LOC Iris 2.2" Build 38mm

[Alan R]

Just posting this here cause I could not find a build thread on the 2.2" Iris.
Good solid kit, heavy tube. This is the 38mm version. Heavy tubes, plywood fins and rings. I'm adding an aeropac retainer and my own fin guide.

Kit includes some decals, chute, nylon shock cord and chute protector.

Downside: These are probably the most minimal instructions I've ever seen in a kit

I've already started, but the only thing done so far is glue forward CR to the mmt, attached shock cord, and glued in the rail buttons.

 

[waltr]

Yes, LOC kits have minimal instructions. So study and think about the build steps before applying glue.

I build this IRIS kit. Made it full Dual Deploy with decals from Stickershock.
Paint is Createx Wicked colors. The silver is Createx W357 Quicksilver over #4258 Gloss Black.
Createx Matt Clear top coat.

 

[Alan R]

Only the forward CR is glued at this point.
Motor tube is marked for mid-cr to match the fins and accommodate the retainer.

Added a wire pull tab on the aft CR so I can have a little room to fillet fins.

 

[Alan R]

Yes, LOC kits have minimal instructions. So study and think about the build steps before applying

Ha. Ya. I read all the way through. I think it was the last step that simply said "attach rail buttons" ... which was the first thing I did.

 

[crossfire]

Ha. Ya. I read all the way through. I think it was the last step that simply said "attach rail buttons" ... which was the first thing I did.

What questions might you have?

 

[waltr]

I also left the rear CR out until internal fillets where complete. The IRIS used bolt on fins so NO fillets externally.

I didn't think the keval cord on the MM was heavy enough so replaced it with much heavier cord (1500#) that is just long enough to exit to top of the BT.

 

[Alan R]

I also left the rear CR out until internal fillets where complete. The IRIS used bolt on fins so NO fillets externally.

I didn't think the keval cord on the MM was heavy enough so replaced it with much heavier cord (1500#) that is just long enough to exit to top of the BT.

No questions yet @crossfire but thank you for the offer.

My dream for this rocket is a mile-high shot. OR said I'd need an I-280.
I don't do dual deployments so the coupler and bay will just get glued in as body tube extension.

Motor mount now installed with exception of aft ring. Next task will be some fin sanding.

 

[Alan R]

What questions might you have?

OK. One. Have you ever loaded this with an I motor? I'd like to hit the mile mark. Sim says I-280 will do it.
I believe it could handle a sub-sonic I, but obviously not manufacturer recommended.

 

[waltr]

With the smaller farm fields here in Eastern PA I go G motors at most. Get 1000-1400 feet.
Mine has a 29mm MM, looks like yours is 38mm.

OR sim shows 3800' on an I205 and Mach 0.75.
An I280 should put it just past Mach. Unsure of how well the fins will hold up.
An I132W might be better, Mach 0.85 and over 6000 feet with a 5 sec burn.

 

[Alan R]

OR sim shows 3800' on an I205 and Mach 0.75.
An I280 should put it just past Mach. Unsure of how well the fins will hold up.
An I132W might be better, Mach 0.85 and over 6000 feet with a 5 sec burn.

I'm limited to SU/DMS at this point in time.
I have no experience with mach speeds. Is that a situation where they need to be fiberglassed?

 

[Alan R]

After a good night's sleep, research, conversations, and lots of sims I'm thinking that trying to push this particular rocket over the mile mark might be a bit too much.

It's not designed for that.

 

[Alan R]

We got fins.
And that last fin is not quite seated correctly.

 

[Alan R]

I thought I had this measured right but screwed up somewhere along the line. I thought I had mmt set so the retainer screw was only about 1/4" past the end of BT.
ah, well. que sera.

 

[thzero]

After a good night's sleep, research, conversations, and lots of sims I'm thinking that trying to push this particular rocket over the mile mark might be a bit too much.

It's not designed for that.

Stock and H45W-10 kicks it over in OR... with a JLRC and drogue chute it kicks it over 5422... so it'd be hovering right there. Even adding an altimeter to it still says 5414.

