RE: Pitot Tube IAS Airspeed Sensor For Futaba ... Very Cool !!!
I've only had 3-4 flights with the box so far, and reception seemed to be fine. We did not stress it my flying super far-away and did not see any dropouts. So far, so good for both the link to the 18MZ itself and the Robbe box. It was interesting to see a voltage alarm on the main RX battery when setting up for landing .. I am using a smart-fly power expander, so the actual RX voltage is regulated, so I made up a jumper to go from an unused servo port to the aux voltage input of the RX so I could read the "raw" battery voltage. I am using a dual 2300 mah A123 setup. With full flaps I was getting an alarm .. I set the limit to 6.0V .. seems the current flow at full flap extension was enough to drag the system down well below 6V .. this is a LOT of current. Not surprising but very interesting. I am going to see about using on the the current sensors from my RCATS telemetry system to measure current and see how many ma are being drawn. Dave
Posted on: 6/12/2013 8:33 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11541864

RE: Pitot Tube IAS Airspeed Sensor For Futaba ... Very Cool !!!
Steve, correct the Robbe box only reads out in km/hr. I wrote to Emcotec (the dealer I purchased it from) and they confirmed mph not available. They said there may be a software update in August, and it might include the mph setting. Here's hoping that is right! Dave
Posted on: 6/12/2013 6:12 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11541738

RE: Pitot Tube IAS Airspeed Sensor For Futaba ... Very Cool !!!
thanks Andre, as a physicist myself, I learned a long time ago not to argue with physics :-) In the most critical use of the device, to check approach/landing speeds, I suppose that so long as any errors are repeatable, it is acceptable since we'd take the plane up high, put it in landing config (flaps and gear down) and do some stalls to see the reading. For other measurements (e.g. top speed) it's really more of a curiosity. Next step is to experiment with low speed alarms on the TX and find a way not to "arm" the warning until on the air ... so it's not going off while taxiing! Of course the SM VJ is so easy to fly this is hardly needed, but for heavier scale jets, getting this figured out and implemented is a nice safety feature. In fact too fast is almost as bad as too slow if runway is limited. My setup does not indicate any airspeed with the engine spooled up on the ground. For those who know the SM VJ, I put the CB sensor on the "floor" of the fuse under the rear cockpit in an area where there should not be much/any airflow, even with the nosegear doors open. FYI, I used the BVM pitot mount on the side of the fuselage just in front of the cockpit on the left-hand side. Dave
Posted on: 6/10/2013 4:22 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11538750

RE: Pitot Tube IAS Airspeed Sensor For Futaba ... Very Cool !!!
I've been flying the CB pitotstatic airspeed sensor in my Skymaster Viperjet using the Futaba telemetry system in the 18MZ. First flights with the system (the plane was well tested) were down at FIF recently (thanks again guys for a WONDERFUL event!!) Since I had previously used the RCATS system, which has the very nice integral static port on the side of the probe (as someone noted above), I was also wondering about the static reference inside the fuse that the CB device uses. Of course, it's hard to know how to measure "calbirated" airspeed but the readings are sensible .. 1/2 throttle cruise is about 125-130 mph, a little over 160 mph top recorded speed (I don't generally run WOT in level flight). I also have the Powerbox iGyro in the plane and it records the highest GPS-measured speed and it has been within 5 or 10% of the highest recorded pitot speed, which is pretty close given the uncalibrated nature of the pitot system and the variables of head/tailwind. I also have the Robbe accessory telemetry receiver for my spotter (only in km/sec now, does not do mph .. sigh) .. and we've seen pretty repeatable touchdown speeds just under 50 mph. So I think it's a pretty useful too, certainly fun to have in the plane. I wonder if it would be easy to connect a separate static reference CB system .. I do have some of the nicer pitot tubes from RCATS that could be used instead. CB did a nice job of emulating the Futaba GPS sensor, and the setup was very easy, and worked without any trouble. Dave
Posted on: 6/7/2013 5:49 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11536802

RE: JETPOWER 2012 products WOW !
Anyone know what company has the T-2 Buckeye a few posts up? (all in white gelcoat) .. what a nice looking classic jet! Dave
Posted on: 9/15/2012 6:09 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11229161

