Will an 18mm Quest D20W fit in an Estes Engine Hook Motor Mount?

[Starfire73]

I usually grind down some of the front tab on the 18mm Estes motor hook just enough so I can fit an AT 18/20 D engine in it. However, I forgot to do so on my Estes Citation Patriot. I think a C6-5 is going to be way underpowered in that rocket.

Will an 18mm Quest D20W fit in an Estes, 18mm, Engine Hook Style, Motor Mount?

I know Quest shows the D20 to be 70mm long, but I don’t think that includes the 11mm of charge well at the top of the motor, and I don’t know if that will fit past the front tab of the engine hook. Has anyone tried it? The AT 18/20 motor case is a no go. What about the Quest motor?

Thanks,
Doug

 

[mh9162013]

If I recall correctly, it should work, but you may have to twist the motor so the "flat" side of the ejection charge rests under the engine hook.

I think @BEC posted a picture of this a while back.

 

[jmasterj]

I had to file my motor hook to fit the 18mm Q-jets, but I did it after the rocket was otherwise complete.

 

[Starfire73]

I had to file my motor hook to fit the 18mm Q-jets, but I did it after the rocket was otherwise complete.

Wow, how’d you pull that off? Very carefully I expect!

 

[Starfire73]

If I recall correctly, it should work, but you may have to twist the motor so the "flat" side of the ejection charge rests under the engine hook.

I think @BEC posted a picture of this a while back.

Hmmm… good point.

 

[mh9162013]

Wow, how’d you pull that off? Very carefully I expect!

Just use a flat needle file.

 

[jmasterj]

Just use a flat needle file.

Yup.

 

[bjphoenix]

Someone at our last monthly launch tried one of those motors in a scratch built rocket with motor hook- it wouldn't fit without modifying the front of the motor hook.

 

[BEC]

Some motor hooks have a forward leg that is too long to let a Q-Jet's ejection charge container (the hexagonal part) go by and the needle file approach needs to be taken. This was more of a problem with the earliest Q-Jets. One of the changes made was to reduce the size of that hexagonal part some. But yes, orienting the motor so that the flat part of the hex tries to go under the top part of the hook will do it in lots of cases.

I'll have to dig to find that picture. It's been awhile since this was a big issue (several years now).

 

[Starfire73]

Yeah, I usually just hit that front part with a dremel tool with a grinding disc real quick and take it down enough so the extension part of the motor case clears it. I forgot do so this time.

I also wrap the MMT with a 1/4” wide, by 6” long strip of paper, glued on over top of where the front part of the engine hook goes through the tube. I do this to strengthen the tube and give some extra security so the front part of the hook doesn’t try to push up and out of the MMT at all - since it’s a fair amount shorter.

 

[dr-ws]

Just use a flat needle file.

...or a rat tail file.