Electrical help please

[Walter Massa]

I built this 3-light bender utilizing different aspects of different benders I've seen here and elsewhere. I used a caulking gun as my waist press, and created shape specific removable blocks for it (see pictures). Shown is the unit with an OM form installed. I used 1/4" dowels on the base with corresponding holes in the form to keep everything lined up. I covered the interior with sheet metal to protect the wood, as well as reflective pieces to keep the heat from getting below the ceramic bulb bases. Everything seems to work just fine. Now I want to put some level of heat control into this thing. I purchase a device that should do the trick, but I'm not very good at these things. I connected the light bulbs in parallel ok, but this is more complicated. Anyone care to draw me a step by step for this one?

REX-C100 Manual
http://www.rkcinst.co.jp/english/pdf_ma ... zc17e3.pdf

Relay

[ken cierp]

Way, way, way to complicated. Forget the temperature control use a total of 600 watts (3 x200 watt bulbs) and do not use without a 30 minute timer to shut it off -- this serious stuff! Several of our production benders are this simple set up, we bend sets of different materials just about every day. Pre heat for 15 minutes, load, (do you have enough clearance to get the side blank under the caul?) re-set timer for 15 minutes --- let the side cool -- done!

And of course as usual I highly recommend pre-bending the waist curve on a pipe by hand (three minutes work). This is especially important for your bender design since it does not have the spring loaded cross bar supporting the waist during compression -- pretty much required with a tight waisted style like the OM to prevent cracks. Look here:
viewtopic.php?f=8&t=1371

[ken cierp]

Couple of other things seem to be in need of modification on your bender -- the springs actually hold the ends of the bouts in place, and based on what I can see in the picture they are loose at the end of travel, which at that point they should have tension and be some what parallel to the bench top. Also you'll want to have the bender fastened securely to the bench -- if its a moving target you'll not have the necessary control -- and I can tell you a burn from the edge of one of the metal slats is not something you want to deal with (been there done it!)

[John Parchem]

I whole heartedly agree with Ken about both the complexity vs. the value in a light bulb heater for a temperature control. I also think having a timer on the power to the bulbs is mandatory, especially with a temperature controler where you might be tempted to leave the room.

If you were to wire it up. One of the light bulb AC lines will go right to the number 2 terminal on the relay. The other AC line will go to one side of all of your bulbs. The other side of your bulbs go to the number 1 terminal on the relay.

terminal 3 on the relay goes to output terminal 4 on the controller and Terminal 4 on the relay goes to output terminal 5 on the controller

You should have a switch and fused (1 amp, 250V) 110V line attached to terminals 6 and 7 of the controller.

The thermal couple is connected to terminals 9 and 8 on the controller.

That should make it work.

Here is a diagram for the relay.

solid state relay.jpg (29.35 KiB) Viewed 1697 times

[Kevin in California]

Hey Walter. It looks like your waist press pivots and will swing down out of the way so you can remove the bent side?
If not, I think you're going to have difficulty getting the side out. My tower is much taller, and I have to remove the caul from the screw to remove the bent sides from my bender.
Looks good though, hope you can get enough force from the chaulking gun. Might be tough on the hand.

Kevin

[Walter Massa]

Hey Walter. It looks like your waist press pivots and will swing down out of the way so you can remove the bent side?
If not, I think you're going to have difficulty getting the side out. My tower is much taller, and I have to remove the caul from the screw to remove the bent sides from my bender.
Looks good though, hope you can get enough force from the chaulking gun. Might be tough on the hand.

Kevin

Thanks Kevin,
These images will show how the waist press is adjustable. I designed it so I can create different cauls for different forms. This one is specific to the OM I am currently making. It clamps down so tightly I can lift the entire machine by the handle without anything moving out of place.

[Walter Massa]

Couple of other things seem to be in need of modification on your bender -- the springs actually hold the ends of the bouts in place, and based on what I can see in the picture they are loose at the end of travel, which at that point they should have tension and be some what parallel to the bench top. Also you'll want to have the bender fastened securely to the bench -- if its a moving target you'll not have the necessary control -- and I can tell you a burn from the edge of one of the metal slats is not something you want to deal with (been there done it!)

I agree I need to redesign the spring rollers. They didn't turn out like I thought they would. I wanted them to roll over the surface, via a gloved hand, so they wouldn't drag the material with them. They do roll nicely under spring tension but they do slack at the ends. Clearly unacceptable. I will probably remove the springs and replace them with a hook and threaded rod set up that can be controlled at the ends with knobs.