Crescendo Build

Brian Jackson

Platinum Member
Greetings All.

Quick post to start documenting my build. Has been a crazy few months with family health issues but have managed to make some great progress. The airframe is fitting together like a Swiss watch.
angles1.jpgangles2.jpgrender3.jpg

Pictured are the seat and engine mount diagonals' lower termination into the keel (with temporary hardware). The rendering puts the photos into context. The stock GyroBee on which this ship is based terminates the engine mount diagonals into the mast with a bolt. Though I cannot argue with the Bee's excellent safety record, Crescendo's diagonals run continuous to the keel, bypassing the mast. They do bolt-clamp fore and aft of the mast, though no hole through the mast is required at the attachment point.

Two 3-gallon fuel tanks are located behind the seat, shaped to help clean up the airflow behind the pilot. This removes the tank and tray-mount normally between the cluster plates and prop on a stock Bee. Fuel is now closer to CG so changing fuel levels minimizes changes in balance.

I'll be maintaining a builders log on KitLog Pro in greater detail once the software is set up properly.

Respectfully,
Brian Jackson
 

gyrojake

Gyro Rehab Candidate
As Vance said, "Looks Good Brian"!
If I may add some building techniques that are used and accepted.
Your fit looks awesome, but there will always be some movement from vibration and stress.
I never let two pieces touch as your angle does. This can cause some wear and crushing between the touching parts.
Always make sure your washers are not on top of the radius of the corners of your angle aluminum.
This causes cuts in the radius and a bending moment in the bolt.
I only make this statement from what the picture depicts.
Seems as you have planned your project before expediting your build which is a good thing.
From what I've seen so far your workmanship is great and the detail will make your machine stand out.
 

Brian Jackson

Platinum Member
Thank you Jake. Coming from you that is a great compliment and words of wisdom. There will be a finish milling step that creates a hairline gap between the angles to prevent contact. And yes, the washer diameter have been accounted for such that it will not encroach onto the inside radius of the angle. It stops just shy of the tangent, but as close as possible to the 90 degree leg. I've seen photos of some installations where washers interfering with the angle radius has been a serious problem. Thank you for your keen eye and guidance.
 

Brian Jackson

Platinum Member
micrometer-scribe-offset.jpgsetback-closeup.jpgsetback-perspective.jpgkeel-front-cut.jpg
Steady progress on some detail elements of the airframe. Per Jake's direction in another thread I added .0625" of offset clearance between diagonals at the tie point. A stainless steel caliper mic is handy for scribing layout lines on aluminum. In the 2'nd closeup photo you can see a very slight gap between the keel and tailboom tubes. This is to account for the thicknesses of the powder coat finish (2 X ~.004") so the thru-bolts don't bind. I adhered tape of that thickness between the mating surfaces of the tubes before doing any transfer punches. The tailboom tube in the last photo was angle-cut to match the forward plane of the seat support angles via transfer scribe once all of the structural terminations were finished. Nice to see things turning out like the 3D model. But it is more time consuming than I expected tooling up for so many different compound angles.
 

gyrojake

Gyro Rehab Candidate
Welcome to the world of building with intent detail.
Another trick is to use a piece of plastic under my clamps to stop that UnGodly mark the clamps leave.
 

Brian Jackson

Platinum Member
Indeed. And these were plastic-footed clamps designed not to spin. Have been using spacers now. Fortunately the swirl marks buff right out.
 

Brian Jackson

Platinum Member
Spent Super Bowl weekend working on the seat mounting. Extremely clean, solid installation so far. I re-purposed a quite expensive high quality office seat I used to refer to as the Captain's Chair, though I stripped it of all hardware leaving only the upholstered substrates of the bottom and backrest. Though they have threaded inserts, I do not trust them and installing carriage bolts from the inside under the upholstery.

At first I dismissed the idea of using it as a gyro seat but after disassembling it, examining, surveying the parts and weighing them, the idea was plausible. Being a separate backrest and seat rather than a 1-piece shell, the bracketing design also unitizes the two pieces where they meet to aid with offset bending loads. Will share photos this week. Curious if other builders have done the same or similar.
 

Brian Jackson

Platinum Member
Tubes for landing gear arriving today from Aircraft Spruce. Have been getting material and mill certifications from a local Metal Supermarket up until now, but a couple of the sizes were not stock items. I was happy to have received a call from Aircraft Spruce about my online order where I added a note to make sure the pieces aren't scratched. I'm told they all have handling abrasions, which is to be expected, but not to let them be deeper than a light sanding could take down. I appreciated that my note was even acknowledged.

I'm still learning all about Shock Absorbers / Dampers before selecting what I hope will be the optimal units for this configuration. The goal is to attach the vertical strut higher up on the mast with an in-line shock at the mast attachment. I'm hoping to unitize the shock with the vertical strut (rigidly fix them in a straight line) in a way that eliminates the need for an additional diagonal support. This would preclude a free-pivoting connection at the shock's lower eyelet. Any photos, recommendations or guidance would be greatly appreciated. I started a thread in the "Other Components" section about shocks that has provided some insights, and eager to learn more before any saw blades and drills start spinning.

