Custom Aluminum Frame

[skray775]

Had time to cut the mounts from aluminum today. I went ahead with the 19mm servo arms as I was using 20mm before. This should give me a bit more clearance for the scorpion motors.

I had to order a 19mm reamer and some 2.5mm taps so it will be a bit before I have it together.

[Varc]

So how soon will we be flying Kregan Helicopters?

[skray775]

Ha... Not sure I am ready for that. Once it is all together I might make a few for the people interested if time permits.

I still have a lot to learn about CNC machining and getting nice finish cuts.

[kauaicuda]

What are you doing with the 19mm reamer that you cant do on your mill?

Just wondering. Nice work!

[skray775]

The main bearing pockets... I could cut it to full size with the mill but a reamer will be more will be more accurate. Nothing worse then a sloppy hole! LOL

I also need 2.5 mm taps for the servo mounts, already had the 3mm for the side holes. I also needed screw machine length (short) drill bits for both size taps. Regular drill bits tend to wonder around, screw machine bits are about 1.5 inches long and will not wonder offline so easily.

I am fully equipped with drills, taps, and hardware for small 2/56 - 10/32 inch size stuff but not so much in metric even though I like metric better then inch.

[kauaicuda]

Cool info. Do you plan on assembling both bearing blocks on the side frames and reaming them at the same time? I guess that would be the best bearing alignment you could get.

[fastflyer20]

Originally Posted by kregan

The main bearing pockets... I could cut it to full size with the mill but a reamer will be more will be more accurate. Nothing worse then a sloppy hole! LOL

I also need 2.5 mm taps for the servo mounts, already had the 3mm for the side holes. I also needed screw machine length (short) drill bits for both size taps. Regular drill bits tend to wonder around, screw machine bits are about 1.5 inches long and will not wonder offline so easily.

I am fully equipped with drills, taps, and hardware for small 2/56 - 10/32 inch size stuff but not so much in metric even though I like metric better then inch.

A boring bar is a great way to finish the bore for a bearing, then you can hit the exact dimension you want and it can be used for many different sizes. See link below for one example.


http://www.use-enco.com/CGI/INSRIT?P...&PMPXNO=951762

[banditpowdercoat]

I 2nd the boring bar's Excellent tools

[skray775]

Yep a boring bar is another option and I already have one.

OK so I opted for a V7 with the servos well removed from the motor like the picture Big Fil posted.

In my initial planning I had a drawing like that but the elevator servo had to be moved and that meant the loss of the stock anti roll bracket so I ended up trying place the servo's up front. That would work with a norrow motor but not a wide motor like a scorpion 4024 series.

In version 7 will have a new anti roll bracket that will be screwed to the back of the upper bearing housing.
It looks like everything is working out so I will cut a left side frame tomorrow.

Here are some pictures.

[couchcommander]

Awesome work! I cant wait to see it finished.I will be the first one ordering!......

[skray775]

OK I am just about done test fitting. I have made and installed:
Left frame half
Lower G10 frames
Landing gear brackets

Everything seems to be working out so I plan on pulling it apart cleaning it up and assembling it as soon as I have a bit more time.

I tried glass beading the aluminum and I like the matte finish it gives so that will be done also.

One it is all together I plan on ordering some black G10, gray would like nice if I can find it. I also plan on going back and tweaking the frame a bit more to lighten it some.

Here are some pictures from today.

[Stillakid]

That is some nice work there Kelly, we all look forward to seeing the Kregan Kopter flying.

[Varc]

Nice!

[fastflyer20]

I bead blasted parts for my motorcycle and also liked the matte finish. A clear coat will keep them looking great, the uncoated aluminum discolors easily.

[whoanelly]

[clank72]

How would you go about making hubs and blade grips?

[skray775]

Update,

I spent some time and tore everything down to finish things up. I am now starting to put is back together for a test flight.

While everything was apart I did some weight comparisons:
Roto Works frames, stock landing gear mount, and the push pull system weigh 9.2 oz.
My upper and lower frames, bearing blocks, and landing gear mount = 9.2 oz.

In order to get this in the air I need to buy another micro beast or I have to take the one I have off of my current machine so it may be take a bit to get it in the air.

Here are some pictures.

[Varc]

Nice but quick question. What's with all the triangular shapes in there? Is there an engineers reason behind it?

[fastflyer20]

A triangle is the strongest geometric shape, just look at a Ducati motorcycle frame

[Corvette & Copter Guy]

Originally Posted by Varc

Nice but quick question. What's with all the triangular shapes in there? Is there an engineers reason behind it?

Triangles make for great load distribution/strengh. If you look at a roll cage or steel framework of a building, you will see the same thing.