conventional piston and liner set up. As Tim says let it rev fast but sightly on the rich side.

Depending on the pitch the 12" prop should be okay - 4 r 5" is ideal - a 10 x 6 on a 46 is a bit on the small side. I run 46's in aerobatic control line models and they use 11- 12 diameter x 6 or 5 pitch respectively.

I have quite a few '46's' with ABC set ups but one in particular, a Ukrainian 'Stalker 42', despite considerable use, has a very tight piston liner set up. It will often 'seize' at TDC when flicking it due to the squeeze on the piston It takes considerable force with a high degree of tortuous sound squeaking to free it. Heating it with a hot air gun is an option if that happens - not always available on the flying field though!. Flicking it backwards on to compression is much the better way to start it. Apparently all the other engines in that specific batch were similar so not a one off. A very powerful and consistent runner I should add that I never use any form of starter motor - just hand flicking.

A pic of the engine would be nice - most usually have some indication of makers name - maybe we can identify this one for you.

Tug

Are those 1/72 scale Spitfires? I thought the 1/48 kits they produce were supposed to be some of their better mouldings. 1/72 is far too small for my eyes now, even 48th is pushing it on the smaller types.

Lovely work on the bomb bay - just the sort of modelling I like to do myself but shame it's all rarely seen once the model is on it's feet. Have decided my next build (Trumpeter 1/32 F-100F) will be OOB - no after market save he exhaust and a closed cockpit - at 78 detailing at length is just too time consuming.

Once the Phantom is on it's base I'll pop a pic or too up.

Well I don't envy you there Doc - the one thing I can say is I do have a warm workshop to hibernate in.

I guess that's as good a reason to 'hit the plastic' over the winter as any. Though not for the same reason I took a break from the marine engine for the same distraction and am just in the finishing throes of a 1/32 Phantom.

Take care with that one mil drill tonight - 1.5 might be a bit safer?

Good result Doc - hope the second turns out as well for you.

Here you are this will explain it

The locknuts on top or bottom is entirely up to you

Yes - Jason Is spot on here Doc, the cap just holds the bearings in place and should not distort them - if you think about it if the cap is fully tightened down to the housing/pedestal and the shaft is free to rotate then the shell must have a gap - the slightest distortion will tighten things up considerably - any wear cannot be taken up unless the cap is further reworked.

The caps are usually relieved each side of the bearing cavity to allow this. 'Setting' the locknuts will soon reveal just how little movement is required between locked tight and running fits. IE the clamping pressure is entirely set by the bearing cap bolts.

I thought you were aware of this situation.

I advocated the 'bearings first' method Doc simply because it is much easier to try a pre-made bearing on the shaft than to use the shaft as a plug gauge with it's attendant risk of wringing the part in the chuck due to it's length.

The very method of soldering the parts together introduces the situation you refer too. However, the solder thickness should be quite thin but does always leave a residue on breaking apart. lapping the solder residue away on something flat will increase the tightness of the bearing as you say. Though miniscule there will always be a slight 'out of circular hole' as a result so that's when a little scraping or fine removal with wet and dry on a smaller diameter shaft comes in - just in the bottoms of the bearing shells and not on the sides.

If you do this right you should not have to lap the bearings to the shaft on assembly. This is why I suggested to you to make the base and build the engine up as you go - dealing with any such misalignment in turn before moving on to the next addition.

These three bearings were done exactly as described and not line bored in situ. The shaft is a good fit laterally and the bearing shell tops slightly tweaked to allow the bearing caps to pull up without the shaft binding - it runs very freely in fact.

BTW you may note that the bearings are in place to act as 'masks' whilst painting the base. Once removed the paint was cleaned off the bearing shells with a soak in cellulose thinner - perfect fit without having to make allowances for paint

Not saying that radial clamping is wrong - just, in my opinion, unnecessary and certainly unwieldy using the bearing pedestal. Nothing wrong with using a four jaw either but on a mandrel all bearings are identical to the bore with nothing more required to achieve accuracy one to one than setting it in place on the mandrel.

It's just a different way of going about it without the possibility of creating slight inaccuracies that will manifest them selves on assembly.

Besides there is no way of 'knowing' if a part in a four jaw is axial especially if the chuck is old - it's a facility I try to avoid if there is other means. Though I use it a fair bit in other ways I have never used it to make identical bearings because of that possibility and to me its always easier to bring the outside to a bore - on a mandrel - than the other way.