RE: How to Correct Measured Thrust for Density Altitude?
Remember on Gilligan's island when Gilligan would hear and argument and agree with both sides? I think that Dr. Honda is saying that it's hard to compute thrust for a specific turbine design just from basic parameters like inlet diameter, rpm, etc. That seems reasonable, they are complex beasts and there is so much art in the combustion chamber and NGV to name two that seem a little spooky .. you would not expect to take the mechanical drawings of a model turbine and make an accurate prediction of thrust with hobbyist-level math and computations.. if you had access to supercomputers and hydrodynamics codes as P+W does .. well different story .. but sadly we don't :-( But rctech2k7 (resistor code username? geek! :-) ) is saying that for a given specific engine, you can pretty accurately scale its own performance (not compare to any other) by ratio of density altitude for the two test sessions that are to be compared, e.g. one at done at standard atmosphere, plus any other. Again, pretty sensible to me. I'll bet its close enough for any needs we have. I believe it's what most of the testers actually do but perhaps they will comment. Regarding people's natural fascination with specs .. I have learned over the last several years of climbing the turbine learning curve that small performance differences are insignificant in determining actual utility and enjoyment in our hobby, and what really matters is reliability, predictability of operation, and great service when you need it. Dave
Posted on: 9/12/2012 8:49 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11226839

RE: Air Pressure (Retracts/Doors/Brakes) Telemetry
Hi PP. There is an "off" for the TJ failsafe .. you hold down the button for 1.5 seconds to disable it. Also, if you have a spare voltage input on the JR telemetry system, you can buy sensors that transduce pressure to voltage (in fact there is one inside the TamJets unit) .. you can get them "raw" and wire yourself if you are handy electronically, or buy a unit pre-packaged from one of the other telemetry vendors (e.g. RCAT systems part no 470, $80). Hope this helps Dave McQ
Posted on: 8/27/2012 6:13 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11208348

RE: Futaba 14 question
Peter, Agree, use servo reverse, not hardware reverse. On my 14MZ, I set the slider next to the throttle (it's on the left of the stick) to be the trim for the throttle channel (called J3). You can do that swap on the function menu, on the linkage screen. When inside the function screen, press the trim box next to the "throttle" box .. that brings up the menu where you can use the "Sel H/W" option to select LS. That box will probably be labeled T3, the name of the digital trim that is the default for J3 (throttle). When you do this swap, you have an analog trim, like the JR units do (which I think is a nice feature). Depending on how much difference the Kingtech wants to see from low throttle to off, you may need to increase the trim rate, also available on the function menu. Once in the function menu, press the trim box (which should now say "LS"), I have mine set to -20%. FYI, I have "trim mode" set to ATL and "ATL reverse" set to "Norm" (I believe these are the defaults). Also FYI, my ATV settings for throttle are 100% (on the left/up side) and 82% on the right/down side. This gives almost exactly +/- 100% travel with the full stick and trim motion. You can inspect the setup using the servo monitor menu as a double check before "learning" the ECU. Don't forget to go to the failsafe menu and set the failsafe properly .. simple way is to go again to the linkage screen, then select the Fail Safe menu, on the throttle channel change it from Hold to F/S (failsafe) .. then take the throttle and trim to full down, and press the F/S position button .. that will set the failsafe position turn the turbine off in the event of a failsafe. If you want to get fancy, you can use the ATV to set the failsafe far "below" low throttle which will register as a failsafe command to the ECU, and be displayed as such. Then set the ATV back to the previous position once ATV is set. Most people just set it to to off position (low stick and low trim). Your call. Hope this helps Dave McQ
Posted on: 8/9/2012 8:03 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11187715

RE: Futaba Users, HELP please!
Here is the thread Aussie Bart started to do a review of the PSS2018 for those who would like more info and some user reports: [link=http://www.rcuniverse.com/forum/fb.asp?m=11032674]http://www.rcuniverse.com/forum/fb.asp?m=11032674[/link] Dave
Posted on: 7/2/2012 12:14 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11139470

