[TheForge] Lamps and pipe slitting.

Tue Jan 1 19:07:00 2002

        Don( you sneaky promotionalist you),  Thanks for the notes on making
a jig to push the material thru the bridgeport.  I was dealling with an 8"
slit so I was able to clamp and slit with the saw in the bridgeport.  I will
also apply this jig process to the feed table I'm making for the verticle
band saw.
        Looking forward to seeing your new book.........is this also going
to be for sale at said Gichner gathering you are asking me if I am
attending??
        At this time I don't plan to come down.  I usually ride with David
Court and he isn't going this year (so he says now anyhow)........but that
could change when Bill calls looking for some Maple syrup or any other
excuse to get David to come visit.  :-)
        Thanks for the note, let me know when your book is available.

Ralph


----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Tuesday, January 01, 2002 9:44 AM
Subject: [TheForge] Lamps and pipe slitting.


> In a message dated 1/1/2002 5:54:09 AM Pacific Standard Time,
> [email protected] writes:
>
> << Anyone have any other wonderful ideas for pipe >>
>
> Ralph,
>
> Just finishing up a book called "Advanced Metal Working Techniques with
Peter
> Renzetti". Here's how he handled the pipe slitting for some 6' torchieres.
> Thought you might find it of interest. Might be a bit difficult to
understand
> without some diagrams. If you want them, let me know off line.
>
> And all too obviously, I am sure, this is an underhanded way of promoting
> this book.
>
> Will you be coming down to Gichner's this year?
>
> Don Plummer
>
> The columns for the torchieres are about 6 feet in height and each of the
> total torchieres are 7-1/2’ high. They consist of 4 1-1/4" naval bronze
tubes
> setin a square with four 6' filets filling in the spaces between the
tubes.
> Each tube is 72” long and that means each of those thin filets must be 72”
> long also. Here’s the technique I used to get those filets.
>
> The filets are segments of stainless steel tubing that are half the size
of
> the larger tubes. That is they are cut from stainless tubing that is 3/4”
ID.
> The photo to the right shows the simple device that will work well for
this
> application. This is a piece of plate aluminum that is probably about 3”
> thick. This piece will be subsequently clamped in a milling machine or
> something similar. For your own application choose the aluminum stock
> according to how you will be clamping it. Then drill a hole exactly the
> outside diameter of the tubing you from which you will be cutting a
segment.
> Make it near an appropriate edge because you will want to cut a slot in it
> that will allow a slitting saw to run through this channel. In this
instance
> I used a slitting saw with a 4” blade that is 1/16” thick. This fits on an
> arbor on the milling machine that is on a vertical shaft. Saw is cutting
> horizontally. Also, you will need to drill a small hole through which you
> will later insert a guide pin. Note this at the top of the aluminum block.
>
> It is very important that everything be rigid. That’s part of the beauty
of
> the Bridgeport milling machine is you can lock all the tables and keep
> everything very positive.  It needs to be solid cause you are always
pushing
> everything. Feed to the saw needs to be very positive and you need to
control
> that feed rate into the saw. It actually takes quite a bit of effort to
push
> this through the blade. RPM of blade is important and it needs to be
> controlled to prevent bounce. You also need to have fluid because
stainless
> can be difficult to cut as it is a resistant material. It is very abrasive
> and plastic so need something to keep it from gumming up, must be
lubricated.
>
> Also, controlling of the movement of the rod being cut into the blade is
> worth some consideration as there is considerable resistance from the
blade
> revolving against the tube. Thought should be given as to how this will be
> handled AND controlled. In this case I used a simple device that is much
like
> the doohickey used on the piston of a storm or screen door to hold it
open. A
> similar device is used on the newer caulking guns.  I fixed a lever to the
> top of the Bridgeport table and attached a cable to a tab of metal drilled
> larger than the tubing and with a slight bend to it.  When I pulled
against
> the lever it would lock and pull into saw. The other way it could slide
> easily for repositioning. This gave me more mechanical advantage and
allowed
> me to pull it through with little effort and a more positive feed.
Obviously
> one could accomplish the same effect with a rack and pinion, a mechanical
> feed, or something more automated. But this worked quite well for the
limited
> number we had to to.
>
> One of the basics of metalworking is that you gotta figure out how to do
> things. And one of the best ways to do that is to apply other experiences
> from your life. One must constantly think about what you are doing and how
> can it be done better, faster, cheaper, safer. Part of my theory of
> relativity.
>
> Once your jig is appropriately made we can begin cutting the filets. Mount
> the jig in your milling machine or whatever you are going to use to make
this
> initial cut. I use a milling machine because I have one. With a little
> imagination I am sure you could come up with some alternative device that
> would perform the same function cleanly and safely. This will be a form of
> conventional cutting. That is, the blade will rotate toward you as you
push
> the tubing into the jig. Set it’s depth to cut cleanly through the walls
of
> the tubing. We ran our first 6 foot segment through and it cut a slot from
> one end to the other.  The 3-5’ diameter of the blade will keep the first
cut
> straight and longitudinal.
>
> Now to cut out the segment. Remember I mentioned a paragraph ago about the
> guide pin. Well, you will have to now insert a metal pin in that guide
hole.
> It will be used to follow the slot just cut. It must be positioned so that
it
> will give you a segment filet that is the correct width for your
application.
> Now run the tubing through again and you should have your filet.
>
> If you used a slitting saw as suggested you should have a filet that is
> without burr. An abrasive disk or alternative blade may introduce a burr
that
> could complicate the subsequent fitting and soldering. Slitting saws have
no
> offest in the teeth and they cut very smoothly. I was able to get three
> segments per 3/4” stainless tubing.  We needed four of these per torchiere
or
> sixteen in total. Once the jig was in place and correctly positioned this
> task did not take long at all. And every filet was exactly the same. But
we
> did have to cut about 100 feet of the filets in total.
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