Homemade prop balancer

Another small bag of goodies has arrived from Hobbyking. A power distribution board, low battery alarm and some prop balancers. The prop balancers are the only ones I can use at the moment.

After looking at prop balancers I went for the small handheld options and planned to make my own frame. The only thing I need was some magnets. I got these out of a white board paper holder. they were the perfect size 10mm diameter, they may be a little strong but will do the job.

First task was to use a screw driver to pry the magnets out so I could glue then to the frame arms.

As you can see they can easily hold the balancer and a 10x4.5 prop.

I measured the upright arms to be long enough to allow for the 10x4.5 prop, I cut two arms this length and glued the magnets to the top of the arms.

Next I cut some feet that were long enough to allow for the width of the prop balancer, arms and extra footing to give a stable base. This was all done by eye and the feet weren't measured.

Once cut the first arm was glued to the feet, the square was used to make sure it as perpendicular to the feet. Once dry the other arm was glued on giving 2-3mm extra clearance for the prop balancer so one end was floating.

Completed home made prop balancer.

Next task was to balance a set of props. I got a bag load of 10x45 from RCtimer.com when I ordered the quad frame and motors.  After watching videos and reading I set forth to balance my props.

First stage, balancing the blades, as you can see they took what I considered to be a lot of tape.

Shot of the props with the blades balanced one set it didn't rotate.

Next was to balance the hubs, wow these were way out... I used both sanding and hot-glue to get them balanced.  I second guessed myself was I doing this right .... then one blade was nearly perfect out of the box. So yeah there were some very out of balance props. I would hate to think what it would have been like without balancing the props.

Shot of a prop with the hub balanced.

After this exercise and doing more reading I ordered some 8x4.5 props from Hobby-king  From my reading they should be more than enough for my initial needs and hopefully be closer to balanced than the ones I currently have.

Still the waiting game for all my other parcels so I can get at least one quad flying.

Painting the front guards

While in the garage working on my new "small" winter project I have also been chipping away at the job I hate the most ...painting.

The rear mounts are 95% complete, So I started on the front mounts. These were a complete nightmare to wire brush to get rid of the surface rust. Once I did that they got a coat of black hammerlite and then a sand and coat of zinc grey. 

While I was brushing away with the hammerlite the seat subframe also came in for a coat of paint.

 Left guard drying,

All done ready for top coats.

Next up were the underside mounts, they got a good coat of hammerlite. The fiberglass guard also got a coat of the final satin black. 

All bolted together ready for the top coats.

That has take over 2 weeks of even work to get to this stage. Its rough, but should be well rust proof.

Quadcopter frame update 1

After a playing with the frame I found some flex, I want the frame to be as rigid as possible so I thought about how I could eliminate the flex.

So using a old woodworking technic I purchased a 6mm dowel and proceeded to remove the small bolts in the corners and the screws from the middle brace. I then made the hole larger with a 6mm drill and then glued in dowel plugs.

This certainly reduced the flex in the frame.


Drilling out the top holes to 6mm and then gluing in the dowel plufs with CA glue.

Repeated the process for the middle cross member

I also added two extra cross members using the 6mm dowel. They were placed above center so I could run the wires easily underneath. 

Next step was to light and allow airflow for the speed controllers, the handy hole saw came into good use.

Thats the frame to date, I am now just waiting on all the parts to arrive to start the electronics.

As a backup plan I have purchased a BlueSkyRC xRotor IFrame Quad. This is my failsafe as I really dont like the SM450 plastic frame. However in my hast I forgot that its really hard to get 10mm square wood rods here that are any good (this frame uses 12mm). So I am now on the hunt for some 10mm square aluminum rods.  Either way I will have a flying quad of some description .... until I crash it.

Quadcopter build part 1

Well winter is upon us, and with slow progress going on my other large project .... I felt I needed a small ... more likely to complete project. After spending to may hours on flitetest.com I decided to build a quadcopter.

