Rocketry Warehouse X-Celerator -- motor tube too short?

Bat-mite · Dec 12, 2014

I started measuring my new kit, and I have a conundrum.

The motor tube is 21". The length of the fin slots from end to end totals 20 7/8". So if the CRs go on the absolute edges of the MMT, that only leaves 3/8" overage. But I need 1/2" for the retainer, don't I? Is this MMT 1/8" too short, or am I missing something?

Bat-mite · Dec 12, 2014

BTW, I am using a Qwik-lok Slimline.

tim cubbedge · Dec 12, 2014

Have you contacted Rocketry Warehouse to see what they say?

Bat-mite · Dec 12, 2014

They are VERY slow to respond to e-mails.

tim cubbedge · Dec 12, 2014

I was looking at the parts list they have on their web site and 21" is what they list too. Maybe they assume friction fit? Have you "dry fit" everything to see if you can get away with less than 1/2" on the retainer?

Bat-mite · Dec 12, 2014

Not yet. To do that, I have to sand things, and if it turns out it won't work, I'll have to return it. So I thought I would ask before I alter anything.

Bat-mite · Dec 12, 2014

I suppose I can always extend the bottom fin slot (by sanding or filing), which would reduce the distance between upper and lower fins. I'd just have to fill the gap I leave at the bottom.

tim cubbedge · Dec 12, 2014

Bat-mite said:
Not yet. To do that, I have to sand things, and if it turns out it won't work, I'll have to return it. So I thought I would ask before I alter anything.

If it were my kit, I would see about getting a longer MMT.

Exactimator · Dec 12, 2014

Is it possible to notch the front edge of the forward fin roots? That way you could move the motor tube back and still have room for the forward CR?

I have a tailcone and that needs more than an inch of MMT tube hanging out of the back of the airframe. Sounds like I'll have to figure something out as well.

Exactimator · Dec 12, 2014

timbucktoo said:
If it were my kit, I would see about getting a longer MMT.

I guess an Aeropack flange mounted retainer could be plan C.

blackjack2564 · Dec 12, 2014

You can "notch" the front fin tab a bit. [cut off the front of tab only] this would let you move the MM tube back an inch or so, with no ill effect on the design or external look of the kit.

Edit: I read to fast & missed some one else suggested this also. I did it , not wanting to wait for another tube to be shipped.

Exactimator · Dec 12, 2014

blackjack2564 said:
Edit: I read to fast & missed some one else suggested this also. I did it , not wanting to wait for another tube to be shipped.

That was me guessing/asking. Now that there's a CJ confirmation, so it is said and so it shall be done.

chadrog · Dec 12, 2014

Exactimator said:
That was me guessing/asking. Now that there's a CJ confirmation, so it is said and so it shall be done.

It's practically "The word of the Lord", ain't it?!?

BalDave2 · Dec 12, 2014

I'm using the Aeropak flange retainer.

Bat-mite · Dec 12, 2014

Well, I already bought the Slimline. I am going to check it tonight to see how deep it is. If I have to notch my fin slots an 1/8", I guess it isn't a big deal.

However, RW doesn't answer their phone and haven't responded to my e-mail sent on Wednesday.

KenRico · Dec 12, 2014

Exactimator said:
That was me guessing/asking. Now that there's a CJ confirmation, so it is said and so it shall be done.

I think you will need to exchange your MMT like Dave and I had to on our 3 inch rockets to use the Tailcone Retainer you picked up from Aeropack.

Kenny

Wayco · Dec 12, 2014

KenRico said:
I think you will need to exchange your MMT like Dave and I had to on our 3 inch rockets to use the Tailcone Retainer you picked up from Aeropack.

Kenny

That's what I did to add the tailcone to my X-Celerator. Fortunately, I had a piece of 54mm tube that fit the bill and didn't have to order it and wait.
Since this rocket isn't exactly designed for high performance, the tailcone is really only a cosmetic addition.

Onebadhawk · Dec 12, 2014

chadrog said:
It's practically "The word of the Lord", ain't it?!?

He is awfully impressive ain't he.............
Hey Jim,,,
How long have you been flyin rockets ????
Let's see now,,,
Moses was how old ????? lol...lol...

