Here is a list of all the postings Steve Hargreaves - Moderator has made in our forums. Click on a thread name to jump to the thread.
|Thread: Prop size?|
I would say go & try it....yes you are a handful of watts down but as you say there is lots of thrust & I'm sure there will be enough to fly it....after all these are full power figures & you rarely fly on full power for long. The two blade prop will be slightly more efficient than the 3 blade & at 15" diameter will be moving a larger column of air so you may even find it flies just as well on less input power which will equate to longer flight times....
The weekend weather looks very good so as a wise man once said "Don't just stand there...get one up!!"
Just watch the ground clearance as that prop tip is now a whole inch closer to the ground.....
I'd use what you can lay your hands on Simon....if only to guide you in the right direction.
Eprops possibly a tiny bit more efficient & certainly lighter than an equivalent IC type prop so probably worth fitting at some stage.....
I think a 1" increase in diameter to compensate for the "missing" blade is a little conservative. I seem to recall a rule of thumb something like going down 2" in diameter & up 1" in pitch when converting from a two blade to a three bladed prop. If we reverse that logic a 15x6 would be the appropriate size two blade prop to replace a 13x7 three blade.
Simon's figures would certainly indicate that a 14x7 is too small as his power has dropped away significantly. To get the power back Simon you need to increase the load on the motor...which means a larger prop......I'd try a 15x6 or a 15x7 & see how that works out.....do you have the ground clearance for these sizes?
Ironically the main reason for full size multi-blade props is to allow a smaller diameter prop to be used so that ground clearance can be maintained. Imagine the diameter required for a two bladed prop fitted to a full size Corsair....
|Thread: Seagull Models - Arising Star Refit|
Check all the wood to wood joints too Luccaaa.....ARTF manufacturers are not noted for their liberal use of glue so now is the time to check sufficient has been used.
If in doubt wick a bit of CA into the joints. Gussets can add a huge amount of strength for very little weight. Check the firewall too & you might consider pinning it in place with a couple of cocktail sticks either side (drill 1.5mm hole through the side & into the firewall....dab of white glue or epoxy & tap a cocktail stick into the hole. Trim off & sand) Adds masses of strength & no weight.....
|Thread: ASP 61FS Just Stopped !!|
Blimey Brian that IS a coincidence.....I rebuilt MY ASP91 fourstroke that had suffered a similar fate this weekend.....new crank, con-rod & bearings (the ones in it felt OK but I can't help feeling the rear one was probably full of aluminium shavings)
Not run as yet but turns over nicely....
|Thread: How to set flaps on a Futaba 10J Transmitter|
Can you not simply adjust the ATV of the flap channel to get the amount of movement you want?
|Thread: How can I reverse a plan to build two wing halves|
This is what I do.....use the carbon paper "carbon side" up though so the lines you draw over on the plan side appear on the rear of the plan....
As others have said all you really need are the spars LE/TE & ribs.....
|Thread: Doubler mistake|
I managed to build in some left thrust to a fuselage once......my excuse was that the fuselage had to be built upside down......
|Thread: Electric setup advice|
Both electric & IC power have pluses & minuses Will, it really depends on you & what you enjoy. It's your hobby after all...you're supposed to enjoy it.
Personally I like engines & get great satisfaction from running them. I find electric power a bit soul-less but will readily acknowledge that it's clean efficient & convenient. But that's just me.....
Choose whichever power source appeals to you....both will power your model well & one is not "better" than the other....
Hi Will...yep that's it...a 12" prop is 12 inches in diameter so will have a radius of 6 inches. The 11x6 PeterF alludes to is pretty much the same size prop as the 40/46 glow motor would have used so should fit very well & probably provide the right sort of power (this is where the wattmeter comes in...it fits between the battery & the ESC & tells us how much power is being consumed). If you needed more power then you'd need to fit a larger prop (either in diameter or pitch) to make the motor work a bit harder. If ground clearance gets a bit marginal you can always fit larger diameter wheels too but again don't forget that going from a 3" to a 4" wheel will only gain you another 1/2" ground clearance....
