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RE: Tip Stall
[quote]ORIGINAL: Rob2160 [quote]ORIGINAL: gerryndennis My advice to all modellers is stall your model lots, <span style=''color: rgb(255, 0, 0);''>get used to where the elevator stick is when it stalls. Every time you put the stick in that position your model will stall. If you find yourself turning final low and slow or making a tight turn and you notice that the Angle
Posted on: 5/19/2013 6:18 PM by Author "gerryndennis"
in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=11516518
RE: Tip Stall
[quote]ORIGINAL: FLYMAD Could someone tell me how to tell the difference between an asymmetric stall and a tip stall. What are the visible differences. [/quote] In an asymmetric stall (stall developing from the root) the wing will drop and a spin may develop if no correction is made. In an asymmetric stall (stall developing from the tip) the wing will drop and a spin may develop if no correction is made... much more violently and quickly. In an asymmetric stall (stall developing from the root) aileron (gentle) will at least reduce the roll and may be sufficient to prevent the wing drop. In an asymmetric stall (stall developing from the tip) aileron will make the wing drop worse.... much worse. Flymad you're post said 'in reply to... me' in the bottom right hand corner, which is why I wondered. Dave H
Posted on: 5/19/2013 5:38 PM by Author "gerryndennis"
in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=11516490
RE: Tip Stall
Hi Flymad, I guess you meant to reply to me? I broadly agree with most of what you posted, but I think you missed my point a little. In a normal symmetrical stall it's common for the stall to develop in one part of the wing before the rest. Full size aircraft designers mostly try for the root to stall first with the stall spreading towards the tip as angle of attack is increased further. In some models the opposite can occur with the tip stalling first. Depends on the design of the wing. So a 'tip stall' can be perfectly symmetrical. You are dead right when you point out that applying aileron, when the tips are close to the stall, will likely stall the tip with the down going aileron. There shouldn't be any full size pilots surprised by this phenomena though, we'll good ones anyway. 'Obviously tip stalls occur when one wing reaches the critical angle before the other'. Nope, that's when an asymmetric stall occurs. Now if the wing is one of those that tends to stall from the tip to the root then obviously one tip stalls first. The resultant difference in lift and drag is far worse than if one root stalled first. And that is an asymmetric tip stall. But not many wings stall tip first so even though one wing will drop it's not a 'tip stall'. When the wing drops most modellers call it a tip stall but most times it's not, just an asymmetric stall. For what it's worth I agree totally with the advise to be careful with the ailerons close to the stall and picking up the low wing with rudder is a better idea. Especially for beginners. But there are plenty of models that will still respond to aileron well into the stall and this is because the tip is still flying, it's the root that has stalled. Dave H Who has spent a lot of time at and beyond the stall
Posted on: 5/19/2013 3:51 AM by Author "gerryndennis"
in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=11515824
RE: Tip Stall
[quote]ORIGINAL: essyou35 [b]G force is a function of speed and turn radius, not bank angle.[/b] I can make a turn banked at 45 degrees and have 1 G or 9 Gs depending speed. [/quote] G force is also a function of how hard you pull on the elevator. If I want to fly [b]straight[/b] and [b]level[/b] I will have to adjust the elevator to achieve exactly 1 G. If I roll to 60 degrees bank and I want to stay [b]level[/b] then I will have to pull on the elevator until I have exactly 2 G. If I pulled to 9 G I would definitely wouldn't stay level. So for level flight G force is a function of bank angle. Now to achieve a specific turn radius does imply a given G dependant on speed. I can't just pull that G though, I need to bank, otherwise I'll just pitch up. If I match my bank angle to the required G then I can stay level ( if I'm not level the radius will be wrong anyway). It's normal in flying to do it the other way round though, choose a bank angle and apply G to maintain level, climb, or descend as required. If a smaller radius is required then increase bank and adjust G to match. Dave H Who has only ever pulled 6 G
Posted on: 5/19/2013 12:15 AM by Author "gerryndennis"
