 Search Results - Recent posts as of less than a minute ago |
11 Pages 1 2 3 4 5 6 7 8 9 10 11 »Showing 1 - 30 (301 results found)
|
|
|
Is the use of the light tail limited to the very lightest of the MiniMAX designs, ie:Is it strong enough to use on a heavier MiniMAX? The light tail is more time intensive to build and wonder if that might have been the reason to go to the now "normal" tail that uses the laminated (solid) leading edge and generally heavier material construction as opposed to the light tail built-up tail spars.
Thanks to anyone who has some idea of the engineering analysis of the light tail's capability to work on heavier planes. I had a copy of the whole engineer analysis for the basic 1100 MiniMAX, but I might have passed it along to the gentleman I sold the plane to.
Personally, I enjoyed building the light tail on my 1st build. Good thing I did too as it still flirted with "tail heavy" with the 277 Rotax I used.
Lynn |
|
|
Thanks for the post. Good point about the wing spar cap size, but I do believe the Ragabond plans call for 1/8" shear web instead of the V-MAX 1.5MM, so that would cancel out some of the weight differences. Reason for being drawn to the V-MAX spars is also because of extending the wing by one bay on each side, plus the higher gross weight I expect compared to the V-MAX. The V-MAX spar design seems to better place material and strength in the right areas.
The Ragabond plans also suggest extending the rear of the fuselage by 20" for "heavier engines" and that would suggest engines heavier than a 503 Rotax. That's one of the problems with the Ragabond plans, there are a lot of blanks that need to be filled in rather than there being any firm directions. There's also probably reason to extend the fuselage length to work with a longer wingspan to maintain rudder and elevator authority, but again by just how much?
I need to continue to study the plans side-by-side but since I'm not an engineer it's still a bit of guessing. I also like the MiniMAX tail construction more than the Ragabond design, so I need to compare square footage of the 2 designs. I just want to be sure I'm not building a 2-place yard dart! I have a couple airplane design books so I may have to try working through some of the calculations. My head hurts already.
Lynn |
|
|
Lynn
the ragabond/pt2s wing spar already looks strong enough.1x3/4 spar cap vs 3/4 sq spar cap for v max.there is a top doubler also for both spars plus wood block packing similiar to v max but 15" vs 30" long.both wings look almost similiar.there is video of ragabond flying with jabiru 2200cc engine so looks like vw2180 should be suitable though probably nose heavy.an engine like viking 90 hp mitsubishi based engine may also be considered. |
|
|
BlueMax....thank you so much for your post. I would have a lot of questions for you but I'll just start out with a couple, and I'll say "Thank You" in advance if you have time to reply.
I still haven't decided 100% that I'm going to pursue building a HiMAX on steroids/V-MAX/Ragabond hybrid plane but I was thinking of using the V-MAX wing spar design, compression and anti-drag rib arrangements but adding one wing bay and also increasing the lengths of the center spar reinforcement members between the spar caps. With a 40" wide fuselage I would end up at a 29' wingspan with no wing tips. Is yours the "normal" 26.5' V-MAX wingspan? Do you know an approximate rate of climb you see? You must have been pretty careful building as 405# empty weight sounds great!
I feel I will have to make a build direction decision soon since I'm at wing rib #17 now, so other building will need to follow soon! My other thought is a 103 legal MiniMAX but using a 2A042 military surplus engine. My first MiniMAX beat the Part 103 weight limit with an empty weight of 246# and I'm sure I have enough weight saving ideas to keep it under 254# again even with the slightly heavier 4-stroke, 2-cylinder engine.
Would you perhaps have any photos of your VW engine and it's mounting? Are you driving the prop off of the VW's flywheel or pulley end? I'm guessing the Slick mag is mounted on the firewall side of the engine? About what is the distance from the firewall to the end of the prop pulley? Did you build your own engine or buy one built from ????
I estimate the plane I have in mind would weigh about 800 - 820# gross weight with 8 to 10 gallons of fuel split between 2 wing tanks, and a total weight of my good friend pilot and me as passenger(co-pilot) at 325-ish pounds. I can see it being for short flights around the area of the base airport and the occasional Saturday morning breakfast run to another nearby airport.
Thanks again for posting the info on your plane!
Lynn |
|
|
I fly a Vmax with a 1600cc VW with slick mag. I weigh 180lbs and my plane weighs 405 empty. She has never felt low on power and will make 90mph wide open in level flight at 3500rpm. I dont think you could go wrong with the 1835 or 1915 but with the 1915 you will definitely have to make sure you dont bust the VNE.
Chris |
|
|
Welcome back Larry! I still log in every month or two and am getting my vmax going again after sitting almost 2 years.
