Sep 28 2009

Prototype Oil sump….done

The sump is done!  At least the prototype is.  It has been sent off to Calif to the fabricator.  I cant wait to see the production model! 

This weekend was a little of a setback.  When started putting the parts in Acad and modeling the sump for the fabricator, I found out it would have been very hard to build.  Oops!  Back to tweeking the angles, distances, positions until I had a fuller understanding of what was need modeled.  After remodeling it again in Acad and all was good. 


I tried bending mock up tubing to be sure I COULD bend it and adjust for slight differences in tube lengths which is a problem when you are making very short straight runs.  I now have to send the fuel servo back to Airflow Performace for a second time to have them reposition the fuel outlet and reverse the mixture valve all of which was done for for  first prototype.


When you look at the first sump, this one is certainly much simpler, easier to build and yes,  ..elegant… but lacks the coolness factor of the first one.


7.3 hrs worked

Sep 23 2009

Oil Sump Prototyping Part 3

Yesterday, I continued work on the sump and made 3 fuel probes.  One for pPod and two for Toan’s plane.  It is surprisingly fast to make them.  Now if I could only get Princeton (the electronic’s part) to finish modifying their system so I can use the probes I’ll be set! 


Today, I almost finished the sump.  I want to ship it off tomorrow.  The last piece of the puzzle was the mixture control arm.  I am using a bell crank which is mounted on the shaft of the throttle butterfly.  It is mounted to a bearing so each control (throttle and mixture) can move independently even thought they are on the same shaft.  Getting the clearances and ensuring it is easy to make for a production enviroment was critical.  I designed the arm in Acad then made about six of them adjusting the size, length and angles a little at a time until an optimum combination was found.  


 The last thing to do is to mount everything, pipe all the fitting to ensure no interferences and ship it off… 


Hrs worked 8.2.

Sep 21 2009

Oil Sump Prototyping Part 2

Work continues on the oil sump.  I tired all kinds of different positions of the purge valve and flow scan which was very frustrating until I found one which I think is perfect.  What I like most about the new sump is that it is very easy to manufacture and you can remove the bracket to do maintenance on the fuel servo.   The sump only needs 8 threaded bosses welded on to attach various  components.  The long welded brackets and bell cranks of the first sump are gone and the piping layout is also simplified.  Overall this sump is much simpler, compact and eligant than the first prototype.



Tomorrow the parts from Aircraft Spruce will arrive and I can make a proper bell crank and mock up the piping.  The sump will be sent to the fabricator in Calif on Wednesday for production. 

Hrs worked 8.1

Sep 18 2009

Oil Sump Prototyping Part 2

Spent the first part of the day ordering supplies from ACS which I dont like to do.   It is not the cost of the parts, but the shipping that kills me.    I usually try to order a bunch of stuff at one time to reduce the costs.  Work continues on the new prototype oil sump.   The fuel servo is mounted and positioning is much better than the first oil sump.


The servo is tilted down which helps with angle of the air tube.


The nice feature of this setup is I only have one bell crank for the mixture which actually uses the fuel servo shaft as a support.  I dont have to weld on any additional brackets for the bell crank.   Mounted is a temporary bell crank which will do fine until I get my bearings in to make the permanent one.


This is where the Pmag coils will mount.  I made a weld template so the fabricator which will ensure the hole spacing is exactly right otherwise the coil mounting will have a problem.   Only a few more parts to locate and then I’ll start welding brackets onto the pan.


Hrs worked 7.4