jamesp
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Post by jamesp on Nov 21, 2019 12:53:21 GMT -5
Done Not trying to "rain on anyone's parade" (pun intended). But, when you build this new tumbler assembly, do you plan on using some sort of weather proof enclosure to house it? forum.rocktumblinghobby.com/post/1075492 It looks like you're outside with your existing tumblers. An exposed capacitor gives me the willies. James I may cover it somehow cosmetal. The connections for sure. Note the tumbler in the link is an open cage motor giving lots of opportunity for shocking experiences with water involved. It is in a greenhouse and not rained upon. A dedicated 6' deep ground rod is near by receptacle and motor grounded. No on/off switches allowed, to service the tumblers it is unplugged. No matter, always treat electrical devices as hot ! Does a capacitor store a charge ? Believe it does.
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cosmetal
starting to spend too much on rocks
Member since September 2018
Posts: 115
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Post by cosmetal on Nov 21, 2019 13:53:47 GMT -5
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EricD
Cave Dweller
High in the Mountains
Member since November 2019
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Post by EricD on Nov 21, 2019 21:01:45 GMT -5
Anyone ever considered using a slow turning ceiling fan motor on a tumbler ? Very quiet. A bit concerned about the start up torque... Then again tumblers are reduction devices. 3/4 inch shaft with an 8 inch barrel is 8/.75 = 10 time more torque. Am I talking to myself ? Please disregard and move on if so compelled. This is a new 225 rpm 1/12 hp ceiling fan motor for $13. Give ya $3 if you can stop the shaft with your fingers. www.surpluscenter.com/Electric-Motors/Single-Phase-AC-Motors/Fan-Air-Conditioner-Motors/Not much 'air over' from a ceiling fan so heat should not be a concern. At 225 rpm you could use small pulleys. Or possibly direct drive to the end of one of the shafts - no pulleys/no belts. ***It does need a capacitor and requires a funky 17mm pulley hole for it's 17mm output shaft. Heck, get a 17mm drill bit and drill a 1/2 inch hole from 12.7 mm to 17 mm using a drill press. Let me plug this one into the barrel speed equation for an 8 inch barrel and 3/4 inch shaft: Two 3 inch pulleys(direct drive): 225 rpm x 3/3(direct drive) x .75/8 = 21 rpm = slow but doable 3 inch motor pulley and 2 inch barrel shaft pulley: 225 rpm x 3/2 x .75/8 = 32 rpm = about right 4 inch motor shaft and 2 inch barrel shaft pulley: 225 rpm x 4/2 x .75/8 = 42 rpm = a bit fast but close, perfect for a 6 inch barrel. Odd, the pulley on the motor would have to be bigger than the pulley on the shaft for 32 and 42 rpm. This interests me: How about a direct shaft drive with no pulley and belt ? Motor directly coupled to one of the barrel shafts. Barrel speed with 1 inch shaft and 8 inch barrel: 225 rpm x 1/1 x 1/8 = 28 rpm. Not bad. It is a shame the motor did not have a 24 inch output/barrel shaft. I think I will buy one(or 3 for that matter at $13), along with the 5 mfd/370 volt capacitors to make it work. Only to try a direct barrel shaft drive tumbler. Just to be a show off he he. I just have to figure out how to connect barrel shaft to motor shaft precisely. The hollow motor shaft is interesting, but that funky mounting system may be aggravating. You could use the "through bolts" of the motor to mount it to flat iron or angle iron. They look plenty long. I would suggest using at least 3 of the 4
Edit: It should start turning just fine. The cap will store enough energy to give it a great start jolt. Enough to turn a car's flywheel I'm sure.
Edit again: I may just go this route making my single barrel tumbler. Direct drive sounds nice to me.
Holy hell. 3rd edit: You may want to switch it between the cap and the motor, so you can have a charge to the cap before the motor engages. If not the cap will drain to the motor when power is lost. Guess not the best of "power outage" motors. You could rig a timer relay into the system. Like a compressor delay in HVAC which I know you are familiar with.
