Wraith, a custom Y6 build

[Thorn3]

Hello all. I am presently designing and building a new Y6 I have named the Wraith. This project was started some time ago and am just now getting back into working on it. Do not expect immediate progress. I am retired and don't rush myself anymore. This is a project that is meant to be fun, not a time based burden.

I have been designing and building my own aircraft for many years (since 1975). I am a bit quirky and refuse to comply with the norm. You may note this in the following build. Being practical is not my way of doing things. One can only take so many years of being practical, before their designs become boring. With that in mind... this build is effective from an engineering perspective, yet is also artistic.

I started out with the motors. I needed six of them for the Y6 configuration. None of the manufactured motors meet my design criteria, so I set upon building my own. It is not that manufactured motors don't work well.. they are just fine. Their design and how they integrate into the rest of the model's design is the issue.

Here we go...

 

[Thorn3]

The first step is to decide which material best suits the need. I decided to use 6061-T6 Aluminum. Easy to get, cost effective, easy to machine and has suitable mechanical characteristics.

The design started in Solid Works. From there, the individual drawings were printed out and the machining began. I do not intend this thread to be a tutorial in machining. I will however provide basic commentary as to what is shown in the pictures. I got carried away with machining at times, so I forgot to take some pictures.



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Started with some round stock. Blanks were machined for the motor bases, with a central hole. A fixture was then machined to hold the blanks (forgot to take pictures of that). Concentric parts are a must, so the fixture was machined and left in the lathe until all base parts were machined. For some reason.. two pictures are out of order. Hmm...

 

[Thorn3]

Next step was to machine the inside of the motor bases. Note that a part of the fixture holds the blank via a screw, to afford easy machining of the interior and lower bearing tube.


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[Thorn3]

The bases were moved to the mill, where they were machined in a variety of processes. They are shown here sitting in a motor mount test piece, just to show how they sit in the mounts. These are not however, the motor mounts for the finished project. I will show those later.


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[Thorn3]

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Next up was to machine the bearing cup for the top of the bearing tube. The base and bearing cup need to be two pieces, to allow the installation of the stator. Again.. pictures post out of order. Finishing the exterior of the bearing cup is not shown as that is another time when I failed to take pictures.

 

[Thorn3]

I am going to have to get used to how this forum deals with pictures. Not used to this method. Sorry if things come out strangely, as in the last post where there are pictures inline as well as thumbnails.. which I did not intend to do but can't seem to change.

Next up are the end bells. Machining them was a real chore. More time consuming than difficult. Once again, the use of fixtures is extremely important to insure concentric surfaces. Blanks are cut, then mounted to the fixture. The fixture remains in the lathe until all parts are finished. The parts are moved to the mill where they are slotted and drilled/tapped for the motor shaft set screws.


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[Thorn3]

Following are some pictures of the various motor parts in partial and full assembly. The motor shafts are hardened and polished tool steel. Clip slots were machined using the rotary table in the mill and a diamond slitting disk. Flats for the end bell set screws were machined the same way. Magnets, magnet rings and stators are waiting for final assembly. The stators are hand wound by me to a Kv of 750.

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[Thorn3]

Next up are the motor mounts. These started out as rectangular bar stock. Shown in one of the pictures is an older motor mount design. Ignore that. For these parts a fixture is used to hold the stock in the rotary table of the mill. The one mount shown in the fixture is also one of the older designs, but it is the only picture I have, showing the fixture holding a piece of stock.



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[Thorn3]

The second fixture is designed to hold a motor mount in the mill, to machine the walls to a taper. The fixture remains where it is through the machining of all three motor mounts, to insure they are all the same. A finished mount is shown fitted to one of the three CF tubes. These tubes are thinner than what most people use. They are also different in that they are made with linear fiber inside, wrapped in braid. They are strong enough to support my weight. One picture shows a motor mount in the lathe. This is just to round off where the CF limb enters the mount. The final blending was done with a series of hand files. All mounts were then polished.





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[Thorn3]

I fly FPV. With this in mind, my setup will have a starlight camera for flying in various light conditions, including at night. I also like to be able to look around in real time, so a gimbals assembly was designed. Here are pictures of it so far. I will post pictures of parts being machined next.

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The second (pan) servo has been installed. Now a connecting rod will be machined to finish off the basic assembly.

 

[Thorn3]

It is important for the gimbals assembly to allow equal motion from a common point on both pan and tilt axis. A servo box was needed for the tilt servo and is the basis for both axis. Here is how it was machined.


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After all exterior surfaces were machined, the interior was pocketed for the servo.

 

[Thorn3]

Here are some pictures showing the servo housing completed and the servo installed. Next will be to machine the bearings, pan and tilt brackets.


