ZDZ80B2 rotary valve positioning help please
I have damaged one of my favorite engines and needed to buy a new backplate for my 80cc boxer twin. During disassembly I inadvertantly let the rotary valve drop off. Now I am screwed, as it fits in any position over the hex-shaped end of the crank, and I have no recollection of where it went originally. Can anyone help? I have not been able to get a response from the factory (which is unfortunately typical, even though these are my favorite two-stroke engines). -Mike
Posted on: 11/20/2009 6:33 PM by Author "mbiedul" in the forum "ZDZ & RCS Support"
http://www.rcuniverse.com/forum/fb.asp?m=9268364

RE: Using a Deans Antenna on RX
In the coil/wire build for a loaded antenna, does it matter which end of the coil is soldered to what?
Posted on: 5/24/2009 9:59 PM by Author "mbiedul" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=8795602

RE: Diesel 4 strokes
[b]Hobbsy and Jens[/b]: I'm not understanding something. Jens: you are talking about 16:1 to 22:1 range on compression (including Lanova cell I think). Hobbsy: you were saying your Saito 80 is OVERcompressed at 14:1. Something is not computing for me there. If the stock Saito is overcompressed, a simple spacer under the cylinder flange would reduce compression, though you would need longer pushrods. Jens is saying he removed material to INCREASE compression. Can either of you clarify this for me? I'd like to fool around with this on one of my Saitos, and now I cannot tell from your comments whether to try adding or or to try subtracting combustion chamber volume before machining a Lanova cell.....
Posted on: 5/26/2005 5:00 PM by Author "mbiedul" in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=3014307

RE: Diesel 4 strokes
Hobbsy: Jens had mentioned earlier that he didn't think Saito was a suitable candidate for dieseling. I suspect there would be problems with the valves clearing the pistons. The Saitos have their valves canted at an angle, kind of complicating the geometry. But I think the worst problem with Saitos is their one-piece cylinder/head; the attachment is the flange at the bottom of the cylinder. I should think the implications of trying to do machining inside that can would be tough. I don't think it's as simple as shaving down the block, though that's about all you could do on Saitos to increase compression: no room for shaving the cylinder flange. Maybe a different piston, with serious recesses for the valve clearance, but then you are changing the mass of the recipricating parts and having to do very fine machining. Man the arithmetic gets complicated too, for me anyway. There were diesel model engines in the 1940s that had fixed compression, but every modern one I've seen has the contra piston. Tweaking compression really is essential I think. On the other hand, I'm the guy that broke a crank trying to get more go out of a 1960 Webra .19 diesel by cranking down the compression and over propping....nice engine up to that point. That chamber Jens has machined is really an elegant solution. If he were to make up a batch, I would certainly buy one. All the critical machining is in that unit; the contra piston really needing a tight fit. Just to experiment, I bet we could just tap a rod for a wide fine thread screw and not use a contra piston at all. Then one could experiment without any machine tools (lathe, screw cutting gears, etc). You would just need a drill, a glow plug tap, and a tap for the "contra" screw; probably want the run of the screw to be pretty long to reduce blow by. Just an idea.
Posted on: 5/26/2005 4:33 PM by Author "mbiedul" in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=3014223

RE: Diesel 4 strokes
Jens: You have sure got my attention with your Lanova chamber idea. Congratulations on a very fine job, and generous sharing of your ideas! -Mike Biedul, Canada
Posted on: 5/25/2005 2:38 PM by Author "mbiedul" in the forum "Everything Diesel"
http://www.rcuniverse.com/forum/fb.asp?m=3010369

ZDZ 80 twin. Can it be upgraded to 100NG?
The ZDZ 80cc twin looks identical in dimensions to the 100cc "NG" twin, except 5 ports for the 100cc engine and 3 for the 80cc engine, and increased bore. Stroke and other dimensions appear the same. Could it be that changing out the pistons and cylinders would allow my 80 twin to be upgraded to the 100NG? Or does the porting geometery start in the case? If the upgrade is possible I would think a kit for low time 80cc engines would be a good seller for you. 40% increase in thrust.
Posted on: 5/24/2005 11:29 AM by Author "mbiedul" in the forum "ZDZ & RCS Support"
http://www.rcuniverse.com/forum/fb.asp?m=3006249

