What tool for homemade CR's and bulkheads?

[Micromeister]

Paparoof:
I'm assuming your looking for a decent way to make centering rings for model and Large Model rocket projects. Mostly for Craft tube type models with Cardstock, Sho-card, fibreboard or lite ply rings.

While is is possible to cut these with the fly cutter set up shown earlier, I've found using double cutters allows the cutters to do the work in small drill presses with minimum pressure exerted on the tool or press.

That said: I rarely use the fly cutter method unless i'm using Plywood or other materials thicker then 1/8".
For just about all my centering ring cutting and cluster mount centering ring cutting, I've discovered stack cutting with a Band or scroll saw, finishing with drum and belt sander is just as quick and I can make a bunch of rings all at once. This way I get the rings I need now and have a few sets leftover for the next time they are needed, over time the collection has grown so that I rarely have to cut rings anymore
Over time it's been learned that a variety of materials can be stacked using Double sided masking tape between each layer, to from a stack of 12 to 20 rings depending on the thickness of the cardstock, Sho-card, G10 and/or liteplywood used in the stack. the big thing is it's possible to cut and sand to some very thin wall thicknesses spacings without breaking the rings Heres a few pics of different cutting compasses, tools and finished rings.
Hope this helps a little.

 

[Lee Reep]

I guess that title sez it all.

What tools are people using for making their own centering rings and bulkheads?

[...] I don't own (and don't expect to own) a drill press, but I see several scroll saws on craigslist for less than 50 bucks. That would work, but I'd like to see what others are doing.

If you are scratch-biuilding, you really NEED a drill press! Besides drilling holes, you can put sanding drums in them. You can also use them as a mini-lathe to turn small balsa nose cones.

A benchtop model at Harbor Freight can be found on sale for $40 pretty often (with keyless chuck, to boot). I usually don't shop HF, but their drill presses are fine.

Also, if you do not have a Dremel tool, then you need one of those as well!

A scroll saw is handy, but I actually use a small bandsaw more often -- cutting thin plywood, body tubes, etc.

Sorry, I'm a woodworker, and not exactly unbiased, but a drill press is one of those tools that once you have, you wonder how you ever survived without.

 

[jadebox]

A benchtop model at Harbor Freight can be found on sale for $40 pretty often (with keyless chuck, to boot). I usually don't shop HF, but their drill presses are fine.

My 8" drill press (not keyless) was $29 on sale at Harbor Freight. I don't normally buy cheap tools, but it was so cheap I figured I could discard it if it didn't work. It's actually worked well. I also got my circle cutting thingy from HF along with an inexpensive set of sanding drums.

I looked at the belt/disc sanders at HF, but they looked really cheaply made, but weren't as inexpensive as the drill press. So I passed and bought one from Amazon.com for $100. It's another tool that's proven itself to be very handy.

I have a small scroll saw that I've used for fins in the past, but lately I've switched to using a jig saw. I bought one with a laser guide and I've found I can make very accurate cuts with it.

-- Roger

 

[KDRaven]

Drill press, table saw, sawzaw, scroll saw, bandsaw, router, belt sander, palm sander, cutting torch, cutoff saw, welder. and yes even a hacksaw and coping saw, I know i cant live with out them and I cant get my car in the garage either. :rotflol:

 

[11bravo]

Gesundheit!

:lol: :rotflol: :lol: :rotflol: :lol: :rotflol: :lol:

 

[11bravo]

Those guides have 1/16" increments. Most body tube's inside diameters aren't even 1/16" sizes. I assume you have router bits in fine enough sizes to adjust for the difference?...snip...
Glen Overby

Stop by sometime and I'll demonstrate.
I'm only 3-ish hours south.
I haven't found a tube I couldn't get a pretty nice fit in yet.
Pick up parafoof on the way and we can have a rocket party. <= that's actually supposed to read "paparoof"
You guys can help me glass my L3 tubes.

 

[RandyM]

Seriously, a plunge router and a Jasper Circle Guide or two.
You could also make your own circle cutter for the router but you would have to do measurements to get it set right.
With the Jasper jigs you just put the pin in the correct hole and have at it.
Standard config gives you holes or rings or bulkheads accurate to 1/16" diameter using a 1/4" bit.
With a 9/16" (IIRC) bit gives you to 1/32".
Plenty good for what we do.
With the two jigs I have I can do between 1" and 18-3/16".

https://www.parts-express.com/webpa...lter=+circle+jig&raid=1&rak=jasper+circle+jig

Greg

I'm going to second the Jasper Jig/Plunge Router route.

