75mm CTI motors in Aerotech case w/ RAS

Discussion in 'Propulsion' started by richP, Oct 10, 2019.

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  1. Oct 10, 2019 #1

    richP

    richP

    richP

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    Getting ready to begin assembly of a few CTI motors that will be using Aerotech hardware. I read over the instruction for both CTI and Aerotech, and needless to say, they are a bit confusing.
    When using the RAS system with spacers, there is a constant reference to the insulating disk and forward seal disk. Are both to be used?
    Test fitting would indicate that the insulating disk (plastic) would not be used, since the floating forward closure and the seal disk seem to fit together very well. Does this mean that the insulator disk is just discarded?
    Not really sure how this all goes together.
     
  2. Oct 10, 2019 #2

    jd2cylman

    jd2cylman

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    Still not Carl... ;-)

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    With CTI loads in AT cases, ALWAYS use the AT forward seal disc. I bought several extra forward seal disc o-ring for such occasions.
     
  3. Oct 10, 2019 #3

    richP

    richP

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    I guess my question is, in what order does it all go together?
    grain-> grain spacer-> forward seal disk-> forward insulator -> forward o-ring-> floating forward closure-> case spacer-> retaining ring

    It would seem that you'd need to put something between the forward seal disk and the forward insulator; unless the insulator is meant to be discarded.
    Does the seal disk o-ring go directly in the seal disk groove? which then gets inserted into the liner? That appears to be the case the more I look into AT instructions for different motors. Why, why, why are the instructions in different formats, with varying levels of detail?
     
  4. Oct 10, 2019 #4

    jd2cylman

    jd2cylman

    jd2cylman

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    Get rid of the CTI insulator. The AT forward seal disc (with o-ring) goes into the liner. Then
    I didn't write them...
    Try this.... Link
     
  5. Oct 10, 2019 #5

    3stoogesrocketry

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    Grain / seal disk / floating clouser / spacer / spacer/ retaining ring
     
  6. Oct 10, 2019 #6

    richP

    richP

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    I assume that you also wouldn't use the grain spacer if using a seal disk as opposed to an insulator.
    Beginning to make a little more sense now, however, seems odd that there isn't any o-rings between the seal disk and the forward closure. Also, does the seal disk take a beating from motor heat and pressure? How long can it be expected to last?
     
  7. Oct 10, 2019 #7

    richP

    richP

    richP

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    Like this?
    upload_2019-10-10_0-2-43.png

    or this?

    upload_2019-10-10_0-9-58.png
     

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  8. Oct 10, 2019 #8

    jd2cylman

    jd2cylman

    jd2cylman

    Still not Carl... ;-)

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    The first This... :)
     
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