whitewolf_573 Posted July 4, 2009 Posted July 4, 2009 I am making my ball mill , and is quite finished now , i only have to change the axle that have the pulley,to one longer axle (now it measures about 55 cm so i will be able to use a jar at time only, but using a longer axle i can have place to put one jar in one side of the pulley ,and another in the other side (like the ball mill of the Passfire article or like LLoyd based ball mill. My table (that is a piece of wood with a steel structure below so is quite resistant and strong) measures about 1,60 m long and 1m or 1,20m wide , so i am going to use a 1,60 m axle and two axles of 1m or like in each side of the pulley (i mean one at the right and one on the left parallel to the big axle) But i was thinking that why i can't use 3 or for jars at time , for example for milling kno3,charcoal and sulfur at the same time. Perhaps i can put 3-4 jars (instead of two) of 1 gallon (160 mm diameter and 18,64 cm long PVC jars with wooden lids ),two in one side,two in the other, but i dont know if the axles will support the forces and will not broke (the axles are steel with a 20 mm diameter),or if the motor wouldn't burn out or get too hot. My motor is from a washing machine , runs at 2800 rpm but i use a big 10" pulley to slow it , so have the required speed in the jar. But i dont know the hps or anything , well , in the sticker of the motor says : 2.9A 170W 2800 rpm 16uF 450VL If the long axle don't withstand the charges of the 4 jars,or the small axles don't withstand more than one jar, i could put two pair of axles,each in one side of the table, and gear it using 2 pulleys of same diameter , one in the "new" axle , and the other in the long axle (putting that pulleys in the end of the axles) so each jar is supported by one pair of axles , like in this sketch that i made for explain it better http://i353.photobucket.com/albums/r389/wh...73/ballmill.png Two jars perhaps is enough but perhaps be able to mill 3-4 things at time could save time and perhaps money. What i will do, is first finish the ball mill like i said , using a longer axle that will hold at least 2 jars, and if i see that all works ok, then , based in your opinions and my investigations and research , see if i can use 3 or 4 jars , or better i only use 2. Do you think guys , is a good idea to try using more than two jars,putting 2 jars in each side of the axles , or making 2 new pair of axles, or is not worthwhile or reliable ?
deadman Posted July 5, 2009 Posted July 5, 2009 If your motor can support the weight of the 4 jars I don't see why you couldn't do this. I may rebuild my mill to support more than two jars at one point. I think it best to set the ratios to fit several smaller jars rather than one extra large. Good luck and please post pictures of whatever you decide. I love looking at pyro tools. Especially home made ones.
Swede Posted July 5, 2009 Posted July 5, 2009 It should work fine if the motor has the adequate HP. 170 watts is about 1/4 HP, not bad, but for 2 or 3 BIG jars, a 1/2 HP unit would be appropriate. Give it a try, but monitor the temperature of the motor. If it becomes too hot to touch for 3 or 4 seconds, it is probably working too hard. One other thing that can be tricky on a homemade ball mill is the tendency of the jar to travel longitudinally. I've got three ball mills, and every one of them does this. It's annoying. The jar bottom or lid ends up rubbing against something stationary, like a bolt head, and a furrow is cut in the jar. An answer is to mount a pair of cheap roller blade bearings with a bolt, and orient them so the jar encounters the ball bearing, which turns and prevents damage. Something like this. http://www.5bears.com/firew/bp018.jpg It sounds like you have made an excellent ball mill. Good luck with it!