RE: ZDZ-80 blue head or not?
The specs of the 100NG models show a slight increase in weight for the blue head version, I guess from the paint and the nickel plating on the case. The cost difference is slight as well, but I think the smooth texture blue version should be easier to keep clean. The bare casting is not absorbant of course, but does have quite a texture. I'm of two minds about it. I am buying the plain one off the shelf from the local RCShowcase dealer, but would take the blue one if it were immediately available. Saito has that black-knight black ceramic-like coating on their engines as an alternative and they do seem to run slightly cooler. Saito says the black coating gives off heat better but I sure don't understand why; it would seem to me the coating would act like an insulator. I would think in the case of the ZDZ that the texture adds surface area and the blue head might rin insignificanty hotter. I suspect the blue coating is just an answer to all the pretty coating the other manufacturers have, and is seen by ZDZ as a marketing requirement. I do think the prop hubs are identical, at least on the 100NG, except for the anodizing colour. Plain or painted; either is a terrific engine. -Mike
Posted on: 5/11/2005 3:46 PM by Author "mbiedul" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=2965505

RE: Roto 35 Gas/Oil Mix
Roto.cz recommends Motul. I wasn't familiar with it, but have been using it in all my gas engines and so far am very pleased. Going 50:1 in ZDZ engine, and 40:1 in the big RCS/Moki four-stroke radial. Haven't bought the Roto 35 yet, but will confidently use Motul when I do. Seems to be a very slippery synthetic, though a bit pricey. -Mike
Posted on: 11/23/2004 1:54 PM by Author "mbiedul" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=2369449

RE: Infrared Thermometer Great for Radials!
There's another infared thremometer/probe out there that's much cheaper than the Raytek units. It's used by the nitro car guys and only costs about $25. Not as good - or at least not as easy to use - as the Raytek units, but pretty darn cheap. You do have to get pretty close for an accurate reading. I think the scanning is on a wider angle than the Raytek, which is pretty narrowly focused. In any case, it's better than NOT having the Raytek. It is much smaller than the Raytek with its pistol grip style. The brand is DuraTrax and it's called "Flashpoint". Measures in farenheit or celcius, will read continously or on-demand, and has a storage memory. Tower sells them for $25. I have one and use it for my heat shrink irons. I use dacron (Stits and vanilla) and temperature is very critical for how much you want the fabric to shrink. The DuraTrax is much easier than my old method of a glass themometer bedded in a balsa block. Just another option. I agree of course that you don't really know until you measure!
Posted on: 10/18/2004 3:39 PM by Author "mbiedul" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=2264945

RE: NEGATIVE FEEDBACK: Northeast Sailplane Products
Very sorry to say I too have had nothing but grief from NESail. Had an order go sour a few years ago. Forgot about it. Ordered recently and was quickly reminded. They checked the stock while I was on the phone, and I ordered Fedex to meet a grandson's visit. Half the order arrived, the rest "out of stock". When the rest arrived, a cheaper speed control was substituted. They said "it's a better one". Pretty flaky outfit. I won't forget this time!
Posted on: 7/30/2004 11:40 AM by Author "mbiedul" in the forum "RC Gliders, Sailplanes and Slope Soaring"
http://www.rcuniverse.com/forum/fb.asp?m=2037948

RE: Cunningham's Lazy Ace
Victor273: You were asking about fabric covering. I recently finished a 96" Super Lazy Ace with the Stits system of covering and can say it is definitely heavier than Monocote, which the late Mr. Cunningham recommended. Stits is similar to Sig Koverall. My gas-powered machine came out at 29 pounds, where a gas version should I think have come out at 25 or 26. Flys OK but I would rather it were lighter. Mine could actually use another clear coat, but I am hesitant to add any more weight. I don't think I would go with fabric if I had it to do over, though it gets a lot of WoW at the field, and is of course completely appropriate for a scale aircraft. I wonder - just plain don't know - if that 21st Century iron on fabric-texture coating is as light as Monocote. Maybe someone else could comment for you. These things do take a lot of covering material. Good luck with it. -Mike Biedul
Posted on: 6/11/2004 1:37 PM by Author "mbiedul" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=1893651

500A gyro
Danny: I have the new 500A gyro on order. Seems like you announced this thing a very long time ago, selling me on the concept. Do you have a REAL date when it will be shipping? I recently bought a 500T on the advice of your sales staff and have been very unhappy with the tech support in the last week. Randy telling me "we don't recommend this for aircraft", then hoping I would go away. I reminded him that one of the Horizon staff recommended it to me ("same thing as the 500A, just don't use tail lock"), and that I'm using the PCM10X transmitter. He sent me some instructions full of really confusing misprints: no response from him yet on what the misprints imply. So what's happening with the 500A? You folks keep saying "next month", but that story started in February. These can't be that tough to produce! I don't mean to sound hostile - I am impressed with JR equipment in general - but somebody is really dropping the ball on this product, at both the delivery and service level. -Mike
Posted on: 6/10/2004 2:15 PM by Author "mbiedul" in the forum "JR Radio & Spektrum Radios"
http://www.rcuniverse.com/forum/fb.asp?m=1890690

