Pacifica electronics

[ronfire 62]

Well now I messed up. Purchased a Pacifica wheel and find out it is a GT500. No one has heard of a gt500 including Languna. I sold my old Estrin wheel and now just fried the controller on the Pacifica. Have plates and wine goblets to trim but no wheel.

Any one know what type of resistor this is so I can order one from Digi-Key.   Dont really want to order a new wheel now.

Edited September 15 by ronfire
spelling errors

[liambesaw 1,479]

.25 ohm 10% 22 watt ceramic cement resistor

Edited September 12 by liambesaw

[Bill Kielb 554]

4 hours ago, liambesaw said:

25 ohm 10% 22 watt ceramic cement resistor

Looks like 0.25 ohms actually. Seems tiny for a power resistor though. Not a normal value if that is true will have to search around.

[liambesaw 1,479]

Whoops! That's what I meant to type hah

[Bill Kielb 554]

Here is what I found since it’s marked  0.25 ohms. Sort of hard to find, but resistor from Newark should fit the bill. Definitely should last longer but made to be mounted to a metal surface for heat sink.

definitely not a popular value to find

 

[ronfire 62]

Thanks Bill. Would I need to mount that with a heat sink being that it is 50w instead of the 22w?

 

[Bill Kielb 554]

1 hour ago, ronfire said:

Thanks Bill. Would I need to mount that with a heat sink being that it is 50w instead of the 22w?

 

without getting too much in the weeds, the heat sink below likely would be fine . A quick look at this says this heatsink likely gets this to about thirty watts dissipation capacity.. You will need some thermal paste between the case of the resistor and heatsink, tightly bolted together.

If I knew your machine better I would find a nice piece of metal and pick a surface mount heatsink in the 5-6 C/W range,  Mount it there and run some nice 16 gauge wire from the board to the resistor.

Not knowing that, you should be able to use the heatsink below and extend the leads on this and free air mount it above the board sort of like it is now. These are nice resistor packages but only dissipate 1/10th the power without a heatsink. So a heatsink is necessary.

This value was tough to find (0.25 ohms), you could search for wire wound power resistors and maybe come up with a size and shape Similar to what you have. (no heat sink required) I just didn’t spot any. Mouser would be another electronics site to browse.

These days the thin film with a heatsink are a pretty nice economical solution to power dissipation and allows the designer to easily over design so no more cracked overheated resistors. Just like yours in the picture. Unfortunately it takes a bit of effort. Fortunately it’s super economical and if done correctly will last a long long time.

good luck

Edited September 13 by Bill Kielb

[ronfire 62]

I found some at Digikey , the shipping was less than 1/2 in Canada. I ordered both of these and will try the one with the heat sink chassis mount style first. Thought for the $4.00 I would have the other as a spare and then never need it. The chassis mount was a little more but might be worth it @ $7.00

Liked your find better priced but I am in Canada.  Bill your search results lead me to be able to find them at Digikey. Thanks.

Edited September 13 by ronfire

[Bill Kielb 554]

12 minutes ago, ronfire said:

I found some at Digikey , the shipping was less than 1/2 in Canada. I ordered both of these and will try the one with the heat sink chassis mount style first. Thought for the $4.00 I would have the other as a spare and then never need it. The chassis mount was a little more but might be worth it @ $7.00

Liked your find better priced but I am in Canada.  Bill your search results lead me to be able to find them at Digikey. Thanks.

Fantastic! Tried digikey first but it kept giving me a 1000 watt. Your chassis mount is fantastic!

[Mark C. 3,695]

How did you fry it??

[ronfire 62]

Was trying to work about 15 lbs of clay and leaned into it. The fuse blew so I replaced it and it still did not work. Opened the control box and could see nothing wrong until I lightly touched the resistor and it broke in half. This wheel is probably 30 years old and no one has heard of the Pacifica gt500.

Better hope it keeps working as replacement boards will be impossible to find. Glad I can at least replace parts with my limited electronics.

Will let you know if it runs after the resistor replacement.

The plan is to cut the legs off the existing resistor and attach the new chassis style one. Wont even have to work on the board then.