Is it the cheapest way to go? No, but it is about the safest way to make them and have something that is accurate and easily reproducible.

I love mine!

 

[vcp]

My very-soon-to-be circle and fin cutter.

Gary

View attachment mini-IMG_0402.JPG

 

[paparoof]

Pick up parafoof on the way and we can have a rocket party. <= that's actually supposed to read "paparoof"
You guys can help me glass my L3 tubes.

Hey I've been called much worse!

And I actually have some experience laying fiberglass too! But I'm not coming Iowa until trout season opens up again. There are some fantastic streams in the NE corner of Iowa (and SE MN and West-central WI).

Due to the mentions of Harbor Freight in this thread, I've now been to their website and found they even have a physical store here in the city! I had no idea! I will definitely stop there soon to look for deals on a drill press.

Micro - thanks for showing a picture of the circle cutter bit installed in the drill press. I'm embarrassed to tell you how I was thinking it was supposed to be used! oh, I still have so much to learn....

 

[vcp]

Due to the mentions of Harbor Freight in this thread, I've now been to their website and found they even have a physical store here in the city! I had no idea! I will definitely stop there soon to look for deals on a drill press...

Save yourself some time, grab a basket when you first enter the store, rather than have to wander back to find one when your arms are full (even if you just went in to 'look').

Gary

 

[paparoof]

will do Gary.

That's one SEXY looking cuttin' machine too BTW....

 

[DaveCombs]

Save yourself some time, grab a basket when you first enter the store, rather than have to wander back to find one when your arms are full (even if you just went in to 'look').

Gary

Also - save yourself some money. BEFORE you go to Harbor Freight, if you know what you want, go to their website and print the page of the item you want with the price. I have found instances where the shelf price will be HIGHER than the price on the web, but they do match the web price. I've bought stuff this way twice now.

 

[paparoof]

Oh dood - now THAT's the kinda advice that a fella can use....

 

[DaveCombs]

Like it says under my handle, "Ask me how I know..."

 

[mrmonteith]

My very-soon-to-be circle and fin cutter.

Gary

Holy smokes Gary, going into mass production there or what? lol
At least we'll know who to turn to.

I think I'm going to use my router with a template. I don't think I
can afford your setup. Not and live through my marriage.

Michael

 

[vcp]

Also - save yourself some money. BEFORE you go to Harbor Freight, if you know what you want, go to their website and print the page of the item you want with the price. I have found instances where the shelf price will be HIGHER than the price on the web, but they do match the web price. I've bought stuff this way twice now.

Oh, absolutely! .. I've done that too.

Gary

 

[fishnutt90804]

Here is the link to EMRR tools .
https://www.rocketreviews.com/tools.shtml
Follow the instructions and stick the paper on the wood and cut away with what ever you have. I use a jig saw and a drill for cutting. and, I have a drum sanding bit for the inside hole finish and a belt sander clamped to the bench for the OD finish.
A prior post recommended the A1 guy for center rings. I did use him and found him to be very professional and very fast. So, if you do not have any tool at all he would be cheaper than buying tools to make your rings. After I used him I did man-up and way over invested in all kinds of tools like dremels with attachments and the like. My preferred method is as I described earlier.

Good luck
Kevin

 

[mrmonteith]

Here is how I made my own centering rings. Hope this comes out okay on here. I used subflooring sheet that I had left over. Thicker than the original centering ring but that's okay for me.

Note:this all assumes you know proper safety and use of a router without having to explain direction, etc.

1. Tacked a centering ring to plywood piece. The best way would have been to use double-sticky tape.
2. Drill hole through center for router bit. (bit with bearing to use to original to follow as template).
3. Adjust router height so end of cutter just barely cuts through the plywood you're cutting. Adjust as necessary to finally get the adjustment so it clears the plywood piece only.
4. Cut the inside out first.
5. Next, cut the outside making sure as you get close to the end you hold the parts as well as the board outside the ring so when it cuts loose you don't have flying parts.
6. Remove your original from the copied piece and sands.

I made several rings pretty quick with this.

Michael

View attachment CRSetup.JPG

View attachment CRInside.JPG

View attachment CROut2.JPG

View attachment CRResult.JPG

 

[paparoof]

Well I picked up the cheap-o drill press and circle cutter at Harbor Freight last night and got a small sheet of 3/16" aircraft plywood at the LHS this morning so when vacation starts later this week, I'm gonna get some learnin' done!

 

[Stymye]

good choice the drill press is indespensable !

main thing about the circle cutter in the drill press ,,keep the >speed down< and watch those fingers , it's not the safest combination by any means but works great once it's dialed in.

