How to solve weakness in Lofrans Tigres windlass

[nmccubbin]

Our 12 volt, 1500 watt Lofrans Tigres windlass does not pull near the its specified capacity.
The Lofrans manual lists max lift load as 1650 lb, and max working load as 418 lbs

It has alsways been weak, and I got no satisfaction from the British distributor (Milvina was in Britain when I bought the windlass)

We ran tests this week. Lifting 14 metres of 10 mm chain off a sand bottom, with the anchor still on the bottom, the weight of the chain is 37kg, or 81 lbs.
Far below the specified working load capacity of 418 lbs

The windlass struggled, drawing 150 to 185 amps. According to Lofras spec, current at max working load is 130 amps

When we started to lift the 100 lb anchor, the 150 amp breaker popped, current 200 amps, yet the load was well below half Lofrans specified working load.

The total voltage drop from battery terminals to motor i 0.8 volts, under above load

The brushes look fine, and slide easily in their mounts

Is it possible that we have a motor with some windings shorted, so that although hte current flows, the torque is not developed?

How can I test the windings ? (We are in the Marquesas, with no high tech equipment available)

Any advice welcome

I will buy a new motor if that will solve the problem, but doing that here is difficult and slow from here.

Comme nts from users who know how much thier Lofrans Tigres will actually pull would also be welcome

[markcouz]

For reference...

I have a Lofrans Tigress 12v 1200W on 125a breaker with 10mm chain and 75lb anchor (Sarca Excell #7). I recently raised anchor from 22m with no sign of stress.

[Jammer]

Can you test the windings? Sure. You have to take the motor apart first.


Start by testing the commutator with a growler.

https://www.youtube.com/watch?v=Lk8UEaEcZME

Any place that rebuilds starter motors will have a growler and will test it for you.


Field windings can be checked for resistance (should be the same for each winding) and shorts.


Typically the commutator is not considered repairable so if it has a short you'll probably end up replacing the whole motor.


It's worth checking the mechanical side of things for proper lubrication, alignment, and sticking. Try taking it apart and turning everything by hand.

[nmccubbin]

Thanks to both for the info
I have no access to a growler here in the Marquesas, but now I understand more. May lug the motor home to Canada

We have had it apart. Mechanically fine

Jammer, do you have any comments on the fact that the motor draws way more than the specified full load current when the load on the windlass is about 20% of full load

[Jammer]

::shrug:: Could be shorted armature windings but that's uncommon without obvious physical signs of problems such as mechanical damage from the armature hitting the stator or the housing, or insulation that's clearly burned (discolored).


Could also be shorted field windings, resulting in less back EMF and excessive armature current.



You can get a new motor from Lofrans for $1000 which is crazy money for what you get. There are places that rebuild armatures but they have become hard to find. It's a labor intensive process. Here's what it looks like in places that don't have EPA or OSHA. Note the growler at 17:21 or so:

https://www.youtube.com/watch?v=fwidB8-q_S4

Here's one place in the USA that still does this kind of work:


https://www.newcoreinc.com/


I have a feeling that they'll want more than $1000 though.

[Sos]

What an incredible video of re-winding that armature!

We had an electro-magnetic fridge winding fixed in Morocco but never saw how it was done. Cast about 20 euros

[Tin Tin]

You may have a build up of carbon dust in the motor, blow/suck it out with a vacuum cleaner, spray electronic cleaner in there and clean it up. The brushes may look OK, but you need to check the wire connections to the brushes, you need to clean the armature so the gaps are not holding any crud. Try swapping the brushes around so the down brushes are now the up brushes. The other thing is the gearbox, is it binding, does it have right oil level. I have never taken a Lofrans apart and experienced only with Quick and Muir.

[boatpoker]

Does it have a dedicated battery ?
Where is the battery located in relation to the windlass ?
How is that battery charged ?
How long are the battery cables (pos and neg) ?
What gauge are the cables ?

[hpeer]

FWIW
I have a Lofrans Tigress, 125 pound anchor, and 3/8” chain. I have recovered from 70’.

