Weld positioner/ table

[Larrysmachine]

I have a steady job that comes into the shop that I need a positioner for. Here goes, the pics are not that good but it will give you an idea of how I am putting it together. The positioner itself is 15"X15" square, 2" drive shaft powered by 1/8 bodine gear drive with 328 inlb of torque. Max speed on shaft is 5rpm. this will have a 19" face plate. the unit is mounted on an old Peterson head surfacer. behind the positioner I have a 2" thick 15" wide 42" long ground plate for smaller precision fit ups. I will get better pics when I get the control and casters mounted.
72992

72993

72994

72995

72996

[ToolBoxTavern]

Great build.

[Thiel-Metal-Fab]

nice work. curious to see what ur welding together with this contrapsion. looks pretty dam heavy duty and well built.

[Shox Dr]

Christ on a bike that looks good. Just bear in mind top RPM* is not where you need it it's the really low speeds, and that's where it gets interesting as most speed controllers are too crude in chopping up the Hz, so you end up with a jerky movements. Out of interest what are you using for the speed control.

If it helps here is my take on one (http://weldingweb.com/showthread.php?t=38381&highlight=positioner) Max RPM on that is 2.06 and it's whey too fast

[Larrysmachine]

Shox Dr
The control is a bodine control that matches the motor (90/130VDC 1/8-1/4hp) and will go to almost 0 without dropping torque. Rotation is very smooth. Once I get the face plate mounted we will see how it works. If I see that I need it even slower I have room to add another shaft for more gear reduction.

[Larrysmachine]

nice work. curious to see what ur welding together with this contrapsion. looks pretty dam heavy duty and well built.

It will be used for bedding plow spindles, they will have the old bearing surfaces machined off, re-welded on the new positioner and machined back to specs. I will get a pic of one this afternoon if I get a chance.
Larry

[forhire]

Looks great. It looks like you have enough room for a larger sprocket if you need to slow it down more.

[Larrysmachine]

OK, I had a few minutes to spare today in between jobs and got the face plate adapter and the face plate mounted. Also got position holes drilled at 0, 45, and 90 degrees for the positioner. Here is one of the parts that that this positioner is being built for.
73332

73333

73334

73335

[Boostinjdm]

I've been wondering if a hole through the shaft is necessary or not.

[Larrysmachine]

I've been wondering if a hole through the shaft is necessary or not.

I machined an adapter plate and welded it to the main drive shaft and the face plate is bolted to the adapter from the back side. I will try to get a better pic when I add some more.
Larry

[Tool Maker]

I suppose I am singing to the choir but you need really robust ground brushes between the position-er and your table because the bearings will not take any arcing through them before they freeze up solid. Mac

[Larrysmachine]

I suppose I am singing to the choir but you need really robust ground brushes between the position-er and your table because the bearings will not take any arcing through them before they freeze up solid. Mac

I have not got that far along yet but I was going to use copper grounding strap and a spring to keep tension on the shaft. from what I have been reading this should work. this is my first positioner so I am learning as i go.
Larry

[Tool Maker]

The copper ground strap will work , however it will eventualy get realy rough from constantly arcing. The best thing I found was to take the brushes from a car starter motor spring brackets and all and mount so they rub on the smooth shaft. the more brushes the better. Mac

[Larrysmachine]

Tool Maker,
I will look at grounding it the way you are saying, thanks
Larry

[zapster]

I have found that putting the ground directly to the piece in the positioner is the best medicine for this procedure..
Make sure the cable will do a 360 without getting caught on something and have at it..
You WILL burn the brushes up fast with anything over 150 amps on a constant basis..

And 2 RPM on the fastest speed is way too much RPM...
You will see that soon enough also..

...zap!

[Larrysmachine]

Zap,
Thanks for the info, getting close to trying it out if the customers will slack off a bit. I will post the results.
Larry

[Larrysmachine]

Ok guys I got the positioner up and going, I don't have all of the creature features on it that I want yet but my customer is on my back to get some spindles out the door. I used stripped #4 welding lead for the ground, wrapped around the shaft and spring loaded as you can see in the pic. I ran this thing for 30min non stop with no arcs or sparks and no heat build up on the grounding cable. I think I had the machine set at 370ws and 20V. I am very happy with it, if you notice in the pics I have an air opperated foot switch for on and off and the speed control is on a swing away arm. it's not pretty but it functions very well. Better than I figured it would actually.
Larry
74094

74095

74096

74097

74098
Nex post for last pic

[Larrysmachine]

Finished spindle
74099

[monkers]

I love the fixture / positioner, and the finished (saved) part is great. How much of a pain is it trying to center your parts on the face plate? Really nice setup, Im sure itll be used for lots of other projects also. Every once in a while it would be handy to have a setup like this, looks like I will have to start scrounging around......thanks for sharing.

[zapster]

You get all the fun jobs...:drinkup:


...zap!

[Shox Dr]

I've used the same setup on the ground strap, and so for I haven't had any problems. Even used it to cut the top off a Propane bottle the other day.:cool2:

[lewray]

Those were great pics.. I like it a lot. Good work

[ThorsHammer]

I'll take that one for an early christmas present. you can deliver it next week. :-D