qazimoto

My Feedback: (1)

A new video of this running prototype PAW Diesel Twin is shown on the PAW Facebook page this morning. It was posted by Chris Eifflander who suggests that it'll be available soon.

Here's a still from it, showing that the engine is horizontally opposed. Capacity is not stated.







The video is at this url. You may have to log into Facebook, search for the group "P .A.W model aero engines owners club", and join it, to view it however.


https://www.facebook.com/video.php?v...type=2&theater

DerFly

Linkie no workee

DF

qazimoto

My Feedback: (1)

Apparently offensive post edited, see below.

DerFly

Well don't you think that just might have been the first thing I tried?

At least work with the assumption that others have a modicum of intelligence before you start spraying big red text about for that matter too.

qazimoto

My Feedback: (1)

Sorry but the simple sentence "Linkie no workee", without any hint of what else you had tried may have given me the impression that you hadn't.

If you are logged into Facebook then try a search within it on "P .A.W model aero engines owners club".

If you still can't see the posts then you may like to join the group.

Otherwise, next time I may not even bother wasting my time (about 20 minutes) posting something I see that's interesting.

DerFly

The search tip worked, thank you.

I read here because I am interested. This is also why I drew your attention to a non working link, not as elegantly as I might have done clearly.

The extra information you've added to your original post would have avoided any unpleasantness in the first place

DF

brokenenglish

Ray, Thanks to your post I've found a whole load of interesting stuff (for me), that I wasn't aware of.
Thanks a lot,
Brian

Recycled Flyer

Educated guess Ray?

(I am going for two 2.5cc pots totaling 5cc.)

fiery

My Feedback: (2)

Thanks Ray.

As I don't do facebook I will look for a copy of the video on youtube or similar.

greggles47

I can't find it on Utube, but Chris Eifflander on FB confirms 5cc. (2X2.5)

fiery

My Feedback: (2)

I could not find it either. I'll ask a friend who has a facebook page to link to it.

It will be interesting to see if this 'boxer' flat twin becomes a production item.

brokenenglish

The video isn't directly accessible on youtube.
You have to be a member of the PAW facebook group, or at least on Facebook, as Ray more or less mentioned.
Chris says that it's 2 x 2.5 cc and that it will be going into production shortly, after just a bit more final development.

Recycled Flyer

Linkee workee - thanks Ray.

scottyo

I've recently moved to the world of internal combustion rc from all electric. I've always had a slight aversion to glow, so I decided to skip it and go straight to gas. I have a 20cc gasser still in the box for a plane that is still on the work bench.

Then I discovered diesels.... I came across a DDD conversion head for a OS 40, so I did tons of reading (mostly here on RCU), picked up a used OS 40, and converted it. Took it out to the field with a friend who had a test stand and we fired it up. I am hooked!

The reason I am posting here is because I am the proud new (second) owner of a PAW .40 that has very low time and is in excellent condition. I want it to stay in excellent condition, so before I run it, I hope to get some advice. Here is one of the photos from eBay and a couple of it mounted in my new test stand.



It is a TBR R/C with a Varijet carb. It came with an extra needle (the owner couldn't remember why) and an extra spinner bolt. He said it had 8 to 10 flights (with 12x6 and 13x6 props), and was kept oiled with sewing machine oil and stored for 3 years. I have a few questions....

When it arrived, I immediately pulled it out of the box to check out the compression, etc. It didn't have a prop on it at the time, so I just grabbed the drive hub to turn it over and I couldn't budge it! I thought "oh god, it's locked up", but I tried not to panic. I mounted it on the test stand and installed a new, balanced 12x6 MAS prop. OK, now I could turn it (whew). I tried a few flicks and although very stiff through compression I assumed it was proper. (My OS 40 conversion is not nearly so "stiff".) So my first question is how should it feel and should I add some oil or something? I am hesitant to put fuel in it until I know what to look for. When I turn it though compression, it has a short stiff "pop" feel followed by a little bit longer less-stiff "drag" feel, then free till the next go around.

Next, I have a quart of DDD Diesel power standard fuel. It works great in my OS, but I don't know the formula and I was wondering if it is suitable for the PAW.

Then I would like some advice about setting the needle and compression for initial start (for me). I've read the PAW documentation, but the compression adjuster turns very freely and I'm uncertain where to put it. I'm also not sure if I should screw it all the way in from how it arrived in order to count turns. (Should it turn that freely?)

I won't be able to wait until spring to run this (impatience), so it will probably be started on the test stand in sub-40F temps.

Thanks for any help. Scotty

brokenenglish

Hi Scotty,

You'll get plenty of answers here!

Firstly, fuel mixture isn't very critical so I'm sure DDD fuel will be OK if it's been properly stored (i.e. well sealed).

Secondly, it looks like you have a wooden propeller. That's good. A frequent mistake made by diesel beginners is that you need a propeller that you can reasonably flick, not a carbon fiber finger slicer that really needs an electric starter (glow engines only!).

Thirdly, the drag that you feel on the down-stroke is due to the fact that some of your compression has leaked past the piston, so on the way back down, you're pulling the piston against a vacuum. This ain't a good sign, but it may be due to the engine being a bit dry. Fuel or oil (3in1 or even automotive) may well cure the problem.

