RE: How do I remove con-rod from crank shaft on my Saito 125??
[quote]ORIGINAL: beachbrada And for all the Cool Power haters, 90% of the people I fly with use Cool Power, unless Horizon calls me and says that the engine failure was due to my fuel Im not switching so you're wasting your time with your Chevy vs Ford posts. And please dont reply saying that Im over-reacting because Im not, this thread wasnt intended for fuel wars. [/quote] The difference between a poor oil and a good oil often only becomes apparent under exceptional circumstances. Good oil is like insurance if you're lucky, you don't need it. If you're not lucky, you'll be glad you've got it.
Posted on: 3/23/2009 7:34 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8608971

RE: How do I remove con-rod from crank shaft on my Saito 125??
Gosh Ed, you must have pretty lousy consumer protection laws over there. Here, unless the dismantling/re-assembly of the engine had clearly caused damage, a supplier couldn't duck their obligation by using that excuse.
Posted on: 3/23/2009 4:26 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8608274

RE: New Hitec Aurora 9-Channel 2.4Ghz Radio System
[quote]ORIGINAL: MikeMayberry XJet- The 2.4ghz system has been extensively tested for over a year now in Korea and a few months in the USA along side all major brands. We are very confident in the technology.[/quote] Good news Mike, I look forward to [link=http://rcmodelreviews.com]Reviewing it[/link] when it hits the stores.
Posted on: 3/19/2009 6:54 PM by Author "XJet" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=8595242

RE: New Hitec Aurora 9-Channel 2.4Ghz Radio System
Mike, it sounds like a great product but can you tell is whether it's had more testing than the Optic 6 did before it was released? Almost all the major manufacturers have had serious problems with their 2.4GHz systems and Hitec's record of software/hardware "issues" on new releases is far from perfect. Has this been taken into account when devising and implementing a testing regime for this system? How long has it been in *actual use* by testers (ie: regularly flown in a wide variety of models and environments) prior to release?
Posted on: 3/19/2009 3:12 PM by Author "XJet" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=8594625

RE: Does anyone remember Aero Pack International's "G-pack" foam?
I remember "G Pad" foam that was touted as the best thing since sliced bread for protecting your radio gear. Exactly the same stuff is now used to make ground-pads for camping. It's a closed-cell foam available in different colors and thicknesses. It used to cost big-money to buy G-Pad but now I can buy a whole ground-pad for $10 and that's about a 6'x3' sheet of 3/8" or 1/2" foam. What surprises me most is how many folks just use velcro or even cable-ties to secure their receivers to the airframe - with no padding at all. I've yet to damage a receiver in a crash, even after some 45 years of RC flying. I put that down to the excessive use of foam padding (oh, and amazing flying skills yeah right! :-))
Posted on: 3/18/2009 1:54 PM by Author "XJet" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=8590942

RE: Saito 115 cam lubrication
[quote]ORIGINAL: DarZeelon Let's go to full-size... In an older, mechanical, flat-tappet SB Chevy engine, one would expect to replace the cam and lifters at overhaul, i.e. after at least 100,000 miles... Let us see how long this is in hours... supposing a ~30 mph average speed, the number of hours is over 3,000. A model four-stroke spins on average 3 times faster than that full-size SB, so each hour is like 3 full-size hours. So, it would be reasonable to expect the Saito/OS to last 1,000 hours, before cam and/or lifter replacement becomes necessary...[/quote] It's not quite as simple as that Dar (and I think you know that :-)) The lubrication system in an auto-engine is far more sophisticated than simply throwing some oil in with the fuel, as is the case with our model engines. What's more, the kind of oil used in an auto engine is far more suited to things like the cam/lifter interface than are the oils we use in our model engines. The addition of EPAs (extreme pressure additives) to motor oils make a huge difference to the wear-rates in areas such as the cam/lifter interface but we don't have those additives in our model oils, because they'd contaminate the glowplug and cause other issues involving unwanted deposits and combustion side-effects. However, I would certainly expect a cam/lifter set to last well over 100 hours of normal use in a model engine and I'm sure that many do. I think my most-used Saito (an FA100) has probably 20 hours on it now and the cam/lifter area shows signs of polishing but no perceptible wear albeit I have been using the manual-assist lubrication routine ever since new.
Posted on: 3/18/2009 3:51 AM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8589859

