Riviting Front Baffle and Spinner profile cutting

Today I completed the front baffle by attaching the angles and brackets that hold the baffle I used some button head rivits to attach the brackets as they were just sitting around and was what I had. I see no reason to go to all the work to flush rivits in those brackets as it really isn’t required for aerodynamics and the button is just faster and easier. I also went up to my friends shear and cut baffle wrap arounds and had formed them to the cylinder profile and rivited them on to the baffle using button heads again. Once that was done I marked the location for the intake and used the fly cutter (dangerous freaking thing but awesome good at its job as long as your fingers don’t get into an argument with it.) I cut out a large enough hole to accept the SCAT duct flange. I then make a backing plate to hold it on because I wanted to sandwich the flange to the baffle so that I could also include a metal screen that I could change as required. The screen is basically a course filter to keep birds or other big bug or FOD from going down my intake. I know that dust and dirt can still go down it but filters will take away performance and most experimental hard core acro birds don’t have them every little bit of perf counts! Once I finished that I cut and attached a new SCAT duct between the injector throttle body and the front baffle. All I have left is to attach rubber seal to the baffle and secure the baffle to the engine permanently.

I got my prop bolts in today from Saber Manufacturing www.sabermfg.com

I ordered 7″  long bolts with thin washers since I already have a 3/16″ crush plate.   They look nice and out to work great…they better for $96 which is cheap for prop bolts but still freakin expensive.

On to the spinner since I don’t want to fuss with the oil cooler hood yet.  It is 26 degrees outside I don’t have a cooling issue right now so I could just fly as is with no oil cooler duct and be just fine but I will probably finish it before I fly I don’t want to take a cowling on and off all the time once I start flying it.   Anyway I have been avoiding cutting the prop profiles out of the spinner since you only get one chance or buy a new one so getting it right the first time is best! I messed around with profiles using paper board until I got one that fit. Then I mounted the prop back plate, front plate and marked on the back plate where the trailing edge of the prop intersected the edge of the back plate. I needed these marks so I could get the profile template on exact opposite sides of the spinner.  I then took my prop profile and tested it 10 or so times rehearsing exactly how I was going to transfer it to the spinner cone. I then disassembled it all and took the back plate over the the cone transferred my reference marks of the trailing edge to the spinner cone. I then laid my profile on to the spinner cone and traced it on to the cone. On both sides.  I made sure to come up 1.5″ from the bottom to account for the back plate depth.  Once I got both profiles transferred I set the spinner cone over the prop to check to see if I was in the “ball park” and it looked as though I was.   I took my angle grinder  with a thin cutting blade and started cutting.  Kinda scary I have to admit.  I cut the blank out roughly and then came in with a thicker grinding wheel to trim close to my traced profile. Once I got the two sides cut I tried it.  I couldn’t first get it slide on so I cut the back side of the prop profile out a bit more and it fit. It was a little tight so I marked locations to trim and continued…rinse and repeat.  Eventually it fit real well.  I was relieved and excited.  I was also exhausted/hungry so I cleaned up and went home. We had a New Years party to go to anyway.  All in all a very long but productive day.

Time spent 8 hours total time spent 54 hours

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