MIA UPS™ Universal Palm-Size Heli Frame.

 

Version 1 and Version 2

 

PLEASE NOTE There are two versions of the MIA UPS frames. The assembly is the same for most of the frame construction,  except for the main shaft bearing blocks and LG.

Version 1 - had G10 fiberglass bearing blocks, and metal spacers for the LG.

Version 2 - most recent, has the white square plastic Telescopic tube bearing cups and the LG does not require the metal spacers since the LG struts are glued on.

The reason for making Version 2 was to provide an easier bearing block for the user and Lighter LG.

BEFORE ASSEMBLY

Please study the photos and test fit all parts first. Make sure you understand how they go together before Gluing with CA glue.  The assembly photos are self explanatory but if you have questions, please email us for clarification.

Version 1

 

 

     Version 2

       

        This Kit is latest and is supplied with pre-assembled bearings blocks to take the Walkera 4G3

       ball bearings. There are some extra white square blocks in the kit, in case you wish to do your

       own bearing blocks, for other size ball bearings, such as for the Walkera 4#3, this would be

       useful if you plan to use this frame for a full brushless 4#3 B conversion or similar. 

 

       The options with the MIA UPS™ frame Kit are many. With some imagination it can also work with   

       other similar small size helis, such as the Walkera CB100, or the Walkera 4G6- 4#6 with a brushless

       motor on the tail.

 

       Note that the 4G6 and 4#6 helis are driven by gears via a torque rod  through the boom,

       Walkera did this after doing the motorized tail version with the earlier 4G3, but many people may  

       find that the geared drive for the tail, as on the 4G6 and 4#6, is more troublesome to tweak and

       repair, and thus one can convert these back to BL direct drive tails with the MIA Frames for a more

       robust and easier to maintain setup.

 

       I started designing small electric helis, more than 25 years ago with motors on the tail

       because of the simplicity and ease of maintenance this particular setup offers, especially for

       beginner pilots or just anyone that wishes a more simplistic and easy to maintain setup. The MIA

       Robin 280 kit was one such early kit and several other MIA sizes, which I designed afterwards, 

       employing a motor on the tail. Similar configurations followed  by other companies for the same

       reasons as I described above.   I still prefer motorized tail rotors vs. mechanically driven tails on

       these small Palm-Size helis. But it is hard to realize the pros and cons of each particular setup,

       mechanical vs. motor driven tails until one tries several RC helis in various sizes and configurations.

     

       Please keep in mind that today's light-weight technology is offering a lot more in terms of power and

       control than it did 10 years ago.  A good BL tail motor coupled with a high resolution, high precision

       ESC will provide precise and instantaneous tail control. In addition, all the MIA Frame Kits are

       designed with longer and more robust booms to add additional natural counter torque control an

       minimize work on the tail section. In many of MIA early G10 frames for the Walkera 4#3, for example,

       you could, and still can, simply go direct drive with a regular stock or BL tail motor, similar applies to

       the MIA UPS™ frames. 

 

 

       The New Ball Bearing Block Details

Some details on the new bearing blocks, in the development of the MIA UPS™ frames, I struggled a bit making a final decision on the the final look of the frames, because the original MIA Upgrade frames had 3/16" square ball bearing blocks that worked well with the 4#3 smaller main shaft ball bearings, but because the the 4G3 has larger ball bearings it requires a much larger bearing block.

I didn't want to change the width of the frame support blocks which are also 3/16", because these work perfect with the required location of the 4-3 servos, both in the Fixed Pitch and CCPM setups. But I needed a way to allow for the use of larger ball bearings for the 4G3 without disrupting the standard separation width of the main frames upper vertical plates. I also wanted total versatility in using the same frame with 4#3 mechanics and other similar size helicopters.

My solution for the ball bearing cups, was to not use the G10 fiberglass ball bearing pieces as in my original UPS design, Version 1, in previous photos above, but opted to go with the telescopic white blocks to manufacture the ball bearing cups for the 4G3 main shaft ball bearings.

Basically the original 3/16" square block , that is used in the MIA Flex and Rigid original frames, sits inside a 1/4" square block, with ball bearing depth set by the ball bearing thickness itself, this is separated into two ball bearing cups, one for the top and another for the bottom. I am very glad I did this with the white blocks, as described for the ball bearing cups, as this worked extremely well.

In contrast, the MIA Flex and Rigid frames come with a 1" long piece of 3/16" square tube with the bearing cups pre-formed on the block ends, top and bottom.

Two small details I should point out, the base of the frame as well as the top rectangular G10 plate act as reinforcements for the ball bearing white block cups, so no need to ever worry about the white pieces cracking, you can see this in the following photos. This is probably the only area that I wanted to focus more on since the rest of the assembly is pretty straight forward, especially if you are already familiar building my earlier MIA G10 frames.

Because I did not want to increase the width of the frame's main vertical plates, by going with a 1/4" frame separator main bearing as well as boom support blocks, I elected to do some cut-outs on the G10 frame, around the ball bearings, top and bottom,  to allow the 1/4" block sections to clear, yet maintain frame inside wall separation width  at 3/16" which makes the frames very slick, and with direct same G10 material tongue and groove pieces for the boom supports. This allows the use of larger OD booms, 3/16" OD without the need for the white square block boom reducers.

In other words, one need not use the white 3/16" blocs as in the original flex and rigid frames but are supplied in the kits, anyway, as press fit boom adapters. This means one can use a 3/16 tubular aluminum or carbon boom, or smaller diameter as in the original 4#3s, or even the original square one in the 4G3. The kits do come with stronger booms as in the Flex and Rigid upgrade kits.