Long-EZ 46 and Bobcat 52???
Since I've been fitting pulsejets to the Long-EZ .46 and the .50-sized Bobcats, lots of people have been asking me where they can buy these ARFs in the USA but NitroPlanes seems to be out of stock. Will these ARFs be restocked and if so when? Pulsejet on a Long-EZ? Here's what I'm talking about: http://www.youtube.com/watch?v=qmbnzCV4vUc
Posted on: 3/16/2009 9:12 PM by Author "XJet" in the forum "NitroModels Support"
http://www.rcuniverse.com/forum/fb.asp?m=8585426

RE: Nitro models pusher Bobcat?
Is the factory that makes the bobcats even still in business? Since I started making pulsejets for these ARFs (and the Long-EZ), all supply of them seems to have dried up so now I'm looking for new airframes. I'm wondering if they might have been the product of one of the growing number of Chinese ARF-makers that have ceased trading in recent months.
Posted on: 3/16/2009 8:56 PM by Author "XJet" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=8585352

RE: What prop to use on a S.T. G90 ?
A 14x6 will give you good vertical and quick acceleration on take-off but a 13x8 will give you a *slightly* higher top-speed. It's also worth trying a MAS 13x6 Scimitar, these have worked *very* well for me on the G90. Also, if you want a really nice prop-noise, the MAS K-series 14x6 or 13x8 will give you that at the sacrifice of some performance. Sounds great though :-)
Posted on: 3/16/2009 3:34 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8584188

RE: 2 dead Saito's in a row
[quote]ORIGINAL: mike109 G'day Thanks for the update. I too love my Saitos but I don't like the way Hobby Headquarters works. They will not sell parts direct to the user, they will only deal through their dealers and my local hobby shop does not like dealing with them so I find it hard to get parts. I am yet to find a reliable source of supply for Saito parts in Oz.[/quote] I get my Saito parts from the USA via friends who are happy to buy them and post them off to me here in NZ.
Posted on: 3/16/2009 3:43 AM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8582621

RE: why are OS Type F glow plugs so expensive?
[quote]ORIGINAL: N2ECW If you're bored and want to do something different, try the HP .49VT engine. It sounds different insofar as it creates gear noise in addition to the usual four-stroke exhaust noise and it runs very well.[/quote] I have an HP .21VT and it's a real darling of an engine. Quieter than any of the electrics at our field but not what you'd call "powerful". It'll swing a 9x6 at around 9,500rpm which isn't too bad I guess until you take its weight into account. Still, it's just the engine for a little parasol-winged monoplane or short-nosed WWI biplane. And it runs for months on the smell of a (castor)oily rag.
Posted on: 3/13/2009 3:14 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8574350

RE: servo pulling power
[quote]ORIGINAL: airservices G'day guys been a ex retired ag-mustering pilot why do I hear so much about the pounds of pull required by servos to move a control surface If I had to pull x amount of pounds every time I pulled back on the stick of a a/c I reckon I would be tuckered out within a couple of hours and have arms like popeye[/quote] You confuse force with torque. The torque is measured in oz-inches so a typical hi-torque servo might have (say) 160 oz/in of torque. 160oz is 10lbs but that's the force the servo exerts at a distance of 1 inch from the shaft-center. Now look at the control stick on a full-sized aircraft (of a type that has a stick).... The stick itself will likely be at least 20 inches long so, to create the same toque as your RC servo (10lbs at 1 inch) you'd only have to apply 1/20th of that actual force at 20 inches ie: 8oz or a mere 1/2lb. As others have stated, modern RC models are grossly overpowered compared to their full-sized counterparts and many types have incredibly large control surfaces with little aerodynamic balancing and no mass-balancing. This means that high torque levels are required for safe operation.
Posted on: 3/13/2009 3:10 PM by Author "XJet" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=8574342

RE: Tapered-Bore Engine Break-in - Upgraded
Remember that although engineers design and build engines, it's probably *not* an engineer that writes the manual. This means that even companies such as OS are open to mistakes. It's much cheaper to recycle parts of last year's manual (for a ringed engine in a steel bore) when creating a document to go with this year's ABN engine hence we end up with the *wrong* information being disseminated. Even OS has to keep an eye on costs and it would appear that in the case cited by Dar, that's probably why the manufacturer's manual is so very wrong in some respects. Remember OS is the company that bought you peeling liners (because their engineers didn't understand the electroless nickel-plating process they were using) the FL70, and 4-strokes with peeling camshafts. They are not infallible and I think the break-in procedure outlined in the manual is further proof of that fact.
Posted on: 3/12/2009 2:52 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8570708