in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=11515767
RE: Tip Stall
Steve, The stall occurs at CL max not L/D max (by definition). A wing is stalled when any further increase in AOA results in a reduction in CL. I agree that most modellers have a very sketchy understanding of stalling, stall speed, critical Angle of Attack, accelerated stalling, asymmetric (wing drop) stalls, and tip stalling. I applaud you're attempt to improve the knowledge, good luck. Some definitions that may help; Stall= exceeding the critical angle of attack or CL max. Stall Speed= the speed at which the stall will occur in level (1 G) flight, power off. Accelerated Stall= stalling at more than 1 G, implies at a speed greater than 'stall speed' Asymmetric stall= one wing stalls before the other, may be due to flying 'out of balance', manoeuvring (turning, rolling etc), wing warp or aileron deflection etc. not all asymmetric stalls are 'tip stall'. If the wing stalls from the root first then the wing drop from an asymmetric stall may be quite controllable with aileron and/or rudder. Tip stall= if a wing stalls from the tip first (bad design feature) then any asymmetric stall will be much more violent. Any attempt to use aileron will likely make the wing drop worse. Most modellers refer to all wing drop stalls as 'tip stalls' even though most of them are just asymmetric stalls. This leads to forum questions along the lines of how do I fix tip stalling with answers along the lines of washout, change of section, root leading edge stall strips, just fly faster, etc. If the question had been how do I fix wing drop stalling then the answers might have included; check wing symmetry, length, sweep, squareness to fuselage etc. try some rudder etc. My advice to all modellers is stall your model lots, get used to where the elevator stick is when it stalls. Every time you put the stick in that position your model will stall. If you find yourself turning final low and slow or making a tight turn and you notice that the Angle of Attack (elevator) stick is near the stall position then be aware that you are near the stall. Speed or angles (bank or climb or descent) are irrelevant. Not quite 100% true in theory but close enough in practice. Dave H
Posted on: 5/18/2013 11:47 PM by Author "gerryndennis"
in the forum "Beginners"
http://www.rcuniverse.com/forum/fb.asp?m=11515760
RE: OS 1.20AX Unexplained Flameouts.......>>>
G'day Taz, This could be a long shot but how long is the threaded part of the muffler pressure nipple? A friend of mine had exactly the same symptoms, engine shutting done after around three minutes with the fuel line full. It turned out that the exhaust nipple was too short and was flush with the inside of the muffler, it was also positioned right next to the exhaust baffle. The pressure line was feeding oil from the muffler to the tank. Droplets of raw oil coalesced at the bottom of the tank and eventually got picked up by the clunk and were fed to the carburetor, resulting in engine shut down. A longer nipple solved the problem. Dave H
Posted on: 9/17/2012 7:22 AM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11231015
RE: can you identify this model sea plane ??
Try http://adamone.rchomepage.com/cg_canard.htm Cool looking model, good luck with it Dave H
Posted on: 9/13/2012 6:57 AM by Author "gerryndennis"
in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11227152
RE: OS 10 FP issue
I've always thought you could probably make the rub pads out of those white plastic vegetable cutting boards that get thrown out from the kitchen every now and again. A few minutes work with a fine tooth saw of some sort should give you a piece suitable for machining. Having said that the only time I've replaced a set they came with the new wrist pin. As FF says it was very cheap. I've only ever noticed them wearing if the rod has seized to the wrist pin though. So whenever I have the backplate off I always check to see if the rod slides fully forward and aft. If not I'll check the rub pads even if I can free it up in situ. Dave H
Posted on: 9/11/2012 6:41 AM by Author "gerryndennis"
in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=11224903
RE: OS 10 FP issue
[quote]ORIGINAL: 1QwkSport2.5r Edit: I didn't think about lapped engines. I would think a linear pinch would work for saving a lapped engine. Maybe. [/quote] I agree, but I wonder if he could pinch a steel liner a opposed to a brass one? It would be good if he could. Dave H
Posted on: 9/11/2012 4:13 AM by Author "gerryndennis"
in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=11217565
RE: Ail differential in friese ailerons?
