--Have been putting together a rotary welding table for doing round
stuff in one go. Photos and a bit of explanation start he
http://www.flickr.com/photos/steambo...7624880649814/
--Device is made from two of those windshield wiper motors available
from AS&S and other folks. More on these motors he
http://www.scary-terry.com/wipmtr/wipmtr.htm

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

On Jul 20, 11:43*pm, steamer wrote:
* * * * --Have been putting together a rotary welding table for doing round
stuff in one go. Photos and a bit of explanation start hehttp://www.flickr.com/photos/steambo.../set-721576248...
* * * * --Device is made from two of those windshield wiper motors available
from AS&S and other folks. More on these motors hehttp://www.scary-terry.com/wipmtr/wipmtr.htm

--
* * * * "Steamboat Ed" Haas * * * * : *Steel, Stainless, Titanium: *
* * * * Hacking the Trailing Edge! *: *Guaranteed Uncertified Welding!
* * * * * * * * * * * * *www.nmpproducts.com
* * * * * * * * * *---Decks a-wash in a sea of words---

Way too pretty, neat, and clean!

Nice.



Dave

What is your method for getting "ground" to the work?

Pete Stanaitis
-----------------

"steamer" wrote in message
...
--Have been putting together a rotary welding table for doing round
stuff in one go. Photos and a bit of explanation start he
http://www.flickr.com/photos/steambo...7624880649814/
--Device is made from two of those windshield wiper motors available
from AS&S and other folks. More on these motors he
http://www.scary-terry.com/wipmtr/wipmtr.htm

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

Pete S wrote:
What is your method for getting "ground" to the work?
--Rotary table will sit atop my steel welding table. Motor section
will be isolated from the rotary section via the rubber connector in the
Lovejoy connection and from the welding table with a thin piece of rubber or
plastic or even wood.

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

--Followup to followup: went to Sebastopol Dorkbot last night and we
talked a bit about grounding paths. New plan is to put a copper plate on the
bottom of the rotating table, then attach a 'wiper' of some kind to this so
that ground path will be thru the table rather than thru the bearings. More
photos after I've noodled it out a bit more.

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

On 07/31/2011 07:20 PM, steamer wrote:
--Created a set on Flickr for the project; all done except for
attachment of ground clamp via braided cable and building a foot controller.

Nice Work!

Here is a pair of them that I built a few years ago.

http://www.metalworking.com/dropbox/...sitioner_1.jpg
http://www.metalworking.com/dropbox/...sitioner_2.jpg
http://www.metalworking.com/dropbox/...sitioner_1.txt

BobH

--Created a set on Flickr for the project; all done except for
attachment of ground clamp via braided cable and building a foot controller.
http://www.flickr.com/photos/steambo...th/5994453177/

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

--Hey that's slick; looks pretty heavy duty too! What does the
spring loaded arm do?

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

On 2011-07-31, steamer wrote:
--Created a set on Flickr for the project; all done except for
attachment of ground clamp via braided cable and building a foot controller.
http://www.flickr.com/photos/steambo...th/5994453177/

Looks nice.

One question -- what happens if the carpet tape gets hot?
Depending on the current, the carbon brush may get quite hot.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

DoN. Nichols wrote:
One question -- what happens if the carpet tape gets hot?
Depending on the current, the carbon brush may get quite hot.
--Welll let's call it a calculated risk.. ;-) If it fails I'll maybe
switch to a piece of circuit board material. Whaddya think?

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

--Oh, I get it. But does it actually work without degrading, i.e.
getting chewed up by constant arcing?

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

On 08/01/2011 04:55 PM, steamer wrote:
--Oh, I get it. But does it actually work without degrading, i.e.
getting chewed up by constant arcing?


It seems to work without getting chewed up. The spring keeps a constant
contact, so the arcing is minimal. I built it with a lets see what
happens approach and it has been OK. I don't have a lot of use on it,
but there is no sign of galling or deterioration yet. I figured that I
would put a copper shoe on it if the aluminum did not hold up.

I built the positioners because I had been doing a bunch of round
welding stuff. As luck would have it, I have done very little since then.

I like the copper and carbon brush piece that you made, that seems like
a lot more elegant approach. Those gear drives you used look good too.

