Discussion Scaled down Lanzo Bomber ?

[tony lechauve]

Thanks Vintage1 and thanks adamtc for your prompt input.

I was wondering about Belair. I was thinking about a Lanzo Bomber or Playboy Senior as I want an oldtimer design, gull-wing, at least 80 inch w/s, with a pylon. I want something that will catch thermals, and may put a camera on it.

Adam your Record Breaker looks very interesting. Are the u/c and pylon from the original design? In piano wire?

I have made 3 ARTFs- is the Record Breaker a reasonably easy first build? Is the Record Breaker easy to electrify?

I am a bit concerned that the Bomber has a short nose so getting the CoG right may be difficult, maybe less so with the Record Breaker?

I found less information on the Record Breaker, does it thermal well? As well as the Bomber?

So many questions! Thanks all for any information

Tony

[starzak]

Originally Posted by Leadchucker

I am using a HUR/C 3548-09 spinning a 13 x 6.5E APC on a full size LRB and it's plenty of power. Remember the original had a Brown Jr. making a whole 1/6 HP turning a 14 x 8 prop @ 7000 rpms on a good day. I have powered the LRB with a O&R .60 sideport (free flight),another with a Super Cyke (R/C),another with a Brown Jr (free flight) and the current one (R/C and build No.4) as described with electric. Avatar was Free flight LRB No.1 with O&R, she went after a station wagon she didn't like but lost the fight.

I'll be flying a much smaller version, a 58" Lanzo Bomber that will weigh about 24 oz. I just don't know how this combination stacks up to the big stuff that you guys have been flying ? ? ?

I'll be using a Hacker A 20-26 M turning an APC 10x 4.7 prop, with a RPM/V of 1130, operating current of 12 A, Peak Watts of 150. The motor weighs 1.48 ozs. Using just 2 LiPo cells, do you think that this combination will have a reasonable climb rate ?

Thanks.

zak

[Leadchucker]

Originally Posted by tony lechauve

.......... I want something that will catch thermals,.....

Both the Bomber and LRB will do this easily as will many other old timers

Adam your Record Breaker looks very interesting. Are the u/c and pylon from the original design? In piano wire?

I should let Adam answer this, but yes the undercarriage and cabanes are original. They made from wire bent to the required angles, cobbled up into the respective assemblies with copper wire lashing and then soldered fast.

A.) is the Record Breaker a reasonably easy first build? B.)Is the Record Breaker easy to electrify?

A.)Yes and there is a partial kit availabale from a couple sources.
B.)Yes, lots of room for everything

I am a bit concerned that the Bomber has a short nose so getting the CoG right may be difficult, maybe less so with the Record Breaker?

Short nose is offset by a lifting satabilizer, C.G. is aft of a "normal" aircraft's C.G. by quite a bit. This was very common on the "old timer" class of aircraft from 1938/9 to 1943,less so on the Antique classes befroe 1938. Lifting stabilizers were used to add the lifting surface square inches to carry part of the weight of the aircraft. This was permitted as long as the total area of the stab did not exceed 50% of the area of the wing.

I found less information on the Record Breaker, does it thermal well? As well as the Bomber?

Yes,with I don't know how many flights on a LRB in various incarnations I suppose you'll have to trust me on this one.

[adamtc]

tony,

- The rb is easy to build as long as you can cut wood, jig the fuselage and silver solder. I learnt to solder building this model, easy! Belairs kit is for r/c so no major changes made to the general shape. I kept to the plans and original set up to an extent but as mine is electric , it needs some reworking. Really not difficult. I can email pics if you need it. She got a huge internal space to fit the electrics and lipos. Motor just mounted to firewall, no adjustments to the shape except to omit the engine bearers.

Mines powered by an eflite 60 with 6 cells ( 2 x 3 cells linked) 4300mah. Loads of power! Vertical at 1/2 throttle. 30 seconds and shes a dot in the sky. At 6llbs auw, she can be powerd for a lot less cost, probably 3 cells and a e flite 40.

U/C modified a bit but essentially just piano wire bent to shape. Cabanes the same. Thin wire so easy to bend. I omitted a few cross braces but it hasnt altered its strength . Silver soldering is easy.

As for flying, well she is a cracker. I ve got the cg back to almost 8 inches from the LE and she just floats and floats and floats...... I cant wait for the summer thermals!!!!

