IMHO - I would glue the wings on next time. This plane is a PITA to store in any form, and I've yet to pull a wing off since it's maiden flight...You will also have peace of mind knowing that the 2 bolts holding each boom on is not the only parts that are feeling the G's. (I cringe every time I do a split S).

The wind has been blowing hard for 2 weeks already...Been surfing, but not flying. I'm anxious to try out the new Weston pipe already!

I was considering making 2 1/8" ply tongues which would be located in the wing root ribs at the bottom. These would then be locked by inserting bolts into blind nuts located in them from the bottom of the fibreglass fuselage, withy suitable packing in place of course. A similar system is used in the 'real' original Bobcat. Has anyone done this?

airbolt,

I have both the nitro bobcat and the BVM Bobcat. I have to remove the wings for the BVM to transport and made the wings removable on the nitro Bobcat. And have not had the need to remove them.
A lot of effort for nothing.
But the BVM metod will work if you stiffen the lower portion of thr wing area that will meet the fuse.
Good Luck!

Does anybody know what the weight of just the airframe with no electronics or power system is? Also is this plane any good for an electric conversion?

Also will these retracts work without any mods to the plane [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXL406&P=7]Retracts[/link] And how many retract servos will I need for those retracts?

Electric conversion has been done. Bare airframe weighs around three pounds the fuse is most of it.

What is the top speed of this plane using a .46 engine?

After looking at pictures of the nitro version of this plane, I see the engine is mounted without an engine mount, so how would I mount an electric motor? Is there a firewall I can bolt it to?

....no firewall. The nitro engines bolt on like this.

FBD.

Any idea how I would mount an electric motor?

.....bend an aluminum plate like this, and cut a hole in it . Bolt the plate to the existing mount,
or modify the wood as necessary. Bolt the electric motor to the plate....you're in.

Flyboy Dave, your prop is on reversed.

so did you call the dentist?

Would this plane be faster with a tower .75 engine in it or a hacker A40/10L? If not the tower, then what engine will give me the most speed?

I can't speak for the Hacker, but the Bobcat .50 REALLY moves with the GMS .76 engine and the Graupner 11x8P prop.

.....yes I know the prop is on backwards....I tried to fly it like that too. [X(]

....yep, I called the dentist. Gotta get them babies cleaned every now and then.

FBD.

No you want pneumatic retracts on the wings.

Mechanical retracts will require some modifications.

You could possibly use a mechanical nose retract, but if you have pneumatic wing retracts why bother?

A bit vague...

It depends to a great extent upon the prop pitch you use and how much thrust you want to sacrifice for speed.

e.g. you could put in an 11x8 prop on the .46 engine, and the plane might exceed 100 MPH but it will take a while to get up to speed in level flight.

Verticals will suck big time.

Drop the prop pitch and verticals will be a bit better, but the plane will not have a 1:1+ thrust ratio, meaning it will be incapable of flying straight up.

Throw a .75 or .76 engine in it with the same prop and it will both accelerate quickly and have good vertical characteristics.

With the .46 an 11x6 pusher ( if you can find one ) or a 9x7P three bladed prop would be better. MA has them.

This would give you a compromise between speed and thrust.

The plane would not go over 100 MPH, but the performance would be up there at 70-80MPH+, while thrust would be decent.

No firewall.

The "LIP" we mount the engines onto is VERY VERY hard wood. ( They did this right on this plane. ).

So you could bolt on any sort of mount you want to come up with.

A pair of hardwood blocks cut to size then epoxied into the fuse works fine, adjust as needed for an electric.

How does it fly using a tower .75? What prop are people using with the tower engine? Will it be comparable to the GMS engine? Will I be ok using the stock muffler or should I upgrade it? If so, which one? Sorry for all the questions, I just don't want to buy the wrong equiment.

With either the Tower or the GMS and the Graupner 11x8P prop, this is a speedy bird especially with retracts.

It flies great.

IMHO you do not need to do a thing with the muffler.

The only thing I had to do was to adjust the C.G. by moving the 1200mAh 6V battery pack I'm using to the nose.

If needed I had planed on putting a second one up front, but I did not have any need to do so.

I have the Tower 75 and it zips along very well. I ran the exhaust down through the wing. Keeps things pretty clean.

Blessings, Terry

When you say speedy how many MPH are you talking about?

WHEW!
After literally months of on and off lost lunches and nights, I've finally made it though this thread. Read every page up to 75 then had to start jumping by fives.

Ton of great info here, kudos and thanks to the testing guys that contributed over the years. Although, I think if we cut out all the pissing matches and cat fights we could lose about 10 pages.

There has been a flurry of questions in the last two days that are answered in the 50's through 70's. Go back and actually invest in your search, your model will thank you.

I'm a SPAD guy at heart and love to scratch build, so I'm working on a slightly scaled down coroplast version, I have a GMS .47 looking for a home. Once I get her up and flying I'll post a link for your veiwing pleasure.

I'll be lurking til then.

It depends upon the prop pitch... I already answered this in the prior post...

The higher the pitch (assuming the engine can sustain the required thrust as well) the higher the speed.

If you REALLY want to know, just use an on-line prop speed calculator...

http://www.rcpro.org/rccalc/PitchSpeed.aspx

You input the RPM's your engine can sustain with the prop you have and the prop pitch and out comes the MPH...

The problem is that while the engine may be able to crank the prop over, the resulting thrust may not be enough to fly the plane as you wish.

It is a tradeoff and balancing act, you can exchange thrust for speed, or speed for thrust...

Decide what you are seeking and then adjust accordingly.

The TH .75's and the GMS .76 seem to easily sustain 13000 RPM with an 11x8 prop with unlimited verticals. Use that as a baseline.