Hi. I make a product (http://basscapos.com/robpin.html) which uses lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point should be both installable and removable by the customer, who presumably has no metalworking skills or tools. Maybe this simply isn't possible.

Right now we're making it with a straight shaft 8mm long, with a tapered end. Problem is that the tube is not all that consistent for either roundness or ID, so naturally some points fit nicely, while others don't work at all.. Besides changing to a more dimensionally consistent tubing, is there a tweak which would make the point more universal? Maybe a very slight taper instead of a straight shaft?
Thanks

On Tuesday, July 11, 2017 at 10:27:57 AM UTC-4, robobass wrote:
Problem is that the tube is not all that consistent for either roundness or ID,
Thanks

Many years ago I visited a place that made tubing. They pulled a piece thru tubing to increase the id . So the ID was very uniform and round. As I remember they used hydraulics .

Dan

"robobass" wrote in message
...
Hi. I make a product (http://basscapos.com/robpin.html) which uses
lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a
press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point
should be both installable and removable by the customer, who
presumably has no metalworking skills or tools. Maybe this simply
isn't possible.

Right now we're making it with a straight shaft 8mm long, with a
tapered end. Problem is that the tube is not all that consistent for
either roundness or ID, so naturally some points fit nicely, while
others don't work at all. Besides changing to a more dimensionally
consistent tubing, is there a tweak which would make the point more
universal? Maybe a very slight taper instead of a straight shaft?
Thanks
=========

How about an O ring instead of metal-to-metal friction?

On Tue, 11 Jul 2017 07:27:51 -0700 (PDT), robobass
wrote:

Hi. I make a product (http://basscapos.com/robpin.html) which uses lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point should be both installable and removable by the customer, who presumably has no metalworking skills or tools. Maybe this simply isn't possible.

Right now we're making it with a straight shaft 8mm long, with a tapered end. Problem is that the tube is not all that consistent for either roundness or ID, so naturally some points fit nicely, while others don't work at all. Besides changing to a more dimensionally consistent tubing, is there a tweak which would make the point more universal? Maybe a very slight taper instead of a straight shaft?
Thanks

The easiest thing probably would be to go to a DOM tubing (if it's
available in the SS you're using) That stuff, in carbon steels,
typically is +0.000, -0.003 in. or so in small diameters like that.
But I don't know about SS.

Aside from that, a complicated solution is an expanding-mandrel
approach for the point. Not a very good solution.

A simpler one would be to size the ID of the tube with a reamer or a
diamond hone (Sunnen's diamond hones are very good for accurate
sizing. You can run one in a drill press.)

That is, if you have enough wall thickness to deal with the range of
inaccuracies you have to deal with.

If you press-fit it, it will have to be very accurate for someone with
no metalworking knowledge to replace them. You might want to get the
sizing close, and then turn two grooves on the point that you fit with
neoprene O-rings. Depending on how inaccurate your tube is, that might
even allow you to skip the sizing step.

Good luck!

--
Ed Huntress

On Tue, 11 Jul 2017 07:27:51 -0700 (PDT), robobass
wrote:

Hi. I make a product (http://basscapos.com/robpin.html) which uses lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point should be both installable and removable by the customer, who presumably has no metalworking skills or tools. Maybe this simply isn't possible.

Right now we're making it with a straight shaft 8mm long, with a tapered end. Problem is that the tube is not all that consistent for either roundness or ID, so naturally some points fit nicely, while others don't work at all. Besides changing to a more dimensionally consistent tubing, is there a tweak which would make the point more universal? Maybe a very slight taper instead of a straight shaft?
Thanks
Consider a threaded in point?

On Tue, 11 Jul 2017 08:38:06 -0700 (PDT), "
wrote:

On Tuesday, July 11, 2017 at 10:27:57 AM UTC-4, robobass wrote:
Problem is that the tube is not all that consistent for either roundness or ID,
Thanks

Many years ago I visited a place that made tubing. They pulled a piece thru tubing to increase the id . So the ID was very uniform and round. As I remember they used hydraulics .

Dan
Mandrel forming - works better on larger tubes.

On 7/11/2017 7:27 AM, robobass wrote:
Hi. I make a product (http://basscapos.com/robpin.html) which uses lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point should be both installable and removable by the customer, who presumably has no metalworking skills or tools. Maybe this simply isn't possible.

