Lynn Erickson

use a hole dupilcator, you drill the hole on the top sheet while aligned to the hole on the underside http://www.aircraftspruce.com/catalog/topages/holeduplicators.phpCan be made out of two old hacksaw blades bolted together

Who said anything about single seater A closer look at the picture reveals the copilot sleeping while going 200 KTS.

Bill Ortel's O-320 powered varieze going 200 KTS. does not seem that the little extra weight is hurting him any. if you want a volkswagen use a 0-200, if you want a turbo porsche use a O-320

I welcome you to fill me in with your first hand knowledge of that plane and its condition when we bought it. I could have forgotten some of the problems we had with this gear as there were so many. maybe with your vast knowledge, building and flight experience of canard aircraft with retracts you should start your own thread. then we all will benefit from your trouble shooting ability on this troublesome and un-tested product.

Waiter , just a thought, check the inner tube for cracks or if it is flexing it may have been the reason the pin broke. if the strut outer tube is allowed to rotate then there would be a twisting load on the pin. we believe that may have been why one of ours failed. it was only a few flights after our pin failed that the cracked inner tube was discovered. Interesting how after you had this failure, all the different fixes for other problems with this gear have come to light. everyone that we have talked to that has this gear has had different problems. I think I have heard a failure story about every part in the system now. the "L" bracket flexing, thats a new one I have not heard of before. hopefully the new models will have all these issues resolved, if there is ever a new model that gets delivered to a customer, maybe we will know. does anyone even own and fly this mystery new model gear? has any one even seen this new improved model? or is it still 5 year from delivery and why was it the old models needed to be improved? I thought they all were working just fine and did not need any improvements.

sounds like you may have to much pitch. try flying level at about 5000 ft. put it in a slight dive and let the speed build up then slowly come back to level and see what speed it will hold. on the small engines it is sometimes hard to get up to top speed when flying level. what is the top static RPM you can get? you should be getting 2300 to 2500 static RPM. Does the plane have wheel pants installed and what size tires, these can make a big difference on a O-200 varieze. did you remember to retract the nose gear ?the taper pins are on longer available. the one you made should be fine. if you make the pin out of 4130 or similar steel you will tear the wings off long before you will shear those pins.

the bolts that most are using are purchased from an aircraft supplier and are commonly known as AN bolts. it is a common term that could include many types of special bolts all of which would have a AN number which has been superseded by an MS number (Mill spec). the common AN bolt that most supplier have is a bolt that is made of 8740 steel centerless ground shank, rolled threads, cad plated, 125,000 psi tensile. hex head. may be drilled at on end or the other or both. comes in 1/8" increments with only a short section of threads on the end. there are many other types of AN or ms bolts all of which have there own specs for a special purpose. in our type of aircraft we use the common AN bolts in most applications unless the plans call for a special type AN bolt. I would suggest you get a catalog from Aircraft Spruce or Wicks aircraft so you can see the most common types of bolts that are readily available to the homebuilt aircraft builders.

using accident data to determine the strength of a part is not a valid way to to do this. we have no idea of the loads on the pins while there were loads on some of the parts high enough to remove the gear assemblies from the aircraft. the pins in the aircraft during the accident were not stock pins and no they did not bend.

yes it is and the pins that were that broken are pins that were replaced after the tubes were rewelded, the pins removed and inspected by the factory. so I guess the pins are strong enough to be used to remove an aircraft from a pond just not strong enough for landing loads while using the aircraft flight.

the pin that connects the link to the arm that is welded to the gear leg. yours are welded ? a pin bent on a landing when the arm came loose at the glue joint to the tube. the tube twisted and caused the pin to bend. the original pins where replaced after the gear was welded by JD to the factory type and then during a landing the pin broke about half way through and bent. the break started at the roll pin hole. it was replaced with a fine thread bolt and a short castle nut with cotter pin. Bill had two sets of strut tubes and these pins where a problem on more then one occasion.

I hope JD has solved this problem but why would he if he is in denial that it has even been a problem. if he has changed it on the new models, thats great, but why would he make a change if you knows there is not a problem. post # 15, bottom of page http://www.canardzone.com/forum/showthread.php?t=6268&highlight=infinity+gear

So, Glad to see you are all right. sorry to see what happened. I had been hoping that you had modified every thing necessary to keep those gear flying. I am sure you will come up with a good way to modify the link so that won't happen again. This pin has failed before on other aircraft and has been reported about on this forum but if one does not do a good search they may not have known that this was a potential problem. There should be a thread where all the mods done to this type of gear could be documented but not debated. all the facts in one place that are easy to find. this would be in the interest of safety with just the facts from first hand experience with the method of repair or modification employed.

there would have to be someone flying the factories gear for there to be an accident involving one. everyone that that is flying with gear has had to modify it to be able to fly it. there is no factory stock gear flying so I guess someone is hearing me.

maybe not, but if I can only save one life it will be worth it. and you know I will keep trying

but if you can see the value of the information why can't the manufacture?is it because he considers the value of his product to be the same as you consider the worth of the information. of course the information will have a lot more value to all the buyers if they ever get any of the gear that they paid for.

not having a dyno, I have done some ground testing using max static RPM to compare the different exhaust systems with a club prop to get to 2700 RPM on the ground. we have installed a few on aircraft that had flown with the 4:4 but to do this you need the boat tail to run the new exhaust. the results in all testing did show an improvement in performance. my best guess at this time is that 50% of the gains are from the exhaust. when I first built my system it had the springs, and slip joints on the primary tube flanges and a ball joint between the collector and the megaphone. during the testing phase the only problems I had with keeping the exhaust system working was the springs, slip joints and the ball joint so I eliminated the problem areas by welding every thing solid and no more problems for 300 hours. I have also made a few 4:4 systems without the springs and they have not cracked either. I believe that the builders that have gone to the springs is because they were having problems with the flange to tube joint cracking. on my systems I use two doubler plates on the flange joint to spread the load on the joint to a larger area of the pipe. This is the same way it is done on many Cessna and production aircraft and the don't use springs either.

there lies the problem. your are not the only one with no experience with that gear. but you have has much experience as the manufacturer.