RE: Futaba Users, HELP please!
+1 on the servo selections, including the BLS ones .. silky smooth! I'd love to see Dreamworks carry the Robbe/Futaba Power distribution system (PSS2018) and its accessories ... it's the "dream date" combination of a powerbox or smart-fly function for redundant power and servo line drivers, plus it takes care of a big objection the jet community would have to the S-BUS stuff, the crummy little skinny wires that they offer on the accessories. Several of us have gotten the unit from Emcotec in Germany and it's a beauty. Competitively priced with the powerbox stuff, and other useful functions as well. I suppose it's a business decision if there would be enough volume to stock it .. and for a large order to do up one plane, the % overhead for the international shipping is not too bad .. but still it would be great to have a local source. While it's designed for S-BUS .. it might be of interest to the JR/Spektrum tribe that it also works with the JR/Spek satellite RXs. I did not realize that the wires coming out of the JR satellites are essentially the still-serial data stream of the digitized channels, essentially the same as S-BUS. Learned that on the thread about the PSS-2018. And, FWIW, Dreamworks rocks .. love doing business with you guys! Dave
Posted on: 7/1/2012 9:49 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11138626

RE: Reaction 54 Jet Kit
Not sure if it helps but I have a Wren 100 (about 22#) on mine .. I replaced a Wren SuperSport (18#) and the difference was quite noticeable .. flew fine with the SS, but LOTS more fun with the 100 .. the airframe takes the power easily and it's a pleasure to fly. I am sure it would be great with the Rabbit too. My plane is 20# dry. Dave
Posted on: 6/28/2012 7:41 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11135874

RE: Wren USA service
The only real problem here is that the Wren motors just work .. and work very well. So if you ever need Ron's help with phone advice or any actual repairs or upgrades, he's the best in the business .. and a very nice guy .. The problem? ... finding other reasons to talk to him! I've got 3 160s and a 100 and love them all. One 160 in a SM Viperjet, one in a Der Jet Cougar, one in a SM T-38. It's sorta funny to look at the big viperjet and the tiny T-38 and note they have the same motor. The 100 is in a Reaction 54. All ProJet ECUs and all kero-start. I get a kick out of the "up-down-up" stick sequence for starting .. reminds me when I learned to ski, but that was down-up-down! Also, I got from a reliable source that it's his birthday later this week .. so HAPPY BIRTHDAY Ron! Dave
Posted on: 6/24/2012 5:32 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11130279

RE: UP4 and Jettronics 2 way valve
Tim, The input to the UP4 is the air signal from one of the gear leg inputs (strut down) from the UP2 (remember the UP2 re-closes the gear doors after the struts go down, it creates a delay with an internal air volume and spool valve .. and the UP4 controls the doors that stay open .. as you stated), but I bet you could make it work with some other form of main gear sequencers .. you might be having to do a little experimentation. I don't see how the UP4 could "know" where the air signal for strut down is coming from. It would be interesting to see if it would work .. I'd bet it would! Let us know if you try it. Dave
Posted on: 6/7/2012 5:27 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11109805

RE: Skymaster T38 Talon
Very nice, and interesting how you have recessed the electronics inside the board. What's under the hatch? Dave
Posted on: 6/4/2012 2:52 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11105527

RE: manual fuel shut off before or after pump?
+1 to Jeremy's post. I put the manual shutoff after the pump, before the "Y" that feeds the two solenoid valves so that the one shutoff valve cuts off all kero feeds. Not sure if this is the absolutely proper technique but it makes sense to me. I see a LOT (most, really) of planes with the shutoff (usually a 6mm Festo ball valve) before the pump...which I've always felt was incorrect, for the reasons Jeremy notes, plus the chance of admitting air with Festos on the suction side (for which they usually work but are not designed). Dave
Posted on: 6/3/2012 8:36 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11104714

RE: 18MZ User Manual....
Jan, I am with you .. I use the right had slider for brakes and it is quite a bit more aggressive ratchet than the 14MZ .. perhaps someone can enlighten us on an adjustment... Dave
Posted on: 6/3/2012 8:30 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11104710

RE: Skymaster T38 Talon
Here is my rudder setup. Dave
Posted on: 6/1/2012 3:14 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11102994

RE: Skymaster T38 Talon
Philjac, Very very nice work! great idea on the nosegear .. I mounted the servo in the nose, but your setup as waaay nicer. Agree with the cockpit comments, yours came out great! Dave
Posted on: 6/1/2012 6:07 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11102282