After a fair bit of reading I finally ordered the following  SM450 Kit  from RCTimer. With the free shipping it was the easiest and cheapest way to get all the running gear to New Zealand. I also ordered more props for learning crashes. I went this route to learn and try large quads out, then if I like it I can source better motors and ESC's.

I spent hours browsing HobbyKing and reading up on Transmitters and controller boards, I finally decided to get a TURNIGY 9X and receiver. Next it was a no brainer that I would use a KK2 board from Hobbyking. Since shipping was one of the largest expenses I added items to the order to get the best bang for my buck. So I added silicon wire, bullet connectors, nylon nuts and bolts, servo leads, USB simulator lead for the 9X,prop balancer, LED lighting strips, 2 Lipo 3s 2200 25c batteries and other assorted bits and pieces. That order is still to be shipped as some items were on back order.  

Now please remember this is my first adventure into RC flying besides those little cheap helicopters you see in the mall. So all the items I rattled off above were decided upon based on reading and watching youtube to see what other people did and what they found best. 

I cannot recommend flitetest.com enough for their great videos and information. I also cannot count how many quadcopter/ tricopter  build videos I watched.  Each provided a little more information to the picture of what I wanted to do. I really wanted to do a tricopter, but for my first adventure I wanted something a little more forgiving for a complete novice, so decided on a quad, Then, not sure how I missed it the first time, I found the Flitetest H-Quad. 

So my main objective with this is to do some aerial video, Once I learn to fly. So the H-Quad looked perfect.
Heres the video of the flitetest build.

Now I know I will crash since I am learning so I wanted to have replaceable motor mount booms. Easier said than done. There were designs out there that had foldable booms. But due to the limits of the tools I had I needed to make it very simple. After looking for material I finally finished up with the following.

16mm U aluminium extrusion (Found in most hardware store in NZ)
10mm x 10mm x 1200mm Pine rods (Found in hardware stores, Mitre10 or Bunnings)
4mmx100mmx500 maple plywood (Hobbyshop)
5mmx100mmx900 Balsa-wood (Hobbyshop)

The hard bit was finding 4mm ply, I still need to find a cheap source. I visited the local hobby store and they have 100x500mm piece which was perfect for my needs, but only one and at a ridiculous price. I still purchased it as I wanted to start the build. 

I now had all the materials, "knowledge" and ideas to start my initial build.

So using my gold plated piece of 4mm ply as the dimension base the h-Quad will be a 500mm. The first piece of construction was to create a way of having replaceable motor booms... This is where my first idea comes in ... hopefully it will work. ..

The booms needed to be replaceable, easily in the field if required, and I wanted to use zip-ties as the fastening mechanism. So using the 16mm U shaped aluminium as the holder the 10mm square rod fits inside, its not a tight fit but the closest I could get. One strip of duck-tape on either the rod or on the inside of the aluminium makes it a snug fit. Which will be more than enough to hold centered in-place while zip-tied. 

10mm rod sitting inside the aluminium U

Using the ply as the base I cut 2 lengths of aluminium 130mm long, this allows for 15mm over hang each side. 

 

A test fit, as you can see the 10mm rod fits in and there is a 3-4mm over hang. So to allow the ability to zip-tie the booms in place I measured 5mm in from each end then using a 5mm file cut 2 6mm notches. This has two functions, it stop and laterial movement of the booms when zip tied. It also exposes 3mm of the 10mm rod so that when its zip-tied the zip-ties have good contact with the rod to hold it firmly in-place.

 

 End mounts mocked up on the plywood base, you can see the notches.

 

The boom mounts were glued in-place, time was taken to make sure that they were square.

 

Using the same 10mm rod the 2 side fames we cut and fitted to the base plate. These were also drilled and screwed to the boom mounts for extra strength. Once dry I also added a crossmember and left a heavy weight on it all while if fully cured.

 

I next cut some motor booms, 500mm long. Below you can see them sitting in the frame. I created 3... planning ahead.