 

[Pem Tech]

Well I picked up the cheap-o drill press and circle cutter at Harbor Freight last night and got a small sheet of 3/16" aircraft plywood at the LHS this morning so when vacation starts later this week, I'm gonna get some learnin' done!

Excellent choice.
Now you can not only cut CR's till you are blue in the face but have the capability of turning your own NC's, and many other strange and wonderful things!

You are on a roll now, so start thinking about a belt sander, and a band saw, and a table saw and a miter saw and on and on and on.....

 

[RandyM]

good choice the drill press is indespensable !

main thing about the circle cutter in the drill press ,,keep the >speed down< and watch those fingers , it's not the safest combination by any means but works great once it's dialed in.

Also make sure the cutters are "VERY TIGHT" Even at slow speeds if one comes off it will have quite a bit of velocity to it. If you see me at a launch, I'd be happy to the scar it left! Before anyone says anything, I DID tighten the setscrew and it worked it 's way loose. I would recommend a face shield in addition to safety glasses also.

When that happened to me I broke down and bought the Jasper Jig and a Plunge router. I figured that it was safest and easiest way to make them

 

[paparoof]

Also make sure the cutters are "VERY TIGHT"....

Oh man - guess the kids will stay in a different room too....

 

[paparoof]

Oh man - guess the kids will stay in a different room too....

Well they were in a different room alright, they were in a different room at their mom's house...

I learned a few things tonight, got some pretty decent CR's outta the deal too.

Figured out how to attach the two cutters in such a way that I could make both inner and outer cuts at the same time.

Lesson #1 - $40 drill presses don't have much for horsepower. The cutter kept slowing down and stopping on only 3/16" ply - notice the burning on the outside edge of the one ring. It'll only get worse when I graduate to 1/4" ply for bigger rockets. Solution was to flip the board over and cut the rest of the way through (see lesson #2 for why this wasn't a good solution either).

Lesson #2 - $6 circle cutters basically suck. The blades weren't sharp at all (see above comment about the cutter slowing and stopping). The only component that didn't have a hex screw I could tighten was of course slightly loose causing a tiny wobble in the cutter. The result of this wobble was that I couldn't get the board perfectly centered when flipping the board over to cut through from the other side. So of course, this made for some rough and uneven edges.

I know I should probably just cut the rings a tiny bit too large then sand 'em down for a perfect fit but I wanna use power tools to make things easy and fast - having to sand parts afterward to make 'em fit kinda gets in the way of that. I wanna cut 'em perfect. So for now, I guess I'll give up on making both cuts at once and use both cutters on the same cut at the same time. Maybe then I'll be able to get all the way through without flipping the board over.

I see www.rockler.com has what appears to be a much nicer looking cutter for $30. Think that'll be my next purchase. Then when I finally get around to buying a truly pro drill press, I'll sell this drill press to Noise. For $50.00. :rotflol:

 

[noise]

I see www.rockler.com has what appears to be a much nicer looking cutter for $30. Think that'll be my next purchase. Then when I finally get around to buying a truly pro drill press, I'll sell this drill press to Noise. For $50.00. :rotflol:

niiiiiicce...

 

[Austin]

Looks like you are on your way...I actually bought several of the circle cutters ans set them permanently at certain sizes with some set for inner circles and others set for outer cutting. You can see my "How to make CR's" here https://www.rocketryforum.com/ctulanko/album/?dir=tres where I do a step by step walk through. Good luck and keep us posted on your projects.

 

[narmember]

The result of this wobble was that I couldn't get the board perfectly centered when flipping the board over to cut through from the other side. So of course, this made for some rough and uneven edges.

Having a ridge on the edge of the centering ring isn't a bad thing. It is easy to sand for a snug fit.

If you pre-drill your wood with a 1/4" (or a hair smaller) bit and use a 1/4 steel rod instead of a drill bit in the circle cutter, it will easily center and you won't have the bit eating away at the pilot hole.

 

[Rocket Al]

My very-soon-to-be circle and fin cutter.

Gary

Are you going to be running that with some equipment from HobbyCNC.com, by any chance?



Al

 

[kandsrockets]

My very-soon-to-be circle and fin cutter.

Gary

Gary I am getting ready to build this one.

 

[Lee Reep]

Athough your first centering ring will cost you thousands of dollars - -all the rest will be cheap!

This is an excellent frame of mind to have, and I've used it to buy all my big shop tools. It all started when I bought a compressor 20 years ago to blow out the sprinkler system in the winter. I told my wife the first blowout was $500, but the rest were free ...