Another Big Dumb Rocket

NickG said:

The setup in the above picture seems unsafe to me. I agree that you need to push the workpiece counter to the direction of the cutting or grinding bit. That way your hands are ‘downstream’ of the router bit.

But how do you hold the workpiece (fin) once it is half way through? Seems to me you now have to grab the opposite side of the fin and pull. your hand is now ‘upstream’. If the bit grabs the fin, it will pull your hand into the burr bit.

A better way is to clamp the fin to a LONG piece of wood and offset the router fence by the thickness of the wood. That way hands can be kept ‘downstream’ for the entire cut.

Another way is to cut a small hole in the fence and have just a little bit of the burr bit exposed beyond the fence surface. I’d still use an offset wood block or jointer safety holders for this set up.

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All of the cut happens in one pass, and it is not grabby like a router bit. And, there is not much for the bit to grab and pull after it passes the bit.

In addition, fondness for my fingers has led me to develop a habit of bracing my hands on the top of the fence when running dicey things on the table saw or router. Some processes require fingers close to dangerous places.

After the fin passes the bit, it does not need to be pulled, only barely pressed against the fence. It is mostly held against the fence by the nature of the cut. On some passes, I did not even touch 'downstream of the bit'', and never did my fingers make it into the elevation of the action. The bit is only up maybe an inch. That fence is around 3" tall. I brace my hands so that they cannot be sucked into sharp things. It is something I have practiced for many years now. I still have all my fingers.

Yes, this is not without risk. I mentioned what I felt was most pertinent, about not pinching between a rotating bit and the fence in the wrong direction. As you say, the router is the scariest tool in the shop. As far as router table setups go, this one is very friendly. I would set it up again exactly this same way. It does not need more, IMO, at least for me.


Burying the bit into the fence would be safer, but, then you have to press the fin into the bit, meaning that there is more potential for variation in the cut. In this setup, the bit presses the fin into the fence.

By all means, anyone working with these tools should always be sure to think things through as much as possible, and be extremely careful.

I have worked with tools since I was a little kid, from back when every tool had to be tested for it's digging qualities, and my cognitive memories were barely forming. It was part of growing up in a lineage of engineers and makers. I offered this as an alternative to the setup with the router that I have seen on this site. That one scares me. This is much safer, faster, better, IMO. As far as router setups go, this felt quite safe. There is someone out there that could get their tongue ground off in this, though, or wrapped up in the bit. Careful out there.

IMO, the very most dangerous thing about this setup, and that I have not mentioned, is dust. That router is connected to a powerful dust collection system that is outside the building. I turned on a powerful spray booth fan in an adjacent room, and opened doors that cause air to flow across this work station to minimize any CF dust that has time to settle and mix with the ambient dust in the shop. Most of it is taken immediately by the dust collection system attached to the router table. I have 2 1700 cfm massive V-bank HEPA filtration units in my shop, one runs 24/7, the other is in a downdraft table and runs when I am sanding or when a dusty process is happening. Finally, I was wearing a JSP Powercap, which I love. It has a stout face shield, and a decent level of particulate protection pumped into the mask.


https://www.amazon.com/POWERCAP-CAE602-941-100-JSP-Powercap-Active/dp/B00JVV4744

Some updates....
This bird has flown now. A J800T lifted it into the sky. Exactly as it should have been.


Here is a pic of the AV bay.





And the fins getting glued on. .125 Dragonplate Uni/Twill is the material.

Nothing like about a dozen deadlines all at once to invigorate the soul... This is my paint booth today. All three of these are going to the Playa this next weekend. With some fly fishing along the way.

But for now, three rockets to paint. One will be a neon 'fire tiger' color scheme. Another will be candy apple red. The big dumb one will be a teal candy over silver metallic. 3 rockets to fully polish in a half day. Time for a challenge! I think I can..

Epoxy primer sprayed. Topcoat will be a 2k urethane.