RE: What's YOUR winter project?
1/3 scale Waco YMF-5 biplane from Peter Barth kit. Engine is RCS/Moki gas radial. Covering will be Stits. Should take all winter, but I'm well into it.
Posted on: 12/10/2003 11:09 AM by Author "mbiedul" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=1341667

RE: All Time Favorite Engine
In 1959 it was the Johnson .32, just simply tremendous power compared to the McKoy .35 redhead which was the standard in my C/L crowd. Now its the Moki/RCS 215cc gas radial. Bought it 2 1/2 years ago, the kit's still not finished, but I run the engine just for fun! I like engines! For everyday, I have a Saito .56 that just runs great, with a perry pump.
Posted on: 11/21/2003 3:59 PM by Author "mbiedul" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=1295589

servo arm/wheel post compatibility
Mike: Aftermarket servo arms and wheels from Hangar 9, for example, have two versions: one to fit the posts on JR and Airtronics, and another for Futaba. Does either of these match the posts for Hitec? I'm trying to design a three-way linkage for the 75BB retract servo. Thanks -Mike B
Posted on: 11/14/2003 4:47 PM by Author "mbiedul" in the forum "Hitec/MultiPlex Radios- Ask Hitec Customer Service"
http://www.rcuniverse.com/forum/fb.asp?m=1277718

RE: looking for lazy ace by cunningham
Clarification. I can't speak for any of the smaller kits and short kits, but the larger ones have provision for semi-symmetrical airfoil, should you choose to build that way. That cross-section is drawn separately in the instruction packet. I built the flat bottom version, as shown on the plans, so I could just float around. -Mike
Posted on: 11/12/2003 11:01 PM by Author "mbiedul" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=1273287

RE: looking for lazy ace by cunningham
Mr. Cunningham told me he does not make the Lazy Ace kits or the "short kits" any more; this was two years ago when I bought plans for mine. I'm sure if you write or call he would still supply plans for any of the sizes he designed. Once in a blue moon someone sells one on an auction site, but it is really an easy building plane with constand chord, so all the ribs are the same. If you can build a kit, you should be able to build this one from plans. -Mike
Posted on: 11/10/2003 10:35 AM by Author "mbiedul" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=1265748

RE: Silk covering use - old covering brittle
When the paint on silk or Dacron (Sig Kover-all or Stits) becomes brittle, there are some products made specifically to re-juvenate the dope. aircraftspruce.com that supplies full-size plane folks sells only gallons ($12 or $15 US, depending on whether you are re-juvenating nitrate or butyrate dope). Smaller quantities of probably the same stuff are available in regular size dope jars from Brodak. Actually, I have a small jar somewhere of the Brodak stuff if someone wants to try it....send me postage from Edmonton, Alberta, Canada and it's yours. I wouldn't be surprised if Sig and the others have similar products. This stuff is supposed to restore the flexibility to the PAINT, which dries out over time. It won't do a thing for the silk or Dacron fabric itself, if that has deteriorated. There is also some stuff available for the poly-vinyl paint in the Stits system for Dacron fabric. I have really come to love the Dacron fabrics, by the way, because the shrinkage can be controlled so precisely. I built a glider many years ago, when I first got into that big soaring lightweight building, and used my old (1950's) method of putting wet silk on, doping the edges as adhesive. Well, it shrank great, like on my childhood control line models, but actually collapsed the structure! That's when I thought I'd give that new Monocote stuff a try....I can't speak for the rejuvenator stuff because my airframes rarely last very long - pilot error usually, not covering-system-specific failures if you know what I mean. -Mike
Posted on: 11/6/2003 2:41 PM by Author "mbiedul" in the forum "Golden Age, Vintage & Antique RC"
http://www.rcuniverse.com/forum/fb.asp?m=1257123

RE: Cunningham's Lazy Ace photos
And a couple more snaps if you are interested. -Mike
Posted on: 10/31/2003 2:02 PM by Author "mbiedul" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=1242486

RE: Cunningham's Lazy Ace photos
OK, I think I've got it. Here's a picture of the new Super Lazy Ace, started actually two years ago (long story, including a household move). This sure took a lot of lumber! -Mike
Posted on: 10/31/2003 1:56 PM by Author "mbiedul" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=1242473

