rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 12, 2019 16:30:36 GMT -5
I am trying to make my own tumbler. I would like to make it variable speed so I can set it to run faster or slower with the turn of a dial. I'm fairly lost when it comes to different types of motors and speed controls. I see tons of these motor speed controllers on Amazon:  First off, if I get a motor this will work for, will I be able to control the speed fairly consistently with this controller? If not, what type of controller would work well? If it will work, what's a fairly cheap motor I can use this with? I want it to turn up to six 20 lb barrels at one time. Sounds like people often use motors that are overpowered. Guessing I can get away with 1/20th or 1/12 HP. Does that sound reasonable, and what type of motor do I need? Is a fan motor good? I want to be able to go from about 30 rpm to 100 rpm. It seems complicated calculating what size pulleys I need. I can use pulleys to mess with top rotation speed but what speed motor should I start with? I think fan motors are often around 1550 rpm. Is that a good starting point? |
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Post by captbob on Nov 12, 2019 17:50:51 GMT -5
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rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 13, 2019 0:29:04 GMT -5
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Post by TheRock on Nov 13, 2019 3:42:07 GMT -5
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Post by TheRock on Nov 13, 2019 4:09:05 GMT -5
rockbiter I went to Amazon and read the reviews on the controler and the Guys on there answered a question and they say the controller is for a Non Inductive motor in other words a brush type motor.
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rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 13, 2019 11:48:58 GMT -5
TheRock Okay I've been reading up on ac and dc motors and VFDs and whatnot. It seemed like it was going to be expensive and difficult to set up a long lasting variable speed setup. Then I came across a different option. What do you think about using an EC motor from an inline vent fan? These have speed controllers built in and they are supposed to be not only long lasting (67,000 hours) but also much more energy efficient. I'm thinking I could just remove the fan blade and cut the housing back to expose the motor shaft and put a pulley on it. It's a little fast - 2530 rpm - but I'm guessing I can use pulleys to adjust. Is there something I'm overlooking? 
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rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 13, 2019 11:57:18 GMT -5
Even better:  |
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Post by parfive on Nov 13, 2019 12:08:37 GMT -5
It's a little fast - 2530 rpm - but I'm guessing I can use pulleys to adjust. Is there something I'm overlooking? Maybe that it comes with a speed controller?  |
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rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 13, 2019 12:26:29 GMT -5
It's a little fast - 2530 rpm - but I'm guessing I can use pulleys to adjust. Is there something I'm overlooking? Maybe that it comes with a speed controller? Yes, that's the point. But I want it to adjust to about 100 rpm barrel speed max. If it spins the barrel at 500 rpm at full speed, it will be hard to dial in, say, 30 rpm. |
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rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 13, 2019 12:42:09 GMT -5
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Post by captbob on Nov 13, 2019 13:44:30 GMT -5
Just a thought, but I'm guessing that you want two different speeds. Fast for the coarse grinding stage and slow/normal for all the later steps. If that is the case, why not just have two different drive shaft pulleys that you could easily swap out in a couple minutes to change the barrel RPMs? OR....Better yet, build two roller levels and have the pulleys run one level fast and one slow/normal, so that you can be doing fast grinding/shaping on one level and the rest on the slow/normal level? Best of both worlds being able to run both speeds at the same time.
This is what I would do rather than all that MacGyver stuff.
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rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 13, 2019 17:04:15 GMT -5
Just a thought, but I'm guessing that you want two different speeds. Fast for the coarse grinding stage and slow/normal for all the later steps. If that is the case, why not just have two different drive shaft pulleys that you could easily swap out in a couple minutes to change the barrel RPMs? OR....Better yet, build two roller levels and have the pulleys run one level fast and one slow/normal, so that you can be doing fast grinding/shaping on one level and the rest on the slow/normal level? Best of both worlds being able to run both speeds at the same time.
This is what I would do rather than all that MacGyver stuff.