RE: Skymaster T38 Talon
Hi Guys, I have a SM T-38 almost done, some iphone pics attached here, if it's helpful I can take some better ones later and post. My son is down at USAF flight training at Sheppard AFB, just finishing with T-6 IIs and about to start flying T-38s, so of course I had to have one! SM offers the gray on gray camo scheme that the Sheppard birds use, so I had Matt take some pics of the planes on the ramp, and SM did the tail art and numbers to match one of them. I am hoping the camo scheme won't disappear in flight (but as a friend likes to tell me, "that's the point, dummy!"). The build has been pretty straightforward, I did have a small issue fitting a full-size servo into the aileron pocket as noted above, there is a tiny bulge in the top wing skin that bugs me a little but no so much that I am going to put a smaller servo in! One thing that I am still thinking about how to deal with is the fit of the stabilizers in their bearings. As-supplied the brass "axles" had a fairly rough finish and had to be slightly reduced in size to get the bearings to fit. I did this as carefully as I could but once the bearings went on, there is a tiny amount of slop that I am not really happy with. Considering some green locktite (which I believe is intended for this purpose), and I've read here on RCU that some people used thick CA in the gap (and presumably making stab install permanent!). Also wondering if the miniscule slop is actually ok. My only other similar install was in a Yellow F-18, where the axles are machined titanium and the fit to the bearings was dead-perfect. My current plan for power is a Wren 160, which will call for some prudent throttle management! I was just doing the final equipment install with an eye on the CG, doing battery placement etc. With the 160 sitting in the motor mounts, she weighed 27# with all the tanks and UAT dry. I thought about using a smaller motor to get a slightly lighter plane and perhaps longer flight time .. but the next increment down for me would be a Wren 100, about 22# and I think the pipe inlet is too big (3.5") and the bifurcation would steal too much power, and who wants an under-powered T-38. I've had some conversation with folks who have flown these, and they report that the T-38 flies very well, and actually does not land crazy-fast .. it's scary just looking at the (teeny tiny) wings, but it's clear that the fuselage probably has more "wing area" than the wing! Dave McQ
Posted on: 6/1/2012 5:18 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11102223

RE: Airworld Hawker Hunter, anybody got one?
Hi Shaz, Jorge Escalona had one of the Airworld Hunters at the First in Flight jet rally last weekend. You can often find Jorge here (Jorge*jet is is ID) ... I am sure he'd give you his view of the plane. I always liked the Hunter, it has beautiful lines. Dave
Posted on: 5/31/2012 1:43 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11100870

RE: Powerbox iGyro
Yes, it's cool, even better "in the flesh" than I expected. Reading the manual for it, I did not realize that the Spektrum satellites output was the demodulated serial data stream, just like S-Bus .. so it makes sense it can take Futaba or Spek satellites as inputs. Learn something new every day... I think I'll have to give Brother Gearhardt a call to get an iGyro! Hope to see you this summer at some of the events... Andrew .. let us know how the iGyro works for you. Dave
Posted on: 5/21/2012 8:17 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11089770

RE: Powerbox iGyro
Dave, Do you know if the Robbe/Futaba S-BUS PSS-2018 "powerbox" (see: [link=http://shop.rc-electronic.com/e-vendo.php?shop=k_emcotec_e&SessionId=&a=article&ProdNr=RF1660&t=861&c=1786&p=1786]http://shop.rc-electronic.com/e-vendo.php?shop=k_emcotec_e&SessionId=&a=article&ProdNr=RF1660&t=861&c=1786&p=1786[/link] ..they call it a "power supply" ) might acutally be OEM'd from the Powerbox guys? I note that while marketed toward Futaba users, the unit also can attach JR/Spek-style satellite receivers. I recently got one shipped over from Emcotec and it's quite nice but does have a bit of the PB look and feel. Nice unit, btw. Thanks for the info on the iGyro .. cool device! Dave
Posted on: 5/14/2012 3:49 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11079965

RE: FUTABA 18MZ HAS ARRIVED
maybe not so many experts on SBUS yet! :-) Glad it's working. Dave
Posted on: 5/12/2012 11:02 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11078701

RE: FUTABA 18MZ HAS ARRIVED
So it was the filtered extensions not the JR servos. Interesting. I suppose that the bit rate of signals going down the wire in SBUS is much faster than a standard servo cable .. perhaps the filters were being to aggressive and wiping out the higher frequency waveform. Was the extension (when it was causing the problem) between the RX and the SBD-1 or between the SBD-1 and the Servo? thanks Dave
Posted on: 5/12/2012 9:38 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11078660