New plane
I just finished the Super Lazy Ace, 96" span. Modifications include slight dihedral to top wing (matching the lower wing), less cowl hanging down, Stits covering, ZDZ 80cc twin. It's snowing here, so I don't know if it will get airborne before Spring. I have some images of it, but I can't figure out how to get them into this new RCU forum/post deal. Weight came out at 29 pounds. -Mike
Posted on: 10/31/2003 1:46 PM by Author "mbiedul" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=1242442

BV-138 Triplane Seaplane German/Nazi Amphibian
Yeah the Ekranoplan would make an interesting and loud model with - say - eight RAM750 turbines, but I'll bet not much fun to fly. I suspect you would be on the beach on the other side of the lake in a big hurry, chewing up the sunbathers.....They don't look like they turn real easy. Did you see the one toward the end with MISSLES? Those guys don't do anything in a small way do they? Take care. -Mike
Posted on: 8/29/2003 8:03 PM by Author "mbiedul" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=1093708

Really B I G seaplanes
B & V made some interesting and BIG aircraft, but the biggest hands-down have to be the Russian ground effect machines. If you aren't familiar with ground effects, it's the increased lift when flying very close to the surface. Pelicans use it very effectively. Anyway, the biggest was called by the US Intelligence community the "Caspian Sea Monster". These never were capable of getting far off the ground, but were designed to carry lots of troops or material over water by skimming on the ground effects. Evidently they were simply a nightmare to "fly" because - like a high speed hydroplane boat - once they picthed up and the air got under them they would go right on over on their backs. No computer assist either, like the B2 flying wing of today uses (has to use) for stability. Anyway, the biggest is one of the strangest machines you can imagine with a bunch of turbojets hanging off the nose, like a hammerhead shark in appearance. A web search will bring up lots on this class of seaplane. Including this site: [url]http://www.infinity21.co.kr/non-it/wig_home/wig_history.html[/url] I hope this is interesting to you maniacs! -Mike
Posted on: 8/29/2003 5:07 PM by Author "mbiedul" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=1093706

Anyone have Privateer plans in good shape?
The Custom Privateer is what I was after. Thanks very much for the information! -Mike
Posted on: 8/28/2003 8:05 PM by Author "mbiedul" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=1093296

Anyone have Privateer plans in good shape?
Anyone have Privateer plans in good shape? I would like to build a big one, but have no plans, nor do I know if anyone still makes them. So I'm looking for a set in good shape that I can copy, or the name/address of who still makes the plans. Any help much appreciated. -Mike
Posted on: 8/27/2003 3:40 AM by Author "mbiedul" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=1093294

Cunningham's Lazy Ace
I have the 96" Super Lazy Ace under construction (Almost finished!). I hear the aluminum gear from Abell are nice but there's something I don't care for about aluminum, and have really been reluctant to make up the wire gear from the plans. I'm no good at it and my customary bad landings bend the wire to wierd angles. So I laid up fiberglass gear using the geometry of the wire gear as a starting point. They cant forward from the fuselage attachment point to the axles, so a certain amount of care must be made when laying it out, especiially to get the axles square, but it was easy enough drawing it out completely on a wooden plank, then cutting where the creases are and joining it together again for a mold. Looks good.
Posted on: 8/5/2003 5:00 PM by Author "mbiedul" in the forum "Giant Scale Aircraft - General"
http://www.rcuniverse.com/forum/fb.asp?m=466074

RCS 44cc Twin Fuel Consumption?
Thanks Kevin: I'm sold on twins. I have a ZDZ 80cc twin. It was not fussy at all getting it going, and really very powerful. They say, for the weight, that the RCS/Moki twin isn't as strong as a ZDZ, but a Piper Super Cub is not a Sukoi anyway. I may fire some questions your way if the 44 twin is tricky for me. By the way, I had some correspondance with RCS and they'e dropped the 44 twin I think mostly due to cost. The US dollar has been hammered lately, especially during and after the Iraq war, and twins are pricey anyway, what with smaller production runs and two of every part, so.....not enogh demand and a bad dollar killed it of for the US distributor. Currency variations are double-edged swords. Up here in Canada there are some business that thrive when our Canadian dollar is eating it against US currency. Our exports look great then. But the guy that's trying to import for a living gets wilted. And so on. I think the Europeans are really onto something with a common currency. Levels the playing field over there, and stabilizes European businesses, unlike the poor RCS crew in Maryland who have to kill a chicken to make a cash flow forecast, importing everything. I wonder if I could ask you a question. So much of the dialogue on this site, and regarding engines especially, is just beating and beating on the vendors like RCS. Or Saito. Or OS. Etc. Always on them for slow turnaround on repairs or technical problems. I'm kind of fresh, coming back into the hobby after a break of twenty years, but I don't think of model engines as appliances, with guaranteed reliability, do you? Of course you want them to perform reliably, and I guess the gas engines are pretty good compared to methanol/glow, but after all this is a hobby. At every field I visit people are always landing deadstick, people are fooling arond with engines, and the debates go on and on and on about what's proper procedure with model engines. I enjoy the whole tinkering aspect of this. Am I foolish to think that expectations of world-class customer service from small companies with half a dozen employees are unrealistic? I guess if people want absolutely repeatable reliability they should leave reciprocating hobby engines and go to either the extreme of mass-produced electric motors, or perhaps jets. Of course when I was a kid, a good engine was $10, and now $300 gets a much cooler machine, but it's still $300. Yikes. What are your thoughts? -Mike
Posted on: 7/12/2003 4:33 AM by Author "mbiedul" in the forum "ZDZ & RCS Support"
http://www.rcuniverse.com/forum/fb.asp?m=945181

