DC Motor Gurus?

[lokidog]

I have a new 12V pot puller and I need to slow it down. We use it for plankton research and on our vertical pulls, it pulls just a little too fast. Can I put a voltage regulator on it without damaging the motor?

TIA

[follow maggie]

It depends on the motor. Some will work fine like this and some will be ruined. I found out the hard way that cost me some money. A call to the manufacturer might be in order.

[Stein]

Yeah, just make sure the controller is up to the task (full load current ratings match actual current draw).  I have a 12 V puller I made from a wheel chair motor and I was thinking about speeding it up by getting a 6V battery and running 18V instead of 12.  If your motor is rated at least 12 V and you run it lower it will be fine.  As far as I know, they only danger is if you run it in excess of it's rated voltage or current draw buy trying to pull too much.

[CP]

You might consider changing the gearing instead.

[lokidog]

You might consider changing the gearing instead.

Thanks everyone. I plan to call the company but Quality Products NW is a hard one to actually talk to. It seems that it matters whether the motor is series wound or shunt wound. I pulled the cover off, but there is no information on the motor itself.

I think what we might try is putting a second wheel on it that has an appropriate reduction in circumference. This puller has a large axle protrusion that we may be able to attach a second wheel to, have to talk to the company and see if I can get a parts diagram. Changing gearing is problematic since for our horizontal sampling, it works fine.

[j_h_nimrod]

I’m not sure how deep you are pulling, 50m? Or circumference of your net, .5m?  We always hand pulled, 50m in 90 seconds was pretty easy and controlling speed way easier than a mechanical puller. Too fast and you create a higher head pressure, too slow and plankton would (theoretically) run from the net.

Consistency is the biggest consideration...

[lokidog]

I’m not sure how deep you are pulling, 50m? Or circumference of your net, .5m?  We always hand pulled, 50m in 90 seconds was pretty easy and controlling speed way easier than a mechanical puller. Too fast and you create a higher head pressure, too slow and plankton would (theoretically) run from the net.

Consistency is the biggest consideration...

Pulling at two sites, vertical, 30m and 70m. The net is about 0.6m in diameter and has 20 pounds of weight on it. We also do a 65m out Bongo net, pulled while the boat is moving at approximately 1.5mph. The bongo is a little slow with our new puller, but within parameters but the vertical is a bit fast.  We can be much more consistent with the puller than by hand.

[j_h_nimrod]

Could you set it up as a capstan for more control than a chiv or drum?

[lokidog]

Could you set it up as a capstan for more control than a chiv or drum?

We are using a My-T-Hauler which replaced the two Safe-T-Pullers that have blown gears. Hopefully the worm drive will be more durable. We are not looking at setting up any other equipment if we can do a simple modification of what we have.

[Stein]

I just looked at your puller.  The other option you have is to put a smaller wheel on it.  They aren't too expensive, maybe $40-120 and would be a bolt on switch.  You could get fancy with the math and figure out what percent slower you wanted it.  I've seen 10"-17" at least, maybe other sizes exist as well.  The only thing you would have to watch is the bolt pattern.

https://shop.hamiltonmarine.com/inet/storefront/store.php?mode=searchstore&search%5Bsearchfor%5D=DISC+STEEL+POT+HAULER+PAIR

[lokidog]

I just looked at your puller.  The other option you have is to put a smaller wheel on it.  They aren't too expensive, maybe $40-120 and would be a bolt on switch.  You could get fancy with the math and figure out what percent slower you wanted it.  I've seen 10"-17" at least, maybe other sizes exist as well.  The only thing you would have to watch is the bolt pattern.

https://shop.hamiltonmarine.com/inet/storefront/store.php?mode=searchstore&search%5Bsearchfor%5D=DISC+STEEL+POT+HAULER+PAIR

I think this is what we are going to do, though we will add to it and not replace as the stock wheel works well for half of our project. The axle sticks out far enough to add a second wheel, I think. Hopefully I can get some specs on that from the manufacturer.