Knurrus Maximus FPV build and my general ramble about it

Knurrus Maximus FPV build and my general ramble about it

The last few months I have been saving every penny to build my lastest FPV machine. This is my 5th fpv plane build (may they RIP) and I am hoping to take a lot that I have learnt from previous builds to this one. One thing I have done that I am not pleased about is the location of the GPS. It was meant to be on the other side of the wing but so far my testing shows no ill effects.

Since I have a very limited budget I have had to go cheap in some areas. Some parts I have taken from other planes. I really wanted to try the Zephyr 2 but getting it here to Germany would cost around $200 if not more after tax. Luckily I found the Knurrus Maximus FPV.

I really wanted to try out a good budget motor that had the same kind of specs as the hackler 30L. I went for the HK sk3 turnigy 3542 1185kv. I am sure it won't be as comparable in quality but it is a cheap knock off. So far with a 10 x 7 folding prop I have tested it to 375 watts on S3 batteries.

This was my first thoughts on the layout. Mind the servos as they were just stand-ins. I was waiting for the HS-645MG to arrive. Small budget means I have to buy gear slowly. To get to this point has taken 3 months

Spars arrived as did the motor. I have 3mm spars along the LE and 4mm in the middle. This was done top and bottom.

Motor mount in and holes cut out for where the gear was going in. This plane was going to have the simple osd xl in it but after some testing I decided to go with the dosd. My lovely twinstar gave up the required electronics (DOSD, LC filter, current sensor, GPS and LRS receiver). It needed rewiring anyway!

This is where i am up to. I am using S3 batteries as my budget just doesn't stretch to buying more batteries this year. All up so far it comes in with 2 x S3 3300 mah nano - tech batteries at 1497 grams. I still need to cover it with some light fiberglass in some areas. Light paint job, add servo connection, wing tips and lam. I am sure the weight will add on. I am now at the stage where I am testing the osd and everything else. I have found one wiring issue but it pretty east to solve. So far I have made a battery connection that goes over the top to the batteries. After flight testing of the cg I am going to sink the batteries into the foam and cut a channel to the bay.

I hate wiring hell so I have cut all cables to length. Only thing I really need the bay for is the osd and anything later that I might want to add. The baro is sunk into the foam on the side. The +ve and -ve from the esc will be cut short after all testing.

This is how I sorted my transmitter. This is 2.4ghz but I wanted to be able to change it out quickly with my 5.8ghz. The cover on the end holds the antenna upright. Helps with the quick change over since I need to use CP antennas on 5.8ghz.

Receiver with the chainlink from the twinstar. I am adding a discovery buzzer to the place where the servos should go. I am going to unsolder one set of wires and set the buzzer on a spare channel. It will be turned off on default but I will use a switch as to turn it on and off when I want. Also during failsafe it will be turned on. This might work as planned as I see a few what ifs when connecting it in. This is what the testing stage is about .... I will get it working in some fashion.

that is all so far. Busy weekend with family so I hope to get stuck in again next week.