JS92 Posted October 27, 2008 Author Posted October 27, 2008 Yeh, I was in a hurry to get one sorted in time for 5th Nov. But ive got some bearings on the way so im gonna replace the skateboard wheels and embed the bearings in some wood And its ok to copy Information should be free ( although its not exaclty info ) And then my brother can have his skateboard wheels back XD
FrankRizzo Posted October 27, 2008 Posted October 27, 2008 LOL..you stole your brother's skateboard trucks to make BP...you are going to hell Just spend a few pounds on a cheap roller and bracket set. You should be able to find one at your local wood shop supplier for under £8. I covered mine with a double layer of bicycle inner tube for good grip, but you could use the same wraps of tape idea here as well. Roller and Bracket:http://www.harborfreight.com/cpi/photos/30000-30099/30026.gif
jacob Posted October 28, 2008 Posted October 28, 2008 Actually I suggest keeping the skateboard wheels (or ones like them) I had a woodworking roller fall apart on me with my mill, it was probably the combo of high RPM's, heavy load (I was using about 30lbs of lead) and the fact the I neglected to grease it but I don't know for sure, I'm using a skateboard truck now and I love it, tough as nails, I mean they're built to withstand a person jumping around on them so heavy mill loads are no problem. Also, I thought you should have the drive roller pushing the jar down, squeezing it for more grip?
FrankRizzo Posted October 28, 2008 Posted October 28, 2008 (edited) Skateboard trucks are fine, but equipment rollers are cheap and turn well. The mill should turn so that it lifts the heavy side; it's more efficient transfer of power. Joe: I saw your video on YouTube. It looks like your jar might be spinning a bit too fast. Assuming it's ~10cm in diameter, you want ~95-100RPM for the most efficient milling. Your jar appears to be spinning near 180RPM. Edited October 28, 2008 by FrankRizzo
JS92 Posted October 28, 2008 Author Posted October 28, 2008 Skateboard trucks are fine, but equipment rollers are cheap and turn well. The mill should turn so that it lifts the heavy side; it's more efficient transfer of power. Joe: I saw your video on YouTube. It looks like your jar might be spinning a bit too fast. Assuming it's ~10cm in diameter, you want ~95-100RPM for the most efficient milling. Your jar appears to be spinning near 180RPM. Yeh I know But um, Im gonna sort it out soon when I have the moolah, hence my reason for using my bro's skteboard trucks! But um, I have some bearings on the way! I bought them before I made it, which was a stupid idea cus TBH I dont need them! But im gonna make use of them and give my skateboards wheels back to bro . Er... I have this: http://i103.photobucket.com/albums/m160/porsche911GT/Pyro/SL270485.jpg http://i103.photobucket.com/albums/m160/porsche911GT/Pyro/SL270484.jpg http://i103.photobucket.com/albums/m160/porsche911GT/Pyro/SL270483.jpg I have purchased some bearings specifically for them ends! So gonna try them out and if they prove worse than the skateboard wheels....well i'll be having them back off him
FrankRizzo Posted October 28, 2008 Posted October 28, 2008 Well, the problem is that you're over the critical speed for that jar size. What that means is that your mill won't do *any* milling. The rotation is so fast that the media are going to stay stuck to the outside of the jar like a centrifuge. You need to either decrease the size of the pulley on your motor, or increase the size of the pulley driving the roller.
JS92 Posted October 29, 2008 Author Posted October 29, 2008 But thats what I dont understand, I have made some really fast BP, 7 hours milling is my longest time....and some good results have been produced :S
TheSidewinder Posted October 29, 2008 Posted October 29, 2008 JS92, Increase the milling time to a full 24 hours, then test it again. I'm willing to bet you're going to see a noticeable increase in burn speed (and therefore, performance).
FrankRizzo Posted October 29, 2008 Posted October 29, 2008 But thats what I dont understand, I have made some really fast BP, 7 hours milling is my longest time....and some good results have been produced :S It's tough to argue with success. I was basing my RPM count off the video you posted, but may be completely off-base in my measurement as there wasn't any easy reference mark on the jar while it was spinning. What is the inner diameter of your jar, and what is your measured RPM? If you get a moment, put a tiny piece of colored tape, or a black line on the back of your mill jar near the edge, and do another short video of it spinning.
JS92 Posted October 29, 2008 Author Posted October 29, 2008 ok, ill do that for you ^^^ TheSideWinder: Oh yeh definatly, but I am going to wait and see what the electricity bill is and see what my motor is costing my dad But yeh, um thats the only time ive had and chance ive had at my dads
TheSidewinder Posted October 30, 2008 Posted October 30, 2008 The amount of electricity for one or two runs is negligible, really. Just do it once as an experiment and check the results.
JS92 Posted October 30, 2008 Author Posted October 30, 2008 The amount of electricity for one or two runs is negligible, really. Just do it once as an experiment and check the results. So what do you want me to do? I didnt understand what you said above!?
TheSidewinder Posted October 30, 2008 Posted October 30, 2008 Perhaps I misunderstood what you said. My point was that the amount of electricity used, in one run of 24 hours, would be very small and cost only a few pennies (or pence?). Try one batch run of 24 hours, and compare the resultant performance against the powder you milled for 7 hours. See if it's noticeably better. It probably will be. But if it ISN'T, then there's no need for a run of that length.
JS92 Posted October 30, 2008 Author Posted October 30, 2008 Ahh I see, thanks Will do that and make a youtube video showing it
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