LOC/Precision 4" Yank IRIS Build

[Tyler P]

Even though I've got a decent little collection of kits to choose from, I decided that I needed a bigger build. I was craving the heavy-duty materials of yet another LOC/Precision build!

This is my 5th LOC kit build, and I am obviously a huge fan of their stuff!

I'm not 100% sure how or when this one will be flown. I built the 3" version originally to do my L1, and I may put this one together to possibly do my L2, and if things open up enough and I get all my ducks in a row, maybe do it the same day.

All that being said, here's a few pics to get it going!

 

[Tyler P]

The box:


The goodies including the kit, decals, stickers, and 29mm and 38mm LOC 'N' Ring adapters.


The dry fit:


And an obligatory selfie with the big bird:

 

[Tyler P]

I started out peeling the glassine coating off the motor mount tube. Then I marked it with my line marking guide to make sure I could line up the fin slots on the LOC 'N' FIN can. Then I marked where the centering rings were going to go for when I glue them all in later.

 

[Tim51]

Big Loc kit + a few seasons of DS9 = 1 happy place . Great choice - will be following!

 

[Tyler P]

Did a little bit of fin prep. Rounded the leading edges and fine sanded the surfaces, as well as cleaning the laser charring off the mating surfaces.

I'll probably work on the centering rings and motor mount assembly next.

 

[ChicagoDave]

Watching! I'm considering the IRIS either in 4" or the 3.1" LOC version once I get my Sandhawk broken in

 

[Dipstick]

Hmmm, taking your time on this build?

Just kidding, I'm used to seeing a flood of pics as you post.

Looking forward to your finish/paint again.

 

[Bruiser]

Just got to ask what the "Yank" in the title thread is all about? I feel like I am missing something

-Bob

 

[heada]

Just got to ask what the "Yank" in the title thread is all about? I feel like I am missing something

-Bob

Yank was a previous name for the company LOC. One of the previous owners is the current owner again and so they're re-using the Yank name on some of the kits.

 

[OKTurbo]

Watching you build this one. Looking good! LOC makes some nice kits. FYI...I have my own 4" LOC Iris build going on in the Scale Forum. I'm adding more "scale" to mine than what the stock LOC kit is. Check it out at https://www.rocketryforum.com/threads/winter-build-1-3rd-scale-iris.156469/

 

[Tyler P]

Hmmm, taking your time on this build?

Just kidding, I'm used to seeing a flood of pics as you post.

Looking forward to your finish/paint again.

Lol, yes, I'm a little slower on this one. My brain has the desire but my body decided to call it quits while I was still on the couch last night, haha! I've been working full time through the pandemic and it's catching up with me, so even though I want to work on it, I fall asleep on the couch more often than not, lol!

I'm hoping for a bit of progress Thursday and Friday night, and of course a bit through the weekend!

 

[Tyler P]

Watching you build this one. Looking good! LOC makes some nice kits. FYI...I have my own 4" LOC Iris build going on in the Scale Forum. I'm adding more "scale" to mine than what the stock LOC kit is. Check it out at https://www.rocketryforum.com/threads/winter-build-1-3rd-scale-iris.156469/

That is awesome! I was just looking through it and it looks great!

I'm going to probably paint it in a non-scale scheme. I have a 2.26" and 3.1" that are painted more scale and have some ideas to change it up a bit. Or I may even just go with something a bit more wild. It's a big rocket with lots of space to work with, so I may take advantage of it with something a bit more crazy.

 

[Tyler P]

Getting a little bit done this evening. Centering rings are installed, along with two fins.

I started by rough-sanding the outside of the centering rings to get the laser-char off and filed the inside a bit as well.



Totally forgot how much more epoxy you need to mix up on a rocket this size as compared to 2.2 or 2.6 sized rockets, haha. Didn't leave me much for the centering rings but I had enough.



Mixed another small batch of BSI 30-minute but didn't leave myself much room to spare just tacking these two fins in!

I modified an extra build square I had to make sure the fins were square while keeping them there with a masking tape clamp.

It looks crooked because it is! The two fins on the bottom are just dry-fit to hold up the assembly.



That may be it for this evening, though, as I've had a monster migraine all day and it's getting worse. Time for a break.

 

[Tyler P]

Other two fins are on and curing. Getting a bit of filleting done around the centering rings and epoxied the recovery attachment point.

I'll concentrate on getting everything filleted and cured, and then I'll brush on a couple coats of waterbased polyurethane finishing resin on the motor tube to reseal it against moisture.

 

[Tim51]

Other two fins are on and curing. Getting a bit of filleting done around the centering rings and epoxied the recovery attachment point.

I'll concentrate on getting everything filleted and cured, and then I'll brush on a couple coats of waterbased polyurethane finishing resin on the motor tube to reseal it against moisture.View attachment 416826View attachment 416827

Do you find 1 recovery point works ok on the forward CR? On similar builds I tend to fix two so I can secure a Y - harness:

 

[Tyler P]

Do you find 1 recovery point works ok on the forward CR? On similar builds I tend to fix two so I can secure a Y - harness:View attachment 416832

My typical way of doing it is actually to put in a baffle near the top of the lower fuselage and do a central attachment point, but I didn't think to order another set of bulk plates and a coupler, so figured I just go with the stock setup on this one.

Centrally situated is definitely better to avoid zippers, though.

 

[Tyler P]

All the fins are now cured up and solid. I love this LOC N FIN setup of building the fin can. All 4 fins are perfectly square, as well. So nice.

Just working on the internal fillets. I have seen some guys flood the structure. Personally, I don't feel that adds any more structural strength than normal fillets, and it also adds a tonne of weight that is unnecessary.