Hi Frets, Your ailerons are looking great. Don't worry too much about the theory v practice argument. The idea of Frise ailerons is that they deal with adverse aileron yaw with less drag penalty than other methods (differential or rudder for eg). Obviousely we will never see that efficiency in model flying, however they still work to reduce adverse aileron yaw. So the theory is they are more efficient and as RMH points out that's only theory. But the result is that they work, and they work at least as well as any others. So given that they aren't that hard to build and rig, and most importantly they are correct for your scale model.... We had a large Zero turn up at our field last week, nicely weathered, cockpit detail etc, but huge gaps in all the control surfaces due to the standard 'model' control surface design. After the first flight he said the ailerons were very soft, and he ran out of elevator in the flare. He's talking about adjusting the throws, but I couldn't help thinking if his ailerons looked like yours, and if the tail surfaces where shrouded (instead of 'V' leading edge) then they might have worked better as well as looking more scale. Yes it was the labeling of your diagram that led me to assume you were thinking more down than up, my apologies. Best of luck. Dave H
Posted on: 8/12/2012 6:54 PM by Author "gerryndennis"
in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11189661
RE: Basic Thunder Tiger 130fs carb settings
Hi Cymaz, I'm not totally familiar with Thunder Tiger, but seeing that no one else has answered; You could try setting the low speed screw flush with the housing, or if there is a step on the needle set it flush with the carb throat. Assuming it has one of these features. Alternatively, set the throttle to the idle position, close the low speed needle, blow through a piece of fuel tube attached to he carb fuel nipple, and open the low speed needle until air starts to pass. Either method should get you close. Open the high speed needle 3 to 5 turns, should get you running. Adjust from there. Good luck, Dave H
Posted on: 8/8/2012 12:08 AM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11184761
RE: Magnum 120FS RPM issue
Yes 'opposite the tubes' is fine too, rotate the prop 360 degrees and the dot will now be next to the tubes. It's the same thing. I've had examples of these Sanye engines with the timing dot position a little bit variable. As W8ye and Kimhoff say, a good way is to confirm the timing dot is to check the valve overlap. Replace the cam cover (loosely is fine in the meantime as long as the end of the cam is supported). Remove the rocker cover and the rear cover ( carb comes off first). Rotate the engine until you can see that both rockers are open, and then get them so they are both level (open the same amount), now look at the crank pin. It should be at the very top (12 o'clock) or very slightly before 12. One tooth of on the cam will be noticeable. While you have the rocker cover off check for sticking valves or broken springs like Pe says. Also check the push rods are seated correctly in the adjusters. Check valve lash (gap). You can remove the muffler to inspect for carbon without removing the head. It's not overheating is it? That can make them run slow. You could try much lower (5% or even no) nitro, it may be preigniting sufficiently to lose RPM. Normally you would know if hat was happening though because the engine would sound bad and try to kick the prop off. Can happen though so might be worth thinking about if nothing else works? Best of luck, Dave H
Posted on: 8/7/2012 3:37 PM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11184746
RE: DuBro Vibration Mount
At the risk of going a bit off topic, X2 on the well nuts. They are cheap easy and work. Reasonable vibration and sound isolation, without the engine flopping around too much. I use a penny washer as an extra safety device though. Insert the well nut and tighten the screw. Place a washer over the protruding screw in the tank bay and then put on a nylock nut. That way if the rubber ever fails or pulls out of the hole, the washer will prevent the engine mount from pulling out. Probably over kill though. Dave H
Posted on: 7/15/2012 6:01 PM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11156564
RE: New CG application that does multi-panels
