Brodak Smoothie undercarriage

[kiwibrit]

I'm looking for advice from anyone who has flown the Brodak ARF Smoothie. The undercarriage legs consist of one piece of dural which are screwed on to a tiny patch of 3/16" ply, which is in turn glued to a balsa structure. There are times when my landings are - ahem - brisk, and I don't think that that looks strong enough to absorb my firmer landings. How to come up with a stronger structure in an already built model is another matter.  The 1/8" ply bulkhead just forward of  the wing in the main fuselage just might take a wire undercarriage, I suppose.  But room for the saddle clamps would be a bit tight.  Moreover, my gut instance is that the bulkhead would need further reinforcement, and that would have to be at the front, which would breed significant surgery.

I'd be grateful for any comment form someone out there who has flown the Brodak Smoothie, and whose landings do not always kiss the ground like a feather.  Did the standard kit undercarriage arrangement work for you?  If not, what did you do tot change it so that all was well?

[Paul Wood]

My brother has the Smoothie and the landing gear mounting plate pulled out of the fuselage on the first landing.  His solution was to clean all the excess glue off the plate and sides of the fuselage.  He then epoxied 1/4" square basswood to the fuselage sides.  After the epoxy set, he epoxied the plate back on.  He turned the fuselage upside down and used light weights to hold the plate in place while the epoxy cured.  Worked fine.

[peabody]

I had a Smoothie ARF a few ears ago....good flier and I had no problems with the stock gear, landing on pavement and grass....

BUT....others have, so I suggest reinforcement

[Balsa Butcher]

Use nylon 4/40 screws. They will stay in place in a normal to moderately rough landing. On a hard landing they will shear off and can be easily replaced. Better than having to fix a torn up underbelly. Reinforcement route: Paul has the right idea.

[Matt Colan]

I've had/have two Brodak smoothies. One ARF, one ARC. With the stock landing gear, I had no issues over the couple hundred flights I've had on the both of them combined. I also fly off grass as well. The only time the landing gear came out was when I let my uncle fly it and he had a high speed, 55mph landing with it.

[Gerald Arana]

I to had an ARF Smoothie. I reinforced the LG with 1/2" pine (didn't have bass wood that thick) and it stayed in even through a crash. What happened you ask? Well the lines snagged on a weed (not that kind) and she flew across the circle an roughly 10 feet until it hit the other side of the circle and pulled the handle from my hand............I thought I was prepared for the jolt, not so and I have the scar to prove it!

Jerry

[FLOYD CARTER]

The best suggestion so far has been the internal reinforcement.  Any hardwood is OK, and you can cut it into tri-angular shape to save weight, if desired. Make it as large as you can,. and use epoxy to fasten it. If you move the L.G. to an alternate location, you will change the landing characteristics;  maybe for the worse!

Floyd

[kiwibrit]

Thanks very much for your thoughts, all. I liked the idea of nylon bolts, but knowing my luck, I would wind up with the sheared off bits still in the T nuts being hard to get out. Your other suggestions have helped me figure what I am going to do. I'll post pictures and let you know how I get on.

[Tom Niebuhr]

Another case of changes being made to airplanes. The original Smoothie had wire landing gear. NOT aluminum.

[Avaiojet]

Another case of changes being made to airplanes. The original Smoothie had wire landing gear. NOT aluminum.

Nice to see the comments about the ARF Smoothie are favorable.

I have a Smoothie wing I expect to use as a platform for a different fuselage.

I'll start this as soon as I finish the P-40 which is real close.

[peabody]

Hi Tom.......
I believe that I have never seen a Palmer design (Smoothie, T-Bird) with wire gear......
Bob was pleased as punch at Brodaks when the model was released...

[Mike Keville]

I believe that I have never seen a Palmer design (Smoothie, T-Bird) with wire gear......

====================================================

The Veco kits we built in the '60s definitely had wire gear.

[Balsa Butcher]

Just for the record...the broken off stubs of the nylon bolts do get lodged in the T-nuts but twist right out with a small screwdriver...been there done that but still, just one option that few would consider...but it works. 

[Mike Keville]

...and just for the record, dural gear on Smoothies & T-Birds detracts from the original design - much as sheeted LEs do on other well-known designs.

[Dick Pacini]

I to had an ARF Smoothie. I reinforced the LG with 1/2" pine (didn't have bass wood that thick) and it stayed in even through a crash. What happened you ask? Well the lines snagged on a weed (not that kind) and she flew across the circle an roughly 10 feet until it hit the other side of the circle and pulled the handle from my hand............I thought I was prepared for the jolt, not so and I have the scar to prove it!

Jerry

Safety thong?

[kiwibrit]

Just for the record...the broken off stubs of the nylon bolts do get lodged in the T-nuts but twist right out with a small screwdriver...been there done that but still, just one option that few would consider...but it works. 

Thanks. Will still reinforce the ply mounting, but since you advise the sheared nylon screws are easily removed, will go for nylon M3 ones. M3 more common size than 4-40 over here.

[Gerald Arana]

Dick

Yes, safety thong on the handle...... The plane pulled the handle from my hand when it hit the end of the lines. Surprised me! As it crashed....

Jerry

[Mike Keville]

Probably the reasons that some people feel the Smoothie (and T-Bird) never had wire gear are two-fold:

1) The original designs often added balsa or ply fairings to their wire gear, perhaps appearing to late-comers that those designs used dural gear (which they did not).

2) Those who don't recall the designs using wire gear just weren't there "back when".

