Things are really starting to come together with the prop fitted and the cowling not far behind. Adding a power controller to the landing gear pump has smoothed out the gear operation somewhat but there is still room for improvement.
You guys got some big balls, not only building a plane from scratch with many new methods like composites and such and then to put all your trust into this aircraft. I just finished converting a 1986 Chevy K30 Military Truck by installing a 5.3l LS Fuel injected engine and I’m afraid taking it on the Highway and brake down because cause everything is so new and untested. Lol Much Respect!!!
An excellent long term view of the teal T-shirt. I think we got 10 seconds of the spinner at the end though. It really is a beautiful plane coming together.
My computer must have crashed before my comment was entered, so here it goes again, albeit condensed: Prop looks great; the only way to make it better is to add another one and make them counter-rotating! Landing gear problem: Have you ever considered linking the main gear together mechanically with a bell crank/push-pull tie-rod arrangement? It would eliminate the need to balance them hydraulically and could be powered by a single circuit, and adding a single geared DC motor for a backup along with an manual emergency release to utilize a gravity-assist to lower the gear isn't too hard to imagine. You solved the door lock mechanism with such a mechanical arrangement, so I trust this won't be too far-fetched, and would likely be much less of a challenge than balancing two hydraulic circuits. If you strictly use the single electric servo motor approach, you could probably control and integrate it with your mini-computer system (was it a Raspberry Pi or Arduino?).
That’s one mean looking beauty. 5 blade looks stellar. Mt’s are built like tanks. Love it. Can’t wait to fly this thing high altitude aerial mapping work in Canada!
These are great to watch. You are rapidly approaching that well-known point in complex projects like this: you know, "ninety percent done, ninety percent to go" :-)
One idea to solve your gear retraction problem: Put in check choke valves to the non pressurized side of all retraction cylinders. The choke will cause the system to build constant pressure, thus eliminating this stick slip effects you are seeing. It will also take over the retraction speed regulation. Because of the check valve, the gear will extend like normal.
Excellent job, I fly a challenger 604. And on the 604 the gear handle has to be pulled and the moved up as a extra safety precaution, I noticed that it is the other way around in your aircraft. Take care and keep up the excellent work.
The five bladed prop looks so much better than the four. I bet the Performance is also a lot better with the five blade over the four blade. Very impressive cant wait for it to start flying.
I agree with kevc114, another way is to use cylinders with internal snubbers at the end of travel. I enjoy your videos, reminds me of a friend's build of a Cozy 4. Rollie
There are several Lake Amphibians flying with the MT prop. On the 6 cylinder (IO-540) powered Lake Renegade, there have been some instances of blistering on the side of the prop that faces the exhaust. The theory is that the wood used in the core was not 100% dry and the expanding moisture in the presence of hot exhaust pulses leads to delaminating blisters. This is something you will want to watch for during flight test. Also, it’s hard to tell, but it looks like your blades have the black rubber erosion tape at the blade roots. MT calls it “PU tape”. On the Lake Amphib STC, there is an allowance (and recommendation) to remove these LE “boots”. The exhaust heat will eventually soften the adhesive and you might throw a boot in flight (prop imbalance). Now with diesel power (and the turbo), you might not have any of these issues, but I wanted to share my experience with MT props and pusher setups with short exhaust runs.
I’ve been watching you since the beginning getting excited The closer you get to finishing I think you guys been doing a great job I really enjoy watching your progress. Thank you for sharing happy 2019 PS 5 blade looks amazing A lot better than the four blade
Having the gear go up unevenly is pretty common if you look at retractable Lancairs or warbirds. I wouldn't worry about it, you're in good company! ;-)
Idea for gear - would an adjustable pressure regulator close to each of the three actuators help them all work in unison? 5 blade looks great, higher the number of blades the lower the acoustics and the vibration. Great progress, once the big pieces start coming together it gets really exciting, great video.
Your locking pins are the same design as the CMC Leopard that I restored, make sure you have good drainage in the recess , I had no end of problems with locking mechanism because of no drainage. Love the build by the way.
Wonderful progress Peter & team... I am one of many who eagerly await each video update and will be punching the sky when I first see this baby fly. 5 blade prop is a no brainer ..for reasons stated. Looks great... Re Landing gear retraction, I recall a discussion with a hydraulics expert some years ago about keeping a couple of cogs in "sync".. He told me that there were a couple of ways they used, including putting the action hydraulic cylinders in series, thus, by definition, both will work EXACTLY in sync as each moves the same amount as same qty fluid is passed thru each.. The other way was to put a restriction in the line to both, or in this case, all three actions.. Maybe more restriction in the front and a little less in the rear one (but the same in each rear cylinders). That way you could get the timing right, by juggling restrictions, so that all wheels raise and lower together.. obviously the restriction cannot be too small or will interfere with landing gear down... Keep up the great work !