Hi Ed, I was just pointing out that the subject calculator seems to be allowing for different tail efficiencies for me. You said that it wasn't for you. I'm pretty happy with the results I've been getting with both the Geistware and the Adamsone calculator so I won't go to the trouble of checking the calculations by hand. I'm interested though, are you suggesting these two sites are in error? Do you use different equations on your site? I did spend some time looking at the neutral point discussion on your site and it did raise a few questions for me. You will have to excuse me if I am incorrect about your site I'm working from memory as the site doesn't open for me at the moment. You seem to describe the process as; 1. Determine the MAC. 2. Set the CG. It doesnt say where though. At a standard position? 3. Determine the neutral point. I may be misunderstanding your intention but that is the order (from memory) you describe it at rcaeronaughts. I notice that you have suggested to a couple of other people with trimming questions that they should set the CG to 20 or 25% MAC then use your calculator to determine the neutral point. That seems backwards to me. It makes more sense to me, to establish the neutral point first then set the CG an appropriate distance (5 to 10%) ahead of that point. This is what the other calculators do (maybe it's what yours does too, your site doesn't say). This will often result in a CG way different than the 'standard' 25% MAC but it will give a 'safe' stable position to start from. Isn't this the whole point of the CG calculators? I guess you know that vintage models with large tail volumes often fly with very aft CG's (up to 100%) sometimes, and free flight as well. The small flat foam aerobatic guys fly at or behind the neutral point. So recommending a 'standard' 25% doesn't seem right to me. I would probably be happy to pay you $25 for your calculator if I thought it was better or more accurate than the other two but it seems to me that they work fine. The Adamsone calculator does four panel wings and canard models so would probably meet any requirements that I foresee requiring. Dave H
Posted on: 7/15/2012 1:23 AM by Author "gerryndennis"
in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11155733
RE: CG on a Royal Kit
[quote]ORIGINAL: AERORICH73 Ok Chuck: Not having the calculator program available, I found that Squardron 495 had published their way of finding the CG location. I am not sure just how large this model is, or its weight, but will give you what I learned from 495. Finished repair, and rebuilding a damaged trainer, I hung the model in a large doorway from the engine cs, vertical stab/ top rudder hinge, and leveled it along the longitudenal axis. Hung a plumb bob from the same hanger above the model, and lowered it until it reached the fuse. Where it pointed was the CG location. This location proved out correctly as the model was very well balanced during its flying life before my bad landing. Just finished a 1994 Royal Aire 40T ARF purchased use, and never flown. The instruction manual gave a 4 inch dimension from the leading wing edge for the CG location which mathematically came out at over 38% of MAC. The above method corrected the location to 28% MAC. The plane flys well at this CG location. Cheers!!! Rich [/quote] Rich, I may be completely misunderstanding your post, my apologies if the is the case, but it sounds like you are ignoring the recommended CG and assuming that the actual CG is correct because the plumb bob points at it? You say that your trainer was meant to balance at 38% but you flew it at 28% because that's where it ended up or did you adjust things to achieve 28%? I'm sure that it flies fine at 28 but it sounds like the manufacturer is suggesting that it will fly better at 38 The method you describe will definitely find where the balance point actually is, but it doesn't tell you anything about where it should be. The idea is that you add ballast (or preferably move heavy things like the battery) to shift the balance point to the recommended position. Now if you have good reason to think that the manufacturers position is incorrect well no problem balance your model where you see fit. Most well designed models will balance well enough as built, assuming you don't change things like using a heavier or lighter engine, using a covering that is significantly heavier or lighter than the original etc. but some models will need to have the balance point adjusted to achieve the designers recommendation or indeed to match the pilots requirements. Please disregard if I have misunderstood your post. Dave H Aero rich emailed me to clarify his post, and I have indeed somewhat misunderstood what he was saying.
Posted on: 7/9/2012 3:57 AM by Author "gerryndennis"
in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11132073
RE: New CG application that does multi-panels
[quote]ORIGINAL: edsplane Another is that the tail efficiency doesn't appear in the neutral point calculation and has a strong influence on the results. [/quote] Hi Edsplane, When I change the tail efficiency the neutral point and suggested CG move so I assume it must be in the calculation? I had to push the 'click' button again to get it to recalculate. Dave H
Posted on: 7/9/2012 3:55 AM by Author "gerryndennis"
in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11148392
RE: Cowled Saito Question
Is your fuel filler valve the type that fits between the tank and the carb and blocks of the carb when you insert the fueling probe? If so, just insert the probe then spin the engine over, should be the same as removing the carb line. Dave H
Posted on: 7/3/2012 3:23 AM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11140941
RE: Gyspy Moth?