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[Thorn3]

The pan brackets are machined from 6061_T6 Aluminum, rectangular bar stock. As usual, machine to accurate external dimensions, then proceed from there. Both top and bottom pan brackets are drilled and pocketed together, to insure accuracy between the two.

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[Thorn3]

It is a shame I didn't take more pictures of the processes involved here. Now, two brackets need to be made to hold the camera as well as act as the tilt axis. These are like the other parts, made of the same material, cut from the same type of stock. These two parts are also machined together for the most part, to insure they both align properly with each other at the pivot axis.

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[Thorn3]

Bearings are needed in the gimbals assembly. Igus brand sleeve bearings were chosen due to their light weight and ability to handle the ingestion of debris. Ball bearings would have been a good option as well, but at a cost of weight. All four bearings were machined from round stock. It starts out in the lathe, moves to the mill and back to the lathe to finish. The first bearing is really a coupling to couple the servo output shaft to the tilt axis. It is the longest of the bearings and requires that a spline be cut into it.


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[Thorn3]

Next is on to the shorter, three bearings. These use the Igus sleeve bearings. The process is similar to the servo output bearing/coupling, using the same materials.


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[SoCal Blur]

Impressive! I have a few questions. First, what is it about commercially available motors that did not meet your requirements? Second, How long did it take you to fabricate the motors? And finally, how did you fasten the two motors to the mount? It looks like you actually have to assemble the motors after they are mounted...but that's just a guess from looking at the pictures.

 

[Thorn3]

SoCal Blur: Thanks. My motor requirements are much like a person who builds their own sports car. The engines don't only perform at their peak for a given application, but they are also a work of art inside and out. Form and function follow the overall design. Purchased motors are not designed for a particular model. They can't be, as they don't know what the motors will be used in or for. My motors are designed to be part of the overall design, down to the parts and materials used and processes. Manufactured motors that meet my specs would be prohibitively expensive. In the end, it is fun to develop my own motors. I get exactly what I want, for far less than a manufactured motor. My designs don't have to revolve around motors. I can design the motor to fit my needs, look the way I want them too and seamlessly integrate into my designs. Can't get that from a manufactured motor. If I were to describe all the details as to why manufactured motors are not for me, it would look like I am ripping on them. I don't want to give that impression. Manufactured motors enable thousands of people to build models and have fun with them at a reasonable cost. To me, building my own motors is simply part of the fun of building the model.

I really have no idea how long it took me to machine the parts for the motors. I wasn't concerned with that. Just doing it was fun. I gave up clock watching when I retired.

In order to maintain a 'single motor' look per limb, the method of mounting them had to be changed from the norm. Both motors per limb are built as 'one' motor. There are both technical and artistic reasons for this. Better airflow across both motors, no need for added coverings to give a single motor look... etc. It is all just part of the overall design, using the least amount of material. These motors are unique to this build. Another build will get its own motors for the same reasons.

To me, it is not enough to fly. Creating the model is just as fun.

 

[RyanMcCrae]

Great work so far on this build. Really interested to see how it progresses.

 

[SoCal Blur]

SoCal Blur: Thanks. My motor requirements are much like a person who builds their own sports car. The engines don't only perform at their peak for a given application, but they are also a work of art inside and out. Form and function follow the overall design. Purchased motors are not designed for a particular model. They can't be, as they don't know what the motors will be used in or for. My motors are designed to be part of the overall design, down to the parts and materials used and processes. Manufactured motors that meet my specs would be prohibitively expensive. In the end, it is fun to develop my own motors. I get exactly what I want, for far less than a manufactured motor. My designs don't have to revolve around motors. I can design the motor to fit my needs, look the way I want them too and seamlessly integrate into my designs. Can't get that from a manufactured motor. If I were to describe all the details as to why manufactured motors are not for me, it would look like I am ripping on them. I don't want to give that impression. Manufactured motors enable thousands of people to build models and have fun with them at a reasonable cost. To me, building my own motors is simply part of the fun of building the model.

I really have no idea how long it took me to machine the parts for the motors. I wasn't concerned with that. Just doing it was fun. I gave up clock watching when I retired.

In order to maintain a 'single motor' look per limb, the method of mounting them had to be changed from the norm. Both motors per limb are built as 'one' motor. There are both technical and artistic reasons for this. Better airflow across both motors, no need for added coverings to give a single motor look... etc. It is all just part of the overall design, using the least amount of material. These motors are unique to this build. Another build will get its own motors for the same reasons.

To me, it is not enough to fly. Creating the model is just as fun.

Thanks for the response. I take it prior to your retirement, you were a machinist? I understand the desire to create every aspect of your model. I suppose if I had the equipment (and the skill set) I would do the same. Great work!