Newbie scratch build/engine mount questions

[invasionusa]

After spending the past couple of years slowly building a few Estes kits, I've decided to start taking on scratch builds. I want to start out cloning simple old Estes models before I move onto more challenging projects.

I need to order engine mounts to clone a Stinger and Super Flea, and I'm not very sure which ones to buy. I was hoping to find a resource or guide that would show me what size mount to get according to the model numbers listed on the old plans. Or at least get a better understanding of the difference sizes of engines. I noticed you all refer to them in dimensions in mm. I just refer to them by their size (B4-4, etc.).

Any advice is appreciated, and if I'm using jargon incorrectly, please let me know as well. Thanks.

 

[cjl]

OK, here's the standard engine sizes to worry about:

13mm - estes mini engines. Any motor that estes makes that ends with a "t" in the designation fits these. Correct motor mount (estes) is BT-5

18mm - estes standard. Your basic 1/2A through C motor mount. The aforementioned B4-4 fits in this. Pretty much the standard for low power rocketry. Fits in Estes BT-20 tube

24mm - estes D size. Estes C11's, D's, and E9's fit in this size tubing. Popular for larger LPR and smaller MPR models, and there are also some more powerful Aerotech engines (through F size) availible for this diameter. Proper size for these motor mounts is BT-50.

29-152mm (and even biger) - mid and high power only, I'm assuming this is not what you were asking about.

As for in the old model numbers, which to choose? Eventually, you'll get a feel for what works best by the size and weight of the model, but you can also tell by the reccomended motor list. If it incudes any C11, D12, or E9 motors, it's a 24mm
1/2A6, A8, B4, B6, C5, C6, and even the occasional old motor like the B14 will all fall under 18mm
1/4A3, 1/2A3, A3, and A10 motors are 13mm - generally only used in small models. There are a couple other odd sizes as well, but these are the mainstays for most low power rockets.

 

[sylvie369]

What you think of as standard engines (e.g., B4-4) are 18mm in diameter. The D motors are 24mm, and the minimotors are 13mm in diameter.

18mm = Estes BT-20
13mm = Estes BT5
24mm = Estes BT50

Center any of those in the tube you're using, add a motor block, and you've got an engine mount.

 

[invasionusa]

Wow that was fast, thank you, that makes it very clear to me now. I'm off to BRS to order.

 

[rokitflite]

I know the Super Flea only had a motor block, not an engine mount... Wasn't the Stinger the same way? Or are you upscaling them???

 

[jflis]

I invite you to view our selection of engine mount kits at FlisKits. There should be enough information on the sheet to help you select the mount you need, including cluster mounts.

In the case of the cluster mounts, you can click on the part number for a detailed spec page of that mount.

You can find our Engine Mount Page here.

good luck! Scratchbuilding is *great* fun!

jim

 

[invasionusa]

Originally posted by rokitflite
I know the Super Flea only had a motor block, not an engine mount... Wasn't the Stinger the same way? Or are you upscaling them???

Ah yes, I realized that about the Super Flea after I posted. I went ahead and ordered a few 18 mm engine tubes for future projects since they were so cheap. I'll double check on the Stinger, probably the same.

I'll also check out FlisKits, thanks for the heads up. I think I'll need some 13mm engine mounts at some point, but I know I'll end up ordering some kits, so I better hold off until next payday!