I've made a fair number of bearings from quite small 3/16 diam to the ones on the Corliss quite large by comparison in the method suggested. Only had one part in two by machining on the mill as the reamer went in due to the the faces not clamped between the vise jaws and one split on an expanding mandrel due to a poor solder joint.

There's a fair bit of work in achieving the fits necessary in bearings to ensure good alignment but as already said the choice is down to the individual.

Some thoughts

The over hang is too long

The centre, however gently applied, will act as a wedge applying a separating pressure on the weakest point - the soldered faces. The act of turning the groove will apply more pressure on the joint too.

Once the OD is turned the 'clamp' of the bearing pedestal needs to be tight otherwise the drilling will apply more pressure to the now very narrow soldered faces

Parting off is likely to be a nightmare. with the 'clamp' in place.

Some further thoughts

Cut off enough to make one bearing (twice)

Hold in mill vise with soldered faces clamped, face, drill and bore. If no boring head drill to within .5mm on diameter and return to lathe in four jaw. Bore to size. Much easier to centralise part on mill than four jaw with the outside surfaces known to be parallel to the split line.

Make simple mandrel with very slight taper that bearing pushes on and very gently face each end true to bore.

Make parallel mandrel and clamp washer and clamp firmly on mandrel to turn OD to finish size.

If the soldering was efficient the bearing can then be held on an expanding mandrel to turn to finish width and any steps etc possibly required on each end.

As always, your choice of course, but having been down the route before without success I'd seriously not be thinking of repeating the exercise.The above will give the certainty of accuracy, with the least stress on the split line but then - what would I know

Good luck with it Doc

Just seen your last post. Easily rectified in the mill op

Edited By Ramon Wilson on 09/03/2023 08:00:03

Thanks Jason, I'd been looking at the first of the thumbnails.

Yep looks like someone really knows what he's talking about

Why on earth would you want a reverser on a pump !

Though all my diving was done on compressed gas - air from a compressor or bottled helium, I did once get the chance to experience diving on a man powered air pump. Very strange as you hear each stroke and the atmosphere smells of neats foot oil. Any ex Navy diver on here of similar age would know too I guess. The deeper you went the more men required to keep the pump powered!!

No definitely not a model of a divers air pump!

Best - R

Do you know which episode it featured in Jason ?

Dougie - I have plenty of Silicon Carbide (Carborundum) powder in 280 (too coarse for piston/liner lapping actually) 320, 600 and 1000 grits.

Send me a PM if you want some.

'TimeSaver' is great but far too expensive when only small quantities are required.

Diamond is a definite no no if the surfaces are not hardened. It will embed itself into the material and no amount of solvent cleaning will release it all. You need a good ultra sonic cleaner to do the job properly.

Silicon Carbide is ideal - does a good job and is easily removed with a solvent such as cellulose thinner. I haven't done any valves but I have done the odd piston and liner.

I am disposing of some of my workshop - Silicon powder is no longer required nor some genuine Kasenite case hardening powder - if anyone else wants some then PM me.

Best Tug

Edited By Ramon Wilson on 21/02/2023 18:38:32

Well there you go Dougie - you (one) can learn something everyday!

A glow plug washer is usually much thicker that the shim washers for steam fittings though of course useable if the plug doesn't go in too far on some engines.

Edited By Ramon Wilson on 14/02/2023 20:21:11

Dougie - I may be wrong but I don't think you will.

In a lifetime of aeromodelling I don't think I've ever seen any as 'spare washers'. All the glow plugs I've bought always came with one.

It's easy enough to turn one though if you have some copper bar but make sure you anneal it before using it.

How many do you need?

Best Tug

Dave - I have to say I'm afraid I can't share your 'suspicion' of eBay for as far as my dealings on there as a seller (and a buyer) I have had nothing but success over several years now.

I follow three basic rules - take several pics of the item. Describe if fully and fairly, warts and all and make it very clear what you won't do ie 'sold as described with no returns accepted', 'no overseas sales' or whatever other stipulation you wish to apply.

I've just parted with an oscillator - ten day auction with no bids until the last hour or so. It made considerably more than the opening bid I placed on it.

A good tip is to take images of it as you pack it and as ready to send - just for extra insurance against potential claims for poor packing.

Yes the risk is there that it may not do as well as hoped - had that happen a couple of times with quite pricey IC engines but that's the way of auction anywhere - and then again I've had more than enough the other way to compensate.

Good luck with selling it however you do it

Best - Tug