exocet-RCU

My Feedback: (1)

Does anyone have a video of a plane powered by a PAW 55?

I am thinking about putting it in a Guillows Zero so I could swing a more realistic prop and have some throttle response. I think a nitro .049 will be too much, especially with no throttle and I think a TD .020 will have a tiny little prop and look strange. I like the idea of a diesel but have only seen videos of them running on a test stand. Would like to see a video of one on a plane in the air.

Oh.., one more thing. I know I could go electric but I refuse to, so please don't tell me to go electric. Real airplanes have real engines. :-)

Thanks in advance.

Tim

AMB

check out the Diesel forum, think you find it if you go back a few pages, all my little stuff are converted from watt eaters to diesel, fuel, flip fly,no hassels with changing batteries charging
etc etc

exocet-RCU

My Feedback: (1)

Thanks, AMB. I was out there yesterday and didn't see any videos of them flying. I did see a video of an event in australia but it seemed the engines were sputtering a lot (missing). I have also seen videos of them on test stands and they don't sputter.

Do you think the PAW 55 would work for the Guillow's Zero? it has a 20 inch wing span

Thanks

LittleRock

The Scoundrel has a 36" wingspan and weighs 12 ozs. The SkyWing has a 52" wingspan and weighs 14 ozs. Both are 3 channel and have PAW .03's for power. Sorry, no video.

ffkiwi

Way way too much power for the Guillows Zero-as well as weight. You'd be better off with an 010 or Pee Wee. One of the 0.25cc diesels might be appropriate-but none of these are currently in production-and the best-the Schlosser 0.25, is very very very expensive. It did though, come with an R/C throttle and muffler as options.

Finally-perhaps the G-Mark 0.5cc glow would be an option-again, out of production (long out of production)-but comes up on Ebay reasonably often-and has (in the R/C version) a very effective throttle and muffler. It will also turn up to about 5.5" props comfortably (though the one that comes with it is only about 4-1/2") and has a decent capacity radial mount tank arrangement. The only down side-apart from needing nitro fuel, is the glowheads are unobtainable.......BUT......a couple of people have successfully converted burnt out ones to take the flat coil Glo Bee style (now also Merlin) Nelson button insert -so a burned out head is not a catastrophe. Powerwise they fall somewhere between a Cox Pee Wee and a TD 020.

For R/C conversions this small to IC, you really have very very few suitable options in the engine department.

ChrisM
'ffkiwi'

exocet-RCU

My Feedback: (1)

correction. The Zero wingspan is 27 inches

Sorry

ffkiwi

That does make a difference-in that case the answer is yes-but how much previous diesel experience have you had-and how much experience converting rubber models to IC? There is quite a lot more weight and bulk in a PAW 03 than in a radial mount 010 or 020 which is what the Guillows plans usually show for an ic power conversion option......you would have to consider what beefing up of the front formers would be required-whether to beam or radially mount the 03 [and there are disadvantages to both options], whether the ABS(?) cowl will stand up to fuel splash, and the heat of the engine, where you locate the tank-and how to access it....and remembering that if you use a commercial clunk tank, the standard silicone tubing is not compatible with diesel fuel.
That being said the PAW 03 should haul the model around quite nicely, on anything up to a 7x4-and if you wished you could run say a 6x4 3-blade for a more scale appearance. Off the top of my head the PAW 03 is rated at 0.07BHP at 12,500rpm-so that puts it somewhere between a Babe Bee and a Black Widow in power, with the ability to turn a Texaco sized prop...........

ChrisM
'ffkiwi'

soarrich

My Feedback: (98)

http://www.youtube.com/watch?v=5HObr...UJCXQ&index=19

http://www.youtube.com/watch?v=1UWji...UJCXQ&index=14

The first one is a scatchbuild design of mine, the second one is my Scoundrel both at about 36" wing spans. The first plane was very light, about 1/2 throttle was all it needed.

exocet-RCU

My Feedback: (1)

Thanks for all the good advice, FFkiwi. I have had a lot of experience building this size model and type of model and am not worried about the conversion from rubber to IC. I've also had a lot of experience with IC .010, .020, and .049s (both TD and reed valve). As I posted originally, I think the .020 would fly it but the prop is so small that it will look a bit strange and a non-throttled .049 might be a bit much for it.

