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  #571  
Old 04-23-2017, 07:31 AM
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DanH DanH is offline
 
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Keep swinging Andy! You're doing fine.

Quote:
Originally Posted by crabandy View Post
Ground run and subsequent test flight went well. The boot does transmit quite a bit of vibration to the oil cooler and the fiberglass duct at idle, above 1000RPM it barely moves.
Remember, your eyes can't see vibratory movement higher than a certain frequency. It's a lot like not being able to see the flicker due to 60 hz AC.

I have an adjustable-rate strobe for looking at vibrating objects. Tuning a strobe to the exact frequency of movement freezes the object so it appears motionless. Tuning just a bit higher or lower puts the vibration in apparent slow motion, allowing visual observation of the entire vibratory cycle or repeating motion.

I have seen propeller blades twisting torsionally as they rotate. I have seen the center of a control pushrod describe a circle about 3" dia at one particular engine RPM; it appeared perfectly still when I released the strobe trigger. I have watched the sides of a fuselage pump like the gills of a fish under the influence of propeller inflow (it was a pusher). And I've watched an entire engine move through its vibratory cycle on the mounts...and it appeared motionless without the strobe.

Point is, although your "no relative motion" observation is probably correct, don't bet on it if failure has a consequence. Put another way, seeing is believing, but your eyes can lie.

Quote:
Part of me thinks I should re-design the boot to be more flexible, part of me thinks it doesn't shake any more than the standard oil cooler location/baffle material/fiberglass airbox. My guess at any failure points would be the adel clamp mounts to fiberglass duct attach points which isn't a safety of flight issue. I plan on more flight time and keeping a close eye on it.
Works for me.

Quote:
I haven't been able to measure any pressure difference in the lower cowling under the cylinders compared to several locations around the firewall.
There's no reason to believe you'll find a pressure variation between any two points inside the lower cowl volume.
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  #572  
Old 06-12-2017, 08:09 PM
crabandy crabandy is offline
 
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Several tanks of fuel later, #4 cylinder dropped 15* and is now right in line with #3 in climb and all cylinders in cruise. Oil temp is close to the same, the lower duct was consistently showing .25 inch H2O less pressure than the lower cowling at cruise speeds. No speed difference was found, structurally everything as installed.

One difference noted, oil temp increases with a power reduction and increased airspeed in descents. I need to measure the upper face of the oil cooler and see how it compares to upper plenum pressure.

I modified the lower duct from mostly constant area to an expanding duct, I sliced off a portion of the duct leaving the attatchment and cowling/engine mount interference points.



There's a Smooth On dealer a couple blocks from work, I grabbed a sample pack of their 3lb density pour foam.



I tapped some damns on my duct and used chunks of pink foam as a "bulk filler." If you use "bulk filler" make sure it is stuck in place, mine wasn't and the pour foam floated the chunks of pink foam to the top as it expanded and I had to do a second pour.



I attempted to make the new lower duct a divergent duct to see if I could increase the pressure differential across the oil cooler.





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  #573  
Old 06-13-2017, 11:44 AM
crabandy crabandy is offline
 
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New lower oil cooler duct installed.





The junction of the oil cooler duct and lower cowling.



I installed a piccolo tube in the upper oil cooler duct so I can measure the pressure on the front side of the oil cooler.

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  #574  
Old 02-05-2018, 08:03 PM
crabandy crabandy is offline
 
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Pic test after Photobucket went rogue..

