doxilia

My Feedback: (3)

I agree, it's possible that Don might not go for a 32 size model what with all the 60 size designs he has now made molds of. However, if you find interest in folks here who might want one, then it might be doable. You could drum up the buyers and then see if Don would take it on for a given number of sales up front.

The complexity is not so much an issue for Don, it's the cost of materials and time to make the mold. The nice thing about this fuse is that it is finless so that makes it more compact and easier (lower cost) to ship. Alternatively, the fin could be built, installed with an eagle eye and then the mold could be made of the fuse and fin. But maybe this is not possible due to the location of the stab.

That's pretty good. I guess it is a 42" fuse without a fin. 55" fuses with fins weigh 16-20 oz. An 8 oz fuse would be ideal for a sub 4 lb model.

Sure, it's meant to be fast but also smooth and graceful. 45's and 50's carry 5-7 lb models so I can't really see a sub 4 lb model with a 42" fuse and 49" wing having a 45 shoehorned in there. IMO, the wing just doesn't have the squares to carry 5 lbs or more in a classic pattern style. What are the root and tip chords of the wing? I have a glass/foam Blue Angel kit with practically identical specs. The model is designed to fly with a 25. I plan to put a piped 25-32 in it with retracts.

Note that if the model is built to sub 4 lbs, you can use light 5 oz trike etracts on it. Either way, I'd build a very light core wing, stab and fin and see how she turns out weight wise. You can always build a wood fuse if you want to preserve this one. I'm fairly confident that you could wind up with a finished 2 lb airframe - painted fuse/fin and covered flying surfaces.

How much do they weigh?

doxilia

My Feedback: (3)

I just weighed some 25-32 size engines:
[ul][*] Norvel 25 with muffler = 231g[*] OS 25 VF RE wo/ header = 233g[*] OS 32 F SE wo/ muffler = 250g[*] OS 32 SX SE wo/ muffler = 274g
[/ul]
I have a Webra 25, 28 and 32 to check as well as a current OS 25AX which will likely compare to the 32SX.

Tops, the model could be powered with a muffled standard and light 40 like an OS LA or perhaps a Norvel which are very light and excellent. The thing is, a piped 32 is just much cooler...[8D]

David

Quikturn

My Feedback: (12)

The fuse is 38" long as measured.

The root cord is 10 1/2", tip cord is 6", length is 24". By my calculations total wing area is about 400sq. in. less ailerons and tips. Stab root is 5 1/4", stab tip is 2 3/4", area is approx. 77sq. in.

OK, a light just went off. I kept asking myself why you keep harping on a sub 4lb airplane so I did some math. Correct me as necessary.

400sq. in = 2.78sq. ft

A 4lb airplane has wing loading of 23oz/sq. ft.
At 4 1/2lbs, 25.9oz/sq. ft.
At 5 1/4lbs, 30.2oz/sq. ft.

looking at a sport plane like an Ultra Sport 40 shows a wing loading of 24oz/sq. ft. Given this, I would definitely want to be at 4 1/2lbs or less.
So what would be a good wing load range for a good flying model? There must be a balance. I think if it's too light it wouldn't handle wind well.

A YS45 is 14.1 oz and a Magnum Pro 45 is 11.6 oz (329g) w/o muffler.
An OS 32SX is 9.5 oz but the Magnum 45 would have about 50% more power.

Like I said before, the Magnum 45 is an OS 45FSR copy. The 40/45FSR engines are the same size and they are slightly smaller than a 46FX and about 1 1/2 oz less weight.

doxilia

My Feedback: (3)

QT,

Now we're on the same page.

I'm not sure why the designer had a 50 size engine spec'd for this lil bird but built to the specs on the plan you'd end up with a 48" span model with a 30 oz/sq ft loading. If you simply want a go fast jet like plane, then by all means, but this plane won't land - it will just hit the runway at speed.

IMO this is a squarely 25 size model (e.g., a Tweedy Bird) and with 400 squares (I came up with ~396) you ideally want to aim for under 20 oz/sq ft. At that loading it will fly nicely which means that you are really targeting a ~38 oz finished model. This allows ~18 oz for engine and radio for an AUW of 56 oz. In other words, a sub 10 oz engine/muffler/pipe combo. A piped 28-32 would do nicely but I'd go for an engine with a regular carb unlike the OS SX.

The Magnums seem to be excellent engines! Do they have a 25 or 35?

Does the 46 put out 1.8 horses spec!? Strong engine! I know the 60's are.

BTW, I'd be interested in fuse/cores if you find other interested parties. Is the wing planform really that tapered along the TE? The LE looks practically straight - unusual.

Would you be able to take some CU pictures of the plans?