Waditup, Does the Tiger on the tail of your model have moth wings? It may be the emblem of the Tiger Club. There is at least one Dh 60 in the Tiger Club I believe. Dave H
Posted on: 6/20/2012 10:34 PM by Author "gerryndennis"
in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11126129
RE: Gyspy Moth?
The Tiger Moth also has more dihedral in the lower wing. When the wings were swept the lower wingtips became dangerously close to the ground in the three point attitude. It was impossible to land or even taxi without touching the tips. The fix was to shorten the interplane struts (purportedly by sir Geoffrey with an axe, time was short and they were in the middle of RAF trials). Viola extra lower wing dihedral and wing tip clearance. The result of all the mods (centre section forward, increased sweep and dihedral) was an aircraft that was not nearly as nice to fly as the Dh 60, but as is often the case in aviation the compromise worked. Dave H
Posted on: 6/19/2012 4:45 AM by Author "gerryndennis"
in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=11123489
RE: Ail differential in friese ailerons?
G'day Frets, Every set of Frise ailerons I've seen incorporate a bit of differential as well ie more up than down. I don't know why you've designed yours to have reverse differential ie more down than up! I would suggest that you don't do that. Make yours with equal deflection or a small amount of conventional differential and I'm sure they will work just fine. Don't worry about them being more effective than conventional ailerons, they won't be. While its true that they are lighter in feel that is totally irrelevant for an RC model (unless you are trying to use weaker servos). You would have to be holding on to the control column of a full size aeroplane to feel lighter ailerons, not a radio set. Someone's got the wrong end of the stick there. Incidentally did you know that the adverse yaw is probably at least as much due the diffence in drag between the wings due to the roll rather than the actual aileron deflection? The descending wing has less drag than the climbing one. Makes no odds though, we still need to 'step into the turn' as you say. Even the best designed ailerons won't exactly balance the adverse yaw for all rates of roll at all speeds or angles of attack. Congratulations on putting some thought into your ailerons instead of just bunging some triangular lumps of balsa on the back. Cheers Dave H
Posted on: 6/19/2012 3:57 AM by Author "gerryndennis"
in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11123455
RE: Building Enforcer - curious about mods
Yes, if you add aerodynamic surfaces forward then the balance point will have to move forward too. Use one of the on line calculators to confirm the new position, a blanket 1 to 1.5 inches might be about right, but it might be wrong also. Depends how big your canard is. Another method is to build a sheet miniature version of your model (12 inch span should do) and test glide and adjust balance with clay ( you will need some 'up' elevator built in, either in the canard or trailing edge of the wing). Try posting in the aerodynamics forum for further advice. Good luck, Dave H
Posted on: 6/10/2012 12:01 AM by Author "gerryndennis"
in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11112947
RE: OS FS 120-E with pump?
Hi Eric, The nipple at the front is to carry blow by oil away from the crank case, attach a short length of fuel tube to it and lead it to the outside of the cowl. The choke is used manually to prime the engine before attempting to start it. Again you run an extension wire to the outside of the cowl. Not strictly necessary if you use an electric starter. It can be removed if you prefer. Yep a stuck valve or perhaps the push rod has jumped out of the adjuster and is holding the valve open. Either way remove the valve cover and you should be able to see what is going on. If the valve is stuck try alternately pushing down on the rocker and lifting up on the valve to see if you can get it moving (OK you can [b]carefully[/b] use a small screw driver or similar to [b]gently[/b] lift the valve). If this doesn't work stop, time to try a bit of heat and/or penetrating oil to get it moving. If this doesn't work you are looking at removing the head, disassembling, and cleaning/polishing the valve stem. If it's just the pushrod out of the adjuster cup, push down on the rocker to compress the valve spring and you should be able to reseat the push rod without disassembly. After one or other of the above oil the valves and rockers, reset the tappets and you should be good to go. If the valve is stuck by solidified castor then you will possibly have similar problems elsewhere in the engine. Carb, bearings, etc. in that case it might be prudent to clean the engine before attempting to run it, but if it's not too bad you might be fine. How does the engine turn over? There are plenty of threads about cleaning engines, from using heat and penetrating oils (if you use WD40 or similar be carefull of loosening any rust, clean up and re oil guickly). You can soak the engine in glow fuel or similar, or there is the crock pot method (carefull of the rubber components in the carb). HTH Dave H BTW the carbs and pumps on these are reasonably complex so try and clear any castor by flushing with glow fuel, avoid disassembly if possible. There are rubber components inside the pump that might not like some solvents or crock potting.