I'm only using this for rough grinding, so I don't really need two speeds at once. My objective is to be able to quickly change to any speed in a usable range so I can experiment with using different speeds. Buying a bunch of pulleys to alter speeds could add up to more than the motor in short order. Also, electricity is not free, so why not use a motor that uses up to 60% less of it? I like trying to come up with equipment design tweaks! Not saying that "tried and true" is a bad thing, but it isn't very exciting, and there seems to be room for improvement in tumbler design. Totally understand if you are more interested in other aspects of rock tumbling, but I kinda enjoy "all that MacGyver stuff". 😉 |
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Post by captbob on Nov 13, 2019 18:43:45 GMT -5
okay... MacGyver away!
Have fun with the build and post lots of pictures.
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Post by TheRock on Nov 13, 2019 21:28:27 GMT -5
TheRock Okay I've been reading up on ac and dc motors and VFDs and whatnot. It seemed like it was going to be expensive and difficult to set up a long lasting variable speed setup. Then I came across a different option. What do you think about using an EC motor from an inline vent fan? These have speed controllers built in and they are supposed to be not only long lasting (67,000 hours) but also much more energy efficient. I'm thinking I could just remove the fan blade and cut the housing back to expose the motor shaft and put a pulley on it. It's a little fast - 2530 rpm - but I'm guessing I can use pulleys to adjust. Is there something I'm overlooking? I don't see any specs listed, but I am Very Familar with these inline Duc Fans (HERE WE GO I'M GONNA SAY IT AGAIN!)  I am a licensed HVAC Contractor since 1982 37 years. SO I have changed out many motors in my years and I don't believe this INLINE FAN has the Kahuna's to get then job done. I have worked on large fan's 30 HP that 3 or 4 guys could climb into and takes a cherry picker to lift the motor to put in place just to change it. But If you are a Prime Member with AMAZON returns are no problem. As long as you don't buck it up taking it apart and putting it back together then you can send it back. But I'm telling you, that spindly Arse Motor wont spin the barrels of a tumbler. Go 220 V get a Freq drive and a 220V Motor 1/2 Hp This is what you need. As you can see 3 Ph Motors are cheap The Freq Drive will cost $95.66 Plus $57.98 fpr a total of $ 153.64 Yes its a large motor but it will spin Those Barrels. I am glad we had this conversation because when I build my tumbler I will use this method.    |
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rockbiter
having dreams about rocks
Member since October 2019
Posts: 60
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Post by rockbiter on Nov 14, 2019 12:40:39 GMT -5
TheRock Okay I've been reading up on ac and dc motors and VFDs and whatnot. It seemed like it was going to be expensive and difficult to set up a long lasting variable speed setup. Then I came across a different option. What do you think about using an EC motor from an inline vent fan? These have speed controllers built in and they are supposed to be not only long lasting (67,000 hours) but also much more energy efficient. I'm thinking I could just remove the fan blade and cut the housing back to expose the motor shaft and put a pulley on it. It's a little fast - 2530 rpm - but I'm guessing I can use pulleys to adjust. Is there something I'm overlooking? I don't see any specs listed, but I am Very Familar with these inline Duc Fans (HERE WE GO I'M GONNA SAY IT AGAIN!) I am a licensed HVAC Contractor since 1982 37 years. SO I have changed out many motors in my years and I don't believe this INLINE FAN has the Kahuna's to get then job done. I have worked on large fan's 30 HP that 3 or 4 guys could climb into and takes a cherry picker to lift the motor to put in place just to change it. But If you are a Prime Member with AMAZON returns are no problem. As long as you don't buck it up taking it apart and putting it back together then you can send it back. But I'm telling you, that spindly Arse Motor wont spin the barrels of a tumbler. Go 220 V get a Freq drive and a 220V Motor 1/2 Hp This is what you need. As you can see 3 Ph Motors are cheap The Freq Drive will cost $95.66 Plus $57.98 fpr a total of $ 153.64 Yes its a large motor but it will spin Those Barrels. I am glad we had this conversation because when I build my tumbler I will use this method.  Thanks for the advice. It's great to be able to pick the brain of a professional! I will admit that that's probably the best way to go. The only thing I'm hung up on is I'm not excited to have to wire in a 220 outlet. Argh, I'm also second guessing whether I want that big a tumbler. Might just do a two barrel to save space. Realistically I probably won't spend the time to keep more than that going. I might try the $200 150w 10" version of the EC fan motor. More versatile being 110v and uses less power than the AC motor. Costs $50 more than your setup but costs around $10/month running nonstop full speed instead of $17/month, so a bit of savings there over time. I also don't have to pay for the supplies for the 220 outlet so I think it ends up being cheaper and simpler right off the bat. What do you think TheRock ? Shouldn't that motor have enough power? I do have prime, so I could order it and see if I can disassemble enough to try it out without making it un- returnable. |
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nik
spending too much on rocks
Member since May 2019
Posts: 315
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Post by nik on Nov 15, 2019 3:23:22 GMT -5
Something else to think about with repurposing a fan motor would be cooling. I would imagine that an inline fan motor is designed with the surrounding airflow in mind.