Right now we're making it with a straight shaft 8mm long, with a tapered end. Problem is that the tube is not all that consistent for either roundness or ID, so naturally some points fit nicely, while others don't work at all. Besides changing to a more dimensionally consistent tubing, is there a tweak which would make the point more universal? Maybe a very slight taper instead of a straight shaft?
Thanks


Isn't gouging a hole in the floor of the venue a bad idea?

Make threaded insert and thread the pointy thing.

On 7/11/2017 10:06 AM, Ed Huntress wrote:
If you press-fit it, it will have to be very accurate for someone

I suggest you use more Astro-glide.

On Tue, 11 Jul 2017 09:35:24 -0700, mike wrote:

On 7/11/2017 7:27 AM, robobass wrote:
Hi. I make a product (http://basscapos.com/robpin.html) which uses lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point should be both installable and removable by the customer, who presumably has no metalworking skills or tools. Maybe this simply isn't possible.

Right now we're making it with a straight shaft 8mm long, with a tapered end. Problem is that the tube is not all that consistent for either roundness or ID, so naturally some points fit nicely, while others don't work at all. Besides changing to a more dimensionally consistent tubing, is there a tweak which would make the point more universal? Maybe a very slight taper instead of a straight shaft?
Thanks


Isn't gouging a hole in the floor of the venue a bad idea?

Make threaded insert and thread the pointy thing.
etter yet, supply an extra "tube" with the pin permanently attached -
or put the pin in the opposite end from the rubber tip - simply flip
the pin.

Thanks everyone. The reamer idea sounds like the ticket. Don't know why we didn't think of it... Threads are lots of work, and they get loose and rattle. I can also get seamless St35Bk non-stainless for just a little bit more money, which is way more dimensional. Thinking about it, but stainless is already in all of the press stuff, so if I change to carbon steel then customers might think I'm cheating. Marking the floor? Good question. Many bassists and cellists prefer a point, both for stability, and some say better sound. Some stages allow it, some strictly forbid it! The reason I can't insert the point myself is that since the rods are interchangeable, there is no way to know which rod will get the point until after the player has experimented a bit. I suppose that if I make it so the player can hammer it on himself, but won't be able to remove it, then that should be good enough.

On Tuesday, July 11, 2017 at 6:07:09 PM UTC+2, Ed Huntress wrote:
On Tue, 11 Jul 2017 07:27:51 -0700 (PDT), robobass
wrote:

Hi. I make a product (http://basscapos.com/robpin.html) which uses lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point should be both installable and removable by the customer, who presumably has no metalworking skills or tools. Maybe this simply isn't possible.

Right now we're making it with a straight shaft 8mm long, with a tapered end. Problem is that the tube is not all that consistent for either roundness or ID, so naturally some points fit nicely, while others don't work at all. Besides changing to a more dimensionally consistent tubing, is there a tweak which would make the point more universal? Maybe a very slight taper instead of a straight shaft?
Thanks

The easiest thing probably would be to go to a DOM tubing (if it's
available in the SS you're using) That stuff, in carbon steels,
typically is +0.000, -0.003 in. or so in small diameters like that.
But I don't know about SS.

Aside from that, a complicated solution is an expanding-mandrel
approach for the point. Not a very good solution.

A simpler one would be to size the ID of the tube with a reamer or a
diamond hone (Sunnen's diamond hones are very good for accurate
sizing. You can run one in a drill press.)

That is, if you have enough wall thickness to deal with the range of
inaccuracies you have to deal with.

If you press-fit it, it will have to be very accurate for someone with
no metalworking knowledge to replace them. You might want to get the
sizing close, and then turn two grooves on the point that you fit with
neoprene O-rings. Depending on how inaccurate your tube is, that might
even allow you to skip the sizing step.

Good luck!

--
Ed Huntress

Actually, O-Rings are sounding better and better as I think about it more.

"robobass" wrote in message
...
Thanks everyone. The reamer idea sounds like the ticket. Don't know
why we didn't think of it... Threads are lots of work, and they get
loose and rattle. I can also get seamless St35Bk non-stainless for
just a little bit more money, which is way more dimensional. Thinking
about it, but stainless is already in all of the press stuff, so if I
change to carbon steel then customers might think I'm cheating.
Marking the floor? Good question. Many bassists and cellists prefer a
point, both for stability, and some say better sound. Some stages
allow it, some strictly forbid it! The reason I can't insert the point
myself is that since the rods are interchangeable, there is no way to
know which rod will get the point until after the player has
experimented a bit. I suppose that if I make it so the player can
hammer it on himself, but won't be able to remove it, then that should
be good enough.

