Ultra Micro Baby Blender

The baby blender is my all time favorite plane, so I decided to see how it would fly if I shrank it, keeping to the original proportions as much as possible. To make one about the size of one of the popular commercial “ultra micro” planes, I printed the plans at 60%. I used depron rather than Adams foam just because I have never used it and wanted to try. It is 6mm everywhere, except the top of the airfoils, which are 3mm, and coated on one side with tape for colour and rigidity. 

I followed the blender plans more or less, so don’t have ‘build instructions’. But I took a couple photos to show a few changes or areas of interest. 

Overall, the plane has the same shape and proportions as the baby blender. The wingspan I went for was about 360mm (14”), or 60% of its big-baby cousin. 

The wing attachment uses the same system, with elastics inside on the back to miss the ailerons. I used sections of bike tire inner tubes, which I always use for high quality elastic bands. All three servos are hextronic 5G. 

The airfoil is created in the same way as the Baby Blender, except the top side is 3mm depron that is taped to the bottom 6mm depron before bending, and the bottom is tapered at the attachment. The 3mm depron is still scored and folded the same way, the tape on the outside provides the support. The spar is 6mm depron. The reinforcements you can see on the struts are advised because depron is more brittle and this is a weak point of the blender in general. These upgrades were added as results of a full throttle collision with a steel fence (only damage was the struts). I put skewers on front and back and attached with some extreme packing tape. 

The tail is just like the big Blender, with a skewer linking the elevators. The only difference is I left out the small piece sandwiched between the fuselage sections that attaches to the rudder, and just taped the rudder to the end of the fuselage. 

 I took the case off an OrangeRx 6ch receiver and replaced it with shrink tube to save weight. Probably the space savings was more important, weight does not seem to be an issue. 

 I stick engine pictures on the front of Blenders in general, and for this one it also hides a quarter coin (Canadian, so its really made of nickel) that is glued on the front for balance. This is the only CG change I made, and was probably unnecessary. The power system is reviewed below. 

Another upgrade I always do is gluing a thin (0.5mm) CF sheet over the foam with the skewers that hold the Power Pod in place. I find these rip out otherwise if you crash a lot. 

This did not need to be swappable, but because I thought it would be cute, I made a Power Pod anyway. Much as in the plan, but thinner to take into account the size/width ratio difference due to the 6mm depron. A scale Power Pod would be too wide. The ESC is a Turnigy Plush 12amp, which barely fits in the pod. I originally tried the Turnigy C1822 motor (14g, 2100kv), but it did not have enough power, so I changed it for the Hextronic 24g (1500kv), and that seems like a good fit. I use a prop saver and an 8X4.5SF propeller. The Power Pod is held in place by the two front skewers through the firewall and the back one, as in the plans, but I also always use an additional skewer just behind the firewall. Great for big crashes. 

Initially I used a 280mAh 2S battery with an e-Flite balance plug, so I just put pins on the ESC to connect it. This was attached to the bottom of the Power Pod by velcro. This give the plane a huge power to weight ratio, but short flight times (5 minutes or so). I also tested (see video) a 3S 1100mAh which I had to tape into place because it is so big (see photo). Despite this battery being ridiculously oversized, the plane still flew great, though it no longer glided well (no surprise there - the plane weighs in at 175g with no battery, and this battery is about 85g), so when you kill the power it nosedives. I have also flown it with a 900mAh 2S, it was fine, glided okay, and gave long flight times (never actually used the whole battery so don’t know how long exactly). I think a 3S with about 900mAh, ideally with a width similar to the Pod will be perfect, but I don’t have one to try yet. 

Here are a couple views of the finished product for scale. It is a bit bigger than my radio, and a lot smaller than a Baby Blender. The big cousin shown here has a Baby Baron ‘paint scheme’ that I plan on doing a post on shortly. 

Flying (see video below) it is a lot like a Baby Blender. It turns on a dime and glides great. Does fantastic snap rolls and takes off fast. I give it huge rates and lots of expo. In fact, its a lot like a Blender, but more so, everything is faster and more responsive. It can probably take off vertical, and can do simple 3D stuff (hovering, weird stationary twists with the rudder, I don’t know 3D, but it looks like that to me). It is also pretty tough. I put my Baby Blender through a lot of punishment, and this seems up to it too. Early on I had a big smash with a fence and it was all fixed in the field with a bit of tape. It glides in for landing well, but then usually flips up side down, like my Blender, but its so light it is hard to break. I put the wheels way far forward and this helps, especially with take off, which is effortless. It is LOTS of fun to fly and you can keep it in a very small space. I imagine you could do a lot in a big gym indoors, and a small park is no problem. I highly recommend making one. Total build time was a few hours - a lot faster than the Baby Blender partly because depron seems to cut better and partly because there is so little surface area to tape.