It looks great!! I am anxious to hear how the MZ202 works out for you. The Tiger Cub uses that engine, and a friend at 8,100' says that he can climb 500'/min with no problem. His TC's weight is 414 lb. He also said he has been up to 11,000'. He lives in southern Colorado, so at 11,000' he would still be flying around some of the peaks!
Power to weight ratio is promising, but of course a lot depends on my prop (http://www.lonesomebuzzards.co.....g+a+propeller/#num24) But I've left some scope to tweak the pitch one way or the other, depending on results. I'm hoping for 1500fpm at my airfield elevation of 1540 feet. At the current pitch of 42" speed should max out at around 85.
Way to go Bruce. Don't let anyone take the pleasure of doing the maiden flight of your own creation! How much pulling force does the engine-prop deliver?
Glad you see it the same way Ricardo! If anyone is going to bend my plane, it will be me
I don't have any suitable scales to measure the static thrust of my setup. But I can say it blew my hat off when I opened the throttle. I don't have a conversion for hat-blowing to horsepower. Or even know how many hats would have to be blown off to give 1500 fpm climb rate. Guess I'll find these things out soon.
With my plane now finished, bar a few fiddly bits involving detail fairings & paint, and safely installed in its permanent hangar at my local airfield, I had by now hoped to be flying.
Sadly, the Powers That Be have decreed otherwise.
WARNING: tediously long post follows, nothing to do with Max's. Those prone to narcopsy should avoid. Large pack of popcorn recommended.
When I moved permanently back to Australia from many years living in UK, I expected to be able to validate or convert my UK pilot licence to an Aussie equivalent fairly easily. The regs say I need 5 hours flying under instruction/supervision in Australia to gain my Recreational Certificate. No problem, I thought, since I haven't flown for a few years I could do with some refresher training.
After my first hour the CFI said he felt confident I would be good to go very soon, & to bring my licence & logbook next time.
Minor irritation at home turned rapidly to major panic when I could not locate either document. I searched more thoroughly, then went through the house - and even my workshop - like a crime scene search team, leaving absolutely no nook or cranny untouched. Nothing found.
Well the loss of my log book really pissed me off, as it is a record of all my flying adventures since 1985, & also shows the various aircraft types I have flown as P1. But nothing to be done about that.
At least I can get a duplicate licence from my friendly UK Civil Aviation authority, thought I. (Oh really?)
I found the relevant info online, & completed my application to CAA & sent it off together with my credit card details for the duplicate issue fee. After a wait of a couple of weeks (I guess designed to remind me of my lack of importance), I was told that they could not issue a replacement licence as my national PPL had been compulsorily converted to an EASA licence - whatever that means. Probably involves new European legislation: most work for our bureaucratic overlords is dictated by Brussels since Great Britain plc surrendered its autonomy to the European Union.
Anyway, the result of this was that to get the EASA document I needed a Class 2 medical from an approved doctor & a Certificate of competence in English language.
OK, if that's what I need, I'll do it. But it was faintly irritating that the paragraph informing me of the need for a language skills ticket contained a glaring grammatical error.
I replied asking for a list of approved doctors & language institutions in Australia to enable me to satisfy these demands. The only reply was one referring me to where these requirements were specified on the CAA website.
So I telephoned the Committee Against Aviation and asked the same question. After a lot of fumbling around & extension hopping, I was told that there are no approved doctors outside of UK, and they could not provide me with a list of organisations who issued language certificates because the Data Protection Act prevented them from doing so. Yes, really! I told the bumbling idiots what they were & hung up.
So basically they have specified a set of hoops through which I must jump, but failed to provide the means for me to do so, unless I take on the 52 hours or so of cattle class crush return flights to UK. Oh, and they debited my card $90 for the privilege of telling me so.
* * * * popcorn break * * * *
I told my CFI the sad story, & said I would just have to start from scratch to get an RAA licence. But being a jolly good chap, he said he would be happy to sign me off if CAA would simply confirm that I did once have a PPL.
So I contacted CAA again, & asked could I just have confirmation of my old licence number & date of issue. And that I felt my 90 bucks at least entitled me to that.
They emailed me back referring me to the appropriate form to complete for 'verification of licence', and said they would refund my initial application fee in a few weeks time.
So as of now I have completed form SRG 1160, and given my credit card details for the payment of the mysteriously reduced fee of $86 that allows them to reply to me with verification of my licence details. Well, actually not me, it has to be a foreign Authority or company they release the info to. But I assume my CFI & his flying school satisfy this requirement. . .
