RickH

hey Facthunyer Certainly there is the hp difference but RPM are similar BMW 7000max Rotax 6800max max torque on both at 5500 given that prop dia is relative to prop speed Ibelieve I can compensate, @ 2.54 reduction, propspeed for BM is 2755max for 503 2577max not that much diff. If I choose a diamater to suit the BM ie shorter of two then surely a re pitching of the prop would be all that is required. why I tend to think of this is the varying Dia of props I see reported as being used on both of these engines ie from 56 thru to 60 on both of them or am I missing something. RickH

Hi to All I am in the finishing stages of building a mid wing version of a Texas Parasol (I gues you'd call it a Texas Midwing) . I have both a BMW R90S Engine (67hp) fitted with a Rotax B type Gearbox and a Rotax 503 (50hp) also B gearbox, due to Finances I am going to mount the 503 initially and will fit the BMW when I have finished its overhall. I don't really want to be buying a new prop when I finally fit the BMW. My thinking is to try to source a prop which can be used on both with a change in pitch. I figure 58" or 60" diameter. Does anybody out there who has experience with either engine have some views on this proposal. I would like to hear. Regards RickH

Water Jet cutting is achieved by pressurising(60,000 p.s.i.) a fine jet of water usually about 0.7mm diameter. A super fine abrasive powder (Garnet being just one of a range of products used) is introduced to the jet stream just prior to the cutting nozzle. These machines are CNC controlled and are extremely accurate perfect for aircraft part manufacture, no heat affected zone or distortion as mentioned above. I had all of the ribs for my aircraft Water Jet cut prior to forming to shape. Most of these machines will cut anything except toughened glass and Tungsten and up to about 100 mm - 125 mm thickness. I sandwiched my rib material into a stack of 26 pieces each 0.8mm thickness total thickness about 21 mm, took about 20 minutes to cut the lot, saved me days of work. Highly recommended. RickH

Hey Pud Should be no need to change the re-drive G\box I have a 503 with "B" type box, 2.58:1 ratio, runs a 58" prop. You would need to look at the pitch tho and this would be set in accordance your climb, cruise performance requirements and is no big secret as to how to determine. Talk to one of the suppliers and they will have charts which can be a very useful guide. RickH

hey Ozzie I don't know a lot about camares but I have an old Fuji 5000 digital slr 12 times optical zoom and 6 megapixels. A mate of mine at the time had a you beaut cannon cost him a packet more than mine we both took a pic of a piece of fruit hanging high in the rainforest. his showed the fruit, mine showed it much more clearly, he was a bit dissapointed in his camera after that. The cannon was 10 mega pixels and 10 times optical zoom so in my opinion what you want is megapixels, opticalzoom and probably the type of lens has alot to do with choice, not necessarialy price. Others may care to comment on this I would be very interested to hear.

Yeah mate. Is 95 the actual hp. as I was under the impression that BM claimed 100 for that engine

Hey fly tornado the BM I used is an R90S bmw claims max 67hp my thinking is that stock standard probably more like 64hp May get 67 with double plugging annd a port and polish RickH

PS there is also another military term that seems your above comment did and that is DROP SHORT RickH

[removed] Heon. Your comment about not being able to build a four stroker for less than $40,000 is pure BS as Bubbleboy pointed out. I have Built a four stroke (BMW powered) Aluminium truss framed Texas Parasol which to date has cost less than $10,000 and no I haven't left something out and although I have not yet completed the wings I do have in stock all material needed. This is the last part of the aircraft requiring completion and unless paint has gone crazy pricewise in the last week or so I can't see this costing me $30,000. [removed] And no it's not a broom stick with a lawn mower engine, I guess that makes me and a lot of other builders out ther pretty bloody good hey. Or is the reason for your opinion that you are a supplier and simply want to suppy aircraft and discourage home building. Regards RickH Some comments removed to keep the peace - Mod