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carver
starting to shine!
Member since November 2019
Posts: 36
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Post by carver on Nov 15, 2019 4:32:42 GMT -5
Something else to think about with repurposing a fan motor would be cooling. I would imagine that an inline fan motor is designed with the surrounding airflow in mind. This is a very good point Nik said. With anything Lapidary, I would think an enclosed motor would be best, leaving TEFC and TENV options in motor jargon. I am no expert but the thermally enclosed fan cooled models would probably solve that issue but will create airflow obviously. I may be wrong on this but I think the TENV, thermally enclosed non ventilated motors need either natural air flow or a machine design that heat sinks into the body or some other large metal surface ideally with something that dissipates heat well like copper. Others feel free to chime in. I thought I posted this the other day but apparently my post did not stay. This is an excellent document from Baldor which clarified motors for me when I was looking to solve nearly the exact issue as you of a variable speed motor. What you generally need is a DC motor, not an AC motor. Also need it rated for continuous use. Then you need it most likely TEFC due to presence of water and need to cool it. That would be my recommendation but read the document and come to your own conclusions as I am just someone that read up on the subject. www.baldor.com/mvc/DownloadCenter/Files/9AKK107303 |
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Post by Drummond Island Rocks on Nov 15, 2019 8:07:55 GMT -5
I am little surprised there is so much talk of electronically controlling the speed. Adjustable speed was very common on older lapidary grinders and was always done mechanically. I have two 8" flat laps that have stepped pulleys on both the motor and the grinder shaft. Endless speed options. For the tumbler one stepped pulley on the motor and an adjustable idler wheel or a tension pulley would do the trick. If your motor is mounted like mine on a pivot to adjust tension then the idler wheel may not even be necessary.  This setup with a stepped pulley would work. put a wrench on the tension pulley and turn that while you move the belt from one step to the next for a speed change.  Chuck |
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Post by captbob on Nov 15, 2019 9:46:02 GMT -5
Sorry Chuck, but that is not complicated enough. But thanks for playing!  |
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Post by Drummond Island Rocks on Nov 15, 2019 9:59:47 GMT -5
Sorry Chuck, but that is not complicated enough. But thanks for playing! Dang. Let me go check my rocket science book and get back with ya. Honestly I think running two sets of shafts with two different pulley sizes like jamesp does is the best solution. I also think adding too many choices for speed adjustment is a bad idea. Tumbling already has a bunch of variables that need to be repeated for success and infinite speed choices just complicate that. Chuck |
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I am a licensed HVAC Contractor since 1982 37 years. SO I have changed out many motors in my years and I don't believe this INLINE FAN has the Kahuna's to get then job done. I have worked on large fan's 30 HP that 3 or 4 guys could climb into and takes a cherry picker to lift the motor to put in place just to change it. But If you are a Prime Member with AMAZON returns are no problem. As long as you don't buck it up taking it apart and putting it back together then you can send it back. But I'm telling you, that spindly Arse Motor wont spin the barrels of a tumbler. Go 220 V get a Freq drive and a 220V Motor 1/2 Hp This is what you need. As you can see 3 Ph Motors are cheap The Freq Drive will cost $95.66 Plus $57.98 fpr a total of $ 153.64 Yes its a large motor but it will spin Those Barrels. I am glad we had this conversation because when I build my tumbler I will use this method. 