RE: Hobbyking or Hobby city 2.4ghz questions
[quote]ORIGINAL: 86waterpumper I'd be content to just get mine to bind let alone cross pollinating with other brands etc [&:] But that is cool someone is reviewing it. [/quote] Review is now up: [link=http://www.rcmodelreviews.com/hobbykingrc.shtml]Hobby King 2.4GHz RC system[/link]
Posted on: 3/11/2009 11:50 PM by Author "XJet" in the forum "RC Radios, Transmitters, Receivers, Servos, gyros"
http://www.rcuniverse.com/forum/fb.asp?m=8569114

RE: Anybody have a Thunder Tiger .61?
Do you want a GP61 prop driver. I've got one I'm not using. PM me with your address and I'll pop it in the mail if you like. ____________ When I'm not here I'm at [link=http://rcmodelreviews.com]RCModelReviews[/link]
Posted on: 3/10/2009 1:42 AM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8562033

RE: why are OS Type F glow plugs so expensive?
[quote]ORIGINAL: controlliner Order them from here. http://www.greathobbies.com/productinfo/?prod_id=FOX4702 The fox miracle plug is just like the type F and it is only $7.99 canadian. They are a bit hot but the idle is fine, I use them in my FS engines. [/quote] I've used the Fox Miracle plug and found it to be a false economy. An OS-F (and in 2-strokes an OS#8) will last quite literally for years of flying. The Fox plugs only lasted about six months before the catalytic effect dropped off noticeably (RPM drop when removing plug-lead). They're okay for a cheap standby but if you want a plug that works *and lasts* then the OS (as expensive as they might be) are more economical in the long run.
Posted on: 3/9/2009 3:22 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8559819

RE: About to give up on RCU
But it doesn't say the sig is locked just "offline for database management". I would have thought that they would at least have the good grace to be honest if they believe I've infringed the rules. And what's the point of removing my edit permissions???
Posted on: 3/5/2009 4:08 PM by Author "XJet" in the forum "Forum questions or problems"
http://www.rcuniverse.com/forum/fb.asp?m=8547147

RE: About to give up on RCU
This time?
Posted on: 3/5/2009 3:20 AM by Author "XJet" in the forum "Forum questions or problems"
http://www.rcuniverse.com/forum/fb.asp?m=8545685

RE: About to give up on RCU
And now I see that the pictures (screen captures) which should have been uploaded do not appear. Sigh!
Posted on: 3/5/2009 3:16 AM by Author "XJet" in the forum "Forum questions or problems"
http://www.rcuniverse.com/forum/fb.asp?m=8545683

About to give up on RCU
I've had run-ins with moderators regarding my wish to be honest and forthright in respect to certain products of dubious performance here on RCU but that's fine. However, what's really annoying me now are the following issues: I can not edit (or even upload) a .sig because for several months all I see is a message that tells me signature editing is currently offline due to database management for THREE MONTHS??? I also can't upload an avatar because that option is permanently grayed out on the settings screen. I also find that I'm prohibited from editing my own messages and instead, I'm told that the feature is disabled or that I don't have sufficient permission. Since I joined RCU I've made over 3,800 postings, almost all of which are in response to the problems that others might be having. I try to be supportive and help other modelers when my skill and experience can be of benefit to them. However, I also call a spade a spade (which seems to upset the mods now and then). So, are the issues I raise (above, with images provided) just RCU's way of telling be to go away or what?
Posted on: 3/5/2009 3:15 AM by Author "XJet" in the forum "Forum questions or problems"
http://www.rcuniverse.com/forum/fb.asp?m=8545682

RE: How hot does 4 stroke exhaust get?
I meant to say that zinc expands at a 50% faster rate than aluminum
Posted on: 3/4/2009 10:11 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8543834

RE: How hot does 4 stroke exhaust get?
[quote]ORIGINAL: dakotanut If it is running lean then it will be hot. Rich and exhaust temps will be lower but not much. I can't see that brazing coming off at that temp. It takes a lot more heat than that to braze. [/quote] Actually, many of the low-temp aluminum brazing alloys do lose a *lot* of strength at temps as low as 500deg F. But, often just as important is the fact that many of these brazing alloys have a very high percentage of zinc. When heated, zinc expands at a 50% faster rate than zinc so every time the muffler heats and cools, enormous sheer-stresses are created along the braze-line where the two metals meet. After a number of heating/cooling cycles, the aluminum around that area will begin to crystalize and fracture due to the metal fatigue that results. This is why I'm *not* a fan of brazing mufflers. TIG welding is the most long-lived way to do the job but it takes longer, requires more expensive equipment and a skilled operator to achieve a good job.
Posted on: 3/4/2009 4:37 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8543828

