FrankenStick - Battery Holder

thingiverse

Here is all part of an idea to make a modular plane based on being able to assemble different wings / tails based on a 25mm round or 22mm square tube 'stick' body. This is ideal for anyone wanting to play with different configurations, based on the idea of a 'stick' plane being an actual stick. I used 25mm plastic conduit but CF tubes would be lighter. Each part has a PDF file with photos to help visualise things plus more info and instructions. I used 3mm and 4mm threaded bar a lot, you could glue CF rods but I liked the idea of just unbolting to replace any damage. This adds weight but not a massive amount. Some of the photos may be slightly different to the STLs as they evolved a bit. This makes the plane in the photos, with a Wingspan of 110cm, Length of 90cm, Front of wing to Prop centre 20cm, and Wing trailing edge to front of tail 32cm. All sizes are not fixed, just recommended averages. The CG is about 1/3 from leading edge of the wing but make it closer just in case, again play around, this is meant to be a chassis for whatever you want to do. Weights are Wing 365g and rest of the plane with motor, servos, nose weight and undercarriage (basically as in photos) 650g. Battery is extra, weight is with PVC conduit 'stick' CF would be a bit lighter. If I make any changes / updates in future I will add them here. If you modify or upgrade any parts (feel free) just link them back to here. Updates – None. So, this is the - Battery. Problem I had was balance on the plane, needed a lot of weight forward so there are two battery holders. Moving the battery forward or back alters the CG depending on your battery weight. Remember slightly nose heavy is better than slightly tail heavy. I glued rubber sheet onto the battery holder and shield for better grip. Print as a perforated grid (see PDF) and you can use a cable tie, or foam block, to stop the battery moving backwards. Printed in 3 parts, holder and two supports. I did the 3 parts as I found it made for a solid print. Needs to be a good print as the holder is also the motor mount. The motor bolts onto the front using 3mm threaded bar. The four motor bolts allows the motor angle to be adjusted easily so you can try different settings (see motor section). There is a battery shield, in case of bad landings, or you could just strap on some foam. There are two versions of a motor ESC holder (Square tube doesn't need this) one loops round the tube to give a flat surface, the other is held by cable ties. Just tie the ESC to this. You can put the ESC in the body if you prefer, or hold it on top with the 170mm battery holder. Battery holders are 145 and 170mm long. The longer one comfortably fits an ESC on top but unless ESC is small the 145mm is tight, but would be ok for smaller planes. 145mm is about the length of a battery, if you worry about the battery slipping back use a rubber band around it. The other battery holder allows the battery to be mounted further back, see photos. My original idea before I realised I needed weight forward so published anyway as may be of use. There is a photo of this. I print the battery parts to be strong and the parts on the 'stick' are wall 1.2mm, top / bottom layers of 0.6mm infill 12%. The battery holder and shield use wall 1.5mm, top / bottom layers 0, infill of about 8-10% and infill line multiplier of 3-4 to give strength and thickness. Other Franken Parts – Body https://www.thingiverse.com/thing:3708532 Wing https://www.thingiverse.com/thing:3708569 Motor https://www.thingiverse.com/thing:3708547 Tail https://www.thingiverse.com/thing:3708553 Undercarriage https://www.thingiverse.com/thing:3708558 Control parts https://www.thingiverse.com/thing:3708544