Old AT G76-10 Mojave green

[Wayco]

I'm building an old G76-10 green load for the 29/40-120 casing (with a copperhead ignitor ) and the instructions have no mention regarding adjusting the delay. The old delay tool I have is for 38mm loads and the delay grain for the 29mm load doesn't fit. Balsa Machining lists an RDK 7 second delay for this motor but I seem to remember that drilling the delay grain 1/32" for each second will give you the correct delay.
Has anyone done this? It's been so long since I did a motor delay I can't remember if it would work.
I also considered adding a chute release to this Nike Smoke, but have had mixed results.

Any advise would be appreciated.

 

[rcktnut]

If you put the G76 delay element in the delay insulator first it should fit in your 38mm. tool. I've shortened some delays that way. 1/32in. per second is correct. I don't know if your old delay grain is accurate yet, never used a green load. For all my old red loads I bought new HDKs because of a known issue with them degrading over time. I got my HDKs from: https://www.siriusrocketry.biz/isho...-hdk-90/hobby-delay-kits-for-29mm-motors-104/

 

[cerving]

I don't even use a tool for those, just put a piece of masking tape on a 3/16" drill bit to mark the 1/32"-per-second drilled off the delay. BTW, the green loads are a PITA to light, and they also seem to have a higher failure rate than some of the other HL loads IMHO. Wildman's smallest igniters will fit in the C-slots, as will the Estes Pro Series II igniters (if you can find them).

 

[tsmith1315]

I seem to remember that drilling the delay grain 1/32" for each second will give you the correct delay.

I flew one of those a couple years ago, with a small bit of thermalite as a helper to the Copperhead.

One of the grains had turned a tan color, much lighter than the other. I put the other grain up top. Didn’t seem to matter.

 

[dhbarr]

should give some options.

 

[cbrarick]

I don't believe this to be a approved modification for hobby line reloadables. it's ok to do it at a tripoli event but not so much at a nar event

 

[rcktnut]

I don't believe this to be a approved modification for hobby line reloadables. it's ok to do it at a tripoli event but not so much at a nar event

It is OK. Hobby line motors are RMS, HPR are RMS=+
https://www.siriusrocketry.biz/ishop/18-38mm-rms-delay-drilling-tool-667.html

 

[Wayco]

Thanks for all the comments.
I tried to slide it into the old delay drill and just rolled the glassine layer back. That might work if I peeled it off, but instead I ran a few other rockets through Thrustcurve and found that Sharon's Arreaux will fly it with the 10 second delay. So I put it over on her side of the work table... The "Smokin' Nike" will fly on a G72DM DMS adjusted to 8 seconds.

Just for the record, out here in the wild wild west, nobody worries about a modified delay grain. G motors at 30 ft. are much safer that six guns at high noon on main street. 'Nuf said...