I will have to say that I've not had diesel experience but definitely would run and practice with it on a test stand until I feel comfortable putting it in a plane. I have read that diesels like beam mounting more than radial mounting and, should I go that route, I would have to account for it in the fuselage. Definitely do-able.

Any other advice greatly appreciated.

Thanks

Tim

combatpigg

My Feedback: (3)

20 inch span?
Maybe 80 square inches..?
What would your weight budget be with the equipment you intend to fly it with...?

DeviousDave

The Schlosser .25's were available with a muffler up until the last run, only the .5's were throttled. The G-Mark is a good engine, but a little homely on power unless you yank the muffler-I've been trying to Cajole a friend of mine into making turbo heads for them as the supply of plugs evaporates. Someday the plugs these conversions use (like Nelson and Globee) will dry up too, but turbo plugs will be around because of the number of people with RC cars. Going to the hobby shop used to be something I looked forward to, now I just get depressed because there are no kits, fuel only for helicopter engines and precious few motors or glow accessories. A 2oz Sullivan tank I looked at this week was $8!!!
I'd look at a PeeWee .020 with a throttle ring.

ffkiwi

Actually -not quite correct-the 0.25 DID come with a throttle option-just not the final batch. Benno Schlosser dropped both the throttle and exhaust collector towards the end of production. Since they're no longer made-if you want one Ebay is virtually the only option-and hence you could still potentially find a throttled one. But such finds are rare and command big $$$ when they come up.

I agree that a PeeWee with a throttle is probably the most obtainable option-and even here you'll have to do some ferretting to find one. On the G-Mark-also agree that the standard muffler robs power-and some experimention is required-IIRC it was the late Ken Willard who ran them with only the front half fitted-if you're prepared to sacrifice an original muffler, then it is possible to fit a bigger volume rear chamber and outlet (which you'd have to make)

I'd still argue though, that the G-Mark has the most effective throttle of any of the tiny engines around.

ChrisM

exocet-RCU

My Feedback: (1)

Sorry, CP. Its a 27 inch wing, not a 20 inch wing.

combatpigg

My Feedback: (3)

I've done the conversions of that scale with .049s but something like a .035 PAW would have been more like it. "Cheating" a little bit with a small increase of wing area would help..by stationing the ribs further apart and splicing some of the kit wood.
The casual eye wouldn't notice [or even care].
The formers are really a PIA to work around once you get ready to make the plane RC functional.
I'd be tempted to glue 1/16" sheet cross grain to the formers and then open them up for more interior room. Sheeting the airframe in key areas goes pretty quickly. I build the wing to the fuselage then make an access hatch along the "clean side" of the fuselage. This saves weight vs having a removable wing.
A flooded engine could rip the firewall off the plane just trying to get it started..so plan accordingly.

exocet-RCU

My Feedback: (1)

Thanks, CP. I'll look at doing that to open up some former space and to strengthen the firewall area. The plans show to put 1/16 cross grain between the stringers and formers but you are suggesting sheeting over the stringers/formers, right? I think that would be much easier. I'm starting to get used to shoe horning radio gear into small planes. The Pageboy called for some creative servo and receiver placement. A bit of head scratching solved that.

Tim

proctor

You won't need throttle on the PAW 55, the thing about diesels is that you can back off the compression and run
them rich to get any power level that suits. If that's not low enough turn prop back to front to reduce thrust.
The ones you hear ' spluttering' have been adjusted like this to reduce power.
Put a 7x4 prop on it on the bench and run and fiddle till it becomes an old friend.
Think it is a bit heavy for your proposed model but you can make it work.
I have a Schlosser and use it all the time in free flight models. It is a complete delight and would be perfect for your model.
I paid £120 for a new in box one and as someone said the quality remains long after the price is forgotten.
My advice is buy one on Ebay while you still can and have time left to enjoy it. Perfect for your 1/2 A models.
6x4 prop max on the Schlosser though but it runs quiet and nice, you will love it.