So, until I manage to overcome the enormous inertia of The System, I am flying off my hours in a little Jabiru light plane. It's good fun, and I can only benefit from more training after a good few years away.
Sorry about a long boring post verging on rant. Time for a beer now I've got that off my chest.
OMG Bruce....a Jabiru...really....is nothing like a Max...I have hours in Both.
Will some one let you do some time in a tail wheel...maybe a Lightwing....as I can see the writing on the wall.....you will get your RAA license which WILL be restricted to nose wheel ONLY because your in a Jabiru,and then you WILL have to do your tailwheel endorsement...which will be more $$$$$.
And when you prove you were once a northern skies pilot....isnt the the CFI suppose to sign you off when he thinks your competent....its not necessary to do 5 hours...???.. ...some CFI's just want the $$$$$$ .
and Im guessing the local guy is charging around $150 to $200 an hour..?
Sorry for the attitude as Ive seen a few guys spend heaps of $$$$$ to become legal when safety wasnt the focus ...however the CFI needed the money.
Home phone 602-999-3715/Mini-max with Hirth 2704 Ace
Posts: 755
Time Online: 40 days 13 hours 26 minutes
Damn Bruce, now you have me eating popcorn for breakfast! Good luck and don't ever, ever lose your birth certificate as I'm not sure you could prove you were born! Dick
What a shambles with your license/logbook issue. But I can't make popcorn, because we do not own a microwave oven (I know, soo old school).
I am sure you thought about everything, but did you try to contact your former flying school(s) regarding license copies? Further the UK CAA might have microfilmed some pages of your logbook during the past license renewals.
Just to let you feel a little better, even Switzerland (non EU member) had to adopt the horrid EASA regulations regarding licensing. The EASA headquarters are in Germany (former Holland).
Thanks for all your commiserations, guys. Makes me remember why I appreciate the minimal regulation at our end of the aviation scene.
Arthur, I'll be doing some time on a J3 Cub for my tailwheel endo. Shouldn't be a problem, as I have a few hours P1 on Cubs. And the Jab is all that's available, so it kind of limits the choice on what I fly for hours building, unless I travel 150km to the next nearest airfield with instruction.
Fair point on the birth certificate Dick. Come to think of it, where did I put that now? OMG, I can't remember my name!
Thanks for the suggestions, Reto. I'm hoping my last request will be successful, but if not, I just can't be ar$$ed to keep beating my head against the mighty brick wall of Authority. I'll just do the hours (only need 20) & get an Aussie permit. But can you send me the beer anyway?
Brian, you may yet beat me into the air, way things are going!
To master flight you must first seek to listen. Flight Leader
Posts: 118
Time Online: 21 hours
Amazing work- I'm about to do that aileron closing gap as a retrofit, very thankful it is documented here!- I sure hope the license thing gets cleared up successfully soon. Your an amazing craftsman. I'm running a MZ202 myself on the little bird if I can be of any help, great engine- and never had any problems with getting any parts or help from the factory.
I'm very glad to have another MZ user to talk to. Which aircraft is it installed in? And what diameter & pitch of propellor are you using? Jet sizes? Fuel burn? Altitude & ambient temps at your local field? Any little foibles on the engine that you've come across?
I've found Leon at CRE to be a very easy & useful guy to talk to. And though I haven't flown it yet, so far I really like the MZ202. It has impressive power to weight at quite low rpm. Any feel for how long before major overhaul? (Though at my age this may be of academic interest only).
To master flight you must first seek to listen. Flight Leader
Posts: 118
Time Online: 21 hours
Yes, Leon is very helpful - any prior forum notes about him being difficult has not been my experience. My MZ was previously on my Aeromax. In all honesty it was overpowered, way overpowered I would suggest 50 AP max on that bird. It is being moved to my highly customized Himax build in progress- this is being mounted on floats. I had a powerfin prop of about 54-56" ( I forget the pitch) most of the time it was on the Aeromax. This prop airfoil was VERY fat and the chord of the blade at the root was huge. With rather humid air at about 200-1800 density altitude I could climb about 1000' per minute with a total weight about 744lbs. I wasnt really pushing the angle of attack it could have done more I think. The largest issue is that on the shorter and light airframes of the minimax you REALLY need to watch the Gyroscopic procession and P-factor. Think of a Pitts S1 biplane with a 200HP engine... its kind of like that with the MZ... I quickly learned to only bring in 1/2 to 3/4 throttle until about 30kts or 35. if you just go full power you are going to dive off to the right and likely break something. be sure the engine mount is slightly angled to the left - I would start with 1 degree to 1.5 left and angled down, I would start about 0.5-1 degree down. I am running the 2.55 -1 gear box and ended up with a warp drive of 60" (or is it 61"?) and 13.5 degrees at the angle of the blade ( I have not measured inches of pitch on that but it is set to the RPM) you want a bit lower RPM at static since it will rise in motion. I am set static at about 900rpm below my personal redline limit on the ground as max. My personal redline I recall is 500 below the book redline since I don't need the power and like to baby the engine. I have to look at my documents to check needle size... but I will say, and for everyone with BING 54's you need to be sure you have the new style needle retention clips with the o-ring. But I guess everyone knows that, its a major AD kind of thing. I came from flying larger aircraft so I had a steep learning curve but now feel very comfortable in the Minimax designs. keeping track of your temps! I have an EIS system and highly recommend that or the MGL E1. PM me as needed but I could not be more pleased with the MZ. I ONLY use BlueMAX oil by the way.
