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Outdoor Free Flight Forum => Dimescale / Pseudo-Dimescale => Topic started by: dohrmc on September 12, 2016, 09:45:31 PM



Title: B.A.T. Monoplane Dimer
Post by: dohrmc on September 12, 2016, 09:45:31 PM
I have had this plane built for quite a while, and finally decided to get off my duff and finish it. Covering it now. With any luck, it will fly well.


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 12, 2016, 09:48:26 PM
I have all the components pretty well finished, so once I finish covering I should be able to have this ready for trimming flights pretty fast.
I have been told 2 loops of 3/32nd should work well. Anyone flown one of these?


Title: Re: B.A.T. Monoplane Dimer
Post by: ZK-AUD on September 12, 2016, 10:27:16 PM
If this is the plan built by John Ernst, his weighed 14.5g and he hoped it would fly on one loop of 3/32.   1 Loop would be great indoors but maybe not quite enough outdoors.   Looks like you can get a massive long motor in there and assuming your weight is around John's weight I think 2 loops of 3/32 braided would give you a lovely long soft motor run with all the power you need.  I have a 16" span KeilKraft Sopwith Camel that weighs about 23g including rubber and it does just fine on 4 strands of 3/32 even with all the drag.


Title: Re: B.A.T. Monoplane Dimer
Post by: flyfac on September 13, 2016, 12:17:26 AM
Hi Dohrm,

That's a great design and an excellent flier.

I went through my notes and found the specs for mine.

Weight w/o rubber:  9.7 g
Weight w/rubber:  13.2g. (1 loop 1/8" 3.5 grams Tan II)
Average flight:  100-120 sec.

I only fly this one outdoors, so 1/8" is fine.  Indoors 3/32 would probably be a better option.

Hope that helps.

Best,

Scot Dobberfuhl
Forest Grove, OR


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 13, 2016, 08:11:10 AM
Thank you for the info.  I am not in your class as a builder. You really do good work.  My trusty BAT will be almost twice as heavy as the one you built.

I haven't found much info on the actual plane. Is that the way they used aluminum panels on the real thing? I don't guess it matters much with a Dimer, but I was curious as to where the al-u-min-ee-um started and stopped. (Obligatory Brit speak).


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 16, 2016, 02:11:20 PM
All the components are finished and it is time to stick them all together and see what it looks like. This pic shows the wings being glued in with the correct dihedral.
I hope to have this all done in the next couple of days. Too bad about that work thingy!
I am hanging it up in November and finally retiring for good. (At least I hope it's good!)


Title: Re: B.A.T. Monoplane Dimer
Post by: flyfac on September 16, 2016, 05:04:18 PM
That's definitely going to fly, Dohrm!

In a belated response to your request for pics of the real one, all I could find in the files was this blurry pic.

There are other online images of the version with skids, but I believe those were drones.

Best,

Scot Dobberfuhl
Forest Grove, OR


Title: Re: B.A.T. Monoplane Dimer
Post by: flyfac on September 16, 2016, 05:05:30 PM
  .


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 16, 2016, 09:40:09 PM
The plan I am using is the Al Backstrom  plan. Thank you, Al!

I am attaching the landing gear. I pre assembled it, did all the staining, bracing wires and all. By morning, it should be good to go. Hopefully, it is on there straight. If so, I will stick the wheels on tomorrow morning, before I have to go to work

Last, I will glue on the kingpost, and rig the flying wires.  Bad news I work the next 6 days straight, so will have to be creative getting some glides in.

I am using a Gizmo Geezer nose button. Got it from George Bredehoft at His Volare store. Each button has 3 inserts so you can use it on 3 different sizes of wire. Good stuff.


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 19, 2016, 11:49:57 AM
Finally finished it up. Now to balance and test glide the little brute.