David

PS An ultra sport 40 probably has on the order of 550 squares so it is just fine at up to 5.5 lbs.

doxilia

My Feedback: (3)

It looks like Magnum used to have a 28 XL and a 36 XLS. 10.8 and 12 oz with muffler, respectively. I'm not sure if they are still available but it appears that the 25 XLS is. Buyers claim better performance than an OS 25 FX.

Not bad for $70 at Hobby People!

At $75 an OS 46LA is 9.6 oz sans muffler and has about the same performance of a 32 SX (1.2 PS @ 15K).

At 8.1 oz the Norvel 25 with muffler is pretty amazing too. I'd drop the muffler and put a 2 oz pipe on it at under 10 oz for power.

Check out nvengines.com

David

Quikturn

My Feedback: (12)

David,

I was just looking at 25-35 size engines that I would like.

I found a NIB Webra Speed 32GT on RCG but Stevster snagged it while I was looking at it. Damn! That would have been the perfect engine I think. Lighter and more powerful than the 32SX!

I'm guessing the Magnum 45 puts out around 1.4 to 1.5 hp. The 32SX is rated at around 1 hp.


Yes, the wing planform is as pictured. There is a slight sweep to the wing but not as noticeable as the taper on the trailing edge. Ailerons are not shown and are not cut out like on other foam core wings.
Perhaps a mod could be to oversize the ailerons to add more wing area?

I won't build this anytime soon so if there is interest in fuse cores I think it would be nice to preserve this kit.

I'll post close ups of the plans for you tomorrow.

Joe

5skyhawk172

The mach 8 was designed by Joe Utasi.  I used to fly with him in the early '70s Fort Wayne Flying Circuits.  I think he lives in Cincinnati now.  I have a Mach 1 in the basement that I am going to restore someday.  Best flying pattern plane I ever flew.  Keith  AMA 50764.  You can tell how old I am by the AMA number!  and by the way i flew it with a PROLINE

Quikturn

My Feedback: (12)

Ok, I uploaded some more pictures of the plans. Hope this helps.

Question on sheeting the wings and stab. The leading edge is very sharp. Do you sheet this with one piece of balsa? If so, how do you make the bend w/o breaking the sheet of balsa?


The Webra Speed 32GT is the engine of choice. 8.81 oz sans muffler and 1.22 PS (1.1HP?) If I can only find one now.

The OS 32SX is 9.53 oz, 1.2hp @ 18k.

The OS 32F abc is 8.3 oz, 1.02hp @ 16k.

The OS 40FP is 8.75 oz, 1hp @ 15k.

There are 2 new 40FPs listed right now at reasonable prices and I have an opportunity to buy an almost new (1 1/2 tanks) 32F abc engine.

I think I prefer the 32F abc because it's the lightest and I don't like bushing engines. I had a OS Max H40 on a Kobra I built and it leaked oily goo out of the front hub during storage, yuk.


Skyhawk, do you know Joe? Is he the home solar consultant? I wonder why the Mach 8 isn't more common? I saw someone posted a Mach F which is also 40 size.

5skyhawk172

Quikturn, yes thats him. Haven't talked to him in probably 30 years. I used to have a mach 8, I used a super tiger 46 in it and proline radio. Sorry to say it's no longer with us. But the mach 1 is. I have a super tiger blue head 60, and I am going to upgrade my old proline and hopefully fly it again someday.

Regards,
Keith

catracer343

Wow, that is sharp! If it were me, I would sheet the wing first, then carefully sand back the leading edge of the core 1/4" and glue on a piece of 1/4" or 3/8"balsa square stock and plane it and sand to the original core/airfoil shape. This will allow you to sand the sheeting down to a bare minimum if needed and still keep good strength in the leading edge. Good luck with the build! I have a brandy spankin' new original Mach I in the box that I'm planning on building next winter. Definitely one of the sexiest pattern ships of all time!

Quikturn

My Feedback: (12)

Skyhawk, you had one of these Mach 8's with the fiberglass fuse? Do you recall how much it weighed? How did it fly with the ST46?

I weighed a couple Super Tigers I have. An ST GS40 is 12.9 oz and a ST 49 Sport is 12.0 oz w/o muffler.

Catracer, that sounds like a good way to deal with the leading edge. I guess time will tell if a wing can be sheeted with one continuous piece.

Man, you guys with your awesome looking Mach 1 kits. I'm gonna have to find one too someday.

Right now I have a NIB Tiger Tail, a Phoenix 6 fuselage pretty soon and a Phoenix 8 with a pumped Enya 60X and Hatori pipe that will be ready this spring.

doxilia

My Feedback: (3)

Joe,

what catracer said. But are the cores cut with a flat front or a sharp LE? Either way, it works out best to have a balsa LE from a construction standpoint. So sheet, then cut back and sand. It is also easier to fix a ding in a piece of balsa than in a sheeted foam LE section. Use the lightest 1/16" contest balsa and laminating epoxy for sheeting or some good 1/32". I'd go 1/32" - everything about this design tells me it ought to be 3.5 lbs but back in the day everything was built much heavier...