John

combatpigg

My Feedback: (3)

No, sheet flush with the stringers and formers..but convert the formers into 2 ply balsa wood before you build the model. doing this will allow you to slice off 1/2 of the original former material that takes up space inside the fuselage.
Use spray adhesive to laminate the 2 ply formers.

exocet-RCU

My Feedback: (1)

OK. I get it. Great idea about making the formers 2-ply. Thanks. That's why I come here - great advice.

Tim

DeviousDave

The Schlosser .25cc does like larger props (Seems happiest on a Graupner 6-3 at about 9800) but it will get nearer 14k with a 4.5-4.1 APC prop. It might seem counter to the old way of thinking, but I think it's better to use a more efficient prop like an APC 4.7-4.2 than an old school sport prop because the RPM can be limited with compression and needle settings to get the speed right but the load and therefore fuel burn will be lower for more duration.

'Course when it takes 25 minutes to burn thru a CA bulb tank worth of fuel the smileage isn't all that important!

DeviousDave

No kidding? I've never seen hide nor hair of an mention of that motor with a throttle-not that there is a lot of mention of the Schlosser .25 anywhere on the web....

I'd give my left @#$ for an RC carb for the .25. I do plan to fly mine but dang to I get a lot of enjoyment running it!

ffkiwi

I have a German friend who used to deal with Benno Schlosser direct-and possibly as a consequence could access items that were not necessarily available to all dealers. I posted the Schlosser 1cc F1J glow here a couple of years back-and there were only 10 of those made!
I don't have a throttle for my 0.25s-nor the exhaust collector-mores's the pity-I was a bit slow in getting out of the starting blocks where Schlossers are concerned-only getting my first about 5 or 6 years ago-by which time production was winding down-though I've been aware of the marque since the mid 90sI think the 0.25 throttle was dropped first, then subsequently the exhaust collector. I do have both items for the 0.5 model though.
Perhaps the throttle was more trouble than it was worth to produce-at that size it would have been very fiddly to make.........

ChrisM
'ffkiwi'

exocet-RCU

My Feedback: (1)

Thanks for all the responses, folks. At this time I'm going to skip the PAW 55 for the Zero. I think, as it will be my first diesel, something with an open engine compartment might be a little better for me. I am planning to buy a School Girl from EarlyRC kits - which I think would do well on it. It says, "for .049 - .074" but that is IC. I think the PAW 55 should be fine for it. Or, since I haven't bought it yet, maybe the PAW.049 would be another choice.

Anyway, thanks for the advice.

Tim

ffkiwi

A wise decision! If you have no previous experience with diesels, you will find there is a learning curve to operating them, and their behaviour is quite different to glow engines in some areas. I grew up with them, so it is second nature to me. Follow the manufacturer's instructions-particularly where fuel content and prop sizes are concerned. The 55, 049 and 061 all share the same design layout, so handling will be similar regardless. Prop sizes will vary slightly-but not much. The 55 is capable of turning anything from a 5x3 up to an 8x4. There's not much use for a 5x3 on a 55-and the 8x4 would only be suitable for a very light, slow flying vintage model puttering around, or a lightly loaded scale model. The 049 and 061 would have a similar prop range-but could-in extremis be persuaded to turn a 9x4-again at very low revs (and a very large prop takes its toll on the rod bearings)
A couple of points to consider:
(1) fuel-unless you can access the components readily, ready made is probably the best option. You will have some difficulty sourcing it-and there are not many suppliers in the US selling it-DDD, Dr Diesel and perhaps Aerodyne. The key issue with fuel is keeping it fresh (ie minimising the loss of ether) by keeping it in closely sealed containers. In practice this means glass or metal-NEVER plastic.