Oh man, What a hassle! Sometimes I don't really appreciate how lucky we can be with our local regulations. Just think there's a land where you can just build and fly without being ask at all. (some disadvantages apply )
When deciding on the MZ for my Max I felt it would be more power than was needed. But I went for this engine on the basis that I'd rather have a (relatively) big lazy engine, operating well under maximum power, than a smaller engine working harder. The fact that the MZ is 10 kg lighter than the 503 specified for the Eros was a clincher. With a fairly chunky battery right forward in the nosebowl my CG comes out close to ideal.
I note your comments on P factor & precession. I have mounted the engine with a 1.5 degree angle to the left, though it has no downward deflection. Given the midwing format of the Eros will result in the centre of drag being closer to the thrust line than a HiMax there may be less need for this? But easy enough to do if needed. (And of course your floats will lower the CofD position on the HiMax floatplane.)
My prop is 65" dia & 42" pitch. I deliberately made it with a wide chord from 50% to hub as my calcs showed I really needed a 3 blader as the diameter is limited by ground clearance. But a 3 blader is harder to make. Happily the combination of diameter, pitch, & blade area seems to be about right, giving me 5900 static rpm. I will probably put a temporary stop on the throttle quadrant to limit the rpm to 4700 for early flight trials. This gives a nominal 50hp on the MZ, which is of course the maximum power on the Rotax 503 specified for the Eros. And like you say, limiting the revs in this way should ensure a very understressed & hopefully long lived engine, with correspondingly low fuel consumption.
When you say your blades are set at 13.5 degrees, is that measured at the tip? or 50% chord? I'm just interested to compare with my prop, but I work in pitch so to compare I need to work backwards from your blade angle.
Re the Bing carb needle clips, in my case I went for Mikuni carbs, just because I've always liked these on the bikes I've had. They look to be at least as well engineered as the Bings on my old 503.
I'm using Castrol TTS oil, as that is what leon recommends. But I have heard good things about Bluemax - most seem to use it at 100:1 with no problems.
Living where you do I'm sure floats on your HiMax will greatly improve its usefulness. And I bet it will make for a really fun little bird. I'm looking forward to seeing some pics of a cool little Max in stunning lakeside scenery.
Though to be fair to Australia, my problems are coming from the British Civil Aviation Authority. Which in turn is driven by European requirements that have come about since I gained my ppl 30 years ago.
For aircraft like the MiniMax over here, although we do need a 'licence', it only takes 20 hours (minimum). Which is probably wise for anyone wanting to fly!
With the building, no inspections are required, only a witnessed weight & balance calculation - again, I don't object to that. Provided we are under 300kg MTOW, with a wing loading of <30kg/sq.m (about 6lbs/sq.foot), we can build pretty much anything - even a twin jet, if we can get it light enough!
Yes, Leon is very helpful - any prior forum notes about him being difficult has not been my experience.
I see Leon fairly regularly as his hanger is on the same row as mine. There's a group of Motorheads (powered paragliders) here that he's active with, more so than flying his planes. He's a quite likeable guy, though a bit cocky at times, quite knowledgeable and I always learn something during conversations. One thing worthy of note... He sells his engines in three categories, according to each engine's spec tolerances. The engines with the best specs are generally sold to be used in small helicopters. The rest are for other aviation uses, ultralights, powered paragliders, etc. Ultralights get the middle of the road engines. Don't quote me, but that's the gist I got from a couple of his conversations.
