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Crossloads Cross-up, Aerotech K1999N vs CTI K1620 - which will win? - Printable Version

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Crossloads Cross-up, Aerotech K1999N vs CTI K1620 - which will win? - MarkH - 06-09-2018

This is a motor build thread of the above mentioned motors. The CTI motor will be assembled in the AT 98 mm 1G case. The AT motor will be assembled in the CTI 98 mm 1G case.

[attachment=1766]


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-11-2018

Performance wise these motors are very close in comparison. Both are nearly a full K.


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - IndianaSteve - 06-12-2018

Should be a fun test at the least 😎


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-13-2018

You may be asking yourself "what is a crossload?"
Yes, no? In case you missed it, the Aerotech 98 mm Crossload information release is attached.

Cesaroni reloads are generally cross-compatible with Aerotech hardware as well in the 75 and 98mm sizes, and include Aerotech size o-rings, except for reloads with large "XL" size nozzles.


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-16-2018

Aerotech Crossload instructions. No big surprises here. Using the supplied CTI style o-rings, the Crossload instructions have you assemble the motor the same as the standard CTI instructions, with the only difference being the inclusion of the Aerotech seal disk.


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-20-2018

On my way home today I came across a turtle crossing the road. I moved him to the side of the road, and lo and behold, another turtle.  I've enlisted the help of turtles, and the turtles are now running the build.  Please bear with us.

The parts for both motors have been opened. Cesaroni K1620 reload and hardware is on the left.   Aerotech K1999N on the right, with blue Rousetech motor.


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-22-2018

Based on smell alone, the Warp 9 load has been declared the winner. The Vmax is nearly odorless with a slight hint of stink, while the Warp 9 has the sweet AP aroma that we all know and love. ...the yellow tint of the Warp 9 is different than Warp 9 grains I've seen in the past.


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-22-2018

The nozzles have nearly identical dimensions.  Both throats are about 0.7 inch.  Or as is written on the K1620 nozzle, 0.69.  The core size for the Vmax is 1 3/8 while the Warp 9 is 1 1/8 ",  which shows the quicker burn rate of the Warp 9 compared to Vmax...  given that the overall burn time of the K1620 is slightly longer than the K1999, yet the K1999 has more web thickness.


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-25-2018

Time to put the Cesaroni K1620 Vmax in the 98/2560 case.  Before we begin, note that Aerotech released an advisory about using Aerotech seal disks on CTI Loads used in Aerotech 75 mm cases.  Though this is a 98 mm load, I still planned to use an AT seal disk on the forward end in place of the CTI plastic washer. However, with the propellant grain installed in the liner, and with nozzle installed in liner, there is not enough room on the top end for the AT seal disk to seat properly.  So we revert to using the CTI plastic washer.  Also note that the AT advisory applied to 75 mm loads.  For 98 mm loads the CTI forward washer has a step in it, providing a better seal compared to the 75 mm forward washer (I'm assuming this is the case) which is just flat washer with no step,  at least the ones I've seen (please correct me if I'm wrong).


RE: Crossloads Cross-up, AT K1999 vs CTI K1620 - which will win? - MarkH - 06-27-2018

The motor was built per standard AT instructions.  CTI instructions also include RMS assembly instructions.  The two large fat O-rings from the Aerotech K1999 reload were used. The thin o-ring is the seal disk o-ring and was not used. One o-ring goes on the forward end on top the plastic washer, the other identical o-ring goes in the nozzle groove at the nozzle/case interface. I believe CTI includes the RMS O-rings with this K1620 reload, but my reload came with no O-rings at all.  AMW later supplied the missing CTI O-rings. The motor went together easily with no issues.