(2) Throttling-the throttles (if you choose a throttled PAW) are fairly simple-whilst they work, you will not get a smooth proportional throttling effect the same as with a glow engine-you will get an effective idle however-BUT beware how long you idle the engine for! If you idle too long, the cylinder cools off, and when you open the throttle the engine will misfire, and continue misfiring until it has regained operating temperature-which could be quite a while-30 seconds or more. This can be disconcerting if you haven't experienced it before-but it is inherent in diesel operation with the smaller ones.

(3) Starting-get used to the idea of hand starting, because use of an electric starter-whilst feasible, is dangerous-especially for a beginner. The risk is from hydraulic lock-the clearance between the piston and contra is of the order of 0.005" at TDC-it doesn't take much liquid fuel to fill that small space-(as occurs when you inadvertently flood the engine) and that hydraulic lock won't move. You can generally feel a lock when hand starting-and take appropriate action-with a starter you won't (and a starter will bring up fuel from a flooded crankcase very quickly)-and something will give-that something will be either the crankshaft, the conrod or the gudgeon pin (take your pick!)....at the very least, you'll have inflicted damage on the engine.

(4) Compression setting-this is probably the biggest part of the learning curve for a beginner-adjusting that screw at the top of the cylinder. Think of it as an 'advance retard' lever-which in actual fact it is-just like the old spark ignition engines of the 30s and 40's. You started them rich and ignition retarded, and advanced the ignition until the engine ran smoothly-that's exactly what you're doing with a diesel-starting retarded then increasing the compression (which advances the ignition timing) until the engine runs smoothly-and then fine tuning the needle and compression (because there is a bit of interplay between the two). With an ignition engine-if you went too far-and overadvanced the ignition, the engine would backfire (often kicking the prop loose)-with a diesel this doesn't happen-but the engine starts to run hard and labour (which is much easier to see and hear than it is to explain in words) if you go too far on the compression

Once you've got totally familiar with your diesel, you'll discover they are very nice and useful units-but they're not the holy grail-just another option for powering a model. They have advantages and disadvantages-just like glows and electrics.

ChrisM
'ffkiwi'

buzzard bait

I have both the 55 (.033) and the 100 (.061). If I were just choosing for the Schoolgirl it would be a close call for me. It would be nice to keep it light and go with the 55, but then again, I'd be tempted to make more of a performer out of it and use the 100. The 80 (.049) has the same dimensions and weight as the 100 so I don't see any point in that one, unless you are entering a 1/2A contest.

I love the throttle on these engines. Yes, it's non-linear, but the sound of those little diesels on low throttle chugging around the field at 6 feet off the ground is priceless.

Also, on the Guillow conversion idea, yeah, save it for later. But there was a guy on one of these forums who did a whole bunch of Guillow and Sterling conversions with the PAW 55. They were beautiful and probably a lot of work to do, but they must have done fine. He had a 24 inch Guillow Bf-109, a 24 inch Sterling Fokker D-VII and a 24 inch Sterling Sopwith Camel. You wouldn't think it would work on such small models but apparently he was very successful with them.

Anyway, the Schoolgirl is a great choice with either engine. Have fun and keep us posted.

Jim

DeviousDave

I managed to obtain both the .25 and a .5 with muffler and throttle right at the end of production-my uderstanding was that the last run of .25's did come with mufflers but they were unobtanium when I was buying mine. RocketRob organized the first purchase during his visit with Benno, the .5 came from David Owen-half of the magic in dealing with David over the Schlosser was finding out he had most of the MP Jet spares I needed and could order what he didn't have. He's been an invaluable resource.

I only hope that the .5 is as much a joy to run as the .25..... Rob insisted that I get the .25 first because the .5's output was kind of typical of .5cc diesels (i.e. just get a PAW55, and a lifetime supply of fuel!) and because it's not every day you find a ballraced .25 diesel. In the end I'm glad I got both because the .25 is so nice to start and run that I would gladly pay more money for the .5 compared to a PAW55. I've got a PAW100R/C that runs fine once started but I can't seem to hand start it. I don't have the same problems with my MP Jet motors, maybe it will improve with age?