new to reloadable motors

[sgirard]

Getting back into model rockets but this time I am using OpenRocket to design and build my own. I have never used anything but Estes single use motors. I fully expect my upcoming projects to lead me into reloadable motors. I think my first casing will be the AeroTech 24/40 (still learning about the reloads). My questions is this, do these reloadable casing work in the standard single use mounts. That is to say do you still use the same motor block and engine hook. Most of mine are made for both D and E motors. You just remove the spacer to use a E motor. I don’t know if you have to make the mount differently when using a reload casing rather than the single use motor.

Also I have not found any information on how much powder is in the ejection charge for Estes D and E motors. Do the reload motors have larger ejection charges? I figure this will become a factor as my designs get larger but don't know how to compair to single use D and E motors that I am familiar with.

Thanks

Steve

 

[rharshberger]

18mm/24mm/29mm work in the BT20/BT50/BT52 respectively, that being said reloads run a bit hotter than black powder motors so a thicker wall motor tube is helpful to extend the life of the motor mount from becoming brittle over time. The 18/20 motors dont seem to have an effect on the standard BT20 mmt tubes, but the 24mm and 29mm tubes really should be the BT50H and BT52H whenever possible. The best method IMO for dealing with the Aerotech Hobbyline casings is to ditch the motor hooks and the thrust block is not needed. The motor hook will be in the way of fully inserting the motor without trimming the tip of the hook off, and the ejection charge cap may or may not fit through standard thrust blocks (ring inside motor mount that stops motor from pushing through), the thrust block is not needed as there is a thrust ring on the rear closure of the reloadable cases. The Hobbyline cases are 18/20, 24/40, 24/60, and 29/40-120 (please do not confuse the Hobbyline cases with high power RMS cases, the loads are different). The ejection charges on reloadable motors are able to be adjusted by adding or removing 4F black powder to the charge well, and iirc the 18/20, 24/40 and 24/60 are pretty close to the same as the Estes 18mm and 24mm motors (actually a bit more maybe).

 

[jimzcatz]

who uses blocks and hooks anymore??

 

[RocketTree]

Getting back into model rockets but this time I am using OpenRocket to design and build my own. I have never used anything but Estes single use motors. I fully expect my upcoming projects to lead me into reloadable motors. I think my first casing will be the AeroTech 24/40 (still learning about the reloads). My questions is this, do these reloadable casing work in the standard single use mounts. That is to say do you still use the same motor block and engine hook. Most of mine are made for both D and E motors. You just remove the spacer to use a E motor. I don’t know if you have to make the mount differently when using a reload casing rather than the single use motor.

Also I have not found any information on how much powder is in the ejection charge for Estes D and E motors. Do the reload motors have larger ejection charges? I figure this will become a factor as my designs get larger but don't know how to compair to single use D and E motors that I am familiar with.

Thanks

Steve

Yes, the 24/40 case fits a standard D (24mm) engine mount. Since they have an outer thrust ring built in, you also don't need an E spacer or internal motor block. I would suggest the rockets have screw-on retainers to prevent unintentional loss of your reload casing. The ejection charge on the reloads are 0.7g +/-. Im not sure how much black powder is in Estes BP ejection charges, since its a solid casting within the motor. Similarly comparable to the RMS, from my experiences.
Good luck!

 

[sgirard]

OK - thanks for responding. I was a little confused at first but after looking on the web sites I think I understand now. I will continue on with my planning and may have more questions as I proceed.
Thanks again for the information

 

[jrap330]

Getting back into model rockets but this time I am using OpenRocket to design and build my own. I have never used anything but Estes single use motors. I fully expect my upcoming projects to lead me into reloadable motors. I think my first casing will be the AeroTech 24/40 (still learning about the reloads). My questions is this, do these reloadable casing work in the standard single use mounts. That is to say do you still use the same motor block and engine hook. Most of mine are made for both D and E motors. You just remove the spacer to use a E motor. I don’t know if you have to make the mount differently when using a reload casing rather than the single use motor.

Also I have not found any information on how much powder is in the ejection charge for Estes D and E motors. Do the reload motors have larger ejection charges? I figure this will become a factor as my designs get larger but don't know how to compair to single use D and E motors that I am familiar with.

Thanks

Steve

I have not use Aerotech composite motors yet, just Estes Black Powder, as you plan and ditch eng block and/or hook....try some Aerotech SU motors in your current kits. You might not like assembling a motor or cleaning the case at your launch field.

 

[bjphoenix]

I would suggest the rockets have screw-on retainers to prevent unintentional loss of your reload casing.

I've used a twist tie similar to what you get with a loaf of bread and wrap it and twist it around the end of the motor mount tube to hold the engine hook in place so the casing can't get out.