Extra work in building a kit?

[Delta V]

Hi,

I’ve been designing a kit for BluShift aerospace of their Stardust rocket, and I’ve thought about changing a few things to reduce labor costs and assembly time.

1) Have people cut slots themselves

2) have people cut the fins themselves

The kits would come with templates ofc, but I felt that since this is already a more advanced rocket people would be OK with a little extra work, but I’d love to hear your thoughts! (After all, you’ll be buying the kit, not me)

 

[Pinetree]

Nobody likes cutting slots.

 

[DragonRocketry]

What is the fin material? If you are talking plywood, that would not be a good move. Balsa or basswood may be okay. As for fin slots, I did kits that where just marked but they had to cut them, and it hurt sales. Some people do not mind doing it, but most do not want to.

 

[neil_w]

I feel like precut fins are table stakes nowadays. Slots are a bit more debatable. If it's paper tubing, I wouldn't mind cutting my own slots.

 

[Scott_650]

Cutting balsa or even basswood fins, especially if they’re a fairly simple shape, wouldn’t be a dealbreaker in the right kit. Cutting slots would be ok if we’re talking about paper tubes - pre-marked would be even better.

One definite turn off would be “sticker” style decals - waterslide or cut vinyl only! Assuming this kit will be sold to the general public that is

 

[SolarYellow]

If I have to do scratch building stuff, I might as well scratch build.

 

[Pinetree]

^ Excellent point.

When I open up a kit, I just want to start building.

 

[Wrightme43]

I would listen to what Scott from Dragon Rocketry says. I am just moving into mid power, and I will move to high power when I am ready.
His kits struck me as interesting, very well made, and within my ability to make a very nice looking and flying rocket.

I am a wood worker, I have the ability and tools to make fins out of solid walnut if I decide to. I just really like building rocket kits. A little bit of extra money to not have to build a one off jig is worth it to me.
A person that has a laser cutter, and a colt router with a slot cutting jig, can save me hours in the wood shop. That has a value to me.

I hope this input helps you.

Steve

 

[Daddyisabar]

I'm super lazy and only want instant gratification. Easy peasy lemon squeezy!

Leave the old world craftsmanship and builder's kits to the few dozen or so out there who want to subject themselves to such torment.

If you can't sim it or 3D print it, don't bother spending your valuable time kitting/building it. NO PAIN, NO PAIN. Be happy!

 

[les]

I do not have an issue cutting slots in paper tubes or even cutting out simple fins, basically only straight edges.
Curved fins, fins with TTW tabs - not so much.

Higher power rockets, with FG or Plywood? Better have all that pre-slotted and pre-cut......
And I fully agree with water slide decals or vinyl and not cheap stickers.
Note - depending on the rocket (and price) I will even accept needing to go to Sticker shock to buy the vinyl.
But if the total cost of the rocket plus vinyl gets too high, I will also pass...

You could offer recovery gear as an option. I transfer my chutes from rocket to rocket, so when the kit comes with a chute I may not use it (especially if a plastic chute. I have a box full of them. I use thin-mil nylon chutes where possible.

 

[mh9162013]

If the fins are balsa, I don't mind cutting them if the template is provided (and the fin shape is simple). No, I can't cut balsa sheet as precise as a laser can, but I paper my balsa fins. This means I'll be sanding the edges anyways. I'm probably a minority in this way of thinking, though.

As for cutting slots in the main body tube, I wouldn't mind that as long as they were already marked on the tube (and the tube wasn't a tough material like carbon fiber or fiberglass).

 

[DocSeuss]

I build my rockets on a table in my living room, so minimizing the amount of cutting increases the likelihood I will purchase a kit. I do not have any shop tools I can use, unfortunately, and since I have muscle tremors, I don't love having to cut fins and slots.

 

[Delta V]

Thanks for the input everyone! From what I've heard people would be OK not having TTW fins as long as the fins are pre-cut. (The fins are balsa and the tubes are paper btw). Please let me know if I missed anything.

Cutting balsa or even basswood fins, especially if they’re a fairly simple shape, wouldn’t be a dealbreaker in the right kit. Cutting slots would be ok if we’re talking about paper tubes - pre-marked would be even better.

One definite turn off would be “sticker” style decals - waterslide or cut vinyl only! Assuming this kit will be sold to the general public that is

Don't worry, the decals are waterslides. the biggest issue with the decals is the white Blushift logo on the nose. I worked around it by printing a sheet of “reversed” BluShift logos, ended up great!

