What tool for homemade CR's and bulkheads?

[paparoof]

I guess that title sez it all.

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

The local HD and Lowe's have holecutting bits for drills, but not in the right sizes and they don't look like they'd make very clean cuts.

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.

Can you also include links to either an online store that sells these tools or to the manufacturer website so I'm sure I'm seeing exactly what you're talking about?

I s'pose maybe I should go look at rockler.com

 

[tbzep]

There's a thread just started this afternoon with the same question. (Well, it was for templates....oops)

Click here.

Now take a circle cutting tool and whip it out.

Are you wanting to cut plywood, or cardstock?

 

[jadebox]

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

I made a jig for my router to cut the rings for my "Heavy Metal Thunder" project. It worked very well - so well that the first time I used it, I accidently cut through both the plywood for the centering ring and the board I was using as a work surface!

I based this on the jig described at https://www.woodworkingtips.com/etips/2004/10/08/sn/.

I used a hand-drill and wood or Forstner bits to drill the holes for the motor tubes.

-- Roger

 

[tbzep]

I use one of these when cutting plywood too large for spade bits.

I use this Hobbico tool for paper/cardboard.

 

[paparoof]

There's a thread just started this afternoon with the same question. (Well, it was for templates....oops)

Click here.

Now take a circle cutting tool and whip it out.

Are you wanting to cut plywood, or cardstock?

Sorry - plywood - for mid/HPR.

 

[noise]

...no longer valid...

 

[11bravo]

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

 

[jadebox]

I use one of these when cutting plywood too large for spade bits.

[...]

I use this Hobbico tool for paper/cardboard.

[...]

I use the same tools for smaller rings. The fly cutter I have cuts rings up to about 6" in diameter pretty well. I use it in the $30 drill press I bought from Harbor Freight. I think it would be dangerous to use it with a hand-held drill.

I also have the circle cutter for my Dremel. It hasn't worked well for me (at least not for 1/4" plywood).

-- Roger

 

[paparoof]

Looks like these ideas are all based on the concept of a compass. Makes good sense, but a router is so big I can't imagine you could make 2.6" through 4" rings.

tbzep - can you say more about this one?

What's it called? how's it work? That one looks like it would work better on the size I'm looking to make. Does the bit go into a hand-held drill?

 

[quinn]

For rings and bulkheads for MPR rockets, I'll print templates on the computer -- I use GIMP, an open source painting program, but any graphics tool that'll let you draw shapes to size will do. I then cut the shape by hand using a cheap coping saw, clean up using sandpaper or a sanding drum on a dremel tool.

It's simple, doesn't take too long, and gives you the satisfaction of doing something with your hands, which I miss in my day job.

--Sebastian

 

[jadebox]

What's it called? how's it work? That one looks like it would work better on the size I'm looking to make. Does the bit go into a hand-held drill?

It's a fly cutter. I would not recommend using one with a hand drill. As I said, I use mine in a cheap drill press and it works well. The drill press I bought at Harbor Freight has served me well. I might have been happier with a 10" or 12" one, but the one I have cost only $30 and takes up less space.

-- Roger

 

[tbzep]

I use the same tools for smaller rings. The fly cutter I have cuts rings up to about 6" in diameter pretty well. I use it in the $30 drill press I bought from Harbor Freight. I think it would be dangerous to use it with a hand-held drill.

I also have the circle cutter for my Dremel. It hasn't worked well for me (at least not for 1/4" plywood).

-- Roger

I forgot to mention that I just use a jigsaw for plywood rings of any considerable size. I think the biggest I've cut with the fly cutter is for 76mm motor mounts and I used the jigsaw for the outer part of them.

I can take the jigsaw and cut it pretty close, then put the outside cut on the sander and quickly make it just as accurate as I can draw it. The inside gets cleaned up with a drum sander on the drill press. I don't own a router, so I make do with what I have.

 

[Nathaniel]

Looks like these ideas are all based on the concept of a compass. Makes good sense, but a router is so big I can't imagine you could make 2.6" through 4" rings.

tbzep - can you say more about this one?

What's it called? how's it work? That one looks like it would work better on the size I'm looking to make. Does the bit go into a hand-held drill?

I have one and I hate it. I have a drill press and it simply does not have the torque for this attachment. I have difficulty cutting 1/4" plywood or Masonite rings, even when I cut half way through one side and then flip it over. Keep in mind, that the bigger the centering ring, the more torque you'll need.

 

[11bravo]

It's a fly cutter....snip
-- Roger

Uh oh.
It's gonna happen again.
Let me stop it before it does.
To a wood worker, it may be called a fly cutter.
It may also be called a circle cutter.

To a machinist, it most definitely is not a fly cutter.
These are fly cutters-
https://toolsandmore.us/index.asp?PageAction=VIEWPROD&ProdID=2627
They are used to make a flat surface with a milling machine.

 

[jj94]

I've used my Dremel and its circle cutter multiple times. The first few tries yielded a huge mess but the next rings were fine. When I start cutting, I turn up the speed to about the 5th or 6th speed setting (I think that's aroung 15,000-18,000 rpm) and turn the dremel slowly. After the cut for the outside of the part is done, I do the same for the inside hole, the one that will hold the motor tube(s). After the ring is cut, I sand the ring to fit if it's not already the right size.