 

[Alan R]

Stock and H45W-10 kicks it over in OR... with a JLRC and drogue chute it kicks it over 5422... so it'd be hovering right there. Even adding an altimeter to it still says 5414.

I saw the H45. But OR sim said only about 1400m

 

[Alan R]

This morning I was going to glue the coupler in place and went to dump out the shock cord ... which I had prudently coiled up and secured with a rubber band ... only to find that when dumping it out it had somehow tied itself into a knot.
Of course the knot is at least an inch or two beyond my fat fingers. Or my needle nose. Or my hemostats.
Currently fiddling with it using a piece of wiper blade spring. If that doesn't work, or I get too frustrated ... the lower BT is going to end up a couple inches shorter.

 

[Buckeye]

After a good night's sleep, research, conversations, and lots of sims I'm thinking that trying to push this particular rocket over the mile mark might be a bit too much.

It's not designed for that.

Nah, over the mile mark is no problem for the kit. I have the LOC Vulcanite, which is essentially the same but with a different fin pattern. It was my first mile-high club rocket. I205 to ~8000 feet. I284 to to ~6000 feet. I mostly stayed away from Mach speeds, mainly because I don't like high-thrust motors, but this kit can handle it.

 

[Alan R]

Got my knot undone with a piece of bent wiper spring. Felt like I was rigging a ship in a bottle, but it finally came untangled.

Nah, over the mile mark is no problem for the kit. I have the LOC Vulcanite, which is essentially the same but with a different fin pattern. It was my first mile-high club rocket. I205 to ~8000 feet. I284 to to ~6000 feet. I mostly stayed away from Mach speeds, mainly because I don't like high-thrust motors, but this kit can handle it.

Spring launches are coming up soon. I'll give this some big motors and see what happens. The ones that simmed out over 5k were also going over mach speed. It was the speed more than the altitude that was bugging me. Also need to do some comparisons with sim altitude vs actual altitude.

 

[Alan R]

paint day.

 

[Alan R]

More paint. Had a horrible crackling problem when put down the silver. Just on the body tube. I think it was because the white layer is a super gloss lacquer paint and everything else is rustoleum. But the black went down fine. dunno.

 

[Alan R]

I LOVE PEELING BLUE TAPE... so exciting to see what surprises lay underneath.
Luckily not too much. Just some minor leaks that I'm probably not going to fix.

 

[Alan R]

Another one joins the fleet.

 

[waltr]

Getting there.
I looked at last picture and went "oh no, there is a big drip of silver onto the black". Then saw the paint on the other rockets.
Nice personal touch and hopefully break Vance's law, "the better the finish the better the chance of first flight going bad".

 

[Canadarm]

Very nice!

Where did you get the fin alignment tool?

 

[Adam3836]

Looks great

 

[Alan R]

Where did you get the fin alignment tool?

I 3d print my own. Have to make a new one for almost every rocket because of different diameters, fin thickness, 4 vs 3 fins, etc.

 

[Canadarm]

Thanks. Seems like 3d printers are becoming indispensable!

 

[Alan R]

Thanks. Seems like 3d printers are becoming indispensable!

Not indispensable, but fun to play with and make unique things.

(Not so) funny story: While building this, I think it was at the point of filleting the last fin, I noticed that the engine tube was not centered within the fin guide. I was kind of like "oh sh*t where did I screw up the mount???" It looked like it was a couple degrees off-center.
Kept looking at it and seeing it through the rest of the build. I would eyeball it... then slip the fin guide on and look at it again, and Yup. There it was. off-center.
Not big, just a degree or two slightly cocked in the body tube. Ok, well.. nothing I can do about that. It's just always going to go a little that way once the motors in.
After the rocket was complete. I was using the fin guide as a stand to hold it... Noticed that one set of the guides on the fin guide were not centered. I had tweaked and moved them at some point during design and never ever noticed.

Kind of hard to actually see this because I shaved off the left one after noticing. Look closely. The left-right tabs are not centered. It screwed with my brain all during the build.