PS. Wing tip losses being applicable to only the outer 5-10% RickH

Hey Maj I understand what you are saying and agree with what you say re wing tip losses but if we look at airfoil theory ie infinitely long wing and constant chord and thickness then the lift distribution and hence resulting loads are distributed evenly. or am I missing something. RickH

Hey Guys I agree prety much with everything Maj has said I would like however to ask one question and make one point. Question. if we assume that wingloading ie x lbs/sqft spread over the entire wing, why then would you taperoff the weight toward the wing tips. After all as facthunter pointed out the greatest shear and bending moments are at the wing root, however this does not translate to greatest weight being concentrated toward the root of the wing? Now to digress a little the point I would like to make, when it comes to the actual test is that if you really want to know what is happening to the structure during testing then you realy must be able to measure the total deflection under load (inorder to calculate stress and hence strain) and the absolute safest way to do this is to apply strain gauges to the top and bottom surfaces of the spar. You may think that this is getting a little technical but better to be technical and alive than technically dead. Regards RickH

For anyone really wishing to truely understand the issues of heat affected zone cracking and its various causes I suggest you visit www.deltaschoolloftrades.com they have a very good publication on the subject, there are also several other sites out there that have some very good info. RickH

Hey Dave, No offence meant, Just that all to often on these forums people post well intentioned but inaccurate material(sometimes dangerous), example the idea of wrapping the crack as suggested by the "reputable Repco Rep". RickH

A lot of the carbon fibre prop manufacturers recommend against the "5min" type epoxies. Regards RickH

Hey Dave I suggest you do a whole lot more research on HAZ cracking, I would be glad to instruct you further but the subject is just to involved to go into on this forum.

Hey Guys definitely DO NOT wrap the crack as mentioned above you can be almost certain that this is a result of Heat affected Zone cracking, if this a genuine Rotax exhaust it is probably manufactured from 4130 or similar and these metals are susceptable to work hardening, annealing the whole thing may be a solution but I strongly recommend against wraping. RickH

Good on you Dexter Starti and others you guys are obviously on to it I unlocked my mates Navman MY50T the other day and we took it for a fly around the Mossman Daintree area this morning needless to say he is now a convert. RickH

This is for those of you who want an extremely user friendly and relatively cheap GPS unit that gives you all of the functionality of some of the more expensive units. Some time ago I purchased a Navman S80 GPS unit. I initially approached Navman about Aviation applications for the unit and in short they did not want to know anything about it. After some searching I found links to an application called MIO Pocket(it's completely free), these links are available on the Pajero 4wd club of Victoria site. The application is free however it does rely on OziExplorer for map conversions etc. OziExplorer CE is the program needed for the Navman to readmaps and give GPS functionality to MIO Pocket OziCE cost me about $40.00 the Navman cost about $260.00 from memory. If you Have a Navman I would highly recommend this upgrade as MIO Pocket turns it into a hand held computer. Give it a go I think you will be more than pleased with it. RickH P.S. and before you ask, no I am not in any way associated with any of the above mentioned organisations I just like to help out my fellow flying friends.

there are many and varied types of foam available I'm not familiar with the type you mention but one which is certainly worth a look is a product called multi panel not cheap tho.

Gps Thanks Dexter I'll Have another look. RickH

Thanks Heaps Rong pocket Fms sounds like the go. Thanks to Dexter but too much info I specifically was looking for info on the NAVMAN. Regards RickH

does anyone out ther have any information on aviation maping programs for thS80 navman GPS. RickH

Hey OME Check out the Stits manual couple of very good methods for rib stitching including one that alows you to end up with the Knot in side the the wing under the fabric all you end up wih on the surface are the cross over threads. Regards RickH . [ATTACH]12837.vB[/ATTACH]

Hey Doug seems like your trying to re-invent the wheel(in this case control surface) and causing a lot of unnecessary work into the bargain. Attached is a photo of the control surface frames for my Texas Parasol (mine is a mid wing) Regards RickH[ATTACH]12836.vB[/ATTACH]