[Acro / Fun fly / 3D kits for 4 stroke IC.]

16 hours ago, Nigel R said:

As in, will climb a fair way for a stall turn, or, pull away from a hover / out of your hand?

As in will pull away from a hover.  Seems a fine line between being able to do that and being too heavy for nice flying characteristics but there must be a combination that works.

 

[Acro / Fun fly / 3D kits for 4 stroke IC.]

I'm looking for a good general hack model that I won't get bored of too easily and is fairly resilient to being bashed about a bit .  I would prefer a kit but would consider ARTF.  It must fly well (vertical performance preferred) on a 4-stroke glow engine (any size as I will buy it new).  I have previously asked about Acro Wots and H9 Ultrastick but there are very mixed opinions on using large 4 strokes on these models so looking for any other recommendations.  (SLEC funfly maybe - anyone tried these on 4-stroke?)

 

 

[Exhaust pressure fitting OS 15LA]

Thanks Denis.  Mine is definitely the wrong thread so I will just order a new OS one which will hopefully come with the washer.  

[Exhaust pressure fitting OS 15LA]

Thanks very much David and Denis.  Mine has clearly been pinched and replaced with the wrong one (and there is no washer).  

[Exhaust pressure fitting OS 15LA]

OK I have just established that somebody has put a M3 nipple in but it's not the correct one for the thread on the silencer.  I tried one from a Thunder Tiger pro .46 and it fit's perfectly proving that the thread is ok.  Does anybody know what thread size it is?  It's between M3 and M4 but that's all I know.  I can't see M3.5 pressure nipples for sale so maybe not metric.  I think OS call it a No.7 but don't say the thread size.

[Arrows Viper problem]

Thanks Frank.  As luck would have it I just bought a watt meter that I haven't tried yet so will give it a go.

 

[Arrows Viper problem]

Good idea,  I will try it tomorrow.  Cheers.

[Exhaust pressure fitting OS 15LA]

Thanks,  that could also work.  

[Arrows Viper problem]

It's possible but I've probably flown it 50+ times with the same batteries (I have about 10 the same and rotate them with each flight).  It has been a lot colder though.  I think I will change out the ESC and see how that goes.

[Exhaust pressure fitting OS 15LA]

Thanks Andy / Don.  That is a handy website that I've not seen before.  

[Arrows Viper problem]

The other day I was flying my arrows viper on a 3s2200 Lipo and I suddenly lost all power but still had control for a dead stick.  I checked the battery which is in good condition, and tried again and it was fine.  Had a few more flights no problem.  Today on the second flight it did the same thing again.  The speed controller (original one) also starts bleeping (I think 3 times repeating).  I'm pretty sure this was with a different Lipo.  Anybody know what the problem is likely to be? 

 

[Exhaust pressure fitting OS 15LA]

Today I ran up my OS15La (brand new but quite old) and noticed that the pressure nipple on the 871 silencer was loose.  It looks like somebody has over tightened it or cross threaded it.  It screws in but just keeps turning and never tightens (and leaks when the engine is running).  I'm not sure if it's the nipple or the thread on the Silencer but I expect it's the silencer.  Is there any way to fix this without buying a new silencer?  JB weld maybe?  

[IC engine choice for Hangar 9 Ultra Stick 10cc]

Fantastic help from Horizon Hobby when I asked them the same question : "Unfortunately, we do not have a 4 stroke Glow engine recommended for this plane".

 

[IC engine choice for Hangar 9 Ultra Stick 10cc]

2 hours ago, GrumpyGnome said:

 

There must be other planes more suited for this type of flying - an H9 Ultrastik perhaps, with at least a 90 2 stroke.....

It's the Hangar 9 Ultra Stick that I'm asking about GrumpyGnome !  I wanted 4 stroke because of the noise from a big 2 stroke.  A 90 2 stroke might be too much for my club site.  But if it's not to be I might can the idea and get a smaller plane that runs on .60 2 stroke or less.

[IC engine choice for Hangar 9 Ultra Stick 10cc]

2 hours ago, GrumpyGnome said:

Mine has a 90 four stroke in it, and seems a perfect match - not indefinite vertical but certainly enough for nice big loops.  I think anything bigger/more powerful would be overkill - it's not a pylon racer.

 

(previously I tried a 70 and 82 four stroke - both left it a little underpowered)

Thanks GrumpyGnome.  Interesting that the 82 is underpowered.  I was wanting to be able to pull out of prop hangs and do some 3D stuff but doesn't sound like even a 90fs would be able to do that from what you say.  I'm coming to the conclusion that 4 strokes are not really going to work for anything other then usual club style aerobatics and warbirds.  

[IC engine choice for Hangar 9 Ultra Stick 10cc]

Any recommendations for the best IC engine for the Ultra Stick 10cc?  It needs to go vertical indefinitely but not be stupidly over weight.  It's for a general every day hack and 3D stuff really.  I would prefer a 4 stroke to keep the noise down.  Saito FA-82 or Saito FA-100 maybe? 

[Props for OS 15LA]

It's to go in a 1m delta wing so you may be right.  Just going on the recommended one for running it in then I will experiment a bit (if I manage to avoid oak trees 😂)

 

[Props for OS 15LA]

Thanks again both.  Yes Master seem to have a smaller pre drilled hole that is smaller so I will go with them.  Same problem with spinners now as most seem to have a 6mm hole.  JP seem to come with adapters,  one of which is 5mm - seems about the only option there too.

[Props for OS 15LA]

I'm looking for a prop for an OS 15 LA in the recommended 8x4 size.   The problem is that APC props seem to be for prop shafts from 6mm and the OS15 is 5mm (or just under according to my calipers).  Can anybody recommend a prop or a solution please?  Other manufacturers don't seem to say the prop shaft size (Master etc.)  Can I get some sort of adapter ring like the electric props sometimes come with?

 

[OS Max 15 LA help please]

Thanks Graham and Engine Doctor.  I'm going to set it up on a test bench to run it in by the method you describe.  It's all good learning for me.  I will read the manual too 😀.

[OS Max 15 LA help please]

Thank you David,  I don't think it's prop driver.  It does it when that is removed.  I have been told by somebody that used to sell these engines that it is as Dave Windymiller suggest - just the piston being tight at the top due to the engine being new.  Normal apparently for ABC engines.

Not sure why that happens with the video JD8.  I can go to my attachments and download it but not from the post.  Maybe it's too big (but it's under the size that it said was the maximum).  

[OS Max 15 LA help please]

Thanks Dave,  that is good to know.  I didn't want to put fuel in it and try it if there was a chance it would get damaged but sounds good to go then.

[OS Max 15 LA help please]

Can't get the video to work so trying another one

[OS Max 15 LA help please]

I have this OS Max 15LA that is supposedly brand new and never run.  When I turn it over there is click as the piston gets to the top (just before the compression pop).  See attached video. Is this normal?  My other two stroke doesn't do it and I can't remember any of my old ones doing it back when I was all glow fuel.  If it's not normal,  any suggestions as to what could  cause it?  Does it with the plug in or removed. 

Thanks.

[Wot4 Mk3 IC engine recommendations]

Thanks you everybody - some great advise here as always !  I'm going to have a re-think.  I used to have a WOT4 with an Irvine 46 2 stroke many moons ago.  It always flew really well so maybe just something more balanced is the way to go.  I have lots of electric 3D stuff,  this is more for an all round winter hack.  No idea why I want to go back to IC as I've been completely electric for the last few years but I just like them for some reason !