 

[Scott_650]

Cool! Which fin shape, the Nike style or the triangular fins on the website animation?

 

[Delta V]

Cool! Which fin shape, the Nike style or the triangular fins on the website animation?

Kinda a bit of both. The animation on their website is their new Starless Rogue rocket, it’s meant to carry experiments up to 180km. (There’s some great videos of the MAREVL 2.0 engine firing on their yt!) Stardust has trapezoidal fins. Sascha, (BluShifts CEO) said he might want me to make a Starless rogue one too.

 

[Bluegrass Rocket]

What you’re showing is a simple model rocket. Laser cut fins with no through the wall tabs would be more than sufficient. If you want tabs on the fins, then you need to provide tubes with slots. I don’t think there are any model rocket kits being produced today without laser cut fins, no matter how big or small the company. Gluing fins directly on the tube without through the wall tabs has been done since the beginning and continues to today.

 

[86mustang408w]

I cut slots all the time and make fins its very easy. Measure well, get your fin finished thickness for the slots, and keep them on the tight side. They won't all be straight, and you can use couplers too on the inside for supper while cutting as well as your fingers. The fins I make from balsa and then use self adhesive shipping labels or poster board with glue. Plywood fins get cut out and then either poster board or all purpose sealer and then primer. I make them from balsa(balsa machine service)and plywood(Hobby Lobby/Lowes/Home Depot, etc..), by hand mostly. Getting a laser cutter to help. I've also been adding tabs and slots to all rockets down to the Wizard(Olympus pictured in far right photo). What other questions do you have?

 

[SolarYellow]

They won't all be straight...

That's the problem. They should all be straight. A manufacturer can set up so they are, 100 percent of the time for all customers. That's one of the advantages of buying a kit.

 

[86mustang408w]

That's the problem. They should all be straight. A manufacturer can set up so they are, 100 percent of the time for all customers. That's one of the advantages of buying a kit.

I was referring to me or a person cutting them by hand. He asked if people cut slots and fins themselves in regards to the kit he is designing.

But I agree 100% they should be correct from the factory, and I haven't found many yet that are not straight from many companies. But there is most definitely extra work in building some kits. For me? Almost every kit because I build it to my standards. LOC kits seem to be the best so far.

 

[techrat]

Have you test flown this rocket?? Those fins seem very small for a rocket that size. Just asking.

 

[Delta V]

Have you test flown this rocket?? Those fins seem very small for a rocket that size. Just asking.

Yep! Flies great. It was pretty windy in this video and it normally flies better. Gets around 15% stability on a D12 (~2cal)

 

[bjphoenix]

I was referring to me or a person cutting them by hand. He asked if people cut slots and fins themselves in regards to the kit he is designing.

I don't mind cutting fin slots myself but looking at most rockets at our launches this is beyond what most builders would like to do. I see rockets at our launches with the fins stuck on and no fillets- glue the fins on, spray paint it and launch it.

In thin tubes I cut the slots with XActo knife. I don't mind if they are a bit larger, once the fins are in place and glued to the motor tube I lay down a thin fillet with Titebond Thick and Quick. It will stay put and not leak through the gap like normal Titebond or epoxy would. In heaver tubes like LOC I would saw the slots with a hobby razor saw.

 

[86mustang408w]

I don't mind cutting fin slots myself but looking at most rockets at our launches this is beyond what most builders would like to do. I see rockets at our launches with the fins stuck on and no fillets- glue the fins on, spray paint it and launch it.

In thin tubes I cut the slots with XActo knife. I don't mind if they are a bit larger, once the fins are in place and glued to the motor tube I lay down a thin fillet with Titebond Thick and Quick. It will stay put and not leak through the gap like normal Titebond or epoxy would. In heaver tubes like LOC I would saw the slots with a hobby razor saw.

I do the same way now with slots/tabs and T&Q for fillets. I was kind of nervous to cut slots earlier this year as im right handed and have nerve damage, but every rocket gets them now. But like you said some it would scars away.

I thought using a ruler as a guide over free heading the cuts would be easier for me. Its really not, free hand and following a mark with about 1 inch cuts at a time, seem to be the best for me and cutting slots. Another trick I found is putting a coupler in the tube and use the to cut the tube, its almost a perfect cut. I stick the hobby knife into the body tube enough that you can see it, push the coupler against it, then just basically spin the tube and cut it. Then if the tube isn't at a 90° cut or angle, I use the coupler inside the tube as a guide to sand the body tube until it matches the coupler so everything seats properly. One thing I've bought too is a hacksaw to cut tubes. A mitre box make that even easier, as the band saw I use can only cut up to 3" tubes.