whitewolf_573 Posted July 7, 2009 Author Posted July 7, 2009 (edited) It should work fine if the motor has the adequate HP. 170 watts is about 1/4 HP, not bad, but for 2 or 3 BIG jars, a 1/2 HP unit would be appropriate. Give it a try, but monitor the temperature of the motor. If it becomes too hot to touch for 3 or 4 seconds, it is probably working too hard. One other thing that can be tricky on a homemade ball mill is the tendency of the jar to travel longitudinally. I've got three ball mills, and every one of them does this. It's annoying. The jar bottom or lid ends up rubbing against something stationary, like a bolt head, and a furrow is cut in the jar. An answer is to mount a pair of cheap roller blade bearings with a bolt, and orient them so the jar encounters the ball bearing, which turns and prevents damage. Something like this. http://www.5bears.com/firew/bp018.jpg It sounds like you have made an excellent ball mill. Good luck with it! Thanks Swede.I will give it a try and see how works.I hope it will work for two jars without get too hot . But if not i would look for other motor. My motor is thishttp://i353.photobucket.com/albums/r389/whitewolf_573/motor-1.jpg I remember that when i used this motor in my old ball mill,it became too hot to touch it or at least quite hot,but never stoped work or anything. If i use it and it starts getting very hot or too hot to touch it,that would be bad , because earlier or later would burn out,or stop working , no? If i need one perhaps better one about 3/4 to 1 hp , so be sure that is enough power for turn 2-3 jars , no ? I have another motor,that i think is 1hp but i bought it in ebay and i dont't know how to wire it,and i think is from USA,so is not 220v / 50 Hz like in spain. I will try first with this motor , and if gets too hot or burn out , i will try getting work the other motor or buy one. I will post information about the other motor ,and tell you if this motor works or not In 2-3 weeks i will finish the ball mill, and i will upload some photos to the gallery . Edited July 7, 2009 by whitewolf_573
Swede Posted July 7, 2009 Posted July 7, 2009 The heat is a sign that the motor may be pulling too much current, and that can come from a heavy load. If the motor is DESIGNED to handle heat, it'd probably be OK. Check the front and rear bearings. If you see something that looks like brass or copper, you have bronze sleeve bearings, and if so, it is a sign that the motor will not handle heat as well as one with true ball bearings. If you have sleeve bearings, oil them occasionally with 10 or 20 wt oil. If they are ball bearings, no maintenance is required. It looks like your motor has a little fan at the rear - that's a good thing. If a motor overheats and fails, it can arc badly, creating a danger. That is why I think it is best to have the motor offset longitudinally from any jars that might leak, or shielded well, and it is a good idea to use a GFCI outlet. These can be purchased as short extension cords, turning a normal outlet into one GFCI protected. Good luck!
FrankRizzo Posted July 7, 2009 Posted July 7, 2009 Wolf, Here's a setup one of the Passfire members came up with.
whitewolf_573 Posted July 7, 2009 Author Posted July 7, 2009 Wolf, Here's a setup one of the Passfire members came up with. Thanks FR. Is interesting , me i have finally adopted the Passfire / LLoyd model,with a 1,60 m axle and two small (90cm) axles pararell to it,each in one half of the table,so i have place for 4 jars or like, and i think , that as i use steel 20mm diameter axles they will support well the charges of the jars. I have asked to the shop where i bought the bearings,because they sell motors too , and a 1/2 hp single-phase (here in spain the hauses have single-phase) motor is about 81 € that are about 113$. I dind't remember to ask them the motor speed (rpms) so i have sent them a email asking it ,and asking how many would be the price for a 1 hp motor and it speed. But as they have many pulleys there souldn't be problems to find the one i need to mantain the relation between pulleys and jar speed (the pulley of the long axle is 10" , so if the motor speed change i will have to change the motor pulley to have the same speed in the jar) Until i buy the motor , perhaps the 1 hp, i will try with the actual motor i have , and see if all works , and then change it to the 1 hp or 1/2 hp, so be sure that the mill will manage 2-3 jars without too much effort. The heat is a sign that the motor may be pulling too much current, and that can come from a heavy load. If the motor is DESIGNED to handle heat, it'd probably be OK. Check the front and rear bearings. If you see something that looks like brass or copper, you have bronze sleeve bearings, and if so, it is a sign that the motor will not handle heat as well as one with true ball bearings. If you have sleeve bearings, oil them occasionally with 10 or 20 wt oil. If they are ball bearings, no maintenance is required. It looks like your motor has a little fan at the rear - that's a good thing. If a motor overheats and fails, it can arc badly, creating a danger. That is why I think it is best to have the motor offset longitudinally from any jars that might leak, or shielded well, and it is a good idea to use a GFCI outlet. These can be purchased as short extension cords, turning a normal outlet into one GFCI protected. Good luck! I will look in the motor and see what bearings has,but i think i will buy one 1/2 or 1 hp motor. The motor is below the jars in a closed area (the table has something like shelves , and i removed them to put the motor) so i think is well protected.
whitewolf_573 Posted July 8, 2009 Author Posted July 8, 2009 well, i have gone to the shop ,and i bought the 1500 rpm 1/2 hp motor http://i353.photobucket.com/albums/r389/whitewolf_573/motor1.jpg http://i353.photobucket.com/albums/r389/whitewolf_573/motor2.jpg I think is quite pretty and functional,with a fan and well protected. I don't know the diameter of the pulley that have , but it can be removed because i see that the pulley has a nut in it , or like.