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Last edited by crabandy : 02-05-2018 at 09:46 PM.
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  #575  
Old 02-06-2018, 08:36 PM
crabandy crabandy is offline
 
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It's been a while....
AnyWho, I've got a litter of older Odyssey PC680's littering my hangar shelves. Seems after 1 year they fail to start the airplane, take a correct charge etc. I've put in various old Pc680's sitting on my hangar shelf 3 times now and it starts the airplane decent. Granted the old battery now starting by RV was removed several years ago because it wouldn't start my RV. I generally fly 3 times a month minimum and (I don't use a tender) only used an Odyssey charger when needed, which seems to be right about a year. Hard to trust an older battery once removed for not starting the airplane for Xcountry trips.
So I did some reading and bought an ETX680 EarthX Battery, why buy their pre-made battery box when I can make one for $4/hour minus materials I already have....
I recieved the EarthX in the mail today, really is hard to believe the weight difference with it and the PC680 in the other hand.
I made a paper pattern to hopefully figure out any mistakes first, it was also way warmer in the kitchen than the garage.



Cut some .063 oversize and started bending things with my el' cheapo brake...



Checking the fit on the battery, the bend radius can vary and change dimensions a lot if you're not careful.



More Bending and Fitting....







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Last edited by crabandy : 02-07-2018 at 08:01 AM.
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  #576  
Old 02-06-2018, 08:51 PM
crabandy crabandy is offline
 
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I used 2X4's along with a scrap chunk of 2X4 and a hammer to bend the smaller lower flanges, I pre-plan the bending as much as possible but on multiple bends you usually have to compromise.



By bending the side flanges first I was able to use the brake to bend the longer lower flange.



I really liked the idea of no hardware to loosen/tighten/loose in the lower cowl to bolt the battery in place so I'm trying to copy the retention flange EarthX has on their battery boxes.





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Last edited by crabandy : 02-06-2018 at 08:55 PM.
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  #577  
Old 02-11-2018, 09:37 PM
crabandy crabandy is offline
 
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The bendable retention flange wasn't so bendable, I ended up using a couple small angles on the side of the box and little tabs as hold downs. After lots of holes it weighed 6.9 oz , I'm curious if the one EarthX sells is .032 material.





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  #578  
Old 02-12-2018, 07:56 AM
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Nice work.

You have over-voltage protection, yes?
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  #579  
Old 02-12-2018, 08:51 AM
crabandy crabandy is offline
 
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Yes, Overvoltage protection via PlanePower Alt and B&C SD8/crowbar module. I also reset the voltage parameters/alerts in th G3X as suggested in the EarthX manual. I’ve hooked up the fault wire to a discrete input, need to call Steinair for verification on wiring.
I do have a bit of concerne about an Overvoltage from the plane power also shutting down the EarthX via the BMS, my SD8 powers my EBUS fine in cruise but lacks the necessary amps below about 1800 RPM. At some point I’ll become a glider in order to land.

I also received a pm about adding a heat shield on the bottom to prevent heat from the exhaust warping the bottom of the battery.
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Last edited by crabandy : 02-12-2018 at 09:08 AM.
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  #580  
Old 02-12-2018, 12:35 PM
EarthX Lithium EarthX Lithium is offline
 
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Quote:
Originally Posted by crabandy View Post
Yes, Overvoltage protection via PlanePower Alt and B&C SD8/crowbar module. I also reset the voltage parameters/alerts in th G3X as suggested in the EarthX manual. Iíve hooked up the fault wire to a discrete input, need to call Steinair for verification on wiring.
I do have a bit of concerne about an Overvoltage from the plane power also shutting down the EarthX via the BMS, my SD8 powers my EBUS fine in cruise but lacks the necessary amps below about 1800 RPM. At some point Iíll become a glider in order to land.

I also received a pm about adding a heat shield on the bottom to prevent heat from the exhaust warping the bottom of the battery.
Hi Crabandy,

Please note, the over voltage protection on the Plane Power is for the alternator to be shut down. The battery would continue to work and run the EBUS until you deplete all the energy in the battery, same as a lead acid battery. For example, the ETX680 has 12.4Ah of energy. If your over voltage protection is activated due to a failed regulator, you are then on battery power only to operate your equipment. If you use 12 amps an hour, you need to find a place to land in an hours time. If you use 24 amps an hour, you need to find a place to land in a 1/2 hour. Hope this clarifies things.
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