Scribing around a "squashed cone" shape...

Lt. Z0mBe · Post by **Lt. Z0mBe** » Thu May 18, 2006 7:09 am

Wise and Sagely Modelers,

I have been rescribing panel lines for a long time now. I've got my own system that works perfectly for me, complete with some custom tools. I've scribed just about every kind of line, rivet, vent, and access door you can imagine in sci-fi. But, I have happened upon something I've never tried to scribe before: A propeller hub that's a "squashed cone" shape.

Basically, I need to scribe lines around the hub dome that run parallel to the base of the hub. When viewed from the side, they should look like this: ||||, with the right side being the tip of the hub. Oh, did I mention I do not have a lathe?

The hub is too small for label tape - it lifts up - and I can't seem to get a perfect line all the way around with double-layered masking tape. There's nothing flexible enough I can hold in my hand to wrap around the hub either.

I ask the Council of Styrene and Resin this: Have you all ever attempted such a feat? Can it be done safely? Should I hire a professional?

Any tips or advice, as always, would be greatly appreciated. Now, back to the workbench.

Thanks,

Kenny

Kylwell · Post by **Kylwell** » Thu May 18, 2006 9:36 am

Can you just hold the cone against a flat surface (like the orkbench) & mount the scriber to a board of the correct height and just walk it around the cone? Or is it too small for that?

My trick it to CA it to a rod and chuck it into my lathe, but you migh be able to do the same with a drill. Hard part is holding the scriber steady & working lightly.

Treadhead · Post by **Treadhead** » Thu May 18, 2006 11:13 am

Use several pieces of styrene that have different diameter holes -- put these onto the cone as a guide and scribe around the styrene.

The only challenge here is making sure that the styrene template is parallel to the base of the cone while scribing.

You might have to do some guesswork in making the holes for the styrene template so that they match the circumference of the cone at each section that you want to scribe.

Sorry, I know my explaination is hard to understand. I've got a clear picture in my head of what I'm saying -- it's just that translating it into words is difficult

Mr. Badwrench · Post by **Mr. Badwrench** » Thu May 18, 2006 1:45 pm

Robb's method works well. You can see here that I've done something similar to scribe parallel lines into a hemisphere. The hemisphere is larger than a prop spinner, but the technique is still the same. I used an industrial height guage with a scribe, because I have one. But it works equally well by using the back side od an exacto blade, shimmed up from the table top with styrene strips, wooden blocks, even putting the blade between the pages of a book.

Lt. Z0mBe · Post by **Lt. Z0mBe** » Fri May 19, 2006 5:45 am

Yes, yes, yes, both Robb's and tread's methods will work for me. Robb's will work around the base and my draftsman's templates will do the trick around the top.

Excellent ideas, guys! Thanks a bunch. It's tough trying to scratchbuild a contra-rotating prop hub.

Kenny

Treadhead · Post by **Treadhead** » Fri May 19, 2006 1:29 pm

Mr. Badwrench wrote:even putting the blade between the pages of a book.

Now why didn't I think of that?? The book idea is excellent!

Thanks