Jump to content

Engine Doctor

Members
  • Posts

    4,271
  • Joined

  • Last visited

  • Days Won

    4

Everything posted by Engine Doctor

  1. High Manis . Just my thoughts as have run quite a few bigger engines over the years. Lots of engines use a single center nut , sometimes with a lock nut system to hold props on with no problem. Four stroke engines give the bigest shock to the hub on the firing stroke and many of these up to 30c + use a center nut fixing without issue. Your flat twin should be quite smooth but have plenty of torque As your prop hub has already been drilled it has already been weakened and if its a wooden prop will crush more easily if using a single center nut. Certainly do not re-drill the hub for different pattern multi bolt fixing whether it made from wood or composite as it will weaken the hub further and could throw a blade causing engine damage or possible injury. Wooden props and some composite with a wooden infill wiĺ crush and loosen . Tighten the nut and all is fine for a while . Then as the wood fibres compress the prop loosenes . If its a composite prop it should be ok a try in a safe place so that it it loosens no harm will come , Beware though as not all composite props are the same quality and strength. I would opt for a new prop and try the center nut fixing but get used to checking it regularly incase it loosens. Unless you intend to use a spinner with an ally backplate then it must be a multi bolt fixing. If you opt for new prop and go for multi bolt then check bolts regularly and change the supplied bolts to a higher quality high tensile steel type as the Chinese butter bolts have been known to shear.
  2. Hi Jeff I bought soome clip together belts for my Myford ML2 . It is i believe a "between the wars" model that uses an over- cemter cam to act as a clutch. The clip together belt was intended for the drive ftom motor to the intermediate shaft. Its noisy (constant clicking) and slips. So its now sitting waiting for a home ! It comes in different section sizes and I obviously have an inappropriate sectionfor the pulley "v" I'll be sticking to fan type belts. The annoying part was it was it comes in 1mtr lenghts and one meter was just too short so bought another 😁 If anyone is interested its going cheap £10 plus postage. Enjoying the trials and tribulation of the build 911Hillclimber. Keep going. Re brazing a pin into the crank web. If its pressed in without clearance then brazing will be inefective as it will only run around the outside and you would then have to clean it off ? A good press fit would be the way id go using a roller bearing as Martin suggested. A lot of the chinese engines use a press fit crank pin( roller bearing)and only occasionally do they come loose ; but then some of the crank shafts were turned from not the best grade steel and bent easily. Fortunately this meant they straighten very easily.
  3. Had an issue opening it on Saturday . All ok on Sunday and since.
  4. Jim . Go and speak with Justin at Rapid RC . Analouge servos will be fine . If you do go for digital make sure to up the battery capacity to cope with the higher current draw. Dont trust any servos offered at bargain prices on ebay and be careful of any others on the net unless from well known suppliers ps your JR servos arw only ok on 4 cell Ninms..Any higher voltage can let out the Magic Smoke .
  5. Most model shops should stock piano wire. 26 or 28 gauge is thin however its very springy compared to filler rod . Music shops probably wont know what your talking about these days 😶. Ive used 26g on Frog 45 and a Taylorcraft both powered with Frog 1.5cc diesel engines. Used for elevator and rudder control its fine even when engjne is maxed out . The Frog 45 is quite quick for a smallish high winger when maxed out but is usualy flown at more sedate speeds and the 26g wire has been fine . The glider pictured below which I have just converted to rc uses 26g wire running in snake inner for elevator . Its a bit over powered and is stupidly quick for what it is as it was the only motor yhst would fit in the box of bit i had. If in doubt try a slightly thicker gauge, say 24g , provided it will slide easily in the outer tubing. I always smear the wire with silicone oil on assembly as it deters rust and reduces any friction. Carbon rod is also very stiff and the "z"bends can be bound on using thead and cyano to lock the join . Dont use epoxy with carbon as small quantities mixed can go rubbery in time and let go.
  6. That is an odd place for a puncture although are those marks scuff marks in the pic or reflections ? Have you been off road or on a verge near some blackthorn by any chance ?
  7. Good to hear your re-kindling those school day lessons . We did similar things in metal and woodwork lessons .As you say back in the 60's schooling was totally different and did teach you many practical skills that todays students miss out on , hence the throw away society . Ironically for coming 1st in year. I won a Stanley smoothing plane for metal work ! Still have it . They even taught us to sharpen the blades . Imagine that now !
  8. Hi Neddy what size is the model ; presumably its quite small if you are using a 9g servo ? For light weight models I use 28g or 26g piano wire run inside a snake inner . The hollow white ones are ideal if available . Ive never used the 0.8 Mig wire as its not as springy as the piano wire and bends comparatively easy and already has a bend from the roll . Stainless may be better but if its like the stainless filler rod used for Tig then it also bends with little spring back. Ive just converted a Lidle big glider to RC and used 26WSG through a snake inner foe elevator and its more than adequate . Just don't leave too much unsupported wire between the end of the tube and the control horn don't forget the more weight at the rear will affect the CG