To master flight you must first seek to listen. Flight Leader
Posts: 118
Time Online: 21 hours
They sell the mosquito copters here in FL, they generally run full throttle all the time or very close to it, that speaks to the reliability of the design. The MZ202 is pretty much the best version of that jug/crank combo- but Based on the website I'm sure most of his volume of sales is in the powered para group. I'm installing the engine on my new bird very soon and I'll post some pictures Bruce if it helps you. I'm adapting a Zmax cowl after a lot of reglassing. Should look pretty nice.
I'll be interested to see your MZ installation, PP.
Bit late for me, though! I had to make a cutout in the engine bay floor to allow the fan casing to fit. I made a removable, but sealed, cover for the underside. Also made some ally baffles to inhibit hot air from the exhaust m/f being drawn into the fan intake. Because the carbs are lower than the 503, I made an additional 'power bulge' and used some elbows to suit the cowl supplied. (see pix on this thread, posts 134-5-6). Your own cowl will no doubt be more elegant than mine, since you can design it to suit the MZ.
I would like to make my own cowl one day. The existing arrangement is a pain to take on & off without scratching the paintwork. I might make some access doors for plugs and/or carb boot inspection. I need to do something, otherwise my preflight inspections are either going to be less thorough than they should be, or make for a lot of wear & tear on the cowl & surrounds.
Still on the subject of cooling, this post is related to Reto's in 'Eros in Thailand' and his shroud mods to his Hirth engine.
My MZ engine only has the fan forced draught directed over the cylinder heads. The cylinder barrels are left open, though I suspect the rear barrel gets a bit of airflow from the fan.
Because the cylinder head cooling fins are angled forward at 45 degrees, I made a shroud attached to the engine ducting that had some turning vanes in it. This fits very loosely inside another duct attached to the cowl. This too has turning vanes. You can see these cowl vanes in the first photo. Between the two lots of vanes the airflow is turned 90 degrees, exiting rearwards.
There is also an outlet on the centreline of the cylinder head shroud. Since this is the first thing the air from the centre line cowl bulge intake sees, I made a little duct from the shroud outlet & fed the air back into the ducting described above. See second pic.
As long as the air does what is expected of it, I hope these shrouds & ducts will cool the cylinder heads. But that still leaves the cylinder barrels, & also the heat radiated from the engine - & particularly the exhaust - to be extracted from the engine bay.
There are 5 air intakes moulded into the cowlings for the Eros. But not a single exit air vent, other than a small slot along the lower edge of the nosebowl cowl. So it seems to me there will be very limited airflow through the inlet scoops if this air has nowhere to get out of the engine bay.
So I made a few outlet air cutouts. On the port side, there is an exit space behind my carb housing. Also a slot on the underside of the long lobe of the cowl. See first 2 pix.
On the starboard side, I cut a hole immediately behind the exhaust manifold elbow, where the exhaust is hottest. I hope the air from the starboard 'power bulge' intake will choose to escape partly through this. I also cut a similar slot on the underside of the aft portion of the power bulge lobe. See 3rd & 4th pix.
Since these cutouts are all in areas of low pressure, I hope they will encourage a flow of air through the engine bay to take away excess heat.
But I don't expect to spend much time at high throttle openings. For general pottering around, I don't need more than 4000 rpm tops, & perhaps as low as 3500 rpm, which still gives me 35hp (and presumably lower fuel burn & longer TBO). So with luck, there won't be too much heat to dissipate.
13.5 deg on a 60" dia gives a pitch of 45", and on a 61" dia prop, a pitch of 46", by my calcs.
This compares quite closely with my pitch of 42", so that's encouraging. Your slightly higher pitch should give you somewhere around 88 to 90 mph at an engine rpm of 6000 (since you have the 2.55:1 gearbox). Though this will be affected by the drag of your plane, of course.
When I was designing my prop, my figures showed I needed about a 67" dia prop to absorb 60hp, though in practice I have made mine 65" to give a tad more ground clearance. So your diameter looks like you might be underpropped a bit. Unless you have a 3 blader (my calcs were based on 2 blades), in which case applying the correction factor of 0.933 my book tells me is about right, this would give 62.5" diameter for a 3 blade prop.
So thanks once again. It's good to know the theory looks like it has at least a chance of being in the right ballpark.
To master flight you must first seek to listen. Flight Leader
Posts: 118
Time Online: 21 hours
Yes a little under proper by design, I need the clearance and perhaps a bit less gyroscope when on wheels. I can easily change pitch in about five minutes so we will see how it goes. Three blades would be nice for noise and vibration but a tad harder to balance. Also if you have never done a Dynavibe balance I highly recommend on any prop. Really nice cowl job you have going I hope to finish mine up in the next few weeks - young eagles event this weekend but I'm trying to finish my panel regardless.
Logged