RE: TT .46 Pro Failure
When a friend of mine suffered a similar failure with his TT46Pro we found that the piston did have some scoring (but the liner was fine). I got him to run it really hard with a brew of fuel containing 20% castor. By running it very hot and hard for a couple of tanks full of that fuel, the scores were filled with castor varnish and a full piston seal restored. He then switched back to his normal fuel. That engine is still going strong nearly two years later turning a 12x4 prop at around 14,000 RPMs which is damned good for a .46-sized engine.
Posted on: 3/4/2009 2:32 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8543485

RE: Is Cool Power cool fuel?
[quote]ORIGINAL: RappyPilot I am keen on possibly substituting a small % (Maybe a 20% castor and 80% synth) of Klots with Castor making a castor/synthetic blend.[/quote] Just buy their "Super Techniplate" oil, it has the castor already in it.
Posted on: 3/3/2009 2:43 PM by Author "XJet" in the forum "RC Fuels"
http://www.rcuniverse.com/forum/fb.asp?m=8539840

RE: Is Cool Power cool fuel?
Morgans make great claims for their anti-corrosion additives but the reality is that PAG and ester-based synthetics don't provide good protection against rust. Anyone using a pure synthetic is well advised to either add a couple of percent of castor to their brew or use some form of after-run protection to guard against corrosion. I prefer the castor approach myself since I usually fly until late and can't be relied on to engage in an ARO routine with any regularity. The problem with creating a good anti-corrosion additive is that in order to work, it has to increase the pH of the residue left in the engine crankcase. A low pH (acid) is what kicks off the rusting process. Unfortunately, aluminum tends to be corroded by anything with a high pH (alkaline) so it's a delicate balancing act between trying to neutralize the acid byproducts of corrosion and avoiding corrosion of the aluminum. Castor seems to work as an anti-corrosion additive because it's a polar molecule which is (in effect) attracted to the steel components of the engine and becomes a protective layer (probably displacing the more acidic synthetic lube which then sits atop the castor on steel surfaces). Castor won't completely solve corrosion problems in all cases. If you run hi-nitro or live in a particularly humid climate, or one where the ambient temperature regularly drops below dew-point, then you will probably need to take additional measures for long-term storage. However, a little castor can go a long way towards reducing the effects of corrosion on the steel parts in your engine in my experience that is.
Posted on: 3/3/2009 3:09 AM by Author "XJet" in the forum "RC Fuels"
http://www.rcuniverse.com/forum/fb.asp?m=8538332

RE: TT .46 Pro Failure
[quote]ORIGINAL: vicman Yep, W8 is spot on. Heat doesn't do much good if you don't get just the case hot and [b]quickly[/b]. Otherwise everything just gets hot and you don't get the full benefiet of expanding one component while the other is still small/cool. [/quote] That is especially true of the crankcase/liner fit where the expansion rates of the materials are much closer than for steel/aluminum as with the bearings.
Posted on: 3/2/2009 8:31 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8537206

RE: TT .46 Pro Failure
[quote]ORIGINAL: ScienceisCool The pinch happens about halfway through the stroke. I'm thinking about taking the sleeve back out and checking it for any damage or dents. It was pretty difficult getting it out, had to heat it up, get it started with some needlenose pliers and then knock it out with a hammer and screwdriver (somewhat carefully). The lip at the top is chipped up but the actual sleeve is unharmed. [/quote] Gasp! That's *NOT* the way to remove a liner :-( If it won't come out by hand then using pliers is a recipe for disaster. The liner is only made of brass and can be relatively easily distorted by any compressive force or excessive side-load during the removal process. If your liner has become ovaled, that could explain the tightness. Generally speaking, if the liner won't come out without resorting to tools then there's probably a bur on one of the ports that's catching in the crankcase casting (I've seen this happen only rarely but fragments of broken bearing *do* sometimes cause such burring). The solution in such cases is to find where the burr is and grind it away very carefully. You'll note in my videos that I only use a lollipop stick and a gloved hand to remove the liner. That's really all it should take.
Posted on: 3/2/2009 2:59 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8536061