And the AV bay for the little 54mm minimum diameter rocket, with the dog collar tracker. It will also have an RF tracker. I have an L1030 for it. Should be a cool flight.

Here is the base for candy apple red. This is a House of Kolor Shimrin 'Spanish Gold' base, with SEM mini gold flake sprayed over top carried in a Spanish Gold candy. Now it is time for the red.

Chris_H said:

Here is the base for candy apple red. This is a House of Kolor Shimrin 'Spanish Gold' base, with SEM mini gold flake sprayed over top carried in a Spanish Gold candy. Now it is time for the red.

Click to expand...

Wow, that looks great the way it is!

NickG said:

The setup in the above picture seems unsafe to me. I agree that you need to push the workpiece counter to the direction of the cutting or grinding bit. That way your hands are ‘downstream’ of the router bit.

But how do you hold the workpiece (fin) once it is half way through? Seems to me you now have to grab the opposite side of the fin and pull. your hand is now ‘upstream’. If the bit grabs the fin, it will pull your hand into the burr bit.

A better way is to clamp the fin to a LONG piece of wood and offset the router fence by the thickness of the wood. That way hands can be kept ‘downstream’ for the entire cut.

Another way is to cut a small hole in the fence and have just a little bit of the burr bit exposed beyond the fence surface. I’d still use an offset wood block or jointer safety holders for this set up.

Click to expand...

^ This. I have beveled several fins in manner pictured, and Nick G's quote above is the epiphany I had after a few questionable passes. It also prevents the risk of the bit taking too much material in the event it's not perfectly hard against the fence.

Nice work!

Nice rocket and a great color base for your candy apple red finish on the Playa.

Both of mine will be flying "nekid" down and dirty so to speak ... both on experimental motors and both first time flyers ... so paint happens when I get back with them ... if I get them back

C'ya out there ... BTW Gold base candy apple red is my all time favorite color

John

The candy apple rocket is fully polished now. It took about 1 hour total from the first wetsand to the last buff. My girlfriend made some video of how it was done. The entire rocket was wetsanded with a DA sander, except for a couple of 'fat lips' on the bottom edge and on a fin. I needed a careful block to bring those flat. The first sanding was done with 3m 1200 grit film, wet, on a DA, followed by 3000 grit Trizact on a DA, wet, followed by buffing on a buffing jack with 14" wheels. It looks like you would expect a show car to look.

Here is the next one up. It should be polished tonight. The clear is drying now.

Good luck with the flight!!

blackjack2564 said:

Good luck with the flight!!

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Thank you, Jim.

Those are some good looking layers of paint, Good luck on the flight!

Thank you.

Just before the CATO... The forward closure and forward end of the case let loose. The AV bay and nosecone were immediately ejected. Consensus of those who looked is a likely faulty grain. Drogue chute was torn, harness picked up a little char, but is still very usable. Everything else on up survived, electronics are fine. The thing left the pad and did some skywriting before being tossed across the launch area. The airframe is easily salvaged, fins were unscathed, paint unscathed except for where the blow torch came out.

Thank you Gary, CJ, and Joe. I really appreciate the guidance and help along the way. Also, a big thank you to all the people whom I have reached out to, and have graciously helped.

The blue bird will be rebuilt, and probably fly on a baby M for the next L3 attempt.

The motor hardware and M2245 reload should be replaced under CATO warranty by CTI. I think that a new rocket will be built for that motor, another bird to fly at Balls next year. A couple of ideas are swirling around...

2 other flights were successful. One was a 54mm minimum diameter project flown on an L1030 to just under 24k at just under mach 2. It landed 1.5 miles away, an easy catch with the DC40. The other flight was the red rocket, flown on an L995 to just under 13k'.

This was a great time. BALLS has to be one of the best launches imaginable. The amount of creativity and effort involved in the many, many flights during the event is mind boggling. An amazing group of people! Thank you to all the people who are BALLS!


Here is Gary, one of my TAP's at the pad with the rocket.