Posted on: 5/31/2012 3:51 AM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11100918
RE: Suevia 1.50 RC Engine
Thanks for the vid Earl, looks like a beast of an engine. Another benefit of an intake stack would be an improvement in fuel economy, I'm guessing it uses a fair amount. Would you really want to modify an original engine though? Dave H
Posted on: 5/31/2012 3:08 AM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11100902
RE: Suevia 1.50 RC Engine
Hey Earl, Great to see it running. You had me worried when you said you would need to re drill the locating holes in the needle holder/spray bar. I figured, being a German engine especially, that it would either fit perfectly or be adjustable. Glad you sorted that out. Yeah I guess that's another feature of 'loud popping sound' intakes, they spit. You might have to make an intake horn for it. Dave H
Posted on: 5/27/2012 11:26 PM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11096964
RE: Suevia 1.50 RC Engine
Hi Earl, Is the brass helical thread visible inside the carb and the brass needle holder with the fuel inlet on it the same component? If so does it rotate if you loosen the two set screws that you had to replace? Does the throttle barrel turn past wide open without bottoming out? You may be able to draw the throttle barrel further into the carb at WOT by turning the brass component. This would of course leave the fuel nipple in the wrong place, so wind the barrel back out of the carb until it just disengages with the thread then back to the next thread start (it's a multi start thread by the look of it). Wind the barrel back in and adjust the brass bit. I reckon you might be able to find a position where the barrel hole and carb hole are concentric at WOT and the fuel nipple points in a suitable direction. I hope this makes sense? Dave H Hobsey I think this form of induction is more correctly called 'side port', sub piston induction refers to supplemental induction through the exhaust port under the piston skirt. I knew what you meant though. Sorry Hobsey I just retread your post, you didn't say SPI at all. You are right the intake occurs under the piston, and I know you know what that is called.
Posted on: 5/26/2012 11:01 PM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11095864
RE: Club ED
[quote]ORIGINAL: fiery To kick off, a 1957 ED Mk III Racer 246, magnesium case. It's noisy, it's oily, and it's well used; but it has character aplenty. [/quote] Noisy and oily is right. An old modelling friend of mine has been slowly getting rid of his extensive collection of engines on the bay, and decided that I needed a couple of diesels so sent me home with a suitably lightened wallet and a couple of engines that 'every modeller should have'. A Mills .75 and two Racers. One of the Racers (RA1094 would that be Jan 1954?) has done very little running and is in pretty good condition. It also has a loose piston pin and one of the bridges between the exhaust and transfer ports broken out of the liner. I presume one led to the other. The other one (RD86 Apr 56?) has been well used with faded anodising, bodged up tommy bar, prop driver, and spinner, missing the prop washer, and with the exhaust completely filed off. I guess it's done some time in a team racer. The piston has a reasonable score in it and the compression isn't great but the engine runs OK I think. Well starts OK most of the time (other times it's quite bitey, I'm just a beginner at this diesel stuff) and turns a 9X6 Master at about 8800. So transfer the old piston and liner into the good engine and I hopefully have a reasonable engine for a vintage radio assist model. I'm thinking either a KK Junior 60 or KK Super Scorpion. I'll only fly the Racer on the odd special occasion though (that noise thing aqain), the rest of the time the model will fly with a DDD OS 20 FP. I suppose I could use the newish piston (with the loose pin) in the old (but not broken) liner, but I have no idea if it's possible to tighten up the gudgeon pin or if you can swap pistons and liners. Thanks for the video Fiery, what size prop and RPM are you getting? Also what fuel do you use? I'm using 20% Klotz castor, 30% ether, and 1% ignition improver. I'm thinking 10X5 or 10X4 prop might work on the vintage model (one of the club crusty old bug aaah, veteran modellers seems to think they might have used 8X8's team racing) Oh you're right about the character too. Dave H
