Creating a tapered hole

[Norm Dresner]

After much consideration, I finally decided to try out the new RTV casting stuff I have. I'm going two ways:

1. I made a negative mold with a bottom section of a cup upside down in a cylindrical hole. I'm going to pour RTV into this and use the rubber directly as a holder for the cups.

1. I took some Sculpey clay formed a base and then drove the bottom of the cup into it to form the master from which I'll pour RTV to make new molds.

Assuming none of this works, I'll probably take a few used cups, cut them down, and glue them onto a plywood base which I'll use as holders for new cups.

I'd love to have actually been able to drill a tapered hole into a block of wood but it's really infeasible and most of the other suggestions are sort of like taking a shotgun to a fly.

Thanks for all the brainpower that went into this.

Norm

[Joe Gorman]

Chairmakers bits

someone else used to carry them, but I can't find my link nor did I see them at Lee Valley. If this bit isn't big enough then you'ld have to get or make a reamer.

[CW]

[David]

The OP's last statement takes the cake! He claims that all the suggestions are like taking shotgun to a fly, yet he is talking about RTV and molds! A straight hole would have sufficed and he has been told that here, repeatedly... remind me never to respond to him if he asks another question about ANYTHING.

Dave

[RicodJour]

Frankly, there were a fair number of suggestions that required a fair amount of effort and probably buying new tools. I love wood, but I also love being efficient. Making a holder for paint and glue cups...the thing ain't going to be looking good for long, so why go to the effort? The only reason I mentioned a wood frame, was to keep some wood in the project. Otherwise, I would take the foam box from a dozen eggs and pour in some plaster around the cups. That's as high tech as the thing needs to get. You know, a kindergarten project.

R

[fredfighter]

Even easier was taking some spare cups andnailing them to a board.Then drop the workiing cups into them.

[Norm Dresner]

| >

| The OP's last statement takes the cake! He claims that all the | suggestions are like taking shotgun to a fly, yet he is talking about | RTV and molds! A straight hole would have sufficed and he has been told | that here, repeatedly... remind me never to respond to him if he asks | another question about ANYTHING. | | Dave

I've tried straight holes. Unless the block is almost as high as the plastic cup, it's worthless. That's why I want a tapered hole.

Norm

[Norm Dresner]

I agree. But there are two reasons why I'm going my way: 1. I don't want all the cups nailed to one board. I want to be able to reposition one or two without moving the rest.

1. Have you ever bought a new tool and then looked for a project to use it on?

Norm

[David]

and yet you didn't respond on this thread when I suggested that you add a second layer with smaller holes for the bottom of the cups to sit in. that's going to solve your problem if you don't like having only a straight hole at the top. 2 straight holes of different diameters, spaced apart a bit will accomplish the same thing. I quit.

Dave

[David]

I learned not to do that.

dave

[Lew Hodgett]

RE: Subject

Time to find a buddy who has a machine shop and barter.

What you want is very easy to make if you have access to a small metal working lathe and a "Bridgeport" (universal) milling machine.

Many years ago I needed exactly what you are looking for to install tapered thru hulls in boats.

My friend, also a boater, had a machine shop and came to the rescue.

Lew

[CW]

A universal milling machine is a type of horizontal mill, not a Bridgeport. You're quite right though, a custom made cutter would be easy enough. Now, can he pay for it.

[Earl Creel]

14 degree dovetail router bits are available from most router bit suppliers. 14 degrees is ~15 degrees ? Earl Creel

[Lew Hodgett]

CW wrote: > A universal milling machine is a type of horizontal mill, not a Bridgeport.

Right you are, guess I've been away from machine tools too long.

The operative word is barter.

Lew

[Norm Dresner]

| The OP's last statement takes the cake! He claims that all the | suggestions are like taking shotgun to a fly, yet he is talking about | RTV and molds! A straight hole would have sufficed and he has been told | that here, repeatedly... remind me never to respond to him if he asks | another question about ANYTHING. | | Dave

Step 1. Drill one hole (1-7/8") with a Forstner bit Step 2. Take one paint cup and cut it down to ~1/2" high Step 3. Glue to the bottom of the hole. This completes the mold

Making the holders: Mix 1/2 oz each of 2 chemicals and pour into mold. Wait

4 hours and remove completed holder.

This ain't rocket science. It's simple, The holders are perfectly shaped every time and because they're rubber they grip the cups.

Of course, there's still one thing I didn't accomplish: Learning how to drill a tapered hole!

But we'll leave that for the next time I guess.

Norm

[cdo]

If you really just have to overkill this and spend some money, go buy some chairmaker's spoon bits. They make tapered holes. They also cost about $60-$80 apiece .

cdo

[RicodJour]

You were told several ways to cut a tapered hole. Whether you learned anything from this thread is another question.

R

[Leuf]

I know this is a little late, but who says the support has to completely surround the cup? 3-4 short 3/4" square pieces with 15 degree cuts on the ends glued around the cup.

-Leuf