Fourthly, you can't "set" the correct compression for starting, you need to find it. It would be best to start by unscrewing the compression screw a lot then, when you know you have fuel in the cylinder gradually increase compression until the engine fires. For the fuel needle setting, just start with the needle set as per the instructions. If you don't have the instructions, start with about 4 or 5 turns open, and be aware that it will probably be a bit "rich".

Finally, it's dead easy once you get the knack! I've posted a couple of videos of starting and running PAWs. You can see just how easy it is.

My PAW 60 is running here:
http://www.youtube.com/watch?v=6xl1HLZADAI

And the PAW 19 is running here:
http://youtu.be/1e_RH7i0U2o

Let us know how you get on, and we'll try to solve any problems.

scottyo

Thanks Brian! I've watched your videos before (watched them again tho). I hope this one is that easy to start.

I think your diagnosis of "dry engine" was right on. I put some 3in1 oil in and now it feels much better - no secondary drag - more like I thought it should feel. I will probably wait until the temps here get into the 40's to try it out, but it's 37F right now and it's early yet... I'll try to get video....

So no muffler pressure required on these?

brokenenglish

No Scotty. Most diesels have smaller carburettor throat diameters than similar size glow engines, so fuel suction isn't a problem and no-one ever needs pressurized fuel on a sport-flying diesel. Like all engines, just make sure that the fuel level (i.e. the top of the tank) is roughly on the same level as the fuel needle and that'll be fine.

buzzard bait

I wouldn't mess with the compression screw on the first try. It's probably close. Same with the needle. On the test stand, just put three drops of fuel into the carb (open) and give it a sharp flick, and be ready for something to happen. Once I was holding a PAW diesel in my hand and did a short spray of WD 40 into the carb to loosen it and for some reason, gave the prop a flip. BRPPTTTT!! Scared the daylights out of me!

You can also hook it up to a tank and choke it to bring the fuel to the carb, then another choked turn.

Btw, WD-40 will often loosen old gunk, but then follow right up with oil. WD-40 by itself will dry out and then things will be stuck again.

You can use a composite prop if you use a stick. I use a length of radiator hose from NAPA with a 3/8 inch dowel inside. The ID of the hose is 3/8. I just pushed the hose on over the dowel. Took a bit of patience, but it has lasted me for years. Don't use it on a wood prop...it will snap it like a match stick. With the wood prop, just use your fingers.

Jim

scottyo

Thanks Jim! Hey, you wouldn't happen to be the previous owner of this fine diesel would you? He was from Ithaca, too. (Flyingviolinist?)

buzzard bait

Ha! Ya got me. Yes, I owned it, and I hope you enjoy it. I found it very easy to start and run. It vibrated like crazy on the first run, but smoothed out as I broke it in.

I'm using two kinds of glow fuel, and the diesel made a third one, and I just wasn't taking it out. I'm hanging on to my small diesels, thinking I'll get back to them some day. Feel free to ask more questions. I hope you are successful with it.

Jim

meninspex

Starting a new tack here. Amongst my late father's engines (which I'm not looking to sell) are two "Gig Eifflaender Specials". The larger is fairly easy to place but not the smaller one, of which photos attached, and could be 1.5cc. Any help out there? I live in Macc. so could easily go and ask Tony E. but I've already asked his advice once and am loathe to keep pestering him. I should add that I am not an aero-modeller and am only looking to display these engines as a tribute to my dad.

brokenenglish

I've been interested in Gig's engines ever since his early "personal" production.
First of all, are you sure this engine is a 1.5.
Gig's early engines were notoriously compact and light for their capacity, and I'm inclined to think that your engine could well be a 2.5.
It wouldn't be very difficult to approximately measure the bore, through the exhaust ports, and at least get an idea of whether it's a 1.5 or a 2.5.
I don't think that there's really very much to "know" about these engines.
Gig produced some excellent early stuff, before PAW engines, in very small volumes, and your engine is one of those (you're very lucky!)
If I manage to attach this scan, you may find it of interest. It shows an engine very like yours...

fiery

My Feedback: (2)

Great find. Hang on to it ...

meninspex

Thanks brokenenglish, that is exactly like my engine - would you have any info on the other special (photo)? Have no fear fiery, I am hanging on to all the engines although I have lots of queries for other parts of the forum. Apart from the Eifflaenders, 2 Mills an Oliver Tiger MkII, an Enya 29 and a Super Tigre G20, all the engines are American - my dad had an American friend who sent him loads of stuff in the early post-war years.

brokenenglish

Unfortunately, I don't know anything about that particular engine. However, it is very like the first PAW (the PAW Special, made from late 1957), so it would be reasonable to assume that it's just about the end of Gig's personal engine development. So it's probably about the last of the real Eifflaender Specials, and was only changed very slightly to become the PAW Special, and start PAW production.

Note that Tony really caused a bit of confusion in the nineties, by releasing a "replica" Eifflaender Special. He probably called it an "Eifflaender Special" for understandable marketing reasons, but it was actually an "approximate" replica of the PAW Special...

Here's the first PAW I mentioned, you'll see the similarities.