Title: Re: B.A.T. Monoplane Dimer
Post by: Mooney on September 19, 2016, 12:00:58 PM
Looks great. This plane has always interested me.  I admit, however, I don't quite understand its function.  Was it a manned bomb? That idea doesn't seem consistent with the way the British would've addressed a problem.  Ahhh, very well Tommy, now let's get on with it...of course, I'll tell your wife... Alright then...
Or was this some kind of trainer?


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 19, 2016, 12:10:33 PM
There is not a lot of info out there. From what I have read, it was intended to be used to attack Zeppelins and other targets by radio control. They were plagued with problems with this idea, taking off before the radio was switched on caused at least one crash.
The idea was quickly shelved, I believe.


Title: Re: B.A.T. Monoplane Dimer
Post by: Mooney on September 19, 2016, 05:00:28 PM
Thanks Dohrm, I thought I recalled a radio control guidance but don't consider my memory reliable enough.  That coupled with the fact that I probably read too much on these kinds of things and begin to confuse details.  I do recall seeing a nicely built dime Bat mono floating around at Geneseo on my first ever visit.  Really impressed me.


Title: Re: B.A.T. Monoplane Dimer
Post by: scrubs on September 29, 2016, 11:02:32 PM
Nice job on these guys. I built one way back and it was a nice flyer once I got rid of my aversion to nose clay.

Question tho. Does FAC allow simulating silver with white tissue? Didn't think they did anymore.

bill


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 29, 2016, 11:12:21 PM
Well, I'm a little slow, don't understand that.

At present carving a prop for the BAT. It is impossibly nose heavy.


Title: Re: B.A.T. Monoplane Dimer
Post by: Mooney on September 30, 2016, 09:41:51 AM
I think you're correct, Bill.  I say think, because I didn't bother to check the latest book.   But that used to be so.  Too bad, cuz I think it is in line with a dimer's simplicity to have white tissue as silver.  As I think about it, it may have been your BATMono I recall at Geneseo way back then


Title: Re: B.A.T. Monoplane Dimer
Post by: ILM Tarheel on September 30, 2016, 01:38:58 PM
Per the 2016-2017 FAC rule book: Section II Primary Rules All Events

(paragraph) G. Scale models: metal silver / gray finishes must be represented by silver / gray colored tissue and/or paint. White tissue alone is not acceptable.

Jimmy J


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on September 30, 2016, 08:12:18 PM
Luckily no one alive knows the actual color of a B.A.T. Monoplane. Impossible to tell from the surviving pictures. I doubt there were many all metal airplanes when it was built.


Title: Re: B.A.T. Monoplane Dimer
Post by: scrubs on December 23, 2016, 10:42:49 AM
I thought I had seen reference to it being silver doped not an all metal plane. In any case I built mine with white tissue too.

sorry for the belated reply.

bill


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on June 12, 2017, 08:52:06 AM
Finally got a chance to fly the BAT at our two day FAC contest here in GA over the weekend. Wally Ferrell and his wife, Julie, drove down and flew with us.
Wally was kind enough to help me with the final trimming and tweaking.
I am happy to report the BAT flew like a bird and did 45 seconds on roughly 3/4 total winds. It flies well enough that watching it caused "I'm gonna lose this plane soon" to go through my mind.
Thank you Wally!

I have always heard these BATs flew well, but was sceptical. Now I am a believer.


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on July 02, 2017, 08:19:25 PM
Still trimming it out, but have put some serious winds on it. In iffy air, I got 85 seconds today. It is pretty stable under high torque, but I need more down thrust and turn in the initial burst.
So far, it is a very good flier. Still no maxes, but that is due to the glide.
Glide is too steep, hope to get that sorted out.

May start over with gliding/checking of cg. That should cure the glide.

David Barfield made a video of it flying. I hope to be able to post a link to that when I get it from him.


