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Bill, not certain I am following your
thought. Are you indicating that my seals became very hot as a result of
the malfunction? - please elaborate. If they did I presume you are saying
that they might have had their hardness reduced by the extreme heat?
Just the failed rotor seals or both?
I was pumping a lot of gas through the engine
trying to keep the rpms up. Of course the fuel going through the damaged
rotor was just blowing through most likely.
However, I really don't know how significant the
difference in hardness between my seals and Rusty's. This may mean nothing
or could be significant. Perhaps Tracy will come back home and give an
opinion.
Ed
----- Original Message -----
Sent: Friday, May 06, 2005 12:38 PM
Subject: [FlyRotary] Re: Seal
Hrdness
You do
have to "temper" this information a bit (so to speak.) It is more than likely
that your seals became VERY hot in the last few minutes of engine operation.
At 07:25 PM 5/5/2005, you wrote:
Thanks
Bob,
Verrrryyyyy Innnteerreessstinnngg. So it does appear that my
seals were "soft" at least in comparison of the Hurley seals of Rusty.
Only one area of the six areas you tested on my seal was above Rockwell 30 -
whereas 11 out of the 12 areas tested on Rusty seal were above Rockwell
30. Also one hit on my seal indicated a Rockwell hardness of only
23.1. I am not knowledgeable enough to know if those difference are a major
significance or not - but it does show the metal in my seal of less hardness
than that of Rusty.
Your findings plus (as you noted) the ridge of metal gouged
out of the seal by apparently its rubbing against the top edge of the apex
slot indicates to me that my seals were likely less that they should have
been.
Appreciate you taking the time and trouble, Bob. Should have
sent you one of Tracy's to test as well - but mine were all in the engine
{:>)
Best
Regards
Ed
- ----- Original Message -----
- From: Bob Perkinson
- To: Rotary motors in
aircraft
- Sent: Thursday, May 05, 2005 8:28 PM
- Subject: [FlyRotary] Seal Hrdness
- OK here are the HARD
numbers, but first let me give some detail on what equipment I used and
how the tests were conducted. The equipment used was an Equotip 2
portable hardness tester, manufactured by Proceq Sa,
Switzerland.
- The following is an
explanation snagged from there web site.
- “The EQUOTIP 2 metal
hardness tester is a light weight, yet powerful portable hardness tester
for all metallic materials. It measures the Leeb value (L) for
materials, which is a ratio of the impact velocity to the rebound
velocity. This L value is then converted to standard hardness scales
such as Rockwell, Brinell, Shore, and Vickers using conversion tables
stored in the display unit and generated from the original Leeb
block.”
- I had mentioned in a
previous post that the numbers that I generated when testing the stock
seal were jumping around. Well like the old saying says, “when all
else fails read the instructions.” The seals are not thick enough to
be tested without providing a good support, in fact they are at the
minimum thickness for the impact device that is used. So the seals
were coupled to a heavy support base for the test.
- The seals were tested in
three locations on each side, the straight side end, center and the corner
seal end. Each set of figures represents 3 impacts, the first figure
is the LOWEST “L” value in the series, the second is the HIGHEST “L”
value, the third is the RANGE the forth is the MEAN “L”, the fifth is the
HARDNESS. In the first series, “L” value is converted to Brinell
hardness, in the second series “L” is converted to
Rockwell.
- Min
- Max
- Range
- Mean
- Hardness Brinell
- Rusty Duffy
- Side 1
- 574
- 581
- 7
- 577
- 298
- 574
- 590
- 16
- 580
- 302
- 578
- 597
- 19
- 585
- 307
- Average
- 302.33333
- Side2
- 560
- 573
- 13
- 566
- 286
- 569
- 584
- 15
- 578
- 300
- 586
- 598
- 12
- 591
- 314
- Average
- 300
- Min
- Max
- Range
- Mean
- Hardness Rockwell
- Side 1
- 571
- 593
- 22
- 580
- 31.4
- 578
- 582
- 4
- 580
- 31.4
- 561
- 563
- 2
- 562
- 28.8
- Average
- 30.533333
- Side 2
- 576
- 578
- 2
- 577
- 31
- 578
- 583
- 5
- 580
- 31.4
- 583
- 587
- 4
- 585
- 32.1
- Average
- 31.5
- Rusty's Broken Seal. Only tested in 2
places
- Min
- Max
- Range
- Mean
- Hardness Brinell
- Side 1
- 571
- 600
- 29
- 584
- 306
- 565
- 588
- 23
- 576
- 297
- Average
- 301.5
- Side 2
- 588
- 592
- 4
- 589
- 312
- 580
- 600
- 20
- 587
- 310
- Average
- 311
- Min
- Max
- Range
- Mean
- Hardness Rockwell
- Side 1
- 558
- 580
- 22
- 570
- 30.1
- 576
- 588
- 12
- 584
- 32.2
- Average
- 31.15
- Side 2
- 576
- 588
- 12
- 583
- 32.1
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