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Post by manofglass on Nov 22, 2019 12:16:34 GMT -5
I would cut the mount off Use that metal strap to hold the motor in place That is what I did with mine
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NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,630
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Post by NRG on Nov 22, 2019 15:43:31 GMT -5
jamesp3 motors = 3 tumblers - Make one of them a vib! 3 motors = 1 sphere machine Just sayin' 😇
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Post by knave on Nov 22, 2019 17:09:10 GMT -5
No matter, always treat electrical devices as hot ! Does a capacitor store a charge ? Believe it does. A permanent split capacitor motor (PSC) will not store a charge in the capacitor, since the start winding is always connected, hence no bleed resistor is required. If starting torque is an issue, a 5-2-1 start capacitor can be added at little cost. (Such as CSRU1)
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jamesp
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Member since October 2012
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Post by jamesp on Nov 22, 2019 23:31:59 GMT -5
To those contributing knave, NRG, manofglass, EricD, cosmetal and others. Consider this motor producing 1/12 hp at a slow 225 rpm. Horsepower is simply the amount of time it takes to perform a given amount of work. Consider work produced from a motor. As a general rule: Motor geometry normally follows this behavior - 1) higher rpm with low torque or 2) lower rpm with high torque or 3) a balance of the two. This motor is certainly a low rpm motor so it should generate plenty of torque like many fractional hp lower rpm fan motors. Typically fractional AC motors that are short and proportionately larger in diameter generate high torque and lower rpm. And long motors that are proportionately smaller in diameter generate higher rpm. For example a large diameter allows electromagnetic forces to take advantage of larger leverage around the shaft. This motor is 5 inches in diameter and 3 inches long. Add the fact it is 225 rpm it should have healthy torque. Will find out. The starting torque is likely a separate parameter though. No starting torque information is listed on the specifications unfortunately. Below tumbler uses a used 1/8 hp (lower rpm) 1140 rpm 'fat' fan motor tumbler. A bit larger in diameter than it's length. It has loads of torque. Turned a 40 pound barrel. And makes little sound. Runs quieter than 1700 and 3600 rpm motors. This tumbler had a used 1/8 hp 840 rpm fan motor on it and ran too slow. It ran really quiet being at yet slower rpm's. It was cheaper to buy a faster(used) 1/8 hp 1140 rpm motor than to buy another smaller barrel shaft pulley. So the 840 was replaced.
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NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,630
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Post by NRG on Nov 23, 2019 1:19:08 GMT -5
jamespDoes this motor have a torque rating? AzRockGeek Tim, have a look at these motors. 1/12 HP 240rpm good inexpensive candidate for a sphere machine.
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Post by knave on Nov 23, 2019 3:03:15 GMT -5
Rpm is determined by number of poles, minus a few % slippage. Less poles = faster. A common (4 pole) motor at 60 hz would theoretically be 1800 rpm, but usually is listed as 1725 due to slippage.
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jamesp
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Post by jamesp on Nov 23, 2019 4:44:17 GMT -5
jamespDoes this motor have a torque rating? AzRockGeek Tim, have a look at these motors. 1/12 HP 240rpm good inexpensive candidate for a sphere machine. Nope. I will let you know Scott about the torque. Tried looking them up and finding more tech info using it's GE part number but part number not totally legible in photo. If the shaft cannot be stopped with my fingers it seems it would have plenty of torque for a sphere machine. ?? I am aware sphere machines use the motors with the face mount gear reducers. Aren't they totally enclosed ? In researching similar GE motors the prices ranged from $80 to $150+. It is likely a high grade well made motor.
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jamesp
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Post by jamesp on Nov 23, 2019 5:44:07 GMT -5
Rpm is determined by number of poles, minus a few % slippage. Less poles = faster. A common (4 pole) motor at 60 hz would theoretically be 1800 rpm, but usually is listed as 1725 due to slippage. These 225, 840 and 1140 rpm single phase 60 hz AC motors mystify me knave. I get the pole calculation to a point. Guessing the 840 and 1140 have like 8 and 10 poles including slippage respectively ? Does more poles often create higher torque ? 225 rpm is like 20 poles ? This 225 rpm motor claims 1/12 hp which would seem to make it mandatory that it has higher running torque than a 1/12 hp 1725 rpm motor. Then I came across this statement and am educated on 3 phase stuff. But single phase is my challenge: "A control can be used to alter the speed of a three phase AC motor by increasing or decreasing the frequency that is sent to the motor, causing it to speed up or slow down. Additionally, many AC controls have a single phase input so this allows you to run 3 phase motors in facilities that don’t have 3 phase power available. However, this ability to alter the speed isn’t typically the case for single phase AC motors. These motors are plugged directly into a standard wall outlet and operate using the set frequency available. An exception to this rule of thumb would be a ceiling fan that runs using single phase AC motor, but has three different speed settings." On a single phase 60 hz AC motor that has multiple speeds do they not wire a tap off of less poles to obtain say 3 speeds ? Lapidary motor applications like tumblers and various grinders are often easier with lower rpm single phase AC motors, so the interest. Finally found a close up view of a low 200 rpm ceiling fan motor. Judging from the multiple windings this motor has a lot of poles: This type motor is used in expensive ceiling fans.