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on July 09, 2017, 12:21:22 PM
Hopefully this link will work. It was taken at our last outdoor contest. First flight is wound to fair amount of turns, still a test hop, but just observing the model. Second flight is moderate turns, where I discover the need for more downthrust. Since this is only my second Dime model, I am more than pleased.

https://youtu.be/jnjv1SHlp2c


Title: Re: B.A.T. Monoplane Dimer
Post by: skycafe on July 09, 2017, 12:58:03 PM
The swallows seem to like it!

Good job, that flew well.


Title: Re: B.A.T. Monoplane Dimer
Post by: Walt on July 09, 2017, 11:22:54 PM
Dohrm, you are doing great.  I think your idea to check out the CG and decalage is a good one.  Keep us posted n your progress.  I think sorting out the CG/decalage first will pay dividends as far as your issues with down thrust as well.
Wally


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on August 13, 2017, 08:19:20 PM
I am continually surprised by how much difference can be made by one little change. For the BAT, I added a 1/2" long piece of 1/20" wood on the left side of the rudder. A Gurney Flap. Right down at the stab intersection level. Just like a HLG. It transformed the plane under high torque. Two flight previous were not bad, but could have been better. It obviously needed help with the torque with that small tail.
I figured the gurney flap couldn't do much worse, so I wound that sucker up.
(Of course it helps to be able to spot the thermal coming through)!

Massively high and long culminating with a glide right into the Chattahoochie River. Unlucky, but......An easy max. I hustled over there and saw it floating.

Luckily, there was a boat of fishermen right downstream. They got the plane.

Unluckily, there was no way down to the river but a steep wet clay covered cliff. Think bobsled run.

Luckily, my cellphone has a lock on it so pictures of me stripped down and going down the slope could not be taken after I gave up the cellphone to Lee Russell for safe keeping.
Even better for the horrible climb back up. I had flashbacks to Survival School in the Air Force.

Just minor damage, and the Bat will be taking the air again. It is a very good Flier. And I am very lucky. It is hard to describe the picture I presented staggering back to the flight line.  Mud, and blood from the briars. Looked like I had been in a knife fight.

Luckily, no pictures!


Title: Re: B.A.T. Monoplane Dimer
Post by: flydean1 on August 13, 2017, 10:25:49 PM
I've seen the Gurney flap thing work on even large power models.  Denny Dock used one to tame a D gasser a few years ago at the NATS.

I met Dan Gurney very briefly at Daytona.  He asked a group of us if we had a plug wrench for his motor bike.


Title: Re: B.A.T. Monoplane Dimer
Post by: Walt on September 04, 2017, 11:27:16 PM
Great story Dohrm.  My Vega landed in the pond last year, just beyond the reach of my 30 retrieval pole.....so yeah, had to strip off my boots and jeans and wade in for it...the stuff we do, eh?
Wally


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on February 07, 2019, 10:53:14 PM
The BAT is no more. Last fall, wound her up for another flight, and as I removed the blast tube, and hooked up the prop, the motor let go. Classic B.U.R.G. Moment. (Blowed Up Real Good)

Will have to build another, as this was a great Flier.


Title: Re: B.A.T. Monoplane Dimer
Post by: Walt on February 08, 2019, 11:47:56 PM
There is an inherent lack of justice in this story Dohrm.......I've had this happen as well.  FF rubber flying does seem to find a way to tax one's patience....


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on February 09, 2019, 12:00:46 AM
What’s funny is I wrote B.U.R.G. on the scoresheet.  There was comical confusion amongst the powers that be. Luckily, a translator happened by.


Title: Re: B.A.T. Monoplane Dimer
Post by: Graham Banham on February 12, 2019, 03:14:13 PM
I'm doing one of these. If you ever build another one, these may come in handy!


Title: Re: B.A.T. Monoplane Dimer
Post by: Bredehoft on February 12, 2019, 04:03:39 PM
These are pretty much the best (only?) photos you will find on this plane.  They were published in the WWI Aero #117, December 1987.

--george


Title: Re: B.A.T. Monoplane Dimer
Post by: dohrmc on February 12, 2019, 04:38:26 PM
I will build another, a very nice flyer.