Chris |
|
|
Hey Fabian
The only taildragger time I had when I'd finished building my Eros was a few hours on a J3 Cub. MiniMax's are a lot livlier (squirrely) than a Cub, as they are so much lighter. So this is what I did to get to grips with the art of taildragging.
I'm lucky that my local airfield had both grass & tarmac runways. I practised taxiing on the grass runway for several hours. I started at slow speed, gradually building up to near rotation speed. At low speeds, I kept the tail on the ground, just practising keeping straight. When I had got the hang of slow speed taxiing, at higher speeds I raised the tail, and practised until I could taxi the whole length of the runway with the tail off the ground.
When I was happy I had full control on grass, I repeated the exercise on the asphalt runway. This is much harder, as there isn't as much drag on the tailwheel to keep the plane straight. But it's worth doing as some airfields don't have grass strips.
What you will achieve by spending all this time taxiing is to teach your feet to tap dance on the pedals, learning to anticipate the onset of a groundloop. I found it helpful to wear very light, thin-soled gym shoes, so that I could better feel the pedals. After several runs up & down the airstrip, you should find your responses are much quicker, almost automatic quick little inputs, keeping the nose straight. This in turn will lead to much easier landings later on.
The other purpose of extended ground runs is to fully check out the engine. Hopefully, if there are any problems they will show up while you're still ground testing.
As has been said before, Max's fly beautifully. They are very light on the controls, but respond instantly. You're going to have so much fun in your new aeroplane.
Good luck!
Bruce |
|
|
Good evening,
many thanks for your message, I wrote to John.
All the best
Fabian |
|
|
fabian
long ago i asked john friesen how it flew.he flew kitfox for 4oohrs. he told me it flew fine once in the air but was tricky on the ground.john is not on this group.but he is a nice chap.he might help wth answers. jhnfrsn@yahoo.com.two of his friends groundlooped it who were Citabria pilots.other chap actively flying is chris duncan.he is on weedhopper ultralight facebook group.he is very experienced.another nice chap having flying vmax is rob newall.he has videos on youtube. |
|
|
Dear Minimax Pilots, thank you very much for all the help.
Finally the V-Max is nearly ready, so I wanted to ask for tipps, which are good to know for beginners:
I am flying gliders since 9 years, but am relatively new to motorized planes (except from motorgliders), at the moment I am doing a tailwheel conversion training on a Piper Cub. I kindly ask for any tipps, how the V-Max generally behaves and what is important when flying one during takeoff & landing?
Many thanks in advance and all the best.
Kind regards
Fabian |
|
|
ISTR = I seem to remember
(Sorry - texting shorthand) |
|
|
Plan would be a VW. I'm curious...what is ISTR? No, I haven't flown a Ragwing. I have a couple posts on a Ragwing Facebook group hoping to find a Ragabond builder who can fill in some "blanks" in the plans to build the 2-seat Ragabond vs the 1-seat version.
Lynn |
|
|
That looks to be an interesting aeroplane. Seems like a better bet than the (stillborn?) Epic 2 seater.
I see the little wheel is in the right place. ISTR this caused you some difficulties with your Max. Have you flown a Ragabond?
Will you use the 503 engine, if you can still find them in USA, or go for a VW unit?
Good luck with your project.
Apologies to Tim for piggybacking his thread. |
|
|
I have started on a RagWing Ragabond 2-place. Comparing the RagWing plans to the MiniMAX 1550 V-MAX plans, I plan to borrow the spar construction methods of the 1550 as it seems the spars are more robust than what is called out on the Ragabond plans.
Lynn |
|
|
| Which plane are you building, Lynn? |
|
|
I have not flown a V-MAX but MiniMAX did the engineering years ago, drew and sells plans and kits, so I'd feel safe with the full VW. People have been putting 447 and 503 Rotax engines on MiniMAXs for years and the 503 is basically the same HP as the full VW. I personally would be more comfortable any day behind a direct drive 4-cylinder 4-stroke VW than a 2-cylinder 2-stroke or any engine that required a reduction unit. The big difference in the V-MAX construction to handle more weight and more speed is in the wing spars and design. The fuselage strength on the MiniMAX runs through the entire plane line-up with very few differences between the lightest designs and the heaviest and fastest.
I'm just beginning construction of a 2-place side by side plane similar to a HiMAX. The designer borrowed a lot of MiniMAX methods and materials including basically a copy of the wing rib design. My plan is to use the robust structure of the V-MAX wing spars, compression and anti drag ribs in my build. It's a much more robust spar and wing in general than what the plans call out for in the plans for the plane I'm building. The gross weight of what I'm building is comparable to the V-MAX.