========================

These used to be allowed to fasten down scenery:
http://www.bullworks.net/daily/20070729.htm

However raising splinters in the stage floor with them was said to be
a good way to discover how hard a dancer can kick.
-jsw

On 7/11/2017 10:27 AM, robobass wrote:
Hi. I make a product (http://basscapos.com/robpin.html) which uses lengths of SS hot formed tube 10mm OD x 8mm ID. Some customers want a press in, hardened point on the end of one of the tubes.
http://i389.photobucket.com/albums/o...ps8uuji8py.png
The design wants the tubes to be interchangeable, so ideally the point should be both installable and removable by the customer, who presumably has no metalworking skills or tools. Maybe this simply isn't possible.

Right now we're making it with a straight shaft 8mm long, with a tapered end. Problem is that the tube is not all that consistent for either roundness or ID, so naturally some points fit nicely, while others don't work at all. Besides changing to a more dimensionally consistent tubing, is there a tweak which would make the point more universal? Maybe a very slight taper instead of a straight shaft?
Thanks

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How about epoxying a neodymium magnet into the tube to hold the tip?

Like these:

https://www.apexmagnets.com/8mm-x-8m...i2wAodE JwD3Q

robobass wrote:
Thanks everyone. The reamer idea sounds like the ticket. Don't know
why we didn't think of it... Threads are lots of work, and they get
loose and rattle. I can also get seamless St35Bk non-stainless for
just a little bit more money, which is way more dimensional. Thinking
about it, but stainless is already in all of the press stuff, so if I
change to carbon steel then customers might think I'm cheating.
Marking the floor? Good question. Many bassists and cellists prefer a
point, both for stability, and some say better sound. Some stages
allow it, some strictly forbid it! The reason I can't insert the
point myself is that since the rods are interchangeable, there is no
way to know which rod will get the point until after the player has
experimented a bit. I suppose that if I make it so the player can
hammer it on himself, but won't be able to remove it, then that
should be good enough.


How about taking a page from camera monopods and walking sticks. You
machine a screw into a point that can be press fit into the end of the
tube, then add a rubber foot that can be screwed up to reveal the point
or down to have a rubber foot. Making a retractable point foot.

Like
https://cdn.photographylife.com/wp-c...ripod-Feet.jpg

or
ebay item 171751891766

or google Gitzo GS5030VSF Rubber Feet, Spike Tip

Gives the best of both worlds and can be sold as a "product accessory"

--
Steve W.

How about epoxying a neodymium magnet into the tube to hold the tip?
I like this a lot, but I'd have to put one in each tube.

How about taking a page from camera monopods and walking sticks. You
machine a screw into a point that can be press fit into the end of the
tube, then add a rubber foot that can be screwed up to reveal the point
or down to have a rubber foot. Making a retractable point foot.


Cool idea, but with the size constraint it would be way to delicate.

On 7/11/2017 11:38 AM, wrote:
On Tuesday, July 11, 2017 at 10:27:57 AM UTC-4, robobass wrote:
Problem is that the tube is not all that consistent for either roundness or ID,
Thanks

Many years ago I visited a place that made tubing. They pulled a piece thru tubing to increase the id . So the ID was very uniform and round. As I remember they used hydraulics .

Dan


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You can get better SS tube cheaper at "Trent Tube" in Wisconsin. Just
mention my name, my sister Pat was VP sales for many years.

On Thursday, July 13, 2017 at 9:20:01 AM UTC+2, Tom Gardner wrote:
On 7/11/2017 11:38 AM, wrote:
On Tuesday, July 11, 2017 at 10:27:57 AM UTC-4, robobass wrote:
Problem is that the tube is not all that consistent for either roundness or ID,
Thanks

Many years ago I visited a place that made tubing. They pulled a piece thru tubing to increase the id . So the ID was very uniform and round. As I remember they used hydraulics .

Dan


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You can get better SS tube cheaper at "Trent Tube" in Wisconsin. Just
mention my name, my sister Pat was VP sales for many years.

I should have mentioned that I am in Germany! both of the types I've mentioned in 10mm x 1mm tube cost me about eight bucks per meter, so price isn't a big issue for this project.

On Wed, 12 Jul 2017 23:19:06 -0700 (PDT), robobass
wrote:


How about epoxying a neodymium magnet into the tube to hold the tip?
I like this a lot, but I'd have to put one in each tube.

Remember...O rings come in different flavors (material)...some will
work well..others will disintegrate like spit in short order.


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