LOC/Precision 4" Yank IRIS Build

[heada]

Charges are either in charge wells or vials attached to the av bay. Yes, both the drogue and main are wrapped to protect them. That's why I find having a baffle is pointless in my DD setups. It'd only work for the motor eject, not the electronic based events.

 

[Tyler P]

Charges are either in charge wells or vials attached to the av bay. Yes, both the drogue and main are wrapped to protect them. That's why I find having a baffle is pointless in my DD setups. It'd only work for the motor eject, not the electronic based events.

I understand the use of charge wells. I've seen setups with the charge wells on the top of the AV bay to blow the main but where would you place the wells for the drogue? On the bottom of the bay?

 

[heada]

I understand the use of charge wells. I've seen setups with the charge wells on the top of the AV bay to blow the main but where would you place the wells for the drogue? On the bottom of the bay?

Exactly. Wells on both the fore and aft of the av bay.

 

[markg]

I understand the use of charge wells. I've seen setups with the charge wells on the top of the AV bay to blow the main but where would you place the wells for the drogue? On the bottom of the bay?

That's where I put all my charge wells (3D Printed PLA), on AV bay lids. The BP charge is pressurizing the compartment to open up the airframe, so it doesn't need to be behind the parachute or drogue. The energetic separation of the air frame will pull the chute out into the airstream.

Also, attach your chute and nomex blanket a couple of feet away from each other on the harness, that way when the harness is extended the chute is pulled out of the blanket.

cheers

 

[ridnharley]

You don't have to use an ejection charge.
You can use dual deploy.

 

[Tyler P]

@markg and @heada , thanks for the answers! It all makes sense to me now.

Aside from keeping the laundry from sliding around and giving a solid attachment point closer to the fore end of the booster section, hopefully reducing the chance of a zipper, I guess baffles aren't really necessary in DD setups.

 

[mbeels]

Not really a big deal, as the drogue can be buritoed in a blanket, just wondering if I have the right idea.

Yeah, in that case the baffle is doing no harm, just taking up space.

I guess baffles aren't really necessary in DD setups.

Not really, there generally isn't room for them. But I suppose it could be done.

 

[heada]

Yeah, in that case the baffle is doing no harm, just taking up space.



Not really, there generally isn't room for them. But I suppose it could be done.

Pistons are much more common than baffles in DD setups and serve the same function.

 

[Tyler P]

I've been in more of a workshop mood lately, so I decided to put in a little more work and start on the fillets. Nothing too exciting. BSI 30-minute epoxy mixed with SIG micro-balloons until a nice slightly-lighter-than-peanut-butter paste.

Because I haven't ordered any fondant tools yet, I trimmed up an old gift-card to a pleasing radius and used that to shape the fillets and then used my finger dipped in alcohol to feather the tape edges.

Round one turned out pretty decent.

 

[Tyler P]

Round two is looking pretty good. I mixed a bit more this time, as I cut it too close in the first set.

Should have enough time tonight to do the final two sets and then I'll start filling spirals.

 

[Tyler P]

Round three setting up. Going to grab some dinner and do the final one.

 

[Tyler P]

Round four.

 

[Tyler P]

Tube spirals are filled. I typically use a plastic model putty but this rocket is just too big for squeezing that much putty out of a tube.

I decided to try some LePage Poly-filla spackling compound instead. Dabbed on and quickly spread with an old gift card. What doesn't stay filled when I sand will be filled with Deluxe Materials Eze-Kote waterbased polyurethane finishing resin anyway. I always do a couple of coats of that before I prime anyhow.

 

[Tyler P]

When sanding spirals, happiness is a beer and a fresh sheet of 220.

I had run out of sand paper so my project sat for an extra day. Now I have paper so I'll get this all sanded up and then I'll shoot a couple coats of Eze-Kote and give it a quick pass with 400 before I lay the primer. I'll give it quick passes of 600 grit in between a couple coats of primer and then get to masking.

Going with the scale scheme on this. I'm going to pick up a non-scale kit to paint up in a more wild scheme. Maybe an EZI, or something along those lines.

It just doesn't feel right otherwise.

 

[Tyler P]

220 grit sanding finished, including the nose cone. Time for some dinner.

 

[markg]

When sanding spirals, happiness is a beer and a fresh sheet of 220.
I had run out of sand paper so my project sat for an extra day. Now I have paper so I'll get this all sanded up and then I'll shoot a couple coats of Eze-Kote and give it a quick pass with 400 before I lay the primer. I'll give it quick passes of 600 grit in between a couple coats of primer and then get to masking.

Do you thin the Eze-Kote before you spray it? What size needle do you use with it?

cheers - mark

 

[Tyler P]

Do you thin the Eze-Kote before you spray it? What size needle do you use with it?

cheers - mark

Mark, no I don't thin it. I use my HVLP gun that has a 1.4mm needle. I have sprayed it with a .5 needle in my airbrush as well, but this rocket is way too big to do it all with my airbrush.

