Discussion in 'High Power Rocketry (HPR)' started by conman13, Dec 3, 2018.
I like Proline 4500 for fillets. Sets fast and makes a pretty sweet fillet. And it is black.
How would it be to use strips of carbon twill for the covering layer of the fillets? Glue with JB as normal and the layer a strip on top for looks.
I do it...[JB ]just add only the drops needed to dye black...no more.
Most folks use WAY too much.
Shake the tiny dye bottle well. It does settle. I would guess only 1 maybe 2 drops most for tiny set of fillets .
Heck on 4inch rocket with 12inch long fillets I only use 4 drops for a set [2 fillets] in Rocketpoxy.
Adding too much [just a few drops more than needed] will change cure time and make runnier than without.
I have tinted many JB fillets black on small rockets especially mini's, no issue. First one i did is 7-8 years old and still flies fine. Granted your doing extreme...just wanted you to know the dyed fillets have stood txt of time without getting brittle.
If I were going for a record my rocket would look like crap...sanded/polished smooth is slicker than any gloss finish and yields a smaller OD. every little bit helps...form follows function.
Thats great to know about dying JB Weld.
My main set back is that I'm on the East coast so I can only fly so high. The club I'll be flying with has an 18k waiver and right now I'm awfully close to surpassing that in the sims which is why while painting it won't maximize my performance but will decrease it enough to be comfortable with flying without worrying that I'll surpass 18k. Even with painting the rocket I'll be breaking mach 2 and 16k.
This is another thing I've thought about however I haven't been able to think of a way to do it clean enough to make it worthwhile.
I finished sanding the coupler down so that it had a very loose fit so that I can apply a couple epoxy coats in order to get it to the finish I want and to fit snug in the body tubes.
Here it is after the first epoxy coat
The payload tube is also cut to size.
I did one more very thin epoxy coat as I had some epoxy leftover from the coupler.
I’ve been designing some charge wells and avbay bulk plates in SolidWorks that I plan on having machined out of aluminum. I will also be going to a normal dual deploy setup for this. It’ll be drougeless from apogee and I’ll shoot the main out of the payload at a lower altitude.
My package with the fin alignment guides is out for delivery today so I began getting the fin can prepared to have the fins tacked on once I have them in hand.
I started by drawing some lines to sand an even area where the fins and fillets will be. After the fins are tacked on I will sand more to accommodate the fillet radius. I beg and with 80grit and then went over it very lightly with some 30grit.
I was able to sand down the epoxy coat on the coupler. I think it will be good to go after one more light coat of epoxy.
The payload tube is done. As I did before I started sanding with 150 and worked my way up to 1000.
I received the fin alignment guides from Wildman as well as a new aluminum tipped VK 5:1 nosecone which I’ll be using instead of the all fiberglass madcow cone. To further prep the fins I notched the root chord of the fin to allow for a better bond between it and the epoxy.
The fins were tacked down using JB Weld using the double dip method.
Tomorrow I’ll get the fins alignment guides off and hopefully begin work on the fillets.
Is that magenta in the fin weave real or just a trick of the light? If it's real, how did you do that? It's pretty cool-looking.
It is real, it’s a special fabric offered by carbon envisions that they call purple reflections. It’s pricey but I had some left over from when I made panels for my car so I used it in the plate. It’ll look even cooler once it’s shiny.
Subscribed - better late than never.
Is that this nosecone?
Any chance you could measure the outside diameter at the bottom? Thanks!
Yes it is the same cone. The OD at the base is 41mm.
I got the fin guides off and gave the fins a light sand to get rid of the spots that had some JB Weld.
View attachment 370542
I got the battery mounted to the sled for the AVbay.
View attachment 370541
Currently I’m post curing the coupler and once it’s done I’ll lightly sand and test fit it to the body tubes. I’m pretty confident that this was the last epoxy coat it needed.
I’ll be running one shear pin on the payload tube so I got that hole drillled and tapped.
I need to pick up some masking tape later in order to mask off the fillets. I’m hoping to be able to do at least 2 set of fillets before I head back to school.
I’m not sure why those 2 pictures won’t show.
View attachment 370548
I still can’t see one, were you able to see the pictures I posted of the JB Weld fillets?
I wasn’t able to see that those pictures. Something strange is going on with the posts as there should only be 2 pictures, 1 of the sled and one of the fins. I see the same thing you do for the unavailable photo but when I go to edit it only 2 images show up.
I’ve seen that when you edit a post and add the pics after the initial posting.
Last night I began work on the AV-Bay. I started by cutting out some oversized bulkheads out of the carbon plate with a hole saw.
To sand them down even I put a bolt through the center hole and attached it to my drill, using 80grit sandpaper I knocked them all down to size. I then epoxied them together with some 5min epoxy again using the center hole and a bolt to keep them aligned and pressed together.
I had to make a quick pit stop at Lowe’s to pick up the hardware. I’ll be using 3 8-32 threaded rods to hold everything together and I’ll be ordering 1/4” eye nuts to use for the shock cord anchor in the middle hole.
My plan was to run the aluminum tube all the way down the sled however thanks to Lowe’s slightly bent all thread it wouldn’t have worked as it was such a tight fit. Due to this I cut 1” long pieces to use at each end.
After getting everything to fit the way I wanted I used some loctite on the forward nuts to keep them locked in place so the sled can slide in and be tightened down from the aft end.
I’m probably not going to be able to do much else until I’m back at school so it’s going to be a week or two before I can do anymore major work on this.
Alright I’m back to having some time to do some work on this build now that I have a small break. This morning I taped up 2 of the fins to do the first set of fillets. I’m using a 1/2” piece of copper tubing as my pulling tool. I ended up using the JB Weld with a couple drops of the Aeropoxy black dye.
I used some isopropyl alcohol to help smooth the epoxy out. This is the first pull:
After the first pull I pull of the tape and do the final pull to form the fillet at each end to how I want it to be. Here’s the final product. Once cured I’ll sand them lightly with 180 to make them very smooth and they’ll be ready for the clear coat.
I was able to get the second set fillets done last night using the same method I used for the first set.
One more of what they’ll look like after sanding and clear
Amazing work. What's the all up weight going to be for this project?
I have a WM BH38 I will be building and flying this summer, plan to push the 20k waiver with it on the Loki 38-1200 hardware as well.
Thank you. This build will sit at about 28 oz. with it set up for dual deploy. The BH38 is a great rocket can handle anything you throw at it!
I finished up the sanding with 180. Next I’ll move up to wet sanding with 400. After the sanding is done I’ll be able to get the clear coat done.
Looking great mate. Can’t wait to see this finished
Purty! Those magenta accents really make the fins pop.
I haven’t had much time to work on this as of late however tonight I got the 6 4-40 holes drilled and tapped to accept 1/8” long 4-40 set screws to hold the avbay to the payload tube. I also drilled the static port hole for the electronics. This wraps up the upper air frame and it is officially ready for clear coat. I still have some sanding I want to do on the fillets to get them perfect however things are coming along. If all goes well I’m hoping to be able to to a test run on a G motor to test out electronics and tracking at the first URRG launch at the end of April.
Ill be going home this weekend and plan on bringing this with me so I can get her painted. Everything is done “mechanically”. I plan to hopefully test fly it for the first time on a g motor to test out the electronics and will progressively fly her on larger motors a couple times before we go for K1127.
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