Battery sounds fine....quite a large capacity so probably heavier & physically larger than it needs to be but the model should handle it just fine. Do check you can get it in through the hatch though & if needs be go for a smaller capacity like a 4500mAh or even 4000 mAh.....these should still give you plenty of duration. (In case you didn't know the capacity of the battery in mAh or Ah represents the amount of energy it can hold...& this translates as how long the motor will run for. Hence a 5000mAh battery will hold twice the energy & last twice as long as a 2500mAh battery for a given set up but of course will weigh much more & be physically bigger too. Words & phrases like "compromise" & " you don't get something for nothing" are very useful to remember with electric power )
|Thread: Wot 4 Saito 62|
Saitos are pretty light & a 60 4 stroke won't be very much different to a 46 2 stroke when you add the weight of the 2 stroke muffler (Saito list the 62 as 420g & an SC46 is 438g so not much in it). I wouldn't worry too much about moving the firewall for CoG reasons.....shifting the battery around should be enough to fine tune it....
|Thread: Electric setup advice|
Are you sure its a 25 glow engine Will.....58" span sounds quite big for a 25.....might it be a 40 perhaps? Do you know the name of the model at all?
If a 25 will fly the model then the motor/set up you have there might be a bit too powerful. On the other hand it looks pretty good for a model of that size. A "40 sized" Trainer is usually around the 5lb mark & a good rule of thumb for electric powered high wingers would be around 80-100 watts per lb. The motor is rated at 60A so if we combine that with a 4S battery that's a max of about 800 & a bit watts......as mentioned earlier we can reduce the size of the prop to reduce the power produced. Do you have a Wattmeter? If not then go & buy one....you can't really do much experimentation in electric flight without one.
Another thought.....with the kv of that motor you'll likely need a fairly big prop to allow it to develop full power. (I see a 12x9 is "recommended" but this isn't much use as it depends what battery you use....a 12x9 on that motor connected to a 7S battery will release the magic smoke very quickly I suspect.) How much ground clearance do you have? a 25 is likely to use a 9" prop so much smaller than the electric set up is likely to need.....
IMHO you are on the right track here but maybe a little extra thought through some of the "Gotchas" might be useful....
|Thread: Wot 4 Saito 62|
I'm sure there's some info in the WOT4 instructions relating the length of the engine to the position of the firewall. What you are aiming to achieve is that the cowl covers the engine with a small gap between the front of the cowl & the rear of the spinner & a reasonable overlap of the front of the model by the cowl to allow for cowl fixing screws.
A few minutes with all the relevant parts (fuselage side, engine/mount, cowl & spinner) should tell you where the firewall goes....
|Thread: They Shall Not Grow Old|
For those (like me ) who missed this the first time around & then found it had been withdrawn from iPlayer after 7 days (meaning I missed it TWICE....) this film is available on iPlayer once more for another 29 days.....
|Thread: Electric setup advice|
Long lost Great Great Grandson perhaps Ken.....
Will, you can easily reduce the amount of power produced by an electric set up by simply fitting a smaller prop so if a set up fitted with a 10x6 prop produces say 500 watts dropping to a 9x6 will reduce that to 400 watts (NB these figures are purely to illustrate the point....).
But I guess we are a little way off that bit.....start at the beginning, read lots, ask lots of questions & it will all start to become clear.....you could do a lot worse that starting here... **LINK**
|Thread: Hi everyone|
Welcome to the forum Will & to your new hobby.....ask all the questions you want; there's centuries of experience on here so it's very likely someone will know the answer....
Quite similar to the Eric Clutton "Sharkface".....
|Thread: Ben Buckle Mini Super - Build|
3 months is nothing Luccaaa....some build can last years....
|Thread: Forum members' new models: Let's see them.|
Ooo a CM Pro Yak 54 Paul.....used to have one many years ago...they fly very nicely but be careful with the elevator....too much applied too quickly & it will flick.....hence the phrase ...."used to have one"....
|Thread: Dave Burton (BEB)|
As David noted above we have put together a "Book of Condolence" for Dave's family containing all the kind & thoughtful comments expressed by the forum members. It also contains a few pictures of DB as I am sure he would like to be remembered, with fellow forum members at various fly-ins over recent years.
I thought I would share a few pictures of the book.
My thanks to David Ashby for the pictures & to Chris Bott who did all the hard work downloading all the posts from this thread.
The document will be presented to Dave's family during his Funeral on Monday.
With special thanks to all members who posted their condolences.
Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!