 

[Tim51]

Going with the scale scheme on this

Red fins or black 'n' white..?

 

[Tyler P]

Red fins or black 'n' white..?

I'm going to say red fins because I haven't found a picture of a full-scale IRIS with black and white.

I did my 3" with black and white because that's what LOC had for their artwork, but I did my park-flyer version with the red fins.

 

[3stoogesrocketry]

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.

Or Loc legally obtained the designs

 

[Tyler P]

First coat of Eze-Cote down. I have to go pick up another bottle. I'm all out.

 

[Tyler P]

And here it is with a second coat. A quick swipe of 400 to rough it a little bit and then I'll lay a white primer base-coat.

 

[Tyler P]

Primer is down. I use Auto-Air 4001 white sealer for the base. I use their dark sealer a lot as well, and will use that as a base for the silver areas.

Just for the record, white acrylic paint is the absolute worst for clogging a gun, so I highly recommend straining it, and apply with a heavier gun like pictured. This one has a 1.4mm needle, so it flows pretty well. I spray the white at about 40psi.

I am going to try a different brand for the colours this time. The Mission Models RC line has some nice colours and I've wanted to try them for a little bit. The shop I work for started carrying them a while ago, so I figured I'd give them a shot on something not too fiddly to see how they cover, etc. I'm waiting on a restock of the Auto-Air line at work.

The nose cone is going to get Tamiya primer, as the acrylics don't stick great to the plastic.

 

[Tyler P]

Here's a bit more going on. I gave a quick mark around the body to mark where the roll pattern sections are going to stop and then masked the lower portion so I could apply the first coat of red on the fins. I'll probably do the next coat in a couple of hours and then let it cure at least overnight before doing anything else.

The next step after that will be remasking the fins and then masking the roll pattern to put the white down.

 

[CPUTommy]

I have a question about the paint itself.

Does humidity / temp affect the paint curing

Is it similar to rattle can paint or is it the new water based paint the auto guys are using.

Compressor that your using and the water capture system.

I cant for the life of me spray rattle cans in the house... so its either buy an outdoor shed and heat it or wait till summer

 

[Tyler P]

I'm not sure exactly how much humidity affects the acrylics because I never spray outside. My shop sits at about 67 or 68 farenheit. I flash it dry with a hair dryer. I'm going to say that humidity probably will have very little affect even if I was spraying it outdoors.

I use a 20 gallon stand-up compressor without a moisture trap, mainly because it's waterbased paint, so a tiny bit of moisture isn't going to hurt it. If I was spraying oil-based I would use a trap.

I find that the majority of acrylics that are either designed for automotive use, or that used for lexan RC car bodies, work pretty much the same. VERY low smell and can be flashed off and dried quickly. I can remask an area as soon as the paint is dry and cooled to room temps after using the hair dryer.

I'd never paint at all if I had to rely on the weather to use rattle cans. Acrylics are all I work with except for priming the nose cones.

Also, my shop is in the basement in the house and I get no complaints from the family except for the noise of the compressor when it kicks on, haha.

 

[Tyler P]

Second coat of red is done.

 

[TheBru]

And in it goes.

This might be a basic question but I’ve seen a few folks build the motor tube externally as you did but I’m not quite 100% on how you get the tube in after assembly. Are you just cutting the end of the airframe aft of the precut slots and slipping it? If yes, is the risk of damaging the airframe while doing that pretty low or is it more of a gentle hands and patience type of thing?

 

[Tyler P]

This might be a basic question but I’ve seen a few folks build the motor tube externally as you did but I’m not quite 100% on how you get the tube in after assembly. Are you just cutting the end of the airframe aft of the precut slots and slipping it? If yes, is the risk of damaging the airframe while doing that pretty low or is it more of a gentle hands and patience type of thing?

Yup, you just cut slits at the ends of the fin slots and slide the whole assembly in. I cut a small piece off the coupler tube and glue it in the aft end after the fin can/motor mount assembly is glued in. That just ensures everything is solid at that end.

 

[Tyler P]

I finally got some time to myself to do a bit more work on the IRIS. I've started masking and my intentions are to lay down the white portion of the roll pattern.

Everything got measured off and then marked with a pencil and masked. I use a good quality masking tape. For those in Canada, I bought this at Canadian Tire. It's the Premiere brand. It has been my favorite masking tape over the last few years.

I use a good sharp hobby knife to cut the excess tape off. If I'm doing an intricate pattern I'll opt for a fresh blade.

Before I start laying paint, I'll run my finger over the seams to ensure they're stuck down well. Not super crucial at this point except at the fins where I'm edging up to the red. When I do the black portion, I'll respray white over the edges of the white masked off areas to ensure it is sealed before I lay the black.

Off to spray some paint.