Upscale Time!!!

[DM1975]

So I picked this partial LOC Expediter kit at a local shop several years back for $10 and have been sitting on it for a while. I figured that since it didn’t have the fins that I’d just do something different.

My first rocket kit coming back into rocketry over twelve years ago was an Estes Guardian. I measured things out last night and while it may not be a true upscale I think it should be close enough. Now I’m sitting on a pile of parts to make it happen too.

 

[Flyfalcons]

Cool subject to upscale! Looking forward to this one.

 

[DM1975]

Thanks. The nose cone and transitions are profiled differently but other than that I believe I’ll only need to remove 4” from the upper airframe to get it close to scale. At least that’s what my late night zombie brained calculations said.

 

[Andrew_ASC]

Subbed. Because Upscaliens.

 

[Andrew_ASC]

What motors are you thinking about for it?

 

[DM1975]

What motors are you thinking about for it?

Well I’m putting a 54mm motor mount in it so I figure anything big and loud enough that’ll fit.

I haven’t simmed it out or anything yet so I’m not sure what motor exactly but it’s either gonna be a dark matter or a blackjack or something like that. I have a Rouse-Tech 54/1706 casing so that and the DMS motors are my limitations as of now.

 

[DM1975]

I figure over ten years is long enough. Gonna replicate this photo of my boys and me. I’ll probably use the same paint scheme as well.

 

[grouch]

Cool

 

[Andrew_ASC]

I’m just eager to see a build thread on a Saturday.

 

[DM1975]

Well I’m working as my kids taxi service today so I’m only hashing out numbers now.

 

[Wayco]

Awful lot of fin area on that little rocket, can't imagine what that's gonna do to CP on the upscale. No doubt that it's gonna fly like a scalded ape on a K456 or K540 though.
Be VERY careful how you mount those forward fins, bad things happen if they aren't just right.

 

[DM1975]

Oh yes for sure. I’ll probably mount those forward fins like how the ones on my Giant Leap Crossbow are done, if I can remember how I did those lol.

As for the fin area it should keep the CP back enough with those big fins in the back.

 

[Andrew_ASC]

The sweep angle will help shift cp rearward. Bust out some number crunching into open rocket or rocksim for some more positive answer.

 

[DM1975]

I’m thinking this may be a good candidate for a jolly logic chute release? I may still build it to handle a true dual deployment also, but the chute release should give it some scale “feel” to the recovery without having it drift off too far in the Kansas winds.

 

[Andrew_ASC]

Yeah JLCR it or Dual deploy your choice.

 

[DM1975]

Ok so I’m trying to figure out what fiberglass cloth I want to use. I usually just use the bondo stuff at Walmart. I’ve been thinking of maybe getting a better quality of glass, not because I don’t like the bondo stuff as I do, but it’s all I have ever used so what would I know right?

Anyone have any suggestions, advise, anecdotes, or tips they would care to share? I’m not even quite sure where to go to get any other than maybe GLR?

 

[Steve Shannon]

Ok so I’m trying to figure out what fiberglass cloth I want to use. I usually just use the bondo stuff at Walmart. I’ve been thinking of maybe getting a better quality of glass, not because I don’t like the bondo stuff as I do, but it’s all I have ever used so what would I know right?

Anyone have any suggestions, advise, anecdotes, or tips they would care to share? I’m not even quite sure where to go to get any other than maybe GLR?

Wildman sells cloth and I bet Chris Short does too. I’ve ordered most of mine from Aircraft Spruce.

 

[DM1975]

Wildman sells cloth and I bet Chris Short does too. I’ve ordered most of mine from Aircraft Spruce.

Thanks Steve, I had remembered about aircraft spruce after I’d posted this. I’ve just got to figure out what I need.

 

[terryg]

https://www.uscomposites.com/

 

[DM1975]

So I’m looking at the glass available and I’m thinking maybe two wraps of 4oz e glass or a wrap of 6oz or other? I’m usin West Systems epoxy and will be vacuum bagging.

I’m going to start an open rocket file on it today, print some fin templates, and do some sims. I’m very curious about that L1000 DMS.

 

[Andrew_ASC]

L1000 DMS outta make it go fast.

 

[DM1975]

Mach 1.16 @ ~ 6k ft. According to my quick simulation.

 

[rharshberger]

So I’m looking at the glass available and I’m thinking maybe two wraps of 4oz e glass or a wrap of 6oz or other? I’m usin West Systems epoxy and will be vacuum bagging.

I’m going to start an open rocket file on it today, print some fin templates, and do some sims. I’m very curious about that L1000 DMS.

Raka Inc is a good source of FG fabric at good prices, and as linked earlier US Composites epoxy is good quality and reasonably priced.

 

[DM1975]

Mach 1.16 @ ~ 6k ft. According to my quick simulation.

Just to state that the K1000 was a joke. I’m not gonna go over four grains with it though.

 

[DM1975]

Raka Inc is a good source of FG fabric at good prices, and as linked earlier US Composites epoxy is good quality and reasonably priced.

Yeah but 4oz or 6oz cloth?

 

[Nytrunner]

1 wrap of 6 should be stiff enough (and obviously lighter than 2x 4oz). Keep an eye on your fins, wouldn't want them to flap away

 

[rharshberger]

Yeah but 4oz or 6oz cloth?

I prefer 6oz as its easier for me to work with. The lighter weight cloths, say under 4oz or so seem to want to float on the epoxy (not sure if thats an apt desciption) and slide around easy, the 4oz and heavier are better in that regard. For wrapping airframes I like two wraps of 6oz on 5" or larger and two wraps of 4oz on smaller airframes ( this personal preference no scientific methods involved, I am just adding durability not indestructability for nearly indestructable use FWFG).

 

[DM1975]

Thanks, I’ll go with the 6oz then. I’m going to build the fin can separate and glass the fins to the motor mount with centering rings on each side of the fin tabs and fillets on the inside and out of the BT. I wonder if I need to do T2T with fins that big?

I have some sheets of Kevlar so I may use that to affach the fins to the mmt.

 

[Andrew_ASC]

T2T increases fin thickness and wouldn’t hurt fight the flutter. Span is the enemy with flutter.

 

[DM1975]

T2T increases fin thickness and wouldn’t hurt fight the flutter. Span is the enemy with flutter.

Yes, well aware. My main concern is that it’ll be flying in the transonic zone on most K’s and I’m trying to make an educated/uneducated guess as to what would be best. I’m going to glass the fins regardless, just looking to eliminate as much overkill as I can.