If you make a sketch of the wing and stab core planform with dimensions and trace the root and tip airfoils, I can draw up a set of CAD plans them. Something like the drawing below which is in progress (this one is framed up of course).

You will like the 32F's - true ABC engines. I can't pass them up, just picked up another recently. The Webra's with TN2 carbs are nice too although I haven't run one yet. I hear that they can tend to spit fuel a bit but I'm not sure if this is a carb issue or a front end design issue. I have a 32 with a Dynamix carb and a 25 with a TN2. I plan to test them with each carb. The TN2 is probably easier to set and might transition nicely. The Dynamix probably has more top end power - it has a larger throat. The 32F's are a good solid engine though.

Thanks for the pics of the plans. I'll take a look at them in more detail during the day.

David.

doxilia

My Feedback: (3)

Joe,

Some glass/foam kits had cores with produced rounded LE's. The Phoenix kits were among them - see Crankpin's build threads. The cores would be sheeted with contact cement by wrapping the sheeting around the rounded LE. This is easier to do with very thin HW veneer than balsa but if the balsa is pre-molded by several wetting, wrapping, wetting cycles, then it can be done with balsa too.

In the end, with a sharp LE like that, it will be easier to use a piece of 3/8" balsa to produce the LE. Sheet the top and bottom of the cores with two separate "planforms" of sheeting. If you want to be detailed about it, you can keep the grain parallel to the LE back to about 2-3" from the TE at which point you switch the grain to parallel to the TE. Otherwise, if you want to keep it simple, I'd recommend keeping the grain parallel to the LE all the way. I'd also recommend marking centerlines on your cores everywhere: root, tip, LE and TE. And, of course, if you use retracts (5 oz electrics are just the ticket for this weight class), do that work on the cores before sheeting. It can be done afterward but its a little cleaner if you do it beforehand.

Man, with that LE, this ship was not meant to fly Mach 1 - more like Mach 8! [X(]

Just some suggestions.

David.

5skyhawk172

Quikturn yes it glass about 5.5 lbs  flew great

jet22b

catracer343
Looking at the date that is on the sale slip, you have a 37 year old kit on your hands!!! You are so lucky!! Looking at the price we paid for this kit back in the 70's, take my back to the good old days. Good luck on the build and please keep us updated.
Sonny
aka
jet22b

catracer343

Will do Sonny! Pretty cool having an airplane that's a year older than me, but sad to see how many people today refuse to build and preserve these classic birds! I picked this up at a local auction 2 years ago for a measly $60.00! My biggest decision is going to be powering it. I'm all for finding the perfect "era" motor, like a Webra speed 61 for it, but I'm also torn over the possibility of using a new lightweight powerhouse motor like the O.S. .55AX... I just recently purchased a K&B .61, (still in the shrink wrap!) and I'd like to send it out to Clarance to do his magic on it, then possibly use it on either my Miniflite "Cutlass Supreme MKII" , or my Airtronics "Acrostar" bipe. It's tough being me lately!

doxilia

My Feedback: (3)

Say Catracer, is your avatar a bipe?

Nice model!

David.

Quikturn

My Feedback: (12)

Guys, I almost snagged a Mach 1 on RCG but was second in line. Missed it by that much (Maxwell Smart)! Oh well, there are more out there.

Doxilia, I'll have to set up a bigger work area to make a sketch but I did take some pictures. Hope this helps. As said before, the cores are not the best shape. This was an attic find where cores, shucks, fuselage and plans were all in different boxes & places. I think it would be best to cut new cores. I looked into a home made bow foam cutter but it looks to be a project in itself and I'm not sure if I'm up to it. My buddy thinks they're repairable with micro balloons, epoxy and reshaping.

Anyways, here are some measurements:

Wing (measured trailing edge sweep instead)

Length 23 3/4", root cord 10 1/2", tip cord 6", sweep (from bottom edge to trailing edge tip) 3".

Stab (root & trailing edge are 90 degrees)

Length 9 1/2", root cord 5 1/4", tip cord 2 7/8".

Both the wing and stab appear to be fully symmetrical with a sharp leading edge and a flat trailing edge. Mach 8 indeed!!!

I like the idea of a balsa leading edge but I want to stay true to the original shape.

Skyhawk, good to know it was a good flyer @ 5 1/2lbs. I may have to use a GP adjustable mount and try different engines. I bet the Magnum 45 would be a good fit too.

Passport1

My Feedback: (8)

not sure this is appropriate but I am going to pass it on. I saw a Mach one kit for sale on Craigs list. Its owned by a tucson guy that s named Patrick. I am sure someone can get it cheap. I know the guy he is a good person to deal with don't worry.

C

Tucson Craigs list, Search patrick or look under toys

Quikturn

My Feedback: (12)

I'm on it. Thanks.