PemTech Bucky Jones

[dpower]

So last fall I posted a poll about which mid-power kit to use a birthday gift for. The poll winner, IIRC, was the Madcow Jayhawk, which was sorely tempting, but my heart was won by the Bucky Jones.

I spent a while going through the destructions, they were so entertaining that I didn't start the build until recently (well, that, and I didn't want to suffer the consequences of not reading them ).

After filling the spirals and making the angle cut, I just finished cutting the TTW slots. A new #11 xacto blade worked just fine on the thick walled 3" tube, though I cut one slot just a bit wide, so was unable to run around the house making rocket sounds, for fear of that fin falling out. Well, at least the optional small furry mammal worked out.

One minor problem is that my lower 2 wing fins are about 1/4" ahead of the aft BT, I would have expected them to be flush. The dorsal fin lines up exactly with the aft end of the BT, and the TTW slots all line up perfectly. Either this is the way it is supposed to be (and the pics on the EMRR review do seem to show this), or I goofed somewhere; maybe after a bit of therapy and hot cocoa, this won't bother me.

I now need to decide whether to fly this on RMS (29/40-120) or SU motors, so I can line up the engine retention correctly; What is the height of the AT SU aft thrust ring? Is it different between the Econojet, LMS, and hobbyline? How about roadrunner? The RMS case aft closure is specified at 0.25" height. I'm leaning towards SU, since I don't have a case yet; maybe an Econojet F42T-4 for the first flight, then move on to the full F50T and G79W.

 

[JAL3]

I just finished a Little Bucky Jones but have not gotten to fly it yet.

Yours is looking good but be careful. It looks like a sneaky alien is trying to infiltrate through the exhaust pipe.

 

[Pem Tech]

Yours is looking good but be careful. It looks like a sneaky alien is trying to infiltrate through the exhaust pipe.

Yeah, you gotta watch those small furry mammalian exhaust pipe creeping aliens.



As far as the fins go, a little overhang is OK. As you assumed they should be flush with the edge of the tube but have a cup of hot chocolate and try not to worry aboot it.
Also, try not to worry about the motor retention, the original was fitted for the 29/40-120 RMS casing and works fine for Aerotech SU, LMS, and Road Runner motors. Just to be on the safe side wind a bit of tape around the retainer and thrust ring, I just hate it when a case get squirted out the rear end.
Can't wait to see the rest of the build.

 

[Handeman]

I now need to decide whether to fly this on RMS (29/40-120) or SU motors, so I can line up the engine retention correctly; What is the height of the AT SU aft thrust ring? Is it different between the Econojet, LMS, and hobbyline? How about roadrunner? The RMS case aft closure is specified at 0.25" height. I'm leaning towards SU, since I don't have a case yet; maybe an Econojet F42T-4 for the first flight, then move on to the full F50T and G79W.

The hobby line aft end caps have two 5/16" notches in them that go down to flush with the end of the casing. The roadrunner had a 3/16" high thrust ring, and the last Aerotech SU I flew didn't have a thrust ring, I just wrapped some tape around it, you can make that as high as you want.

I would go out and get the Hobbyline RMS as soon as possible, a 29/40-120 and a 24/40. I've had both for years now and the only SU I've bought in the last several years was a couple of roadrunners, just to try them out.

 

[dpower]

Also, try not to worry about the motor retention, the original was fitted for the 29/40-120 RMS casing and works fine for Aerotech SU, LMS, and Road Runner motors. Just to be on the safe side wind a bit of tape around the retainer and thrust ring, I just hate it when a case get squirted out the rear end. Can't wait to see the rest of the build.

Thanks Layne. Stopped at a LHS last night, they only had F20 and G78G-7 SU motors, and I'm *not* sending it up on a G78 for the first flight. While waiting for motors, I read ahead, again, and it seems the only thing holding the wire retainer from sliding fore/aft is a couple drops of epoxy at the fore end and a wrap of tape. Am I just paranoid or would running a bit more epoxy along the length (maybe 1-2") hold it more securely from the ejection force?

 

[dpower]

The hobby line aft end caps have two 5/16" notches in them that go down to flush with the end of the casing. The roadrunner had a 3/16" high thrust ring, and the last Aerotech SU I flew didn't have a thrust ring, I just wrapped some tape around it, you can make that as high as you want.