Thanks again everyone.

Brian Jackson
 

Brian Jackson

Platinum Member
Quick update, sorry no photos this round. Spent the weekend on the landing gear attachment system and currently awaiting arrival of Aurora rod ends from Aircraft Spruce. Though projects like this are an exercise in patience and planning, it's wonderful to see progress, slow as it may be sometimes. I hope the quality is evident to all who inspect it. It's amazing that we live in a time that allows us to even do such a thing.
 

Brian Jackson

Platinum Member
All_In;n1130767 said:
Dang you do suck good work!!! Thanks for sharing!
Freudian slip? Sorry, couldn't resist :) And thank you. Looking forward to posting some photos of the other detail areas.
 

All_In

Gold Supporter
Brian Jackson;n1130773 said:
Freudian slip? Sorry, couldn't resist :) And thank you. Looking forward to posting some photos of the other detail areas.
There I go again!!! But at least I crack myself up too once someone who can read points it out. I corrected it.
 

gyrojake

Gyro Rehab Candidate
Dang John, why did you change it? I'm tired of being the only one here people say you suck to.
I think it's time for some new blood.
I'd say good job Brian, but I ain't seein no pictures.
 

Brian Jackson

Platinum Member
Yeah John... we gotta keep it like it was. I suck at a lot of things. Belly dancing for example, and I need to be reminded of that.

Jake, photos soon when laptop fixed. Doing a photo-documentary of pretty much every operation for inspection, from which a few I'll post when able.
 

Brian Jackson

Platinum Member
No Title

Wow, 3 months and I haven't posted any photos. Shame on me. Much progress though. Took possession of a new lathe yesterday for fabricating the myriad of small spacers and inserts. Haven't been able to get the ship on her landing gear yet without the turned inserts, and local manufacturing prices made buying a machine the less expensive option. Plus I'll learn some new skills and own a lathe in the process.

In the mean time, here are a couple of shots of the engine mount fabrication and test-fit. Missing in the photo is a tie channel that unitizes the two engine diagonal supports from the upper attachment hole down to 3 inches below the radiused notches. It is hard-fastened between the diagonals, There is similar notching on the GyroBee plans at the bottom end of the original diagonals for clearance around other components. I'm not a fan of a lone, unbraced angle leg (which the notching leaves) supporting such a dynamic load. Hence the tie channel.

The plates' edges are beveled 11 degrees only because the upper plates are 1/2" narrower than the bottoms (per DynaFocal). When stacked under compression with the Barry isolator mounts the bevels align. A completely unnecessary detail that makes me smile.
 

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Kevin_Richey

Yamaha gyro...Oregon, USA
I admit to not having studied the Bee plans other than a cursory look.

But, instead of having to shave off so much material on the ends of those diagonal engine support angles to fit that way both at the top & bottom ends to allow clearances, why not leave the angles alone w/ little-to-no removal of material? If small amounts are needed to be removed for clearances, then it is only a small amount, instead of a large amount.

They could be placed on the outside of the horizontal engine mount angles (instead of the inside), and place a small 2"x 2" plate on both sides of the mast bottom (or keel, whichever way the plans show) of the same thickness to keep the same flat angle. That small plate could be attached at the same bolt hole that would be there anyway for attaching the supports. Or, make the small plate a piece of angle, and it could be tilted to match the angle's angle, giving further strength by nesting to the the angle on it's outside.

You'd have an extra attachment point available for other items down there, such as a rudder cable attachment, or a brace attach point for the axle, or, as a tether point for your Beluga whales while you are away from your gyro at flying events!

With this thought, I still think the braces you described holding the two support angles are a good idea.
 

Brian Jackson

Platinum Member
No Title

Kevin_Richey;n1134150 said:
... or, as a tether point for your Beluga whales ...
Can't believe you still remember that Kevin! Good times.

Thanks for the reply. I had explored the options you described which I believe would have worked, albeit requiring four 1/4" thick stand-off plates in order to pull the engine diagonals outward to the external side of the horizontal engine mount angles. The "tie channel" seems to be the lighter, cleaner solution. I can't say if this is a solution in search of a problem or not since the original GyroBee also has a long notch at the connecting end of the diagonal (at the mast). It is also shown on the plans as a sharp inside corner, which is a no-no. That arrangement obviously works structurally since so many of its type are flying. But I would have more confidence in the design if the load were transmitted to a point further down the diagonals below the radiused notch where the angles have maximal compression strength, which is what the tie channel will do.

I have attached GB docs showing the original parts in context. In the plans the engine diagonals stop at the mast and are thru-bolted. I opted to continue them past the mast (clamped with fore/aft bolts) and terminate at the keel into a concentrated tie point.
 

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