I was going to mention the restrictor but someone (ahem) stole my thunder. A restrictor to the nose gear would slow it's motion down to better match the speed of the main gear and allow more volume to divert to the mains as well. The size of the restrictor would have to be determined. Restrictions to the mains could be needed as well. An accumulator may be necessary to take out the bouncing/jerking motions of extension and retraction and should also ease the motion slamming to the end of travel. As a former A&P who helped build a Velocity I thoroughly enjoy watching the progress in each new video.
There are small, pure mechanical "rotary gear flow dividers" for some $200 that would do the job. They make sure N hydraulic cylinders (with same volume) stay in sync.
Congratulations, you are at last seeing the fruits of all of your labors. Many trials and tribulations have preceded this moment and probably a few more to come as the moment of truth approaches. Now you know how many of the early air pioneers felt.
Imagine the possible upfront options that may become available for us 2nd Generation Deposit Raptor Pilots. Looking forward to Future Raptor fly-ins. Although no problem at all with current configuration, should a 6-passenger, turbo-prop model Raptor ever become an option, we'll be all in for that too.
I am very impressed by the shear will power that you, Jeff, and Devin have to put in the long hours in this project! But please ask Devin to wear safety glasses!
The 5 blasde prop amd spinner in black look great and of course it wil look just like the main picture once flying. Great job guys, looking forward to seeing it all together and the start of the taxi runs - I take it you are going to place multiple cameras on and inside the aircraft for the taxi runs and test flights.
12” prop ground clearance at taxing sounds a little tight. At what angle of attack would the prop make contact with the runway? The rear landing gear look a long way away from the prop. That sweep the field before taking her out. The prop will eat all the stones kicked up from the landing gear.
You should be able to find hydraulic balancing valves where you can meter flow equally (or unequally as necessary) to balance the gear. This may also help with the aggressive finish as the last gear gets 100% of the flow at the very last second.
Awesome. I love it. Lower noise is to me even more important than performance, as landing fees are almost always tied to noise - And they can easy rival fuel cost - especially when considering the proposed milarge of the raptor.
@@HansFranke sorry brother, I love Germany but it's the only place I've ever flown where they dictate specifically how you are allowed to fly your visual approach. Don't want to disturb the neighbors!
@@marcanderson7748 Oh, I don't mind such regulations. After all, Germany is (for most parts) rather dense populated and we need to get along. What's worse is all the buerocracy , mostly geared at making flying next to impossible. Basically a left over from after war regulations to keep Germans grounded. It's geared to keep everything as is, no changed, not improvement whatsoever. Just think of it, publishing a GPS aproach for an airfield is handled (amlost) like establishing a new one - no matter how many decades the airfield is operating or how much a GPS aproach would improve noise levels and security. And then everyone acts as people flying are incredible wealthy. Every fart is associated with fees and restrictions. Sometimes I expect some guy showing up after landing and count my steps until leaving the apron to charge me for each separate - plus tax ofc.
That is gonna be a pretty awesome looking plane when it’s all complete. What kind of paint scheme are gonna put on it? Gotta do something special for being a raptor!
Been watch this series now for at least 3 years now, really coming together and a credit to you and your team. Would an accumulator help smoothing out that landing gear? What I know about engineering could be printed on the back of a postage stamp mind you, just a thought. Just lovin watching a fellow Aussie do some great stuff overseas.
Nice catch on the four blade resonance situation. I can't imagine there are more than a few people who would have thought of that. The prop looks high tech and slick. Very Audi.
Cool! very. I wonder, is the prop variable pitch? like, planetary gears? also, is the surface area, profiles, much different than the 4 blade? I'm thinkin that that five blade has less diameter? (more ground clearance). very cool build.
Hi! What a great build! Does the landing gear have locks? I mean; in passenger jetliners the landing gear lever has 3 positions, from top to bottom: up, off and down. When the gear has been lifted up it locks into place, the pilot can then set the landing gear lever to the Off-position. This way the landing gear system and hoses are not under constant hydraulic pressure, which adds general safety and prolongs the lifetime of the equipment. -edit: typo.
depending on each props pitch, more prop blades generally means more static thrust but less top speed but should definitely be smoother less blades generally means less static thrust but more top speed and normally much more efficient
If not using sequencers the landing gear coming up at different times is a result of stiction. The hydraulic fluid will flow to the gear with the least resistance.
