Not a whole lot to report since the last test. Work work has been time consuming and I haven't had much time to work at the work shop. work.
Last weekend I tried adding a tapping to the bottle jack so I could install a pressure gauge. When drilling the hole I drilled too far and ruined the jack. I bought a replacement jack today but destroyed it in the process of opening it. I think I will just cut my losses and get a hydraulic ram to use with my hydraulic pump (the one i use for pressure testing) as it has a gauge in it.
Today Buren weighed all the components for the vehicle. Excluding wiring, propellant, quick disconnect and relief valve it is looking like the final vehicle will be about 5.9Kg. I am still not sure exactly sure how much I can push the 20mm cat pack thruster but assuming a modest 4Kg thrust the vehicle should be able to start with 5Kg of propellant which should give a decent run time. I have given a significant amount of worry that 3 thrusters wouldn't be enough to lift the vehicle so it was good to get some facts.
We now have most of the bits we will need to complete the vehicle. We have made a few small deign changes around the placement of the engines. It was going to be difficult to have them mounted to the base plate as it would mean lots of bending in the stainless tube. They are now mounted on extensions which are attached to the base plate. I was also worried about the plate heating up from contact with the hot engine so the new arrangement also fixes that.
The plan is for Burren to get most of the structure finished by the end of this week. On the weekend we are going to do another thruster test to make sure we can get smooth thrust then next week we can machine and assemble the 3 engines and install electronics. There are about 2 days of machining in the 3 engines which I will do. After thats done I will move on to programming and Burren will be installing and wiring electronics.
I doubt the vehicle will be at the point where I will feel comfortable doing a hanging test at the end of next week but I don't think a strapdown test is too much of a reach.