 

[jadebox]

Uh oh.
It's gonna happen again.
Let me stop it before it does.
To a wood worker, it may be called a fly cutter.
It may also be called a circle cutter.

I just went by what it said on the package. (And we are generally working with wood ....)

To reply to another comment, my cheap-o drill press seems to work well with the fly ... err ... hoojimajig. The hoojimajig I have has two cutters rather than one as in the photo. I don't know if that makes a difference or not.

I set the blades to the same radius and cut the discs slowly - turning the wood over half-way through.

-- Roger

 

[hokkyokusei]

 

[Pem Tech]

Looks like these ideas are all based on the concept of a compass. Makes good sense, but a router is so big I can't imagine you could make 2.6" through 4" rings.

tbzep - can you say more about this one?

What's it called? how's it work? That one looks like it would work better on the size I'm looking to make. Does the bit go into a hand-held drill?

As stated before, DO NOT use this tool with a hand-held drill, unless you just aren't that found of your fingers.
Use the fly-cutter/hole-cutter/thing-a-mabob in a drill press set on the lowest rotational speed, with your wood stock securely clamped in place. Cut halfway through on one side, flip it over and cut the rest of the way.
This is how we cut our 1/4" 38mm CR's for the Space Ark and 3" Kraken.

The drill press we use is an inespensive Ryobi <$150 and it works fine.

 

[KDRaven]

Myself I use rocsim for the template, spray glue it to the plywood(Wall panaling works for me), tabletop band saw for the outside cut, jigsaw for the inside cut

 

[Bohica]

As stated before, DO NOT use this tool with a hand-held drill, unless you just aren't that found of your fingers.
Use the fly-cutter/hole-cutter/thing-a-mabob in a drill press set on the lowest rotational speed, with your wood stock securely clamped in place. Cut halfway through on one side, flip it over and cut the rest of the way.
This is how we cut our 1/4" 38mm CR's for the Space Ark and 3" Kraken.

The drill press we use is an inespensive Ryobi <$150 and it works fine.

I hate to sound like a broken record but I must...I have seen the damage that these babys can cause when used in a hand drill...it's uuuuggggglllyyyy!!!

 

[11bravo]

I hate to sound like a broken record but I must...I have seen the damage that these babys can cause when used in a hand drill...it's uuuuggggglllyyyy!!!

Oh, you were plenty uuuuggggglllyyyy before the accident.
You're just using it as an excuse.



Sorry, but that one was coming so nice and slow over the plate; I had to take a swing.

Interestingly enough, I have a 3-1/8" forstner bit that says it can be used in a hand drill; thing is HUGE and heavy.
I think the people that wrote that were on something.

 

[Bohica]

Oh, you were plenty uuuuggggglllyyyy before the accident.
You're just using it as an excuse.



Sorry, but that one was coming so nice and slow over the plate; I had to take a swing.

Interestingly enough, I have a 3-1/8" forstner bit that says it can be used in a hand drill; thing is HUGE and heavy.
I think the people that wrote that were on something.

Hey!! I resemble that remark!

 

[Oliver Arend]

I made one of these last week

https://www.audiocad.de/u/bauvor/fraeszirkel/d_fz.html

and it works great. It's just that you have to figure out which setting gives which diameter exactly before cutting, but you only have to do that once.

Oliver

 

[Bigander]

Hmm I'll have to check w/ my gf's dad, Ken Burton. He writes woodworking books and I know in the one on the table saw he outlines how to make a jig for cutting circles on it. That would help for larger projects for cutting the outside diameter.

 

[11bravo]

I made one of these last week

https://www.audiocad.de/u/bauvor/fraeszirkel/d_fz.html

and it works great. It's just that you have to figure out which setting gives which diameter exactly before cutting, but you only have to do that once.

Oliver

Ausgezeichnet!

 

[Maagic]

Ausgezeichnet!

Gesundheit!

 

[overby]

Seriously, a plunge router and a Jasper Circle Guide or two.

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?

I have a drill press and a couple of circle cutters. I bought one heafty circle cutter at Sears, and a second lighterweight one at Menards. The problem is getting them adjusted "just right" for each body tube or coupler. I make cardboard centering rings (quick, easy & cheap) until I get it right, get it close enough, or get frustrated then make a bunch of bulkheads. I haven't found a safe way to hold a bulkhead so that I can punch a hole in it to make a centering ring.

Glen Overby

 

[paparoof]

I am SERIOUSLY leaning in that direction. I'm quite sure I already have one of those stashed away somewhere.

 

[jderimig]

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?

Glen Overby

I use the Jasper guides and have not found the 1/16 increment to be a problem. The maximum error you will have will be 1/32" on the radius (and often less than that) which can be easily and quickly sanded to fit.

 

[kandsrockets]

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?

I have a drill press and a couple of circle cutters. I bought one heafty circle cutter at Sears, and a second lighterweight one at Menards. The problem is getting them adjusted "just right" for each body tube or coupler. I make cardboard centering rings (quick, easy & cheap) until I get it right, get it close enough, or get frustrated then make a bunch of bulkheads. I haven't found a safe way to hold a bulkhead so that I can punch a hole in it to make a centering ring.

Glen Overby

just by a 7/32 and 1/4" bit and you can cut any size centering you want. I have cut centering rings from 1.5" up to 16"