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jamesp
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Post by jamesp on Nov 23, 2019 6:45:33 GMT -5
Running coils and starting coils on a ceiling fan motor video. Looks like 14 poles knave. Concern is 'how much starting torque ?'. Some of these ceiling fan motors have a thru shaft. Shaft may be able to be pressed out and replaced with a long shaft to serve as a tumbling barrel shaft That would make an interesting 'motor on shaft' tumbler. Start at 2:15
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Post by knave on Nov 23, 2019 10:03:21 GMT -5
jamesp Wow, you sure know how to drill into something. Good grief you’re making me think, brain hurts. Man after my own heart. I just don’t have the time with 4 kids. 60 hz x 60 seconds x 2 current changes per cycle = 7200 pushes per minute. 7200 / number of poles is the unloaded rpm, when the motor does some work it loses a tick or 2. This is why the available rpms jump from 3500 or so all the way down to 1750, then 1375, 1175, 850, etc. I guess a 3 pole would be around 2300 but I’ve never seen one of those. The single phase A/C has 180° phase angle so without a cap it just hums, draws LRA, motor doesn’t know which way to go. If you spin start it, it will continue in the direction you started it. The start winding creating a fake extra phase so the motor knows which way to travel, it also raises the efficiency, ie a PSC is almost 2x as efficient as a shaded pole.
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Post by knave on Nov 23, 2019 10:17:14 GMT -5
I will dig into multi speed PSC motors. I have experience with them, I know how to wire them, but never dug into how the speed change occurs. I know the start and run windings wires stay the same. The different speed taps change where the common connects to the start and run winding. (See edit) Without further research my assumption is that the rpms stay the same, you are just changing the torque/hp of the motor. If you over speed the motor due to not enough load, the back EMF will exceed the capacitor voltage rating and take it out.
Edit 1: The lowest speed tap has the longest run winding. The fastest speed has the shortest run winding. Lowest resistance, highest current draw. The start winding remains the same for all speeds.
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AzRockGeek
has rocks in the head
Member since September 2016
Posts: 627
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Post by AzRockGeek on Nov 23, 2019 10:21:01 GMT -5
jamesp Does this motor have a torque rating? AzRockGeek Tim, have a look at these motors. 1/12 HP 240rpm good inexpensive candidate for a sphere machine. NRG I thought the exact same thing when I seen this post a few days ago, these would work perfect for the polishing phases with the diamond pads. I almost ordered some, them I realized I have tooooo many open projects already.
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Post by oregon on Nov 24, 2019 0:42:05 GMT -5
Anyone ever considered using a slow turning ceiling fan motor on a tumbler ? Very quiet. A bit concerned about the start up torque... Then again tumblers are reduction devices. 3/4 inch shaft with an 8 inch barrel is 8/.75 = 10 time more torque. Am I talking to myself ? Please disregard and move on if so compelled. I thought I was doing well with my 2A 1/12 water circulation motor... (only run 2 15lb barrels)
lets see a 1 Amp motor would save me an amp
1A at 120V =120 watts, * 30days*24 hrs /1000 = ~ 86 kWh /month, @$0.13/kwh = $11 per month to run it, looks like it'd pay for itself in two months... typing and calculation on the fly here, so somethings probably wrong.
running things 24/7 adds up. See plenty of homemade tumblers with +/- 5A motors, always think that seems wasteful.
