Engine Doctor

We had a chap who always pointed the exhaust on four-strokes on vintage type model up towards the sky . Very quiet in normal flight as the sound is being fired away from us . Downside was model got covered in all the mess 🙁

Operative word is "OLD" 😀

Dont be tempted to try. Futaba often mount the switches in pairs onto a PCB that is double sided. Unsoldering the old switch can damage the board unless you are up to speed on PCB work.

Old credit / key cards are also very handy to set ribs and bits squarely when building.

Thats a very valid pointa as its 9nly a 26 cc . Try blocking each pie in turn and compare . Also some flexi /silicone tube on the ends with holes small punched through the side will also help. Dont ask me why the holes through the sides work but yhey do. Use sharpened brass tube to cut them.

Yes very interesting using a z ish bend on 200 mph job 😮

Sounds like a Reg Prescot sketch ( Kenny Everett) 😀. Not as funny as that though as blood really messesup the balsa .

The point Im making Nigel is that its no good putting it up on a forum . I never suggested informing the police , that was just an example of posting on forums when you should be contacting the appropriate body.

Yes you should . I often see similar statements on our village website such as should I call the Police etc. Forums and websites are useful but... they have their limitations

Do a search on the forum re fake servos. Ive come across them a few times at our club. All were bought online at "Bargain price" . Thats the giveaway but theres nothing yo say an unscrupulous seller wont charge a higher price ! Buy from either a reputable stockist or buy used from a clubmate. Amazon , Ebay or Aliexpress use multiple suppliers and dont know or I suspect care who are trustworthy so long as they get their commission . Sure they will repay you if you can prove products are faulty but wont compensate for injury or loss of model some months later . Most of us have a draw full of servos ..... just in case 🙂. I have just looked on well known auction site and supposedly Futaba 3003 servos are still being sold for an bargain price of £13. 18 . Please do t be fooled they are dangerous rubbish.

And a tottally different animal to the early 120 fs. Design, materials have also developed and modern engin3s like the AX can run on lower oil content the main moviny parts on the 120 fs might cope with lower oil but the camshaft wont. If it fails you just might be able to fit a cam shaft from a later model but check dimensiobs first. Better lobe profile etc gives much better performance. I fitted a camshaft from an OS52 surpass into an early OS40 fs recently and the increase in performance is really noticeable.

Thats an early mk1 OS 120 and not very powerful so will be well down on power if run on petrol. Use the spark ignition by all means and run on methanol ( normal glow fuel) That old engine suffers with camshaft wear and needs decent bottom end lubrication . Remove cam cover and give it a regular shot of oil an cam will / should last ok.

Have you tried spraying Rustins aluminium ?

Yes think its a different batch of alloy . Consistency in colour and intensity is really difficult hard to achive. Try to achieve 1 ampere from a 12 volt supply . Also a auto stirer helps .

Yes automotive basecoat volvo bright silver. Either in polyester basecoat or water base coat. Water basecost will need some protection / clearcoat . If you take model along yo a car paint factors they can match it exactly and make an aerosol if you want.. Dont use polyester on expanded polystyrene as it melts it.

Hi Jeff . It probably is but if i can find another i can be doing something else.😉

Hi Alan Unlikely Ill be down there .I know Bert but rarely see him , I live in kent and likely will be at the southern model show .otherwise could you post ? Will Pm you my address . regards. PM sent PS anyone looking I'm still looking for a second ehxaust

Hi Jeff . Thanks , ill get back to you re the flywheels will take some measurements . What problems are you having with your anodising ?

Thanks Alan . E.D.

This might be of interest to some of you. I bought a couple of old Laser 75's at a swap-meet earlier this year. Both have decent compression so thought I would give them a refurb. I originally intended to convert one to a marine unit as a marine four-stroke sounds really good . However the cost of some brass rod of the diameter needed was rich so shelved the idea for now. I wanted brass as our local lake is brackish and it kills alloy in short order . I might have a go later making a water jacket from alloy and use a heat exchanger so not to cause damage to engine . Anyway with engines all cleaned and ready to re-assemble using new bearings i found i had to make a replacement PTFE gudgeon pin pad as one mysteriously disappeared ? Piston rings seemed ok so after removing and cleaning the grooves were re-fitted . I decided to brighten them up by anodising some of the casings . The results can be seen below . All parts were done in the same bath at the same time but obviously the different alloys take up the dye at different rates . Im currently looking for a couple of laser mufflers if anyone has a couple lying around . The ones i have have been battered and dented so a couple of fresher ones would be nice . If you have anything let me know but no silly prices please.

looks good keep us posted how it performs .

Ken the soldering iron tip has to store enough heat to quickly transfer it to the job . If heat source is not enough then excessive heat will soak up the wire or into the plug possibly causing damage. Tin both parts before joining and plug a socket onto the XT plug to prevent any distortion should the plastic get too hot. Dont wish to tell you how to suck eggs but remember to remove watches and rings or cover ring with tape to prevent a short .

Why start with a bar so thick ? Just made a couple for an old 75 and PTFE can be bought in much smaller diameter . Seems a bit wasteful ? Or is the video a clip off of youtube ?

Dont be put off of buying on line . I have just bought a new drill .............or so I thought . Advertised as Brand new unopened in original box . Imagine my surprise when it turned up and was scraped and chipped, covered in grease and paint and had obviously been used extensively . A message and a couple of pics and a refund and an apology was given.. It may have been a return sent out by mistake , Who Knows ? so the search for a drill starts again . Not all dealers are tared with the same brush . Amazon dont sell all of their items themselves but use dealers in their network as do Ali Express and probably a few others . Occasionally a duff dealer get through the checks .

Why on earth would you be banned from the forum just for stating fact ?