RE: To my customers
Best wishes for a fast recovery for your daughters ... you have lots of friends thinking good thoughts to help! Dave McQ
Posted on: 5/11/2012 7:09 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11077544

RE: P200SX Intermittent Flame Outs
If you consider engine stopping with a LOW RPM message and no white vapor trail, logic would say the fuel supply was interrupted. As suggested above, it could be the pump stopping (bad pump, bad wire connection, bad sensor somewhere causing ECU to stop pump), or it could be the solenoid valve closing in an un-commanded way. I've seen several reports of solenoid valves doing this, though never from a JetCat user .. but it is something to consider if all else strikes out. The thought was that the solenoid valve got hot after being energized (open = "on"), and that heat caused the valve to momentarily close. One report was from a modeler who suspected this, and took the valve out of the plane and set it up on his bench with a power supply .. and after 10 mins it started periodically clicking closed. Again, this is probably low odds, and perhaps the JetCat valves don't have this problem .. but if you eliminate all the other causes and don't find anything .. think about this. Dave
Posted on: 5/3/2012 1:02 PM by Author "ww2birds" in the forum "JetCat Turbine Direct Support"
http://www.rcuniverse.com/forum/fb.asp?m=11067087

RE: Post your mid-size install pics
My Yellow F-15 (now, sadly, deceased...). From the Yellow F-15 ARF assembly thread. [link=http://www.rcuniverse.com/forum/fb.asp?m=8533533]http://www.rcuniverse.com/forum/fb.asp?m=8533533[/link] Dave
Posted on: 4/15/2012 7:14 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11042601

RE: Futaba - Robbe - S Bus
I have the Robbe PSS 2018 on the way from Emcotec .. thanks so much Bart for showing us the way! The SM T-38 I am finishing up now will have the stock S-Bus gear in it, I'll put the Robbe setup in one of my larger planes. Here's hoping I got the order right and have the right parts coming! Dave
Posted on: 4/14/2012 5:17 AM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11041326

RE: F9F COUGAR, AIRWORLD OR SKYMASTER?
Bruno, Just to be extra clear .. Please note that in my posts I am only suggesting you have eyes open, not trying to say don't buy from them. In fact I admitted I might do so myself "some day" ! As far as I know "finished" meant "we are not changing it" .. I did not take it to mean "we are discontinuing it". I believe they still offer the Cougar and Panther .. you can check Vogelsang's website... Maybe I got up on the wrong side of the bed this morning... but gosh it's hard to bring up unpleasant facts about the "cult" companies :-) And, while it's great to hear so many reports of good flying (and VERY attractive) planes, it's the attitude of the company that was my point .. and I don't see anyone defending that. Dave
Posted on: 4/13/2012 2:05 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11040568

RE: F9F COUGAR, AIRWORLD OR SKYMASTER?
Hi John, nice to hear from you and hope all's well. I've also enjoyed watching you fly your Cougar many times. I certainly agree AW makes beautiful planes and noted that in my post, and I am happy that many people are successful with them. I was not, and I only reported incidents that happened to me personally, were documented, or where I spoke to the pilots myself. One of the AW reps witnessed my Panther's demise and asked for the empennage to do some failure analysis, which led to the comments from AW HQ that were related to me by one of their reps. Note that AW did not deny the issue, in fact they acknowledged it, and stated they would do nothing. So it's not speculation (we have enough of that) ..but it is a small sample. Again, just restating what I said in my first post. I did not mean to rev up the AW fan club and was trying to be fair and acknowledge the good things too .. just thought this sort of information deserved some airtime for someone considering a purchase .. since the risk of failure can be addressed so easily. BTW I had a 160 motor in mine if anyone thinks it was somehow an overpower issue .. and the flutter occurred at about half throttle on a descending pass. And, if you can even imagine this, I loved that darned Panther so much I might someday overcome my distaste with the company's attitude and maybe get another one now that I know what needs to be addressed to fill in for the engineering shortcomings of the company. Their F9Fs are not a lot bigger than the SM planes (the Cougar or Panther) but it's enough that the presence is noticeably different. Dave
Posted on: 4/13/2012 12:48 PM by Author "ww2birds" in the forum "RC Jets"
http://www.rcuniverse.com/forum/fb.asp?m=11040503