Surprised me too but the more we cut off the better the performance. the one in the pictures is for a O-235 and with the low RPM engine it is very hard to get much gain from the collector. the O-235 uses 1.75" outlets and they are to big for the engine so in this case most of the gain is from having a system that exits the exhaust in the most aerodynamic way possible. dissipating the exhaust into the low press near the prop hub is also far better then exiting into the high press bow wave of the prop blades at mid blade span. the systems on the IO-360s work a bit different and have a different collector. they are tuned better to the engine and seem to give the best performance up in the higher RPM range 2900 to 3000 RPM and the engine comes to life. most of us do not fly much in that range so the collector is tuned a bit different and it is a trade off of getting more HP and making the engine run smooth with leaner fuel settings. If a Lycoming would run up to 18,000 RPM then the exhaust system would look very much like an F1 system. that would be cool. at least mine sounds a lot more like a F1 car then the standard straight pipes which sound a lot like a John Deere most of the resent work I have done is to keep the HP and get better mileage. have you seen the price of fuel?

when it comes to heat and stainless its not the number of hours its the number of heat cycles. the same thing is used for jet engines. every time you heat and cool a piece of stainless you work harden it the same as if you bend it back and forth. hot parts should be changed after so many cycles not by hours. turbo exhaust put a lot more stress on the stainless because of the elevated temps and the pressure in the pipe. the fit of the pipe has a lot to do with how long they last. if you put a load on the pipe and then heat and cool it the number of service cycles decreases. this is one reason why the same pipe on two different aircraft will crack on one and others will not. rate of temperature change also has an effect on the number of cycles. Homebuilts average 100 hours a year so thats 20 years if you use the 2000 TBO for an exhaust system. I don't have a TBO or number of service cycles on my exhaust systems. these systems are experimental as are ALL the other parts on any homebuilt and need to be inspected far more often then any production aircraft. if one of my systems does develop a crack it will need to be fixed or replaced , some day one will crack, thats what happens to all exhaust systems when they exceed a certain number of service cycles. and so the exhaust portion of our flying experiments, continues on.

Maybe a little back ground will help answer some of the questions. first I started with the fact that my plane was going to need an exhaust system for my IO-360C1C6. then the fact that 4 into 1 exhausts do increase HP. the canards have a very draggy cowling caused by the quick turn up of the lower cowling. the cowling needs a boat tail to reduce the drag caused by the detached air flow. I built a boat tail with the correct curves and because the prop is there I cut off the tail end of the boat tail leaving the boat tail open and used it for the exhaust outlet. this eliminates the draggy stock exhaust outlets. the first exhaust I built is a true equal length 4 into one. length is within 1/8". tube volumes where checked and found to be within 1 CC of each other. I tested all the different types of reverse cones and megaphones we could think of and found all of them decreased the HP some. I tested the engine with the 6" long test pipes the same type that Lycoming uses to rate the HP on their engines. and tested the 18" straight pipes that are used on most canards and found them to decrease the HP when compared to the 6" test pipes. the 18" pipes would decrease the static RPM by 100 RPM. as for the short collector, it is not really as short as it seems. the pipes in my design come together a bit different the typical automotive type. the pipes are formed to come closer together in the center which makes for better scavenging with out the use of the fire cone seen in some systems. the fire cones have been known to crack loose and depart the aircraft, and that would not be good for a pusher prop. also you have a big vacuum source just in front of the exhaust outlet. The systems I have built ( in the photos)for the 0235 and 0320 engines are not true equal length as the carb is on the bottom and gets in the way. I have built a couple that are equal length and they do perform a bit better but do cost a lot more to build. some of the best testing was done on a O-320 power varieze which was running the stock exhaust. with the change to a true equal length and the cowling changes to add the boat tail the top speed went from 185 Kts to just over 200 KTs. as for the no springs and slip joints and they might crack, well I am still waiting for one to crack so I can fix it. with the pipes welded together the whole system is very strong and there is no loose end to shake and cause a crack. A vareze that crashed landed and ripped the main gear off had all the weight of the aircraft sitting on the exhaust system and all it did is bent the collector flat on the bottom but no cracks.

Jerry. have you taken any pressure differential readings? the manometer does not lie. you need at least 4" WC of differential pressure to cool a lycoming. making changes on theory is a waste of time. I have seen many plenum designs that work and most of the time it is the duct and inlet design that is the problem. if the duct is to long or to small the inlet can't let the air in and the backed up air makes like a fence for the air to go around the inlet. a short duct is like an orifice and pressure drop is small but if the duct is long and has bends, it will use up all the available pressure before it can get to the engine. every 90 degree bend is like adding ten feet of duct

I have been making the 4 into one exhaust for ez's for ten years. we have seen gains of about 10 to 15%in HP. the biggest gain is in the ability to lean further with the engine still running smooth. the splitter as you call it is the way the end of the pipes come together which is simpler and lighter then the way the car guys do it with all the same gains. the plane shown with the oil cooler is a customers varieze with an O-235 and I believe the knob you are referring to is the primer knob.

A few more that I built.

Something like these?