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jamesp
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Post by jamesp on Nov 24, 2019 4:45:38 GMT -5
Mechanical configurations possibly effecting efficiency of rotating machinery: Energy savings - V-belts verses synchronous flat belt Using a small v-belt verses a thick v-belt: Energy savings yey/nay ? - A giant 18 inch main pulley for driving 1.5 inch shafts verses a 6 inch pulley for driving 1/2 inch shafts(same reduction) as it relates to a smaller higher friction belt wrap: Using no pulleys and belts. knave, do I have the poles and rpm figured ~correctly 110 vac/60 hz ? Going direct drive using large diameter 12 pole(300rpm)/14 pole(257 rpm)/16 pole(225 rpm) stator as used in ceiling fans pressed or coupled directly on to barrel shaft Keep in mind 200 to 300 rpm is about the average barrel shaft speed on a rotary rock tumbler: It can get fancier, this is a brushless DC motor using a permanent magnet. Said to be super efficient. And is amiable to variable speed controls. Beyond my skill set. Anyone ?
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jamesp
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Post by jamesp on Nov 24, 2019 5:55:52 GMT -5
I will dig into multi speed PSC motors. I have experience with them, I know how to wire them, but never dug into how the speed change occurs. I know the start and run windings wires stay the same. The different speed taps change where the common connects to the start and run winding. (See edit) Without further research my assumption is that the rpms stay the same, you are just changing the torque/hp of the motor. If you over speed the motor due to not enough load, the back EMF will exceed the capacitor voltage rating and take it out. Edit 1: The lowest speed tap has the longest run winding. The fastest speed has the shortest run winding. Lowest resistance, highest current draw. The start winding remains the same for all speeds. What type of motor are these 12/14/16 pole fan motors knave ?(you lost me when you mentioned the PSC motor he he.) Are you saying they are PSC motors ? The very subject matter you are discussing is the very subject matter I am uneducated on. The large diameter direct coupled stator interests me for possible energy savings on a rotary rock tumbler. Keep in mind these ceiling fan motors are cheap and readily available to us hobby folks and turn at final shaft speeds useful for rock tumbling and sphere machines.
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jamesp
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Post by jamesp on Nov 24, 2019 6:08:03 GMT -5
EricD Those thru bolts are enticing to mount the motor with. Most people want their rotary tumblers start back up after a power outage. I have mixed feelings about that, some materials will cement up at the bottom of a tumbler barrel when sitting for a spell, causing bruises on the cemented stones at re-start. Then again if the motor does not start up but has power going to it you must ask if the motor will burn up ! You mentioned starting the motor with load. Hell, I'll just hook it up with the 5 mfd cap and see how much start torque is available. At 5 inches in diameter the stator on this $13 motor must be about 4 inches in diameter. Larger diameter for delivering more torque than most tumbler motors... Some ceiling fan motors have ~7 inch diameter stators likely yielding a good bit of torque simply by longer leverage. But the higher leverage theory may not be a factor, not sure.
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jamesp
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Post by jamesp on Nov 24, 2019 6:47:35 GMT -5
Anyone ever considered using a slow turning ceiling fan motor on a tumbler ? Very quiet. A bit concerned about the start up torque... Then again tumblers are reduction devices. 3/4 inch shaft with an 8 inch barrel is 8/.75 = 10 time more torque. Am I talking to myself ? Please disregard and move on if so compelled. I thought I was doing well with my 2A 1/12 water circulation motor... (only run 2 15lb barrels)
lets see a 1 Amp motor would save me an amp 1A at 120V =120 watts, * 30days*24 hrs /1000 = ~ 86 kWh /month, @$0.13/kwh = $11 per month to run it, looks like it'd pay for itself in two months... typing and calculation on the fly here, so somethings probably wrong.
running things 24/7 adds up. See plenty of homemade tumblers with +/- 5A motors, always think that seems wasteful.
OK This is the real dope on efficiency - the cost of power at the electric company ! Thanks for the power cost calculation. 1/12 hp rolling 30 pounds of rock sounds in line with my 1/8 hp/1140 rpm rolling 40 pounds.(yes many other variables are lurking). $11 per month rolling 30 pounds of rock sounds inline with my $30 per month rolling 80 to 100 pounds of rock with a 1/4 hp or 1/3 hp motor. I know the cost was $30 a month because I have a dedicated power company meter that costs me $20/month with zero power on, and $50 per month with the `90 pound tumbler running. Amp draw has a lot of variables. For instance an overloaded small motor can draw more amps than an under loaded larger motor. You are at $121/year and I at $360/year. Cost to convert to more efficient system is certainly in a reduced power cost. This is the reason I wanted to try this direct coupled ceiling fan motor oregon. And many do have over powered tumblers. For instance, this unit rolling 40 pounds with 1/3 hp. Maybe the motor is sized for minimum amp draw. But this seems over powered:
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