 

[Tyler P]

The fin can/motor mount is now finished up and ready for insertion into the lower airframe. A few coats of polyurethane are now on tye exposed cardboard to protect against humidity and moisture.

 

[Tyler P]

And in it goes.

 

[Tyler P]

Sorry I haven't updated recently. Things got busy at work, and then we had our family cat get hit and killed by a car on our street, so things have been kinda poor for building as of late.

I'm also trying to decided whether or not I'm going to just go right ahead and set this up for true dual-deploy. With no high-power launches anywhere near me, and still being restricted on non-essential cross-border travel, I won't be able to launch it for awhile anyway. I'm also thinking about putting in a baffle, as I really do prefer the center attachment point and keeping stuff from sliding back on launch.

So, hopefully I'll be able to update soon. Just need to make some decisions!

 

[Tim51]

I'm also trying to decided whether or not I'm going to just go right ahead and set this up for true dual-deploy.

I would initially say definitely go for dual deploy - this is a 54mm mmt and a 4" airframe and I was envisaging 5K+ flights on big Js or Ks. But now I'm intrigued about how you envisage this without DD - chute release? Or are you thinking of keeping it light and flying it on 38mm / 54mm I motors ?

Sorry to hear about the cat by the way.

 

[Tyler P]

I would initially say definitely go for dual deploy - this is a 54mm mmt and a 4" airframe and I was envisaging 5K+ flights on big Js or Ks. But now I'm intrigued about how you envisage this without DD - chute release? Or are you thinking of keeping it light and flying it on 38mm / 54mm I motors ?

Sorry to hear about the cat by the way.

It could definitely be setup to fly on slightly smaller motors. I haven't simmed it yet to see just how small could be done, but I would think a small H could probably still fly it. Definitely would be using the the JL Chute Release if I don't go full DD. I love the idea of doing full DD, though. I just don't have the equipment yet, and I'm not sure I'm going to fully outfit it this season. I will finish and paint the airframe, however, even if I don't fully decide on the direction I'm taking.

 

[Tim51]

It could definitely be setup to fly on slightly smaller motors. I haven't simmed it yet to see just how small could be done, but I would think a small H could probably still fly it. Definitely would be using the the JL Chute Release if I don't go full DD. I love the idea of doing full DD, though. I just don't have the equipment yet, and I'm not sure I'm going to fully outfit it this season. I will finish and paint the airframe, however, even if I don't fully decide on the direction I'm taking.

Interesting. I'm thinking even with those big draggy fins built stock you could probably still get some pretty nice flights to around 2500' - 3000' on a 3 grain 38 or a single grain 54 I motor. The Loc AV bay kits are very straight forward but of course it adds around a pound in weight. Once I'd added an AV bay to my L1 it made it to c,1750' on aforementioned 30% I motors.

 

[Tyler P]

Well, this project was stalled for a bit while I figured out what to do with it.

I ordered up a LOC baffle kit, LOC AV bay, and a pair of Missile Works RRC2+ altimeters. Just waiting for the AV bay to arrive.

I really like the LOC baffle design. Although it doesn't allow for a centered attachment point, it looks like it will be extremely effective at stopping debris and hot gasses from hitting anything above it. Simple design but very effective.

I'm excited to get this project moving forward again!

 

[Tim51]

Well, this project was stalled for a bit while I figured out what to do with it.

I ordered up a LOC baffle kit, LOC AV bay, and a pair of Missile Works RRC2+ altimeters. Just waiting for the AV bay to arrive.

I really like the LOC baffle design. Although it doesn't allow for a centered attachment point, it looks like it will be extremely effective at stopping debris and hot gasses from hitting anything above it. Simple design but very effective.

I'm excited to get this project moving forward again!View attachment 436019View attachment 436020

Glad this project is in motion again.

 

[Tyler P]

I installed the baffle, now just have to figure out the AV bay setup and how the dual deploy is going to work on this.

What I'm trying to wrap my head around is how to set things up to use the altimeters to do the deployment of the drogue and then again to do the main.

Did I just restrict myself to relying on motor eject for the drogue separation by installing the baffle already?

I mean, I can drill through and install a conduit for wiring but is that necessary?

How do the majority do it? Motor eject and then altimeter for main or do most do altimeter for both events?

 

[mbeels]

Is the baffle in the "booster", or the "payload" section?

 

[Tyler P]

Is the baffle in the "booster", or the "payload" section?

It's in the booster section.

 

[heada]

On all the DD rockets I've built, I exclude the baffle. They limit the length of the motor you can use and prevent me from using a tapped forward closure if I want.

The electronics do both events. If I want motor backup, I set the delay for a second or two past apogee. Electronics should already have fired by then and ideally the motor ejection is firing into an empty tube. Av bay is at the center break point so if I did have a baffle, it'd go MMT -> baffle -> drogue -> av bay -> main -> nose cone. This should allow the use of normal DD and baffle base motor backup.

 

[Tyler P]

On all the DD rockets I've built, I exclude the baffle. They limit the length of the motor you can use and prevent me from using a tapped forward closure if I want.

The electronics do both events. If I want motor backup, I set the delay for a second or two past apogee. Electronics should already have fired by then and ideally the motor ejection is firing into an empty tube. Av bay is at the center break point so if I did have a baffle, it'd go MMT -> baffle -> drogue -> av bay -> main -> nose cone. This should allow the use of normal DD and baffle base motor backup.

But if the baffle is just ahead of the motor mount, where where does the charge go to separate and deploy the drogue? Would it not have to be ahead of the baffle? Not really a big deal, as the drogue can be buritoed in a blanket, just wondering if I have the right idea.