Wood Lathe: Making a Plywood Bulkhead

[lakeroadster]

I remembered this technique today from years ago when we machined large steel discs at the fab shop I worked at. Since the full edge of the bulkhead needed machined we couldn't chuck on the o.d.

1st: Rough cut the wooden bulkhead by using a scroll saw or band saw. Make the bulkhead about 1/6" to 1/8" oversized in diameter.

2nd: Place the rough cut bulkhead against the face of the chuck and use the tail stock to apply pressure against the bulkhead, pushing it against the chuck.

3rd: You can now sand (or cut) the o.d. of the bulkhead to the correct size.

Cutting a short length of body tube or coupler and placing it over the tail stock allows you to get that perfect fit of the o.d. of the bulkhead, or just use dial calipers.

​

 

[Hobie1dog]

 

[cls]

Wow, I guess that does it. I'd use a fly cutter on my drill press, or straight bit on router table, or a swing arm router for large diameter, 1/2" plywood. One cut, no trimming.

 

[JimByrne]

I use hole saws (in the drill press) to cut the O.D. then trim to size in the lathe, then use a hole saw to cut the center hole. Also, I use the lathe to sand the motor tube & the body tube--in a couple of minutes the sanding is done.

 

[lakeroadster]

Wow, I guess that does it. I'd use a fly cutter on my drill press, or straight bit on router table, or a swing arm router for large diameter, 1/2" plywood. One cut, no trimming.

I use hole saws (in the drill press) to cut the O.D. then trim to size in the lathe, then use a hole saw to cut the center hole. Also, I use the lathe to sand the motor tube & the body tube--in a couple of minutes the sanding is done.

There are lots of ways to skin this cat... this is just one way. I didn't want a hole in the center of the bulkhead, so this worked well, based on the tools I have on hand.

 

[rharshberger]

There are lots of ways to skin this cat... this is just one way. I didn't want a hole in the center of the bulkhead, so this worked well, based on the tools I have on hand.

plus you get a convenient center point

 

[cls]

Yeah, the fly cutter definitely makes a hole in the center. The two router methods can leave a small pinprick in the center, depending...

 

[jqavins]

1st: Rough cut the wooden bulkhead by using a scroll saw or band saw.

Or saber saw, or coping saw. Or you're teeth, if you're in a beavery mood. Or a knife if you're very patient. Or...

Nicely done. I'd still go laser cutter (at a maker space) but that's because I'd rather design and assemble rockets than fabricate rocket parts. To each their own.

 

[lakeroadster]

Or saber saw, or coping saw. Or you're teeth, if you're in a beavery mood. Or a knife if you're very patient. Or...

Nicely done. I'd still go laser cutter (at a maker space) but that's because I'd rather design and assemble rockets than fabricate rocket parts. To each their own.

Witchcraft...

Do you have any photo's of your rockets?

 

[jqavins]

Yeah, a few. Anything in particular you'd like to see. Or did you mean this for someone else?

 

[lakeroadster]

Yeah, a few. Anything in particular you'd like to see. Or did you mean this for someone else?

Just curious...

 

[Hobie1dog]

I thought that most people would want the hole in the center to put the eye bolt there, like in a NC bulkhead.

 

[lakeroadster]

I thought that most people would want the hole in the center to put the eye bolt there, like in a NC bulkhead.

Depends on the design, form follows function.

On rear reject rockets placing the eyebolt off to the side keeps the Kevlar shock chord from receiving a direct blast from the ejection charge and it places the eyebolt in the area where there is a void, instead of inside the motor tube.

 

[Hobie1dog]

Depends on the design, form follows function.

On rear reject rockets placing the eyebolt off to the side keeps the Kevlar shock chord from receiving a direct blast from the ejection charge and it places the eyebolt in the area where there is a void, instead of inside the motor tube.

 

[Chad]

Or saber saw, or coping saw. Or you're teeth, if you're in a beavery mood. Or a knife if you're very patient. Or...

Nicely done. I'd still go laser cutter (at a maker space) but that's because I'd rather design and assemble rockets than fabricate rocket parts. To each their own.

was going to suggest a local makerspace + laser myself. A laser cutter seems to be the first thing makerspaces buy, I live in DFW and a lot of libraries even have them.

 

[lakeroadster]

was going to suggest a local makerspace + laser myself. A laser cutter seems to be the first thing makerspaces buy, I live in DFW and a lot of libraries even have them.

That's pretty much unobtainium up here in the wide open spaces.

 

[rharshberger]

That's pretty much unobtainium up here in the wide open spaces.

Same here and I live in an area with over 300k residents between the three cities (actually 4), we have one MakerSpace and it sucks.

 

[jqavins]

was going to suggest a local makerspace + laser myself. A laser cutter seems to be the first thing makerspaces buy, I live in DFW and a lot of libraries even have them.

Agreed, for where I am. There's one maker space with a laser cutter in the region, and it's almost an hour's drive from home at a public library, and it's not open weekends, with hours after 5:00 only on Thursdays... and it's totally worth it. They have a rotary positioner, so I need to learn to use that feature for tube slotting and angled or funky ends such as on the Kraken.

But I must quibble on one point: the first thing maker spaces buy is 3D printers. Which can also make bulkheads, centering rings, and fins for you, but I'd rather have wood or wood products (card stock, etc.).

There is another in-library maker space, close to home, which has two 3D printers and a Cricut. [/tangent]