  9. Ask 100 people about Exponential and you will more than likely get 100 different answers . Do your own thing . Try it and if it works fine . If your uncomfortable with it then dont use it . It works for me at varying rates for the type of model . Max is usually around 20% but thats my choice .
  10. The Moki 50cc 4 stroke i had used a walbro carb . As you know they need a pulsed air pressure to operate the pump. I assume the Saito uses a similar type of carb ? If I remember correctly it still had a crankcase vent nipple to expell excess oil but this was reduced in size so that there was still enough pulse from crankcase pressure to operate the pump. I dont know how the Saito c/case generates much of a pulse as the pistons movement probably canceles out the pulse. I have found that fully blocking the carb with a finger while turning the engine with a fully open throttle until fuel reaches the carb then a couple more turns to prime engine makes for easy starting
  11. No not yet , weather is horrible . Rudder has no affect whatsoever until tail is lifted . I think the bulky fuz and wings block air flow/propwash to the fin . I will try a bit of tow in if uc will bend as its made of quite stout proper piano wire , very springy. I opted for clip on struts using large clothing poppers as per the panic bipe. They clip on easily in seconds and seem very secure. Only had a few flight but seem ok, plus if you have a mishap they will let go without ripping the model apart.
  12. Nice vintage colour scheme 👍plus the old Castrol logo.
  13. Any program that would attract us model makers would undoubtedly be ruined by the woke, incredibly stupid , inclusive,etc etc modern generation of producers that interfere with the original idea. A prime example wasDavid & Jay 's Travelling tool shed. A program that would and should have grabbbed the imagination of viewers only to be ruined bu David Jason trying to be funny and poor production. Too many interfering woke fingers in the pie these days . Even the Repair shop went through a phase of more time spent telling boring life stoies than showing the actual repair process. I think that has been addressed slightly but still needs a bit more of a nudge. Had a so called Celeb like David Jason been involved then hopefully it would not have made a second series; Jay Blades however does his stuff in a no nonsense way as do the repairers. Dom Chinea has an excellent YouTube Channel for those that havent seen it .Have look hes currently doing stuff an a Ranalagh English wheel inbetween resoring an old Porche and Motorbikes. A good watch.
  14. As most say find a local club . Go along and have a chat with a few of the members/pilots and instructors if present. Make sure you get on with the instructor as this is as important as type of model etc . Dont try to run before you can walk as any model appears very easy to fly in experienced hands . The slower flying models are IMO better to start with for us older flyers when learning to fly as it gives our brains time to catch up ☺️ but even high wing trainers can be very different in terms of speed and stability. Ive tuaght many to fly over the years and usually the younger you are the quicker you learn . Im not a fan of foam models although they often offer a quick way to get flying and some are really good models to teach on ; again speak to an instructor as they will have a better idea of whats best for you possibly after a trial flight on a buddy system. A club instructor will also offer advice on what make of radio is best to offer you Buddy flying while learning. Dont make the mistake of talking to a model shop until you have spoken to a club / instructor as many of the assistants simply have no idea about teaching and will often sell you whatever takes you fancy. Its so annoying to see someone turn up with totally inappropriate model etc sold to them by a model shop . Welcome to the hobby and hope you enjoy it.
  15. Just Google Futaba instruction manual
  16. The Kavan starter as per the picture with Leeds link is an excellent ,powerful ,light and due to its smaller diameter is easy to grip. No drop in performance either . I have used one for years now . They are quite expensive and there are other similar types on the market . The Sullivan and others like them are IMO just an old outdated design
  17. Yes it evil stuff but banning it is a bit strong as small birds nest in it and depend on it for protection. But the French authorities dont seem to care about that , do they ? In a rural environment its fine but house developers here in the UK use it in public areas as a decorative shrub then just let it grow wild ! It can be a thorn in the side 😉 but its needed in wild areas like hedges . As already said it help keep out the local two legged wild life.
  18. Here are the pics of the mount i madeto machine the crankcase
  19. If youve removed all the visible residue and lightly wiped over with a degreaser/ thiners then it should be fine. Debonder works by softening the cyano and will evaporate away . The closer fit of the joint the stronger it will be. Good luck with repair.
  20. The thorns on Blackthorne were used as nails in the past. Evil things.
  21. I made a mounting block to hold the case on my Bodo Mills c/ case. It was mounted to this using the mounting lugs and the block was then mounted in the chuck. Reason was so as not to damage or mark the case . Cant find pic on my tablet but have it on my pc and will post later.
  22. I have Just been browsing on couple of well known online auction site and noticed lots of adds for "OS" glow plugs and many are obviously fakes . All of the pictures show the markings on the plugs as etched or lasered on with a dull appearance whereas the markings should be stamped and shiny . and the fakes are not that much cheaper !
  23. If the sub trim is set to high that will prevent throttle cut from working.
×
×
  • Create New...