215 Hopper – GoPro Mounted

Just like that I have mounted the GoPro Session to my 215 Hopper. Having a 3D printer on hand is really cool!

215H-17

There was some delay between coming up with the design and printing it as I managed to break the printers glass build plate, my parts were sticking too well. Previously I was using the glue stick approach for 1st layer adhesion but I suspect I may have been a bit heavy handed with the application.
After replacing the glass I decided to try acetone/ABS slurry applied to the bed and have been very pleased with the results. Applying it is simply a matter of squirting a couple of milliliters of acetone on to the bed and then swirling a failed print (preferably of the same colour) around in it until it starts to become tacky. I’ve noticed a couple of advantages to this process. Firstly the surface quality of the bottom is as smooth and polished as the glass. Secondly, and more importantly, as the bed cools the part almost completely separates itself.  Only the slightest twist or push is required to remove it. Further cleanup of the bed is not required unless you intend to change colour as the next application of acetone will simply absorb anything left behind.

215H-16

The concern I had about prop. clearance to the straps on the side has proven not to be an issue.
I’ve not had a chance to fly with it in place yet so I’m not really sure what sort of result I am going to get with hard mounting and the 20° angle but when I do the footage will be here.

215 Hopper Sneak Peak

It has been a while since my last update. Primarily due to the holiday season followed closely by an international getaway which spanned several weeks (some photos from my adventure will appear here in the near future). Since my return I have started to put together the 215 Hopper. It is not quite complete yet, there are still some wiring details to complete/tidy up however it is close as can be seen below. After the maiden flight I will put together a full write up on the parts, build, what I’ve learnt and how it has worked out.

215H-10

This progress also means that the Spidex 220 has officially been decommissioned.

215 Hopper Ready For Build

Thanks to my friend over at Steelcity Electronics I now have all the required 3D printed pieces on hand to build my 215 Hopper Quadcopter. Unfortunately I was a bit distant from the printing process as our schedules simply didn’t overlap at this time of year. I had hoped to have a closer look at it and learn a bit more throughout the process. That will Have to wait for next time. There is some cleanup and finishing work required as part of the build process but that was by design to ensure a nice fit.

215H-1

Also shown in the photo above is the printed circuit board as received from DirtyPCBs. They are my go to for prototype PCB’s at the moment as their prices and options really can’t be beaten so check out what they have to offer. I will also let you know that the 10cm x 10cm size they state as the limit for the higher price point is not in fact a fixed limit. This board (fabricated as a connected pair as shown) had overall dimensions of approximately 15.5cm x 8.5cm which is just over 130cm². Thats an extra 30% more area that the quoted size of 10cm x 10cm and they were made without a question or hold up.

215H-2

This was the first time I produced connected boards. DirtyPCBs is particularly suited to this as they will happily cut internal profiles/slots at no extra cost. The snap tabs drilled with small holes approach worked very well and the edges clean up easily and quickly with a small file. I have found a couple of small errors on the board but no show stoppers thankfully.

Next up will be a full bill of materials and build log. If everything works out then I will also supply the files for 3D printing should anyone wish to duplicate what I have created. That however (and unfortunately) will have to wait several weeks.

VersaCopter Motor Mounts

Through the cumulative effect of multiple crashes and initially over tightening I managed to snap one of the G4 plates that make up the motor mount tube clamps on the Flite Test VersaCopter. Unfortunately at the time I ordered the crash kit for the VersaCopter it didn’t twig that these plates were sold separately. As such I was faced with either making a very small order with Flite Test for replacements or coming up with my own solution.

I took this as an opportunity to test my tube clamp motor mounting method and the folks over at 3dprint-au.com both of which are critical elements of the MultiChase project. I knocked up a very quick model of a direct replacement part for the Flite Test designed tube clamps and sent it off for printing. 3Dprint-AU use an SLS printer which I hope will provide better dimensional accuracy and a more homogeneous structure than a FDM style printer.

VC-13

The results are not as spot on as I expected but I generally found the parts are oversize rather than undersized. For example the bottom edge of the clamp, as shown above on the right, is raised rather than rounded as designed. A quick touch up with sandpaper (applied only to the motor side) brought the overall measured height down to the designed number. Also interesting to note here is that the ‘black’ material offered is actually just the white material dyed black on the outside. I’m not sure of the specifics of this process, if it is done by the print head or if it is done as a post process but it is something to bear in mind.

VC-10

To ensure a nice clean holes for the mounting bolts I actually printed the hole under size and drilled them out as appropriate, they are shown here as printed.

VC-11

The installation process was simpler than the flight test motor mounts as there are less pieces to hold together. I also think it looks cleaner than the original pieces.

VC-12

Strength wise I have no doubt that this well be less susceptible to the same style of failure as the original design. Everything is nice and snug with no visible deflection when tightening. That does however raise some concerns about the next failure. My mounts fit much more tightly around the tube and seem much less inclined to rotate as the originals would in a crash. This could make the frame itself or the arm tubes more vulnerable. Despite the much bulkier appearance these mounts only add 1.7g per corner. Each printed half weighs 4g for a total of 8g per corner whereas the Flit Test design weighs in at 6.3g per corner.

Now it’s time to get this rig back in the air, it has been several weeks since I broke flew it last.