JK Hawk Retro

Used example stripped by Chris Frost in September 2021

JK Hawk 7

Used example stripped by Chris Frost in December 2021

The motor had gone slow in use. On test it was taking over twice the normal current when free running on 4 volts

JK Hawk 7

Used example stripped by Chris Frost in January 2022
The motor had intermittently been going slow then returning to full speed.
The can is marked with a row of 7s, these don’t show up well in the photo

Appears to be made on identical tooling to the JK Hawk 7

Appears to be made on identical tooling to the JK Hawk 7 stripped in 2013, However it had a row of 7s etched on the can

Appears to be made on identical tooling to the JK Hawk 7 stripped in 2013, Like the one stripped in December 2021 it had a row of 7s etched on the can

Stack dia 13.04mm
Windings tied at comm end, potting penetrates windings at the comm end which retains them better than the earlier sealed motors, but the rest of the windings are unrestrained (like the other motors)

Stack dia 13.07mm
No evidence of the arm being balanced.  

Many other examples of the Hawk 7 do have metal removed from the stack indicationg they have been balanced.

One com segment fell off during dismantling.

Stack dia 13.07mm
No evidence of the arm being balanced.

Windings tied at comm end, potting penetrates windings at the comm end which retains them better than the earlier sealed motors, but the rest of the windings are unrestrained (like the other motors)

Wire dia 0.26mm with insulation Dia 0.0091 to 0.0092 inches (approx 0.231-0.233mm) without insulation

Turns 65 (1 pole counted)

Wire dia 0.29mm with insulation Dia 0.0092 to 0.0093 inches (approx 0.233-0.236mm) without insulation

Turns 59 (all 3 poles counted)

Wire dia 0.29mm with insulation Dia  0.0093 inches (approx 0.236mm) without insulation

Turns 59 (2 poles counted)

Com not tied

Tied com

Different batches have different shaft lengths.

Some tension is needed when unwinding the outer layers of wire at comm end due to the potting of the tied at comm.  This will tend to keep the windings in place which should help with reliability.

No evidence of the com having been tied.    There was no evidence of any potting,  just as in the 2013 example the windings  could simply be un wound with hardly any tension

This motor had 59 turns.          
The Hawk 7 stripped in 2013 had 60 turns.

This motor had 59 turns.