RCS 44cc Twin Fuel Consumption?
Thanks Kevin: No I haven't run it up yet. Got distracted on the project, but I'm back to it now and it should come along quickly. One of the tapped holes for the brackets was stripped out. Not worth sending it back to RCS, but I took forever getting around to running a bigger tap in. Maybe I'll fire it up this weekend....but the weather's too nice and the flying field is only a few minutes away..........Thanks again. I have a 24oz tank all set, and it sounds like the right size, so I'll put it in place. You're right, I have tons of room and lifting capability. We'll see.
Posted on: 7/11/2003 2:45 AM by Author "mbiedul" in the forum "ZDZ & RCS Support"
http://www.rcuniverse.com/forum/fb.asp?m=945179

RCS 44cc Twin Fuel Consumption?
Can anyone comment on the expected fuel consumption for the RCS 44cc Gas Twin? I'm framing in a tank aon a Super Cub and could use some pointers on the proper size tank to use. Thanks all. -Mike
Posted on: 7/10/2003 8:54 PM by Author "mbiedul" in the forum "ZDZ & RCS Support"
http://www.rcuniverse.com/forum/fb.asp?m=945177

Help with kill switch options
The British have an association like our IMAA, but for extra big models called the Large Model Association. Their website is [url]http://members.lycos.co.uk/LMASiteUK/[/url] Very intersting stuff. One of their rules, which is tested at every event, is that turning off power to the transmitter should result in the engine shutting down completely. Starting from there, the cut-off for an engine becomes more than the mechanical problem of getting the thumbs on the switch on the model: which may in fact be at 500 feet over the crowd. Not strictly what this thread is about, but I can describe my solution to this with off-the-shelf stuff. I use a HiTec Eclipse 7-channel transmitter. Computer radios aren't for everyone, but this one work well for me in that the throttle movement is set with end points, and an even lower completely closed setting is associated with the throttle "cut" button on the transmitter. Hitting that button, instead of futzing with trim, closes down the butterfly and the engine stops dead, though there is still spark. Same thing can be done of course with throttle trim, but on my Eclipse I do not use throttle trim at all. Where the system becomes "failsafe", is my use of Multiplex receivers. I use the IPS-Mini 9-channel ($90 US from Hobby Horse) Instead of the PCM strategy, which requires a transmitter signal to do anything, you can set the exact servo positions on the Multiplex receiver, that should be actuated when transmitter signal is lost or corrupted. Set this - on the receiver! - for the "cut" position and the engine goes off when the transmitter goes off, and the Large Model Association rules are met. Another option, easily built, would be for the throttle pushrod to also disconnect the circuit to the ignition when travel goes that far (just a couple of strips of brass sheet that push apart would do fine). Anyway, I think the Multiplex receivers have been missed by people in all the hubub about PCM. It's ironic that HiTec has PCM now on the Eclipse, but also owns Multiplex. On these Multiplex receivers, a simple jumper-looking gadget is provided. You get any servo to the point you want it, pull the servo cable out of that channel, and put this jumper in then out, and the receiver is set on that channel. No fancy transmitters required, and really no fancy receiver, and you have a failsafe condition for when the signal is lost or some moron turns onto your frequency. It may be that the default you want in this condition is engine idle I just use this scenario to show how to get to the Large Model Association's rules with no special hardware or additional switches. In fact, the method people use of shutting down with trim on a non-computer transmitter can be emulated with the Multiplex receiver: just trim down before using the jumper. Then just switch off the transmitter and the engine quits. Long-winded. Sorry....I do that.
Posted on: 7/8/2003 10:18 PM by Author "mbiedul" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=931768