Teddy

Woody's Workshop · Dec 12, 2014

timbucktoo said:
If it were my kit, I would see about getting a longer MMT.

That is also what I would do, and save the one you have for a scratch build.

Woody's Workshop · Dec 12, 2014

Bat-mite said:
Well, I already bought the Slimline. I am going to check it tonight to see how deep it is. If I have to notch my fin slots an 1/8", I guess it isn't a big deal.

However, RW doesn't answer their phone and haven't responded to my e-mail sent on Wednesday.

Has anyone tried a PM her on TRF?

gltruett · Dec 12, 2014

I also bought an X-Celerator on the Black Friday sale and have the same situation as you. Based on the Rocksim file I have it looks like the slots have been moved. Rocksim shows the large rear fins at .25" from rear of BT and the forward fins 11.5" from rear of BT. My tubes rear slots start 1" from the end and have 1.5" between forward and rear slots. With fin chords at 10" and 9" you run out of motor tube unless you push it about .7 forward from the rear of the body tube. I'm thinking about leaving the forward fins off of mine (or getting a 24" mm tube. You can also extend the slots as you have mentioned to match what the file shows. For the price it was a great deal and I would buy it again even if I do buy more 54mm tube.

George

blackjack2564 · Dec 12, 2014

onebadhawk said:
Hey Jim,,,
How long have you been flyin rockets ????
Let's see now,,,
Moses was how old ????? lol...lol...

Teddy

Umm... when I started flying, they were only up to the 6th commandment & Moses was still up on the Mount, waiting for the rest to be written......:smile:

qquake2k · Dec 12, 2014

blackjack2564 said:
Umm... when I started flying, they were only up to the 6th commandment & Moses was still up on the Mount, waiting for the rest to be written......:smile:

Oh man, I remember that! The anticipation was excruciating!

Bat-mite · Dec 12, 2014

Hopefully RW will respond to my e-mails soon and I will either buy another tube or see if they will exchange it.

BTW, is there any difference between a 54mm BT and a 54mm MMT?

Exactimator · Dec 12, 2014

Wayco said:
That's what I did to add the tailcone to my X-Celerator. Fortunately, I had a piece of 54mm tube that fit the bill and didn't have to order it and wait.
Since this rocket isn't exactly designed for high performance, the tailcone is really only a cosmetic addition.

With the AT single use L1000 at 12 lbs built weight, it's sim'ing just a little under Mach. I was going to try the tail cone to see if it reduced drag enough to nudge it over. I explained it to Bob at Aeropack, and he was interested.

rocketrywarehouse · Dec 12, 2014

If anyone that received an X-celerator from Black Friday's sale and would like a 22 Inch motor mount instead, please email us directly with your name and order number and we will send you a 22 Inch piece free of charge and you can keep the 21 inch piece.

email = [email protected]

Thank you
Sales Dept

Onebadhawk · Dec 13, 2014

blackjack2564 said:
Umm... when I started flying, they were only up to the 6th commandment & Moses was still up on the Mount, waiting for the rest to be written......:smile:

Now that's even older then I thought.....
That sure explains the silver beard....lol...

Teddy

Bat-mite · Dec 13, 2014

RW agreed to ship me a 22" mount. Problem solved. Thanks, all.

Rocketry Warehouse X-Celerator -- motor tube too short?

Help Support The Rocketry Forum:

Rocketeer in MD

Rocketeer in MD

Well-Known Member

Rocketeer in MD

Well-Known Member

Rocketeer in MD

Rocketeer in MD

Well-Known Member

Well-Known Member

Well-Known Member

Crazy Jim's Gone Banana's

Well-Known Member

Well-Known Member

Well-Known Member

Rocketeer in MD

'Just the Tip'

Desert Rat Rocketeer

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Crazy Jim's Gone Banana's

Captain Low-N-Slow

Rocketeer in MD

Well-Known Member

Well-Known Member

Well-Known Member

Rocketeer in MD

Similar threads

Join the conversation!

Join today and get all the highlights of this community direct to your inbox. It's FREE!