 

Next was to drill the holes in the boom to allow zip-ting of the motors to the booms, The first hold was drilled 10mm in from the end. I also had to drill out the motor mount holes to allow the use of two zip-ties.

 

All three booms done. It will now be an easy process to create more if / when required and I can get the materials from any hardware store. 

 

Drilled booms on the drying main frame.

 

Later on if required I could also create aluminium booms by just reversing the 16mm U and doing a couple of holes for zip-ties

 

A parcel from RCTimer showed up with my SM450 and all the goodies. I made the frame up to compare to the frame I am building.  

 

My H frame  with the SM450 sitting on top. Depending on how my build goes I might Just sell the SM450 frame. I will wait to see how well the flying goes.

 

UPDATE :

This evening I added a cross member to the top of the two side rails to add some extra rigidity to reduce any flex. These were glued and also bolted through both the side rails and the bottom plate. This shot also gives a better view of the notched boom mounts.

This is how the boom will be secured using zip-ties.

The top balsa-wood plate sitting on the frame. I will have to wait for all the other parts to arrive before deciding the best way to secure the top plate.

Testing the CG for the frame, pretty darn close to dead center.

 I am now waiting on all the other shipments before I can start the electronics of the build.

Uncaged

Uncaged Rat - Mike Partyka's '31 Ford from Surface on Vimeo.

Much Much Go

Much Much Go / Full Version from Fuel Tank TV on Vimeo.

Extra strength for guards and fuel tank subframe

After a "few" weeks away from the project I was able to spend some time on it over the last couple of days. Standing back and looking at the rear guard mounts I decided that I needed to add more strength. After a bit of thinking and trying different options I decided to triangulate down to the bottom roll bar mount.

Once again I had to do this all by hand and hacksaw. The first part required was and angle mount for the bottom mount point. This was done using 50mm angle iron. Once cut and drilled I bolted it to the chassis to start on the tricky up stay. This was not easy as there were no straight angles.

First cut was for the angle off the newly bolted on bottom mount. This was cut at an angle so that the up stay was as close to the guard as possible.

With that cut done, the real tricky bit was to try get cut the top cutaway. As it had to be at the right angle and also be a V to slot on the the angle of the existing mount. After a lot of hacksawing and filling I finally had the cut ready for welding. All I had to do now was repeat on the other side.....

The two finished mounts, all welded ready for grinding and a coat of paint. 

Well after a bit of negotiating I was allowed in the garage for a good segment of time. The plan was to wire brush and grind as much as I could to get ready for some painting. That was the intention, but I took the opportunity to finish off the fuel tank subframe.  

Removed Mounts and subframes that needed wire brushing.

The bulk of the subframe and mounts for the fuel tank were complete. I finished drilling the remaining holes to bolt the tank to the subframe, This was needed as I had to repair and straighten the mounts on the fuel tank.

I had previously purchased rubber stoppers to go between the subframe and the chassis. These were fitted. I could now see the final height of the tank and subframe when on the chassis.

Here it is all mounted up.

 

Now that I was happy with how it all fitted up, I needed to put some cosmetic skins on to cover the subframe and also the fuel tank tap. First up was the sides. After some initial drawing and battling with the tinsnips I had my first side done. 

After tack welding it in-place a test fit was done. I must have taken that tank on and off over 50times. Once happy with the fit, rinse and repeat for the other-side. More trial and error and a little use of the hammer both side plates were fully welded to the subframe.

 

After I had finished the sides, It became obvious that I needed to also cover the gap created between  the tank and the chassis at the rear. So after battling the sheet metal nibbler I had two strips 30mm wide that were used to create the skin for the gap at the rear. This was welded to the side skins and a spacer was welded in the middle. ( I forgot to get photos) Now the tank and subframe look like one unit and visually clean and tidy enough for the RattyT. 

After some wire brushing the first coat of Hammerlite was applied. That was it for the weekend.