Bob

On 2011-08-01, steamer wrote:
DoN. Nichols wrote:
One question -- what happens if the carpet tape gets hot?
Depending on the current, the carbon brush may get quite hot.
--Welll let's call it a calculated risk.. ;-) If it fails I'll maybe
switch to a piece of circuit board material. Whaddya think?

Sounds good to me. Ideally 1/4" thick G-10 (or similar) if you
have a clearance for the heads of the screws in the plate below it, or
with 1/2" thick, you can counterbore for the heads to keep them
insulated. (And likely dull your counterbore bit beyond reuse. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

--Best thing about those worm gear drives: they're common and cheap
so get some and play! :-)

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

DoN. Nichols wrote:
Sounds good to me. Ideally 1/4" thick G-10 (or similar) if you
have a clearance for the heads of the screws in the plate below it, or
with 1/2" thick, you can counterbore for the heads to keep them
insulated. (And likely dull your counterbore bit beyond reuse. :-)
--Yeah clearance is an issue so I'll have to go with 1/16" for now;
if I ever make a version 2 I'll do that tho..
--Latest news: started work on a foot pedal speed control today;
here's a pictu
http://www.flickr.com/photos/steambo...57627324267926
With luck I'll find a potentiometer with a longer shaft that I can
run thru an oilite bushing in one side of the pedal 'box' to keep it from
bending the leads. The loading is fairly light but it should be reinforced..

--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

On 2011-08-02, steamer wrote:
DoN. Nichols wrote:
Sounds good to me. Ideally 1/4" thick G-10 (or similar) if you
have a clearance for the heads of the screws in the plate below it, or
with 1/2" thick, you can counterbore for the heads to keep them
insulated. (And likely dull your counterbore bit beyond reuse. :-)
--Yeah clearance is an issue so I'll have to go with 1/16" for now;
if I ever make a version 2 I'll do that tho..
--Latest news: started work on a foot pedal speed control today;
here's a pictu
http://www.flickr.com/photos/steambo...57627324267926
With luck I'll find a potentiometer with a longer shaft that I can
run thru an oilite bushing in one side of the pedal 'box' to keep it from
bending the leads. The loading is fairly light but it should be reinforced..

Any reason to not mount the pot free of the board, with wires
making the connections? That way, you could either mount it to a
bracket, or mount it on the other side of the side plate, with a small
box over it.

Of course -- first make sure (with an ohmmeter) that the pot is
not electrically connected to one of the leads.

Another possibility is if the sprocket and hub are longer than
the available shaft, is to mount an insulating shaft (Delrin or the
like) on the side panel and use it as a pilot for the outboard end of
the sprocket.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

DoN. Nichols wrote:
Any reason to not mount the pot free of the board, with wires
making the connections? That way, you could either mount it to a
bracket, or mount it on the other side of the side plate, with a small
box over it.
--Hmmm I like it; will mess around with it some more manana.. :-)

Of course -- first make sure (with an ohmmeter) that the pot is
not electrically connected to one of the leads.

Another possibility is if the sprocket and hub are longer than
the available shaft, is to mount an insulating shaft (Delrin or the
like) on the side panel and use it as a pilot for the outboard end of
the sprocket.

Enjoy,
DoN.


--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

On Monday, August 1, 2011 12:54:36 PM UTC-4, steamer wrote:
DoN. Nichols wrote:

Depending on the current, the carbon brush may get quite hot.
--Welll let's call it a calculated risk..

One could double or triple up on the brushes, but it still might pay to
put an insulating barrier between the shaft and the disk (to protect the
gears and bearings from current in case of a stuck brush).

More important, though, the brush holder should be brass or bronze,
the use of aluminum (which can grow an insulating oxide VERY quickly)
is not electrically suitable to that sliding contact at the brush-to-holder
interface. There are solders that can make a good connection from
the copper plate to the aluminum, or antioxide pastes (used for copper
versus aluminum splicing, ask at any good hardware store).

Heavy brushes (like for elevator motors) use braided copper cemented into
the graphite, rather than depending on the sliding connection.

For most use, I"d consider clamping the ground via a braided cable directly
to the work; if the cable is loose enough, it'll tolerate one or two rotations of
the worktable.

"whit3rd" wrote in message On Monday, August
1, 2011 12:54:36 PM UTC-4, steamer wrote:
DoN. Nichols wrote:

Depending on the current, the carbon brush may
get quite hot.
--Welll let's call it a calculated risk..

You could just put some mercury in the gearbox....
;)}