Author Topic: Switch for reversing a dryer belt  (Read 2951 times)

Offline ZooCity

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Switch for reversing a dryer belt
« on: July 21, 2011, 02:37:25 PM »
So I recall, I think, Roger Jennings and possibly others referring to this but I can't remember the details.  I looked up dc motors and found out the basics of what you need to do to reverse the poles on a dc motor but has anyone wired up a switch for this?  I had presumed, erroneously, that simply reversing the wires would achieve this but that's not the case. 

This is a nice, simple, explanation of how it works:
http://www.wisc-online.com/objects/ViewObject.aspx?ID=IAU9708

What we need is the ability to run presses at either end of the dryer.  Reversing the armature windings and thus, belt direction with a simple circuit on a switch would be ideal.  I think I can wire something up but am having a hard time wrapping my brain around reversing the interpole windings, assuming those are present.

If anyone has experience doing this, I'd love to hear from ya.  If it matters at all, we're doing this mod to an American TexAir 410 EEE.  I figure the belt motors on all conveyors are fairly similar. 



Offline Shawn (EIP)

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Re: Switch for reversing a dryer belt
« Reply #1 on: July 21, 2011, 02:40:36 PM »
If switching the wires didnt work are you sure you have a DC motor?  Another printer here threw a switch on his dryer to do this, not sure how he did it though I'll have to ask him and let you know.  I switched the wires on mine and it worked, had to because of where I had to plug it in and where the press had to be located, my shop is set up weird.
« Last Edit: July 21, 2011, 02:43:06 PM by endless ink printing »

Offline mk162

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Re: Switch for reversing a dryer belt
« Reply #2 on: July 21, 2011, 02:52:21 PM »
mine runs backwards as well.  it was either that or put the control panel against the wall.

Online ebscreen

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Re: Switch for reversing a dryer belt
« Reply #3 on: July 21, 2011, 02:58:20 PM »
DPDT switch should do it. Just looked at my TexAir and it's a DC motor so yours should be as well.
Simple as pie really.

Offline inkman996

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Re: Switch for reversing a dryer belt
« Reply #4 on: July 21, 2011, 03:15:32 PM »
DC motor is simple swap the wires, are you sure you swapped the correct ones? We are currently running our drier backwards as well to keep the vent as close as vertical as possible. Never had a problem swapping wires on dc motors.
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Offline Sbrem

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Re: Switch for reversing a dryer belt
« Reply #5 on: July 21, 2011, 03:18:47 PM »
We have one of our Advance TexAir set up to run in reverse from when we use to screen political posters, we had a Filbar at the ass end of the dryer, and instead of dragging it up to the other end, we put in the switch... go for it

Steve
I made a mistake once; I thought I was wrong about something; I wasn't

Offline Northland

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Re: Switch for reversing a dryer belt
« Reply #6 on: July 21, 2011, 03:26:31 PM »
So I recall, I think, Roger Jennings and possibly others referring to this but I can't remember the details.  I looked up dc motors and found out the basics of what you need to do to reverse the poles on a dc motor but has anyone wired up a switch for this?  I had presumed, erroneously, that simply reversing the wires would achieve this but that's not the case. 

This is a nice, simple, explanation of how it works:
http://www.wisc-online.com/objects/ViewObject.aspx?ID=IAU9708

What we need is the ability to run presses at either end of the dryer.  Reversing the armature windings and thus, belt direction with a simple circuit on a switch would be ideal.  I think I can wire something up but am having a hard time wrapping my brain around reversing the interpole windings, assuming those are present.

If anyone has experience doing this, I'd love to hear from ya.  If it matters at all, we're doing this mod to an American TexAir 410 EEE.  I figure the belt motors on all conveyors are fairly similar.

Many conveyor dryers use a "permanent magnet" style DC motor... so there are no interpole windings.
Flipping the armature wires will cause the motor to turn in the opposite direction.. as most folks have observed.

Offline bimmridder

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Re: Switch for reversing a dryer belt
« Reply #7 on: July 21, 2011, 04:41:26 PM »
I just talked to someone about this a few days ago. He mentioned, especially with a longer oven, tracking could be an issue. I was also contemplating a press on each end of the dryer.
Barth Gimble

Printing  (not well) for 35 years. Strong in licensed sports apparel. Plastisol printer. Located in Cedar Rapids, IA

Offline MrBreeze

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Re: Switch for reversing a dryer belt
« Reply #8 on: July 21, 2011, 05:30:27 PM »
We have a Lawson that was set up with a reversing switch from the factory.  We reverse it when we print flat stock.  Never had a tracking issue.  Go for it.
If it's so easy, you do it.

Offline ZooCity

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Re: Switch for reversing a dryer belt
« Reply #9 on: July 21, 2011, 07:57:13 PM »
Thanks folks.  Glad to hear that I don't have to worry about any of that interpole nonsense.  I'll just put a regular 'ol switch on there. 

We too are going to have flatstock presses on one end, textile on the other and sooner 'n later another textile press loading from the side.  This is a 20-footer 5-10-10.   I'm basically parking the thing in the middle of the new floor layout.  We did our first run of art prints last month and were able to tack 'em up with a low-heat pass through our short dryer at low temp so I'm stoked to be able to use the big dryer in the new space with a catch at the end instead of drying racks which take up a ton of space.  We picked the TexAir up from a membrane panel printer so he had built a nice addition to hook up onto the back end to catch the sheets. 

I'll have to see how it goes with the belt tracking though.  That's one thing that seems really sensible about that shorty Vastex we have now is their tracking system.