Drillable Delays?

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gary7

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Are there any Aerotech RMS delay grains that are not drillable? I know the delays are particular to different propellant types, pressures etc. I am looking at some 24/40 and 24/60 reloads that have long delays of 10 and 11 seconds but pictures of the kits show what appears to be a "standard" type Aerotech delay grain. So, would delays of any size ever not be drillable? I have searched but cannot find an answer to this.

Thanks.
 
you can not drill delay grains to less then 4 seconds.

There has to be enough 'grain' left in place to hold the motors pressure.

each motor size, formula and delay formula is consumed at different rates during the motor burn.

Tony
 
Looking for an official option for drilling the hobbyline reloads I have some F51NT and F63R reloads, both with the standard 10sec delay but I want to drill them to 6 or 8 seconds. I could use a 1/8" drill bit and do it by hand but if there is a drill tool or adapter, I'd rather use that.
 
Looking for an official option for drilling the hobbyline reloads I have some F51NT and F63R reloads, both with the standard 10sec delay but I want to drill them to 6 or 8 seconds. I could use a 1/8" drill bit and do it by hand but if there is a drill tool or adapter, I'd rather use that.
iirc the hobbyline reloads are drillable with the standard RMS RDDT tool which covers 18-38mm.
 
iirc the hobbyline reloads are drillable with the standard RMS RDDT tool which covers 18-38mm.
The drill bit in that tool is too wide for the ejection hole on the hobbyline 24mm and 29mm cases I have.

Drill bit is 1/4" but the hole is 1/8" or smaller. "It don't fit no way, no how" Or do you drill from the combustion side instead of the ejection side?
 
The drill bit in that tool is too wide for the ejection hole on the hobbyline 24mm and 29mm cases I have.

Drill bit is 1/4" but the hole is 1/8" or smaller. "It don't fit no way, no how" Or do you drill from the combustion side instead of the ejection side?
You are supposed to drill the delay before it is inserted into the forward closure - drilled end towards propellant grains. Once you get the tool you’ll see the tool cavity that the delay grain slides into
 
You are supposed to drill the delay before it is inserted into the forward closure - drilled end towards propellant grains. Once you get the tool you’ll see the tool cavity that the delay grain slides into
On CTI it's propellant side. On AT DMS it's ejection well side which is the only AT motor I've drilled so far. Now I learn on RMS and Hobbyline, it's like CTI and not like DMS. I wrongly assumed that it was consistent within a manufacturer.

CTI - propellant side
Loki - propellant side
AT DMS - ejection side
AT RMS/Hobbyline - propellant side

Edit: you modify CTI, Loki and AT DMS with the delay in the closure. AT RMS is the oddball thst is modified before assembly
 
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On CTI it's propellant side. On AT DMS it's ejection well side which is the only AT motor I've drilled so far. Now I learn on RMS and Hobbyline, it's like CTI and not like DMS. I wrongly assumed that it was consistent within a manufacturer.

CTI - propellant side
Loki - propellant side
AT DMS - ejection side
AT RMS/Hobbyline - propellant side

Edit: you modify CTI, Loki and AT DMS with the delay in the closure. AT RMS is the oddball thst is modified before assembly
Yes, RMS is modified pre assembly, make sure, the drilled side is toward the propellant, otherwise the ejection bp will filter into the divot reducing ejection charge effect.
 
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