I'm one that likes this hobby too for the design and build aspect, others like you said my not be that far into it, have the knowledge, or just don't care. I make every rocket even down the the Alpha have fin tabs and slots, and the Titebond Q&T for fillets, it pretty much stays where you put it, and just great. I can't stay enough about it.

 

[bjphoenix]

I thought using a ruler as a guide over free heading the cuts would be easier for me. Its really not, free hand and following a mark with about 1 inch cuts at a time, seem to be the best for me and cutting slots

I have a piece of aluminum angle that I use for marking the slots. I draw pencil lines for both edges of the slot then cut along those lines. What I have to be careful of is once you start cutting slots in a body tube it loses a lot of its strength and can be hard to hang onto. If I'm cutting slots all the way to the end of the tube I might cut all the slots but stop a little short of the end of the tube then come back and cut those last bits out.

 

[86mustang408w]

I have a piece of aluminum angle that I use for marking the slots. I draw pencil lines for both edges of the slot then cut along those lines. What I have to be careful of is once you start cutting slots in a body tube it loses a lot of its strength and can be hard to hang onto. If I'm cutting slots all the way to the end of the tube I might cut all the slots but stop a little short of the end of the tube then come back and cut those last bits out.

I have the same angle too, but don't use it much, lol. I've also followed the knife with a coupler while cutting the slots to give the tube strength inside. It really helps keeps the cuts nice. But for the most part take time and pencil line the all the fin slots, cut the ends or width first, then go down each side of the root chord with an exacto and a coupler to brace it. Heck you can stick the knife right into the coupler and drag the knife to make the cut, it kind of holds the blade from the inside.

 

[terryg]

Angle iron to mark the line for the slots. Taped on metal ruler as the guide for an exacto for cardbord tubes (multiple light passes) . A carbide blade in a dremel for blue tube and for fiber glass or carbon fiber scatch builds, tube fins....

 

[neil_w]

I have a piece of aluminum angle that I use for marking the slots. I draw pencil lines for both edges of the slot then cut along those lines. What I have to be careful of is once you start cutting slots in a body tube it loses a lot of its strength and can be hard to hang onto. If I'm cutting slots all the way to the end of the tube I might cut all the slots but stop a little short of the end of the tube then come back and cut those last bits out.

I find cutting slots to be quite satisfying... on LPR tubes, at least (other than BT5 which sucks). For the small flimsy stuff (BT5, BT20), sticking a coupler inside the tube is extremely helpful if you can arrange it. Like everyone else I mark the slots with aluminum angle and then use the angle as a cutting guide. A couple of additional tricks I have picked up:

1) I plunge-cut the two ends of the slot first. Otherwise the last end can be quite an adventure as the little strip of BT pushes into the tube. Not an issue if you have a coupler in there.
2) I do a couple of rounds of cuts on both sides of the slot *before* cutting all the way through. It's easier to get a clean initial cut when the tube is still fully intact. Once you have a good starter groove in there, finishing the cut is easy.

These may not apply to heavier MPR and HPR tubing which has much more structural integrity.

 

[afadeev]

I’ve been designing a kit for BluShift aerospace of their Stardust rocket, and I’ve thought about changing a few things to reduce labor costs and assembly time.
1) Have people cut slots themselves
2) have people cut the fins themselves

Out of curiosity, how much time and money would the kit manufacturer be saving by not firing up the laser cutting to outline the fins, and the fin tab slots?
You still need a laser cutter to slice the precise lengths of body tubes and the coupler, so laser cutter is still a tool that your shop will require.

Thanks for the input everyone! From what I've heard people would be OK not having TTW fins as long as the fins are pre-cut. (The fins are balsa and the tubes are paper btw). Please let me know if I missed anything.

I'm not sure anyone was voting against TTW fins.
I would lean strongly against buying low-/mid-power kits without TTW fins for durability and straightness reasons. If you want, you can provide two templates: TTW and non-TTW fin designs and body tube cutting guides.

Agree on everything else:

• Waterslide decals
• Highest quality body tube possible, with minimal-to-zero spirals
• If you are 3D-printing the nose cone (and other other parts), use highest resolution possible to minimize the need to fill ridges in plastic.

Frankly, I would rather pay another +$5 for higher quality components and parts, then save a few bucks on cheaper uncut spiral-filled tubes!

IMHO,
a