Jonathan W

I'm somewhat late, but have clicked "Like" to add myself to the order list way back on page 6 or so.

Looking good now! I'm wondering though if you lapped the piston, or only turned it to size? Anyway, will see what happens when you fire her up.

Thank you Keith, I have sent you a personal message 😄

Also, if the piston pin bore in the piston is not exactly perpendicular. All these things can cause the piston to bind in the cylinder.

Your Viper looks fantastic, Keith. Where can one find plans for this? Internet search came up with lots of promising leads which ultimately all came to nothing.

Frustrating! Milling is a lot easier in a vertical milling machine than in a lathe. For one thing, you have better visibility of what you are doing without a large lathe chuck being in the way. I think even a practised machinist would find it a challenge with the equipment you are having to use. That has to be the model engine world's longest piston. The amount of friction will be considerable. Something of a detail I know, but I'd be tempted to relieve the skirt below the gudgeon pin by a thou. At least that ensures that the crown is the biggest diameter.

The other option is a redesign to use a brass contra-piston with o-ring seal. I guess they did not have o-rings in 1946, or whenever it was. If the brass contra is made to a close transition fit in the cylinder, at running temperature it should expand to be a tight fit.

I can't speak to the Laser 80 specifically, but generally you would go up in diameter and down in pitch if you wanted to "calm things down".

To give you an idea how things have changed, my father and I used to go to Benson's Chemists on the A6 in Stockport to buy methanol, castor oil and nitro-methane to mix our own fuel. Imagine doing that now!!!

Yes, I think fuel and glow plugs will ultimately be the show-stopper for us glow die-hards. Nobody in UK is making plugs anymore. Optifuel did not continue with the Model Technics plugs. Southern Modelcraft had supposedly sold their fuel business, but the new owner appears to have done nothing with it, as far as I know. That leaves Optifuel and Weston. Alan at Weston is no spring chicken, so who knows how much longer he will continue?

When I have expanded pistons in my impecunious youth, it was just to heat up and allow to cool naturally. So probably the quenching has caused the cracks. Sounds like you are on the right track with the lapping now though. What kind of finish did you have before lapping? Was it from lathe boring tool marks or did you use a reamer?

Also see HERE At least this is a UK company you can phone up and talk to 😏 Listing diamond paste in the same range 1 -40 which you seem to have. They are saying W1 = 15000 to W40 = 400, so the "W" numbers are apparently not the same as microns then. If your paste conforms to this system, I would have thought the difference between 1 (super fine) to 40 to be obvious.

It might be that the numbers are the micron size of the diamond grit??? In which case 1 to 40 = fine to coarse. Just to add that I never used this diamond stuff myself and your Chinesium product might be using a different system, who knows? I do have some silicon carbide lapping compound at 600 grit which I use to good effect on model 4 stroke valve seats, but the manufacturer of this product has unfortunately disappeared. Equivalents of FEPA F grain numbers to microns are 400 = 17, 600 = 9, 1000 = 5, 1200 = 3 etc. See HERE It would surely be helpful if your man Keith would point you towards the specific products he has successfully used. 😊

Just my opinion, but I don't think you should get too hung up on the finish. If you look at a brand new PAW, the bore is as ground while the piston has very coarse honing marks. The honing marks promote oil retention and allow some bedding in to occur. You won't get that if everything is to a mirror finish. I think dimensional accuracy with a slight "pinch" at TDC is far more important.

I have some of the smaller New Power servos (9g, 17g) installed in foam models. I found that the few faulty ones failed very soon in testing and the remaining ones have lived on without issues. Still, I wouldn't buy them again personally because of those few initial failures.

Of the 7 cards cancelled and reissued on Monday, 3 have already arrived today, so not too bad. Although they were the most difficult to get through to on the phone, it is Halifax/Lloyds/BOS group who have delivered the new cards quickest.

Today I have spent hours on the phone, especially to Halifax/Lloyds/Bank of Scotland group who kept putting me on hold and then cutting me off. In all, 7 credit cards now cancelled and reissued due to Jet Frog and Lifewatch transactions. This was across 3 card providers: Barclay, Royal BOS, Halifax group. It seems like a large scale attack. It was suggested to me that the card details being saved in Paypal might be the source of this. However, many but not all of the cards were saved in Paypal. Also, within the Paypal security menus you can see device logon history and there was nothing suspicious there. Still, I have changed the password and deleted all the cards in the "Wallet", most of which were compromised anyway. I'm afraid this is the modern world for you. Personal data is leaking all over the place. For example, in 2022 there was a massive breach from USS (Universities Superannuation Scheme) with names addresses d.o.b. NI numbers etc etc. It's a mess which requires constant vigilance.

I have one of these powered by a SuperTigre G51. This gives plenty of margin for normal aerobatics. Balance is about right with this engine, so I think any of the 2 strokes you mention would also be fine. Not sure of the Laser, depending on how the weight of it compares to a 2 stroke, might then come out nose heavy?

Hopefully all those complainers have time to do so, having already completed their response to the latest CAA consultation!

My schoolboy French very rusty, but did he say, "Traverser le manche"? Go across the Channel in that thing? Notice no footage shown with passenger. Actually, I was more wondering about the other headline, "Dinosaurs found inside a dinosaur"

One time in Northampton, I found one of those things stuck going over a high curb, unable to move forwards or backwards. I shoved it back on to the pavement with my foot, upon which, in a distinguished Queen's English accent, it said "Thank you!!" Maybe we'll have drones thanking each other for avoiding collisions. The air will be full of "Thank you" and "Move aside please".

Hi Leccy, Sorry about that, I did quote you by accident! I meant to quote the more recent post by Futura57 who mentioned cars with illegal number plates not being subject to any enforcement. I was adding to that by saying that cars with defective lights seem to be ignored also, and that's more of a safety concern than dodgy plates. So expect that enforcement of remote ID will be minimal and only occur when a more serious incident leads to an individual being caught without remote ID.

Drive at night and see how many cars have faulty lights. It's commonplace compared to decades ago. No police around to stop and ticket people. Cars without lights are a lot easier meat than chasing after toy planes as well! So I can't see much chance of regular enforcement with remote ID. I expect the enforcement will only occur in cases where there is a higher level incident which then leads to lack of remote ID becoming apparent.

As per Engine Doctor posting, it looks like the piston has glazed with castor oil varnish and the liner will probably be similar. I used Scotch-Brite pads to gently remove the varnish. You can clean out the ring groove by carefully scraping with a micro screwdriver. As I recall, the K&B 61 does not have a pegged ring, so you may not find a peg in the groove no matter how hard you look.

Sitting offshore on my nightshift, I have ground my way through this consultation. Despite all the CAA flubber-lubber-lubber, in end it's quite simple for most of the questions to say "Does not apply to model aircraft operated within pilot line of sight". I did think that the BMFA responses were trying to sit between two stools of traditional model aircraft and FPV "drones". Since my own response was purely from the perspective of traditional model aircraft, it was relatively easy to be blunt and straight to the point. I did find the FPVUK response to be a useful contrast to the BMFA one and between the two enabled me to clarify my thoughts.