 

 

 

Edited September 13 by ronfire

[neilestrick 3,288]

You wouldn't necessarily have to replace it with the same board. You could go with a newer model.

[ronfire 62]

If I replace the board with a newer model will all the plugs fit. I guess the board is only a variable dc power supply.

Might be able to have them send new plugs as well

[neilestrick 3,288]

6 hours ago, ronfire said:

If I replace the board with a newer model will all the plugs fit. I guess the board is only a variable dc power supply.

Might be able to have them send new plugs as well

What plugs? Do you mean the cord grips?

All boards are not equal. Some do a much better job than others, and have more adjustable controls than others.  But if you're going through Laguna/Pacifica, they should be able to tell you what's involved. The bigger issue is whether or not a new one will fit into the current box. 

[ronfire 62]

My current box has plug in for the motor and foot peddle. To reverse the motor you just move the plug over 1 pin.  The unit is so old that the plug has a standoff below it made of wood. You can just see it in the pic.  If I knew it was that old I would have passed on it but into it now with a new bearing and belts.

New resistors should arrive Wednesday.

.

Edited September 15 by ronfire
added to

[ronfire 62]

The new resistor came today, replaced the 22watt with a 50watt chassis mount. Mounted the chassis mount to the aluminum case.

Plugged it all back in and it is back up and running. Thanks to everyone for the advise to steer me in the right direction to find the correct part.

Now to see if I can throw 15 lbs of clay, if not I see a Brent C or CXC  wheel in my future.

 

[oldlady 2,322]

let's hope it doesn't come to that!

[Bill Kielb 554]

11 minutes ago, ronfire said:

The new resistor came today, replaced the 22watt with a 50watt chassis mount. Mounted the chassis mount to the aluminum case.

Plugged it all back in and it is back up and running. Thanks to everyone for the advise to steer me in the right direction to find the correct part.

Now to see if I can throw 15 lbs of clay, if not I see a Brent C or CXC  wheel in my future.

 

Nice work! Back in business for likely less than 20 bucks! No,worries, center  your 15 # gently on that wheel till you get a second or spare. 

[ronfire 62]

Still wonder what HP the motor is, there is no label on it. Would be nice to know so I could compare or know that the next wheel has a larger motor. Guess I would just go with a 1hp model of wheel

[liambesaw 1,479]

20 minutes ago, ronfire said:

Still wonder what HP the motor is, there is no label on it. Would be nice to know so I could compare or know that the next wheel has a larger motor. Guess I would just go with a 1hp model of wheel

It should have a wattage rating on the motor, can ballpark the HP from there

[Hulk 316]

Good question! ...however, regarding published ratings, per Neil: 

"The horsepower rating doesn't mean much. The 1/4hp Soldner can center as much as a Skutt 1/3hp, which can center as much as a Brent 1hp. The controller and pedal have a lot to do with how the power is put to use, as well as the type of motor."

Most modern one horsepower wheels will have lots of twist - not, however, the same twist!

[CactusPots 84]

This might be another opportunity for me to be wrong :), but

I would think the higher horsepower rating would help the motor run cooler, longer under load.  How much it can center probably has more to do with the gearing than anything else.   In order to get the torque from a small rated motor, they would have to use as small a drive pulley and as large a driven pulley as possible.  A higher HP motor would let you use a larger drive pulley and then you'd have more flexibility regarding belts.  The Pacifica 4 O ring belts are a work around because of the small drive pulley, IMO.

I think the higher HP motor is always better. 

[liambesaw 1,479]

I think the horsepower ratings are just marketing ploys, but I agree that within the same brand (does not work cross brand) it's a good way to determine where that wheel is on their product line.

[Mark C. 3,695]

On 9/16/2019 at 4:27 PM, ronfire said:

The new resistor came today, replaced the 22watt with a 50watt chassis mount. Mounted the chassis mount to the aluminum case.

Plugged it all back in and it is back up and running. Thanks to everyone for the advise to steer me in the right direction to find the correct part.

Now to see if I can throw 15 lbs of clay, if not I see a Brent C or CXC  wheel in my future.

 

Model c will center all the clay you will ever need