Posted on: 5/25/2012 8:31 PM by Author "gerryndennis"
in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=11092705
RE: Club ED
Thanks Fiery, will pm you later. Dave H
Posted on: 5/25/2012 8:26 PM by Author "gerryndennis"
in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=11094944
RE: Club ED
Fiery, Some more questions; Where did you get that needle? I noticed on your other Youtube videos that you also have a 40 FP with what looks like a MECOA head. I have a 40 FSR that I am keen to dieselise. The MECOA site reckons that head will fit on a 40 FSR but Davis reckons his 40 FP head doesn't. I'm not sure whether to just buy the Davis head and hope or buy the MECOA head. How do you like your MECOA head? Thanks Fiery, great thread Dave H
Posted on: 5/24/2012 2:44 AM by Author "gerryndennis"
in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=11092717
RE: help
I just made one for a diesel engine. Aluminium kitchen foil is too thin to seal, but two layers works fine. Disposable aluminium oven trays are great but I didn't have any. Then it hit me the foil pouch that I had just got my new #11 blade out of was perfect. Or an adult fizzy drink can will work great as well. Take the cylinder liner out of the engine and carefully hold the foil over the top end. Carefully cut around the inside with a scalpel or sharp modelling knife. Press around the outside edge with your fingers to mark the foil, then cut out with sharp scissors. You may need to make 3 or 4 before you get a nice one. Are you sure it's missing? Sometimes they hide in the cylinder head and you have to carefully work them out with a pin. Don't slip and scratch it or bend it or you will need a new one anyway. You need to be carefull about what thickness you end up using, too thin can let the piston hit the head, or can lead to detonation, overheating, blown plugs and engine damage. Too thick can lead to low power and the plug cooling off and the engine stopping. It all depends on how much nitro you are running, what propeller load, how much cooling the engine gets, etc. But if your engine runs fine now you should be fine with any of the aluminium thicknesses mentioned so far. Daved H
Posted on: 5/21/2012 2:53 AM by Author "gerryndennis"
in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11088484
RE: Are ASP Engine Good Engine??
Hi Sonny, I got an ASP 52 FS second hand with an ARF model I bought. It looked like it had not done much running but had clearly been overheated (the cowl was poorly built with insufficient cooling). There was a bad score in the bore, the cam followers were also badly scored. When I turned it over the pushrods rubbed on their covers. The exhaust valve leaked badly. I gave the bore a light hone, and tried unsuccessfully to get the exhaust valve to seal by grinding, maybe the leaks not at the valve. The engine runs perfectly even with the remaining faults. It starts easily and is totally reliable, idles well and makes good power (I use zero nitro fuel). The engine seems to use more fuel than my OS engines and carbons up way more. I understand that leaky exhaust valves are a known fault with the Sanye four strokes and leaky carbs with both two and four strokes. So personally I prefer the quality of OS or Saito, but if I had to buy another engine I would be very tempted by the price of Sanye engines and spare parts. I am certainly happy with the way my ASP runs. So should you buy ASP or Magnum? I have no idea how well the warranty or repair process works in the states but If you were happy to deal with potential small problems like sealing a carb with silicon, and if you were able to return any engine that turned out to be a total dud then you would probably be happy with the ASP. Is the peace of mind of the Magnum warranty worth 100 dollars to you? Hope this helps, Dave H
Posted on: 4/21/2012 1:06 AM by Author "gerryndennis"
in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11050715
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