RE: Saito 115 cam lubrication
[quote]ORIGINAL: mandtra I have a almost mew Saito 1.80 with less than 2 gallons of Coolpower 15% ran in it . and it just started making a funny metallic noise and when i took the engine apart. the cam area ws bone dry, and and damaged by a lack of lube.[/quote] I don't want to start a religious war but I wouldn't run any of my engines on Coolpower and expect them to last a long time, especially a Saito. Coolpower's PAG synthetic oil has neither the highest film-strength nor the best viscosity index and its ability to hold corrosion at bay (despite the manufacturer's claims) is wishful thinking at best. The Coolpower mantra seems to be "quantity can make up for quality" which is not true if you're only getting tiny amounts of oil through to a critical area like the cambox. If there are only trace-amounts able to reach the cam/lifter interface then you need to be sure it's the best damned oil that money can buy. And using more oil in 4-stroke fuel achieves very little as they seem to establish an equilibrium in the crankcase and once that nominal volume of oil is reached, any excess is blown out the breather. So, if the nominal level is (say) 3ml, then if you run 20% oil as opposed to 10%, all it means is that twice as much will be blown out of the engine. The actual amount of oil doing any good remains exactly the same. Also, all Saitos benefit immensely from the use of around 2% castor in the fuel they're fed. This small amount does a great job of reducing camshaft/lifter wear and protecting against corrosion *without* causing carbon buildup on the valves or cylinder/piston-crown. One of the benefits of castor is that it is polar and therefore tends to wet-out the metal parts of an engine more effectively than a PAG-based synth. The blend of synth and a trace of castor however, offers the best of both worlds providing the capillary action of a low-viscosity lube with the tenatious "stickiness of castor. [quote]When I called Horizon. THey said the cam area has to be MANUALLY LUBED . well I checked my manual and I cant find that anywhere in the manual.[/quote] They are dead right but as you point out, they don't actually tell you about the need to manually lube the cambox area so therefore they are still liable for the warranty repairs. I expect we'll see a change to Saito's engines pretty soon which will result in the breather nipple being placed on the side of the cambox itself. That'll ensure that oil is forced to where it's actually needed most.
Posted on: 3/1/2009 4:37 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8532531

RE: Klotz kl100 4-stroke mix at 5%
But DownUnder, remember also that (unlike the methanol) the oil will not vaporize so you'll actually have more incompressible material in the cylinder/chamber so upping the oil percentage will also effectively raise the CR by a small amount. I must work out the *actual* amount that it's raised one day. I suspect it's too small to make much difference but it could go part way to explaining why the big SuperTigres run *really* bad on hi-oil fuel blends. They knock, rattle and kick when you try to use 20% oil in them and the manufacturer recommends 12%. Maybe going to 20% effectively raises the CR so much that they become overcompressed? I can't think of any other reason why these (big Supertigre, ie: > 23cc) engines run so badly on hi-oil fuels.
Posted on: 3/1/2009 2:35 PM by Author "XJet" in the forum "RC Fuels"
http://www.rcuniverse.com/forum/fb.asp?m=8532119

RE: How hot does 4 stroke exhaust get?
[quote]ORIGINAL: Cherokee Flyer Find a welder that will do AL and have them fix it; that is what I have had to do with all mine. L. [/quote] Been there, done that. The problem is that those "brazed" mufflers have the joins contaminated with that nasty hi-zinc welding material. As soon as you throw a TIG torch on it the zinc boils and contaminates the tungsten. Even if you grind it right back it's still a pig of a job. I can see why they use brazing instead of true welding (it's cheap and even an idiot can produce a job that looks reasonably good) but I think it's pushing the limits of this low-melting-point stuff for a 4-stroke exhaust. 4-stroke engines seem to have a hotter exhaust than 2-stroke engines, probably because there's more complete combustion and there's no cooling from the inclusion of some intake charge (unburnt fuel) as you get with a 2-stroke. Most of the cheap brazed mufflers that come with these Chinese gas engines also seem to fail pretty quickly once exposed to the heat and vibration produced by a bit of regular use. It looks as if the brazed area develops cracks from vibration because the material is too thin and the modulus of elasticity and coefficient of thermal expansion of the aluminum is drastically different to that of the brazing material. This causes metal fatigue just beside the braze-line eventually creating cracks and ultimately, total failure.
Posted on: 2/28/2009 1:29 PM by Author "XJet" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8528296