Swede Posted July 9, 2009 Posted July 9, 2009 SWEET! That is a PERFECT motor for a reasonably heavy ball mill. It probably has a thermal overload switch, too. Most better motors do. You are all set. It even has a nice guarded switch. If you want to, you could drill that switch box and create a remote switch so you can turn the mill on or off at a distance. Or do what most guys do, plug or unplug the extension cord. And that pulley actually looks about right. For the driven shaft pulley, you could go for one about 3X to 4X the pitch diameter. 81 Euros is pretty typical for a 1/2 HP motor of that style, new. I don't think you got a bad deal at all.
Arthur Posted July 9, 2009 Posted July 9, 2009 My mill produces 1000g of comp a batch and takes about 40watts, it has a rubber drum so it is sociably quiet too. One of tha UK suppliers had major problems when his one multi jar mill blew up the motor! I'd seriously look for two medium mills if I needed production quantities.
whitewolf_573 Posted July 10, 2009 Author Posted July 10, 2009 (edited) Well,i write this because i have some dudes about aligning the bearings between them and with the table too My ball bearings,are self-centering and pillow block type. The other day i tryed to fix them in the table i have (using some bolts and nuts) , but when i tryed to insert in them the 20mm steel rod that is my axle,in some of them is very easy to do it,but in other (usually the one that is in the center of the table,or the one of one of the sides) its a bit difficult to insert them Seems that is like if the axle were actually more than 20mm diameter and it gets jammed in the bearing,and is quite difficult to move the axle for example to remove the rod from that bearing trying taking it out (but it turns well,without problems) But this only hapens in some , and not allways,depends in if you have inserted the rod in other bearings first,seems. Finally i am able to insert the rod in all the bearings and align them,but is quite hard. Perhaps is better to insert the rod in the bearings without fixing it first to the table,insert it along the axle,and locate it where you want in the table (moving them along the axle , putting all the pillow blocks on the table and moving them along the axle to their position) and when you have the long axle positioned and fixed,use it to have the other two axles parallel and at right distance from it,and then fix them,with the bearings put in the axle. In this way , you are sure that all bearings are aligned,and that the rod inserts in all of then ,as you did that previously. I have dismantled all bearings and axles because on Tuesday i was working on it,and i put the table outside,and when i finished i covered it with a plastic to protect the table from rain,when i went to the table yesterday the bearings had rust in them,and some of them didn't turn very well,so i think i need to buy new bearings and use the others for other less critical things. Now i have the table without anything in it,only the holes and the marks were go the pillow blocks,and i will re-start mounting the ball mill, but being sure that the bearings are correctly aligned,and that i don't force it or do anything bad with them. What i should do first,align the pillow blocks,mark where screw on them and fix well each bearing ,and try to insert the rod carefully in it Or first insert the bearings in the rod,and then move through the rod to their correct position and fix them ? For align the bearings i can use a large rule,or a laser measuring tool (i have both) and be sure that are aligned to the table and between them , so when you will insert the rod ,it will be easy to do,and that the pulley is parallel to one border of the table. I have fear of not align ok the bearings,and once all mounted , discover that i have to dismantle it and correct it (well ,i have to to it once,because rusted bearings ) I am think¡ng in use a electric sander to sand the table,fill the holes with wood filler or like and buy a pine plank of 2cm or more thickness and glue it to the table,let it dry , and then re-start measuring where put the bearings axles and all,mark with a pencil,think first,and then when i sure is ok,screw on them to the table using some screws with washers. Have a pine plank glued,is good because is prettier than the particle board or like of the table,and all their borders are straight,so if i use some straight thing to align the pillow blocks to the plank,and to align all bearings between them,i will sure that they are straight like the plank. How do you aling a bearing or something like , to a table or plank,and between other bearings , to be sure that are parallel and straight ? Edited July 10, 2009 by whitewolf_573
Swede Posted July 10, 2009 Posted July 10, 2009 WW, I prefer to mount the shafts in the pillow blocks, then bring it all together. Most pillow block housings have through holes, unthreaded. By selecting bolts a bit smaller than those through holes, the pillow block bearing can be shifted in any direction a few mm, then tightened down, allowing final adjustment and alignment. All it takes is 0.001" or 0.02 mm excess shaft diameter to make in uninstallable in the bearing. By clamping the shaft in a vise and using a strip of silicon carbide paper with a "shoe shine" motion, you'll easily be able to ease the fits. It should only take a few minutes. I prefer shafting with a keyway. This does two things - it allows for solid pulley attachment, and it also gives the bearing grub screw a place to bear into without marring the shaft. If grub screws are tightened excessively on a mild steel shaft, the buggering of the shaft is guaranteed, making removal very difficult. If you don't have keyed shafting, you can gently mark where the grub screw bears, then drill a hole in that spot about 2 mm deep, which will take the grub screw securely and keep the shafting clean and unmarred. It is sometimes difficult to prevent the jars from walking over hours of milling, even if you align them perfectly, so some sort of stop works best. As for the rust, it is something you just have to live with, and prevent with a bit of oil. Stainless hardware is cost prohibitive in most cases. Snap some pics when you're done.
