Thread: Junk yard finds and their uses

That is a great idea Bryan. I too suffer from this sickness of repurposing stuff others are throwing away. For example I built my entire Lathe workbench from timber that was being thrown away at work.
Attachment 211537

The store I work at is going through a complete remodel. I have acquired several flourescent lights, wood, and a 1/3 hp motor that was hooked to a CO2 compressor for a soda machine. I thought maybe I could replace the motor on my drill press with it.

Bret

Hi Bryan,
Is that old transformer 24VAC? You'll be getting something like 30V.

Stuart

Greetings Chaps I don,t have the inclination to hang out at junk yards but I do keep an eye out for stuff left on the nature strips. I once asked a passerby to help me load a wardrobe. But the subject here was an old set of shelves I have included a couple of pics previously seen on this forum but there are always new bodies. It had been turned into a multi leaved storage cabinet for my hand tools. The problem is putting the tools back in the cabinet. I also had the habit of scrounging steel from my old place of employ. The offcuts rack was a joy to behold. Yours 4-6-4

i better add this i found at a garage sale for $5 he didnt know what it was

a head off something with 1 1/2 x 8tpi thread on one end
internal number 3 mt
other end has some sort of internal taper but not anything i have that fits
vertical and horizontal swivel with graduations
centre height approx 3 1/2 inches

Originally Posted by Michael G

I'm guessing that those two stiff springs are there to provide an increase in torque that the current sensor can detect.

Michael, what you say could be correct. But there is also a pair of limit switches - the blue thing. The grey sleeve moves slightly at each end of the stroke and that trips the switch. The springs re-centre the sleeve when the pressure is released. Even using hand pressure to simulate the springs it seems to work very well. So I'm not sure if current sensing is needed.

Your advice on the springs sounds... sound. I will only go to the trouble if I decide to use it in linear mode. And you're correct on the stroke, well spotted. I measured about 144mm, taking approx 27 seconds.

You might be able to slow it down by running on 12V. The electronics may not let you, and you won't get the full 6000N, but may do what you want.

Interesting. Would that draw more current? The only electronics I can find are those limit switches and a couple of diodes.

Originally Posted by Stustoys

Hi Bryan,
Is that old transformer 24VAC? You'll be getting something like 30V.

Stuart, yes 24 VAC. But I think I was getting 22.x from the bridge. Did I do it wrong? Tranny output is true to label.

Originally Posted by Bryan

Stuart, yes 24 VAC. But I think I was getting 22.x from the bridge. Did I do it wrong? Tranny output is true to label.

Rapidly heading out of my depth Bryan(not that deep though lol)
22VAC will likely(?) be RMS volts. The peak Voltage will be 22 x (the square root of 2 or 1.414)=31.10
The bridge will cost you about 1.2V so 30V

Also I'm told that DC motors dont particularly like running on full wave rectified AC.

You dont have a half dead 18V cordless drill in the junk pile?

Now if someone would turn up that really knew what they were talking about

Stuart

Originally Posted by tanii51

i better add this i found at a garage sale for $5 he didnt know what it was

a head off something with 1 1/2 x 8tpi thread on one end
internal number 3 mt
other end has some sort of internal taper but not anything i have that fits
vertical and horizontal swivel with graduations
centre height approx 3 1/2 inches

Tool & cutter grinder work holder.

PDW

Originally Posted by tanii51

i better add this i found at a garage sale for $5 he didnt know what it was

I'll give you 10 times that.
Nice score $5 is so close to free that it hardly counts.

Stuart

Repurposing? Is that what it is called? Help, I suffer also. LOL!!

Is there a twelve step program?

Here is a nicely powdercoated Schneider cabinet, thrown out because it was the wrong colour



I purchased a Kincrome tool set some years ago and made a point of reffitting this cabinet rather than buying the purpose built Kincrome one. Took me days, but then I would not have successfully repurposed this sexy cabinet.



Current repurposing activity includes converting this natural gas Aquamax to electric. If it wasn't a stainless steel tank I wouldn't bother. I still have room for one of those cast iron gas rings they sell at Aussie Disposals at the bottom so I can also heat it up off a barby gas bottle as well. The new place has a shed that needs hot water for the occasional washing home brew bottles etc and doesn't have town gas. It's only a 2400w element so I can run it off a 15 amp socket.



Why? I suppose, like many of us, believe that too much good stuff goes to waste without even attempting to put a in little bit of effort to fix it or give it a new life. However I think I have burnt out my roundtoit with these projects

Originally Posted by tanii51

i better add this i found at a garage sale for $5 he didnt know what it was

a head off something with 1 1/2 x 8tpi thread on one end
internal number 3 mt
other end has some sort of internal taper but not anything i have that fits
vertical and horizontal swivel with graduations
centre height approx 3 1/2 inches

Oh great. Now I've got to go and wade through hundreds and hundreds of garage sales full of nothing but moldy clothes in the hope of finding a $5 tool and cutter grinder attachment. Thanks a lot!

I was having a sign thoughts ja
ckal

I meant having the same thoughts jackal bloody voice recognition

jekyll

Originally Posted by Stustoys

Also I'm told that DC motors dont particularly like running on full wave rectified AC.

Thanks Stuart. I won't run it further till I understand its needs better. At least I proved it works and I'm not wasting my time.

Originally Posted by Bryan

Thanks Stuart. I won't run it further till I understand its needs better. At least I proved it works and I'm not wasting my time.

Have worked with Linak systems in patient lifters, hospital style beds etc. The dedicated controllers have a battery pack (2 x 12V bats for 24V DC), a mains powered charger module, controllers for individual functions (frequently more than 1 function on a unit) and a handpiece controller with two momentry switches per function.

Motor control is normally from the 24 V battery pack via a MOSFET to handle switching and a relay to handle reversing, but I seen some units that have a MOSFET for current limiting, and seperate relays for forward and reverse. Most of the units I have come accross used only a 2 pole 6.25 mm phone plug. so there was no provision for the limit switches to connect back to the controller. Hence they must be wired in series with the motor within the module.

With regard to operating from full wave rectified AC of roughly appropriate voltage, this is similar to early model train controllers etc. The motor is being fed a mixture of DC voltage, probably about 18V for a 24V winding, plus an AC ripple voltage of about 14V peak to peak comprising harmonics of the mains frequency up to 1000Hz or so. The DC component will drive the motor, but the current from the ripple component will flow through the motor windings generating heat but no usefull output power. As the motor is more heavily loaded, the DC component reduces and the ripple component increases. This is where it becomes difficult to run the motor off rectified AC, as the motor is loaded up, the ripple power disipation increases to the point where it can cook the motor.

The limited unloaded run that you gave the motor should not have damaged it.

Rectified power is used in many things, in conjunction with a filter stage involving large capacitors individually, or in sets connected by inductors. This increases the DC output voltage while reducing the ripple component significantly. For more critical situations, a regulator curcuit normally follows the filter stage to precisely control the DC output voltage and further reduce the ripple component.