FIRST I would first take off the gypsy and clutch drum and the brake wheel. Who knows, you may simply have some crud or crap stuck in the brake mechanism. Check that your chain stripper is running clear, they can get bent and foul the gypsy. It is cheap, easy, and good practice anyway.

If you are popping fuses/breakers the problem is likely NOT supply to the motor but that the motor is not working efficiently.

A quick thought is to do this.
Measure amperage with no load. The motor should spin freely and smoothly.
Measure amperage with a higher load, say 100 pounds. Listen to motor.
Again with say 200 pounds. One would think an electrical problem would show a proportionate rise in current. A disproportionate rise my point more towards some mechanical issue, something is binding under stress.

Does the amperage suddenly increase or increase proportionately? Does the motor suddenly become rough or noise-some at some level?

This may help you to pin it to either a mechanical or an electrical issue.

In short you are consuming a lot of energy which is being then converted into waster energy. It is because the motor is not using the power efficiently (shorted windings? Of because of some mechanical difficulty, binding or miss-alignment? Mechanical problems will likely create sound or vibration.

[hpeer]

BUT ALSO….check you anchor gear, thr bow roller and the chain lead. Make sure the roller is is rolling UNDER LOAD, not hanging up. And the chain is not snagging something.

[SailingHarmonie]

We have the 24V version of the 1500 watt Tigres. Never an issue pulling a 105 lb anchor with 3/8" chain from 50 feet deep. Something is wrong with your setup. Don't blame the motor before you are sure of the power supply.

Before you disassemble anything, check that ACTAUL voltage at the windlass. You report the voltage drop as acceptable, but you need to be sure that the battery is delivering the voltage needed.

If your battery is dropping below 10V to supply this, it is quite possible that you are drawing 200 Amps and still getting no real torque. If your voltage is OK, then...

Calder's book has a great chapter on the troubleshooting sequence for a DC motor.

[Jammer]

Originally Posted by SailingHarmonie

If your battery is dropping below 10V to supply this, it is quite possible that you are drawing 200 Amps and still getting no real torque. If your voltage is OK, then...

Erm, point of order, current is proportional to shaft torque on a (properly working) series wound motor and is mostly independent of voltage. Voltage only affects speed.

[Loredo]

Since you're in a remote location, let me run this by you.
Several years ago I helped a friend troubleshooting a similar problem also in a remote area. While I don't remember all the details, at the end of a long story the problem was not the motor but the relay. To find this out we provided power to the motor directly from a battery we had taken out of the house bank with a couple short cables. Bingo! Since this is a test you could do no matter where, I'd give it a try first. At least you'll know for sure if it's the motor or something else.

[nmccubbin]

Thanks to all who have provided thoughtful answers.
Those with experience, particularly Sailing Harmonie, have made it clear that the Tigres is fully capable of working well, although our one is wimpy.
We had already tried most of the suggestions to no avail.

The contactor is new. Voltage drop across it is 0.1 volt
Total cable run is under 10 feet. Half is AWG 00 and the remainder is AWG 0000 All lugs are crimped and soldered.

One issue is that the windlass draws 40 amps, spinning freely and quietly, with the chain off the gypsy. I have asked Lofrans about this on three ocasions but never received a reply. Could someone please measure the current drawn at no load?

Oil is mentioned. The Lofrans manual discusses changing the oil, but i cannot find any recommendation in the manual on what type. I used 90 SAE gear oil. Is that OK?

Can anyone tell me the voltage at the motor terminals when the windlass is working hard.

We are laying up in Hiva-Oa in the Marquesas on 25th April. I have to decide what to bring back in the Fall. I would buy a new motor in the US, if I was sure that is the issue.
I could get a new battery here ($$$$) but not before haulout, so no way to test it under load.

[rslifkin]

40 amps at no load doesn't strike me as concerning. Based on that, I'd be giving a really close look to all of the mechanical parts to see if anything might be binding once there's a load on the windlass.