Featured Siegetek DSG "mini-tooth" engaging piston pickup tooth.

Discussion in 'Gun Building, Modifications & Repairs' started by Peeque, May 2, 2021.

  1. Peeque

    Peeque Well-Known Member Supporting Member

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    The Siegetek DSG has these mini-teeth right before and after the first and last teeth of each set.

    It is engaging the pistons pickup tooth and starts to pull it back. I've never seen these little teeth on a gear before.
    20210502_124820.jpg 20210502_124836.jpg

    Is it safe to file it down so that it doesn't contact the pickup tooth or is it supposed to do this?

     
  2. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    They are not really teeth, it's the shoulder of the teeth on the gear set.

    Yes, you can file them down, it not anything structural.

    However, you may have other issues if your piston is engaging on the shoulder of the gear set. The Geometry of the hole position of this mechbox seems to be "off".
     
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  3. Peeque

    Peeque Well-Known Member Supporting Member

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    The pickup tooth only touches the sector at the point where the shoulder starts to curve up like a tooth and forms that mini bump.

    What do you mean by the geometry of the hole?
     
  4. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    The 3 positions on the gears - Bevel, Spur, Sector. That axis of holes on the mechbox.

    Now think bigger picture.

    If the holes are not lined up AND in the right position...the geometry changes. Remember this is Airsoft, things are copied from other things, and there are no standards. Where those holes are to be are not defined in a "standard".

    Thus two things are at play here. ID of the Double Sector Gear and hole position that the sector gear sits in. If the hole position is high (and back thus maintaining radius with spur gear), the sector can ride higher. Riding higher means its closer to the piston and in your case, the shoulder is catching the piston.

    I have never seen this with any mechbox using Siegetek DSG's. Some early (Circa 2014) badly made APS mechboxes were like this, however their "thinner" piston mitigated this issue. But, they failed quickly and aftermarket KA POM or others would bind on the sector in a similar manner.

    One thing to check to see is if the gear teeth is bottoming out on the piston. This will shift the piston high on the rails and that could cause other issues.
     
  5. Peeque

    Peeque Well-Known Member Supporting Member

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    The gear teeth don't appear to be hitting the piston rack.

    It's a Retro Arms gearbox so I doubt the gearbox is the problem. If anything is out of spec it's most likely the piston.
     
  6. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    No...not always the case. While Retro makes nice CnC Boxes. If they copied/developed the box with the wrong geometry, they are the cause of your issue and not SiegeTek. SiegeTek has been around far longer than Retro and this issue has never cropped up before with cast mechboxes from the past.

    There is another thread here where people are talking about how a RetroA mechbox doesn't fit correctly and grinding is needed.

    Remember, this is a No Standards Industry, assuming things will be drop functional is becoming less true with each passing year.
     
    Last edited: May 3, 2021
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  7. 1tonne

    1tonne Well-Known Member

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    Yeh. Retro Arms is not perfect and some of their GB's do need work.
    I have seen this a couple of times with old CM16's. The brass bushings were worn and so the gears were not perfectly centred.
    Try new bushings/bearings.
     
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  8. Peeque

    Peeque Well-Known Member Supporting Member

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    I am reusing steel bushings that have been in use for at least a year. The gears do sound like they're zipping. I bought new F.L.T bushings yesterday. I will switch to them when they get here.
     
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