whitewolf_573 Posted July 11, 2009 Author Posted July 11, 2009 (edited) WW, I prefer to mount the shafts in the pillow blocks, then bring it all together. Most pillow block housings have through holes, unthreaded. By selecting bolts a bit smaller than those through holes, the pillow block bearing can be shifted in any direction a few mm, then tightened down, allowing final adjustment and alignment. All it takes is 0.001" or 0.02 mm excess shaft diameter to make in uninstallable in the bearing. By clamping the shaft in a vise and using a strip of silicon carbide paper with a "shoe shine" motion, you'll easily be able to ease the fits. It should only take a few minutes. I prefer shafting with a keyway. This does two things - it allows for solid pulley attachment, and it also gives the bearing grub screw a place to bear into without marring the shaft. If grub screws are tightened excessively on a mild steel shaft, the buggering of the shaft is guaranteed, making removal very difficult. If you don't have keyed shafting, you can gently mark where the grub screw bears, then drill a hole in that spot about 2 mm deep, which will take the grub screw securely and keep the shafting clean and unmarred. It is sometimes difficult to prevent the jars from walking over hours of milling, even if you align them perfectly, so some sort of stop works best. As for the rust, it is something you just have to live with, and prevent with a bit of oil. Stainless hardware is cost prohibitive in most cases. Snap some pics when you're done. Thanks,is very useful your post I have pics of my pillow block bearings , are this http://i353.photobucket.com/albums/r389/whitewolf_573/ball%20mill%20project/pillowblock.jpg This is my pulley. You can see the pillow blocks and the bearings with the new longer shaft , but i removed all that , because i think was a bit bad aligned,and i will fill the holes with wood filler,and glue a 2cm thickness pine plank on the table,once removed the sink and once glued, measure,align and make the holes again,but first insert the shaft in the bearing first to know if i need to sand it a bit,and because is easier to align it. Once i know that are good aligned , insert the bolts in the holes of the pillow blocks , and align it better if need , previously to tight down them. I am thinking in put the pulley in one side instead on the center ,to be able to put more than one pulley , and be easy to remove them , if need, from the shaft. http://i353.photobucket.com/albums/r389/whitewolf_573/ball%20mill%20project/pulley.jpg Edited July 11, 2009 by whitewolf_573
Swede Posted July 11, 2009 Posted July 11, 2009 That all looks excellent. If possible, it's nice to be able to rapidly swap the pulley on the driven shaft for different speeds. You can take your shafts into a good hardware store, and there should be some vinyl or other soft rubber-like tubing that will slide over the shafts, yet still grip them reasonably. That will help with friction and jar movement. I see the rust you refer to. Pretty normal and hard to avoid. Turn the system on and hit it with some steel wool, and eventually it'll become entirely browned in an attractive way, and further rusting is inhibited. I wouldn't worry too much about it, just don't let it get pitted. One last thing - with that style of pillow block, you can install thin shims (sheet brass works well) between the pillow block and the wood if you need to elevate a bit to align. I worked with a different style of block, each has advantages.http://www.5bears.com/bmk/bmk04.jpg
whitewolf_573 Posted July 20, 2009 Author Posted July 20, 2009 (edited) In the Lloyd's ball mill book he uses a steel rod for the geared shaft (the shaft that has the pulley) but for the two not geared paralell shafts he uses two 14" x 1-1/2" ball bearing equipment rollers with mounting brackets, instead of using two 14" x 3/4" steel rods (for example) Passfire ball mill uses 2 steel rods instead of rollers,as i have seen. What are the differences between using rollers or use steel rods for the not geared shafts ? Use rollers improves the ball mill's design or is better in some way ? Edited July 20, 2009 by whitewolf_573
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