Thanks.

I would go out and get the Hobbyline RMS as soon as possible, a 29/40-120 and a 24/40. I've had both for years now and the only SU I've bought in the last several years was a couple of roadrunners, just to try them out.

Yeah, already have two of the 24/40 cases, and I really like them. Thought I'd try my first 29mm as a SU, then move to RMS, to defer the up-front cost. I'd like to try a road runner too, but haven't found a local source for them yet. The new AT SU motors I've seen in stores all seem to have aft thrust rings now?

 

[Pem Tech]

Thanks Layne. *snip* it seems the only thing holding the wire retainer from sliding fore/aft is a couple drops of epoxy at the fore end and a wrap of tape. Am I just paranoid or would running a bit more epoxy along the length (maybe 1-2") hold it more securely from the ejection force?

You are welcome...

Sure, a little more epoxy won't hurt, and you could even bend the ends of the wire at an angle as further insurance. While we have had no reports of sneaky retainers a bit of caution goes a long way. Matter of fact we may include the bent ends trick in the next version of the Destrcutions.

 

[cjl]

Thanks.

Yeah, already have two of the 24/40 cases, and I really like them. Thought I'd try my first 29mm as a SU, then move to RMS, to defer the up-front cost. I'd like to try a road runner too, but haven't found a local source for them yet. The new AT SU motors I've seen in stores all seem to have aft thrust rings now?

The new Aerotechs do, and the G80T (the new, 130+Ns version) is a pretty awesome little motor too. I would highly recommend it

Of course, the best way to go for the longer term is the hobby line RMS though. I've flown mine so many times that I've lost count, and it's still going strong. Great value. Besides, there's something like 15 reloads available for it.

 

[matthew]

.. I just finished cutting the TTW slots. A new #11 xacto blade worked just fine on the thick walled 3" tube

I must try that. The only reason I haven't started my Bucky is that I don't have an ice cream scoop.

Well, at least the optional small furry mammal worked out.

Is that a gerbil?

 

[dpower]

I must try that. The only reason I haven't started my Bucky is that I don't have an ice cream scoop.

Is that a gerbil?

Yeah, we have one of those thick cast ice cream scoops that is very dull after years of use, so I went the xacto route. Thats not a gerbil, it is a cat! (the Ty version) We tried a rat, but couldn't fit its hind end between the fin tabs. I think the cats name is starbucks, I'll have to check with my son...

I picked up some econoJet F42-4t motors yesterday, so I could determine where to epoxy the retention wire; the glue-on thrust rings are 1/4", so placement should work for econojets as well as the RMS29/40-120 case.

 

[dpower]

After some huge distractions the last few months, NSL motivated me to get Bucky finished. I ended up not filling the fin can with foam, just used some beefy epoxy fillets. I had two moderate issues finishing the build - after gluing in the dorsal fin & one wing, it was obvious the 2nd wing slot wasn't an even distance around the tube, so I widened the slot & filled in the gap with a small pine wedge. Then, when I went to glue in the aft centering ring, I couldn't fit it all the way down to the TTW tabs, due to the masking tape & epoxy holding the fore end of the motor retention wire. So I made a crude 1/4" balsa ply spacer ring, epoxied it in there good, then epoxied the aft CR in. I'm not sure if either of these two problems were related to the destructions or my inability to follow them - this build was gathering dust for quite a while, and life has been kind of difficult in other ways lately too.

Anyhow, here is Bucky, I'm pleased how he turned out. I plan to put him up this weekend at NSL 2009!

 

[Pantherjon]

Looks great Paul!

 

[Pem Tech]

It was great meeting you Paul, and you made us quite proud by displaying your Bucky right at the entrance to the launch site. You did a great job on him.
But, I didn't see the cat anywhere?



Thanks for all your help and advice during NSL, I'll try to post that picture of you, me and Troody holding your Bucky tonight.

 

[PemTech's Squeeze]

Yes! Love the custom display stand too! I've hung some of Layne's rockets from the ceiling (in my rental house prior to the new improved residence) with clear fishing line to sucess. That's another nice way to display them too.
Very happy and proud to see it there!!

Trudy, Layne's squeeze and cheerleader :cyclops: