swtk421

So Iam getting back into my RCplanes. Iam looking at building a BUHOR to play around with again.
The plans say it is meant for a .40 sized engine. Baring that I am not looking for a speed demon, or to do anything crazy with it, would an OS.15 be enough to get it in the air? I am planning to lighten it a little with 2mm wings.

Clean

No, but an OS 15 might get a HOR into the air. It's actually designed for that size of engine. A Friday night midget might work too but for a re-introduction into flying I'd go with a HOR. Bank and yank controls with throttle AND get some help to get you back into flying form.

swtk421

Is there really that much of a weight difference between the two?Iwas looking for something with landing gear, which I guess maybe I could adapt somehow onto the HOR.
What would be the smallest Icould use for the BUHOR?

Clean

36 but then that's a little heavier then a pro 25 and midway between 40 and 46 for power. You also have to worry about the fact that you won't have as big of an engine up front so you'll have to move the wing back towards the tail for balance. things can start getting wonky if there to far back. I've seen HOR's with simple landing gear. I believe they usually just hand launch and then land on the gear.

Listen, there's no use in trying to slay too many dragons at once. Trying to get back into flying, with the minimal power for a too big bird is going to be soo much harder on the pilot then having more then enough power on the correct bird to begin with. Keep an eye out on ebay, purchase an engine there and build the Buhor to plans, you'll be happier in the long run and more then likely successful.

swtk421

Thank you for the advise Clean. I still have my debonair (well partially). I have the fuselage portion along with the OS.46 I used on it. Iremembered how crazy scary it was when I was first learning and thought I over did it then. Iwas going to try something a little smaller at first and then go from there. Maybe I'll just build a new wing for the debonair and use that.

Clean

Do you have access to 2 mil? You can save a lot of weight going to an RNAF style wing OR a lot more going all 2 mil. Now, we usually go with RNAF for the wing on a trainer and sport plane just because it's so darn durable. Ever notice how when you spell D a r n here it looks a lot like d a m? Had to type it twice.

Anyways, the RNAF wing has a 4 mil bottom and a 2 ml wrapped top. Usually bond an inch of the 2 mil onto the bottom of the 4 mil sheet, score the 2 mil and fold it over . Usually just one yardstick at 1/3 chord. You save weight on the 2 mil top, lack of the second spar AND get a better airfoil which lifts better. It will improve the slow speed flight of your Deb.

PatrickCurry

My Feedback: (20)

I'd listen to Clean Swt....  You *could* build a BUHOR wing and stick it on your Deb.  Close in size but the BUHOR has a longer chord for more wing area.  That way you wouldn't have to move your engine seeing as how that and all the control linkages take me more time than building the plane itself.  If you don't like it, you'd have a jump start on building the BUHOR.  But yeah, don't go underpowered or you'll be frustrated, probably won't have the power to pull out if you get in trouble and you'll end up destroying the plane.

swtk421

Yeah, the poor slow speed flight handling is what always made me feel like I was flying just on the edge of loosing it and made me uncomfortable. Which is probably why when I had a run in with gravity and it crashed I put it away for a while (ended up being longer than I liked).
So the RNAF will help with the slow speed flight and also save weight. Both sound good. I found a place in NJ (I think) that would ship me some 2mm. It's obviously a little more than I could get the 4mm locally, but if it will help....
The RNAF it looks like is the wing on the DPS? If I go all 2mm, I would still want 4mm for the ailerons for strength right?
Also, should I still put the dihedral on the RNAF like the debonair had?

swtk421

The RNAF it looks like is the wing on the DPS? If I go all 2mm, I would still want 4mm for the ailerons for strength right?
Also, should I still put the dihedral on the RNAF like the debonair had?

PatrickCurry

My Feedback: (20)

The dihedral is up to you.  If you're still somewhat of a beginning flyer, the dihedral will help with the "self righting" qualities of the wing...... letting go of the sticks and it'll somewhat straighten out itself due to the pendulum effect.  Of course, that's not going to help much if you're pointing straight down.  The flat wing, like on the DPS, basically goes where you point it and continues in a straight line until you change it so it's more maneuverable but you've got to be on your toes.  Yes, you'll want 4mm ailerons in there for the strength. The 2mm is not strong enough for control surfaces.

earlwb

A .15 is too small for a BUHOR made for a .40 engine. A .45 or .46 engine works good, as would the larger 52, 53 and even 55 engines as they use a similar small .45 size crankcase dimensions.
I would look for a nice used .45 or .46 engine, it would work great for the BUHOR.

swtk421

Thanks guys. Iam actually debating now about building a RNAFwith the dihedral for the debonair fuse I have now, vs the BUHOR25 with a TT28 engine.
While debating, Iam also looking for the best place to buy 2mm coroplast. No one locally has any, and will not order it unless I buy enough to build a plane for everyone in the city.

earlwb

Are their any sign shops in your area?  Usually they are willing to sell a sheet or two to a hobbyist. Unless they are low on stock. But you can ask to get  some the next time they order more in.

swtk421

I tried all the ones in town. They all either don't sell stock to the public, or only carry 4mm and 10mm.

PatrickCurry

My Feedback: (20)

Yeah, nobody around here carries 2mm either.  I guess it's just too flimsy for signmaking.  I've ordered a couple times from www.corrugatedplastics.net but it's been a while.  They didn't have a minimum shipping charge, they only charged what UPS charged and if you get a couple sheets cut down to 2x4 it's not too bad.  They don't charge you to cut it either.  It's been about a year since I ordered from them, but they were real reasonable and had most all the colors.

Clean

Think ahead and order extra.  You'll need a full size sheet of 4 mil and a two 2x4 wing blanks for that USS that you're building next, but you won't regret it.  Plus, it flys as easy as a trainer when you have the controls turned down. 

Trust me, you want one, you really really want one.  Dang 84 inch wide wingspan.  Dang near floats on landing.  You want one.  Doesn't take much longer to build then any other spad.  Most expensive part that breaks from time to time is that silly 20 dollar prop and you can get them for half price at Hobbyking where you'll buy the engine from, if you don't convert an engine for it.

swtk421

Thank you Patrick, I will check them out. The one I found charges to cut them.

Clean, did you post in the wrong thread? The BUHOR 25 is a 60" span. What do you mean turning the controls down?

Clean

I'm already talking about your NEXT airplane.  If you have to order coro in might as well plan ahead.

swtk421

Ah, I see.....
And what do you mean about turning the controls down?

Clean

If you have the control surfaces on the USS set for maximum deflection, the roll rates can be fairly impressive. I've even seen one in Hover mode. Mine on the other hand has the controls turned down (not set to maximum) and it's a big ole sweetheart.

Turning the controls down = reducing the control throws so as to make them less powerful.

swtk421

Isee. Ishould probably look into that!