ronfire 141 Posted September 12, 2019 Report Share Posted September 12, 2019 (edited) 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, 2019 by ronfire spelling errors Quote Link to post Share on other sites
liambesaw 2,767 Posted September 12, 2019 Report Share Posted September 12, 2019 (edited) .25 ohm 10% 22 watt ceramic cement resistor Edited September 12, 2019 by liambesaw Quote Link to post Share on other sites
Bill Kielb 1,134 Posted September 12, 2019 Report Share Posted September 12, 2019 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. Quote Link to post Share on other sites
liambesaw 2,767 Posted September 12, 2019 Report Share Posted September 12, 2019 Whoops! That's what I meant to type hah Quote Link to post Share on other sites
Bill Kielb 1,134 Posted September 12, 2019 Report Share Posted September 12, 2019 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 Quote Link to post Share on other sites
ronfire 141 Posted September 13, 2019 Author Report Share Posted September 13, 2019 Thanks Bill. Would I need to mount that with a heat sink being that it is 50w instead of the 22w? Quote Link to post Share on other sites
Bill Kielb 1,134 Posted September 13, 2019 Report Share Posted September 13, 2019 (edited) 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, 2019 by Bill Kielb Quote Link to post Share on other sites
ronfire 141 Posted September 13, 2019 Author Report Share Posted September 13, 2019 (edited) 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, 2019 by ronfire Bill Kielb and Rae Reich 2 Quote Link to post Share on other sites
Bill Kielb 1,134 Posted September 13, 2019 Report Share Posted September 13, 2019 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! Quote Link to post Share on other sites
Mark C. 4,879 Posted September 13, 2019 Report Share Posted September 13, 2019 How did you fry it?? Quote Link to post Share on other sites
ronfire 141 Posted September 13, 2019 Author Report Share Posted September 13, 2019 (edited) 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, 2019 by ronfire Bill Kielb 1 Quote Link to post Share on other sites
neilestrick 4,616 Posted September 14, 2019 Report Share Posted September 14, 2019 You wouldn't necessarily have to replace it with the same board. You could go with a newer model. Quote Link to post Share on other sites
ronfire 141 Posted September 14, 2019 Author Report Share Posted September 14, 2019 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 Quote Link to post Share on other sites
neilestrick 4,616 Posted September 14, 2019 Report Share Posted September 14, 2019 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. Quote Link to post Share on other sites
ronfire 141 Posted September 15, 2019 Author Report Share Posted September 15, 2019 (edited) 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, 2019 by ronfire added to Bill Kielb 1 Quote Link to post Share on other sites
ronfire 141 Posted September 16, 2019 Author Report Share Posted September 16, 2019 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. Bill Kielb 1 Quote Link to post Share on other sites
oldlady 2,811 Posted September 16, 2019 Report Share Posted September 16, 2019 let's hope it doesn't come to that! Quote Link to post Share on other sites
Bill Kielb 1,134 Posted September 16, 2019 Report Share Posted September 16, 2019 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. Quote Link to post Share on other sites
ronfire 141 Posted September 17, 2019 Author Report Share Posted September 17, 2019 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 Quote Link to post Share on other sites
liambesaw 2,767 Posted September 17, 2019 Report Share Posted September 17, 2019 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 1 Quote Link to post Share on other sites
Hulk 784 Posted September 17, 2019 Report Share Posted September 17, 2019 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! Quote Link to post Share on other sites
CactusPots 245 Posted September 18, 2019 Report Share Posted September 18, 2019 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. Quote Link to post Share on other sites
liambesaw 2,767 Posted September 18, 2019 Report Share Posted September 18, 2019 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. Quote Link to post Share on other sites
Mark C. 4,879 Posted September 19, 2019 Report Share Posted September 19, 2019 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 Magnolia Mud Research 1 Quote Link to post Share on other sites
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