Estes E2X Trajector Screw Up

[bibbster]

I managed to screw up the engine assembly on our Estes Trajector. Not sure how to go about fixing it. I epoxied the engine block in the wrong end of the engine mount tube. In addition to that, the excess epoxy puddled and ran down the inside of the tube which, of course, will prevent an engine from being installed. And of course the centering rings are epoxied to the outside of the engine mount tube.

Any suggestions on a fix? I was just gonna start tearing into it but thought I better check with the 'pros' first. :wink:

In in case anyone is interested, here are the instructions...https://www.estesrockets.com/media/instructions/009709_TRAJECTOR.pdf

 

[neil_w]

Honestly I don't see how you're going to be able to repair that motor mount without destroying it. Since you only get one shot at it, definitely take a break and think very carefully about what you're gonna do before you start.

In your situation I'd build myself a new mount, although it will take some effort to recreate the effect of the molded plastic centering rings using standard parts. Should be doable with a bit of creativity though.

I'll let others chime in in case they have any better ideas than I do.

 

[LithosphereRocketry]

Can you cut the motor block out with an exacto knife or something?

Getting rid of the epoxy drips might be harder, but it should be doable with plenty of sanding.

I never put motor blocks in 29mm anyway. I fly mostly composites in that size, which don't need one, and that way you can use longer motors as well.

 

[neil_w]

Can you cut the motor block out with an exacto knife or something?

Getting rid of the epoxy drips might be harder, but it should be doable with plenty of sanding.

I never put motor blocks in 29mm anyway. I fly mostly composites in that size, which don't need one, and that way you can use longer motors as well.

I agree that ending up with no motor block would not be a problem, but hacking out an epoxied-in block without making a terrible mess of the tube will be a challenge. Take your time with it, and also with sanding out the excess epoxy.

If you succeed, then put a coating of CA on the inside of the tube when you're finished and sand it out smooth, so you'll have a decent inside surface again.

 

[T-Rex]

I managed to screw up the engine assembly on our Estes Trajector. Not sure how to go about fixing it. I epoxied the engine block in the wrong end of the engine mount tube. In addition to that, the excess epoxy puddled and ran down the inside of the tube which, of course, will prevent an engine from being installed. And of course the centering rings are epoxied to the outside of the engine mount tube.

Any suggestions on a fix? I was just gonna start tearing into it but thought I better check with the 'pros' first. :wink:

In in case anyone is interested, here are the instructions...https://www.estesrockets.com/media/instructions/009709_TRAJECTOR.pdf

I have not built one, but I looked at the instructions. Can you just flip it around? The instructions make it look like there is not much difference in the length of tube past the centering rings. Your motor would hang out the back end a little more maybe requiring a skoch more nose weight (couple BBs or a very small fishing weight), but it might be better than ripping and tearing.

Edit: Never mind, forgot about the drips.

 

[bibbster]

Terry, flipping it around is what caused me to notice the screw up. It does stick out the back about 1/4 or 3/8". Not a big deal, but with the centering rings epoxied on I can't do that without cutting the fin slots, which I'd rather not get into, or leaving the mount hanging out the back.

I may just have a go at removing the engine block. Worst case I will have to build a new engine mount assembly, and having learned a lesson, well, I'll be much more careful the second time.

Are the blocks and tubes available separately?

 

[Bat-mite]

The E2Xs have TTW fins, and the CRs have to be aligned exactly to the fin slots in the BT. Call Christine at Estes. She might be feeling generous. One time I was building a rocket and I lost a piece. It wasn't Estes' fault; I lost the thing. I called to see if they would sell me the piece. Instead, they sent me a whole new kit. :jaw:

 

[bibbster]

Thanks, John. I sent an email to the generic address. Maybe that goes to Christine?

 

[Bat-mite]

Thanks, John. I sent an email to the generic address. Maybe that goes to Christine?

Yes.

 

[bibbster]

Perfect! In the meantime, surgery shall ensue.

 

[Scott_650]

I’ve built four of those PSII E2X kits - two Trajectors and two Mammoths. One with an engine block, the rest without. Not that that makes me an expert but I know what the parts are like. If I was working on PSII E2X number five and did what you did I’d probably grab my stepped drill bit (it’s a Harbor Freight cheap-o since it rarely gets used) and start, carefully, slowly, drilling out MOST of the engine block - not all, just most, then either using the Dremel with a sanding drum, or a sandpaper wrapped dowel and finish by hand. The motor tubes are fairly strong but as a poster stated above you might want to use some CA to add some insurance strength.

Flying these on Estes BP motors using tape to make your own thrust ring is pretty simple - it’s even the recommended technique in the PSII Star Orbiter instructions. Good luck!

 

[bibbster]

Thanks for the tips, Scott!

 

[bibbster]

Some good news! I contacted Estes and Mike happened to have some spare parts for me.

Most of you probably know this, but he said that they have not had a dedicated parts department for 12 years. Any spares they have are from damaged or defective kits, so they may or may not have what you are looking for at any given time.

I'm going to go ahead and try to salvage this assembly using the tips you guys suggested. If I screw it up, I have backup parts on the way.