CG was set on the spar to start and shifted back by removing the lead .

[tony lechauve]

Thanks for your input Leadchucker & Adam; really useful.

Is it clear from the plan how to jig the fuselage? I have never had to do this
Loads of power? Is that more efficient than slowly climbing then?
Finally I read that the RB has to land into wind because of the polyhedral wing. OK, but what is the RB like in wind anyway?

Thanks guys, Tony

[adamtc]

Tony,

Im going to recommend you look at buying a book that explains the noble art of building models as there is a bit to learn. Its not hard but just requires the right approach. If you want a simple easy to build intro in building look at something like the simplex 60 from belair.

The RB climbs vertical and gets to 1000ft in about 25 seconds. No faffing. You can elect for a slow climb out if you wish, but traditionally the aim was to get as high as poss using a short engine run of about 25- 30 seconds. It was a competition model at heart.

Handles winds up to 10 mph OK. Always land into wind irrespective of model....

[starzak]

Speaking of that " polyhedral wing " , what is the best way to join the tip sections to the center section ? The angular difference is so great. Do you just butt glue the sections together at the ribs, or splice in a spar ?

zak

[adamtc]

Butt glue the 2 pre set wing sections together with the outer ribs pre set at 12.5 degrees. Bring them together and you have a 25 degree tip dihedral. Finally add a few ply braces either side of the spar.

I also add gussets to the LE and TE joints. Tough as hell.

P.S Its not a polyhedral wing as thats one with 2 changes in diherdral like a gull wing. The RB simply has tip diherdral.

[Leadchucker]

Originally Posted by tony lechauve

.........
Loads of power? Is that more efficient than slowly climbing then?......

Originally Posted by adamtc

.........traditionally the aim was to get as high as poss using a short engine run of about 25- 30 seconds.......

This was true later on on the original free flight era,but the LRB and it's early free flight flying lumberyard cousins were mostly fuel allotment birds. This would be similar to the Texaco and Antique Fuel Allotment events today where the aircraft recieves either 1/4 oz. or 1/8 oz. of fuel per pound and the engine runs until the allotment is consumed. If you look at the plans of most "Antique" class of old timers almost across the board there is a Brown Jr. .60 sitting on the nose in the drawings. A Brown Jr. pulling a 5 lb.LRB is not the quickest climbing model,but if the engine is going to run until it uses up 1 1/4 ozs. of fuel altitude is not a real concern.

The arrival of the Forster .99 around 1938 took thing up a notch especailly with Sal Taibi's Powerhouse being designed to use this engine. Later on around 1940 along came the O&R .60's, the Super Cyclone and the pylon models.This changed the free flight contest scene with models having high power to weight ratios and the resulting fast climbs which now required timed engine runs. The difference in the models from the early era up to about 1938 to the later era is the reason there is an "Antique" Class in SAM contest as the older planes generally can not compete one on one with the later models.

The point of this jibber-jabbber is you can go fast climb or slow climb depending on your point of view, if you are going to just fly for fun, or go for a somewhat more authentic flight character with stately climbs or still again set up for competition. Sorry to babble on,but I thought some insight might help you if you are not familiar with old timer models Tony.

[tony lechauve]

Hi Guys. Thanks for all your input, very interesting and much appreciated.

I am vacillating. I really liked the parasol [is that right?] wing of the LRB but for a first Old Timer I was inclined to the L Bomber. I gather the L Bomber thermals slightly better?

I was thinking of making a full size LRB/LB as my first proper build, probably with ribs etc ready laser cut tho. Then I noticed an ARTF 80% LB from Australia, so with little time or willpower I have also put that in the equation too! I will get to do something, probably around Christmas time.

Thanks for the observation on taking off/landing into wind Adam, I nearly always do- especially after I was committed and came in crosswind on full left rudder with nothing to spare a few weeks ago! I was just examining the limitations of 3 channel, which I am not used to.

[tony lechauve]

Oh, by the way Adam, I bought a book- Aircraft Workshop by Kelvin Shacklock. I am reading thru it. I have been collecting build articles from RCM&E for some time too.

I have a failing that I don't tend to do easy, I tend to go for it (safely of course), even tho I have a lot to learn. So altho the simplex 60 looks good I am inclined to stay with a LRB/LB
Tony