[kiwibrit]

The Air Trails cut away of the original model, as shown in Outerzone shows a wire undercarriage. So does the plan,  which appears to be based on the Air Trails original.  Maybe Bridak has a standard dural undercarriage which they specified to save costs. Pity. A wire undercarriage would have been better.

The instructions show the undercarriage with three holes on the fuselage face, with the front holes inset a reasonable distance from the fuselage sides. The supplied undercarriage has four holes, almost on the fuselage sides - the screws would go very close to the ends of the ply. I shall revert to the hole layout shown in the instructions.

Maybe the engine bearers could be made of better wood, but apart from the undercarriage, this does seem to be an excellent kit.

[Tom Niebuhr]

Recently, I was was asked to bend an original Veco T'Bird gear, using an original gear as a pattern. I was surprised that one leg was slightly longer than the other.

Uncle Mikey is the tops. He is correct. All those original Veco kits had wire gears.

It seems that more and more changes to those designs have been accepted as the norm. Many of the Brodak kits have taken this "license".  While we encourage people to fly, these examples sure can not be considered for any extra awards.

Another example of a "redesigned" airplane is the "Barnstormer" with solid flaps, a bubble canopy, and dural gear.... Yuck....It just wasn't like that! Those changes just destroy the personality of the "Barnstormer".

The purpose of Old Time Stunt is to do it as was, not to revise history and do it the way you think should be.

[kiwibrit]

Agree with that. This Smoothie was sold to me by another modeller a year ago, and has been resting in the workshop rafters since. I recently lost my Cardinal when its motor cut when the model was high up in windless conditions. The Smoothie is being pressed into service as a replacement trainer pending obtaining, covering and assembling a replacement Cardinal. Hence my concerns about the undercarriage!

I have every expectation that it will have a good life - and have hopes of flying it in a taster stunt competition in September - and assuming that I continue to progress, maybe BMFA Class 2 next year. I don't see it being Vintage or Classic over here.  When the next Cardinal is complete, it will become my main trainer again; it's the most delightful CL model I have flown so far.

[kiwibrit]

Progress.  I discovered the undercarriage had holes very close to the fuselage edges - I would have preferred them a  little more inboard, but decided to stick with them.  I liked the nylon mounting nuts idea.  The blind nuts had to be smaller than anything I could get commercially, so I made my own from brass, with a ribbed 4.5mm diameter body the full depth of the ply (6mm) and a 7mm top flange. Tapping is M3.  Epoxied in place, then covered with cherry strengthening webs, also fixed with epoxy.  A little extra weight, but I will feel a lot happier.

[Scott Richlen]

Something to consider for landing gear: a strong, flexible joint would be better than a strong, inflexible joint.  Try a polyurethane glue, such as Gorilla Glue.  It is extremely strong, yet flexible.

However, here is where not to use it: my Nobler ARF had very weak motor mounts that broke after a minor crash (as in nose-over on take-off.  Yes!  That weak!)  So, just for kicks, I reglued them with Gorilla glue.  You could not pull them apart.  However, their flexibility was evident in how the motor ran (you could actually move the motor), so that is one application to avoid.

Scott

[kiwibrit]

Good point thanks, Scott.  I have not tried Gorilla glue yet - but have made a mental note to do so.  I've already used epoxy now, but I hope the nylon screws will prevent damage to the structure on a hard landing.  I also hope that my landings will improve so that this is no longer an issue!

[Scott Richlen]

By the way, the polyurethanes can be messy.  Don't get it on your clothes or skin, as it doesn't come off.  Also, use it sparingly as it foams.  Spread it thinly on one surface and wet the other surface with a Q-tip.  Hold or clamp the two pieces together.  It sets up pretty rapidly.

Scott

[kiwibrit]

Thanks, Scott - noted.

[john e. holliday]

That must be a different type of Gorilla Glue than I have used.   I use it for laminating and it is very rigid and hard but sands easily.  Yes the stuff does grow and will show you where all the holes in the balsa is.  Triangle stock is great for beefing up mounts, engine or landing gear with epoxy.

[Mike Lauerman]

Back in ''72, my brother-in-law Carl bought an S-1 Ringmaster kit at a garage sale. Some parts were missing, but as we were building and crashing at an alarming rate (!) my flying buds and I had parts, tools, and equipment.
The ol' S-1 was a popular number then, we had 4 or 5 in various stages of 'salvage' and repair!

Carl came over, and prepared the fuselage, (he's a superb builder) but wanted to 'improve' and 'modernize' the S-1...
He epoxied a 1/4" thick ply block, 1" X 1.5" to the bottom of the fuse, right at the wing leading edge. (this block was used as a 'platform' for a Dural gear, which screwed into the block)

He also used a plastic R/C clunk tank, and the new Goldberg slide-in hinges. They even came with a 'tool set', a 'gouger' and a 'hook'.
Carl covered the S-1 with Monocote, fairly new then. He even used a muffler on the Enya .35, also 'new' at that time...(to us, anyway)
I liked the plane, BUT.  It seemed like he had desecrated something somehow 'holy', a sacrilege.
Sure looked funny sitting with our paper & dope jobs...Flew O.K., just...'modern'...

[kiwibrit]

Well, the Smoothie is finished now.  Once the main structure was assembled, I fitted thin (about 1.5mm) rubber sheet between the undercarriage dural and the fuselage - and used nylon M3 screws to locate.  There have been some rough landings (the last one was a series of bouncers) there have been no problems. This model seems very promising - worth the effort.  Enya SS40 powers. My thanks to all who gave advice.