Now....the choice of what HP VW to chose....I'll leave that up to you but the V-MAX specs say 50 HP so I think that would be a very good place to be. In the last few days I looked at Great Plains VW engine kits for self assembly. No disrespect to Scott Casler and Hummel Engines, but if the prices online at Great Plains are current, they are substantially less money, but you do have to assemble the engine.
Best wishes!
Lynn |
|
|
Good to see you back Larry! I usually only check the general discussion section so I just saw your post. To those of you new to MiniMAX Larry is a wealth of information about the planes!
Lynn |
|
|
The current 1030F plans have the light tail drawings. I don't recall for sure, but there might be very slight differences but they might give you the information you want.
Lynn |
|
|
Thanks for the input. That is really interesting! Just out of curiosity, I would like to learn more about that Briggs and Stratton option. Is there a forum or anywhere online that details how to transform those B&S engines you mentioned?
I have seen a few of these flying with a full VW online. When you say these engines are too heavy for these planes, are you referring to ALL the full VW engines I listed? What makes these too heavy? Does it make even the modified V-Max air frame more susceptible to damage or negatively impact the handling characteristics, etc.
I am building the V-Max, not a part 103 ultralight, so it is my understanding the Mini-Max plans, especially the fuselage, are built around accommodating that engine. Are you saying the weight of these engines is too much for the V-Max model, or Ultralight version?
Anyone out there reading this thread that have flown both Mini-Max planes? V-Max and it's lighter smaller engine versions? If so what are your thoughts.
|
|
|
These engines are too heavy for such a small plane.
There are better option on the market, with almost the same power, with half of the VW weight. Furthermore, the work on these engines to make them aeronautical are huge.
Better think about stationary engines, such as B & S, 438cc (single cyl) that is the model I use in my Himax, or the heavier 2 cyl 638cc, which is also a good option.
You just need to remove the RPM governor, instal a 2.5/1 belt reduction, and, if you want to make it safer, a new stronger valve rocker arm, which is readily available in the market.
My engine, complete, with propeller, belt reduction, and silencer, weight only 66 pounds.
Think well! |
|
|
I just got wondering in the last couple days if the 2-place Epic Sport MiniMAX has been completed? I just started on a 1100/1030 MiniMAX, so not wanting to start anything, just wondering if it is up and flying?
Lynn |
|
|
I fitted a 60 -65 hp engine MZ202) to my Eros. I modified the engine mount from the as drawn plans for a Rotax 503, but nothing else. There didn't appear to be any problems in 2 years of flying, and I certainly appreciated the extra power for super short takeoff & a climb rate of over 1000 fpm.
Bruce |
|
|
I am currently building a V-Max and have begun thinking about engine options. I believe the V-Max would typically call for a 1600cc VW engine. However, I am curious if anyone has ever tried anything larger, what considerations come into play and at what size this becomes a problem. The weight penalty from moving up in size seems low, for the most part. From what I gather thus far, the larger concern would be stress on the air frame from a higher HP rating. Curious what other folks experience is with this. including some comparisons below from the Hummel engine website.
From Hummel Engines:
50 HP at 3600 R.P.M. – 4 Cylinders – 140 lbs. (Slick Magneto w/New Case, Hand start 1600 cc) - $5,100.00
60 HP at 3600 R.P.M. – 4 Cylinders – 145 lbs. (Slick Magneto w/New Case, Hand start 1835 cc) - $5,300.00
65 HP at 3600 R.P.M. _ 4 Cylinders _ 145 lbs. (Slick Magneto w/New Case, Hand start 1915 cc - $5,325.00
76 HP at 3600 R.P.M. – 4 Cylinders – 147 lbs. (Slick Magneto w/New Case, Hand start 2180 cc) - $7,200.00
To add a little more to this - I am not trying to build a 'beast' of an aircraft. More likely, I am wondering if a good deal pops up for a 1915cc VW, should I completely avoid it.
|
|
|
| I forget the name of the pilot with apologies but he has a nice vmax with many videos on youtube.its got a 1835cc engine.he sent me the weight/balance chart.maybe you can have a look if its of any value. |
|
|
| I have used these numbers for the range of motion of the control surfaces in my build: |
|
|
| I couldn't fine anything, but it's pretty much set by the aileron yoke and control horns. Should be more up than down aileron. It takes very little movement to roll it over into a turn. |
|
|
I'm pretty sure there's a figure for up and down deflection in the builders manual but I can't find mine right now. If I had to venture a guess I think it's 30* up and 15* down, but that's off the top of my head. I hope I didn't send my builder manual with my 1st MiniMAX when I sold it.
Also, if memory serves a safe number for aileron nose to wing trailing edges is around 3/32" (about .080" to .090" in decimal)
Lynn |
11 Pages 1 2 3 4 5 6 7 8 9 10 11 »Showing 1 - 30 (301 results found)
|
|
