Aussie Lapidary Forum
LAPIDARY => Cabbing and More => Topic started by: texta on September 16, 2018, 05:48:47 PM
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i have been reading the cabbing machine build threads in this forum as i am about to build my own too , but there is one thing that is bugging me and that is how people have locked the wheels to the shaft to stop them free wheeling . yep there is spacers to keep them in position but i dont see on some of the bigger builds any device to cramp them all together . on the ends its just a matter of a large nut to squeeze them all up but when wheels are between 2 bearings as they are in some builds ??????????? the one i am building will have a brass nut 1" x8tpi (which i made last night ) that will go on a threaded section close to the end of the 1" shaft then from there out the shaft will step down to 3/4" for the out board bearing . so how have other people been keeping the wheels from free wheeling . also mr aussie saphire i need to come over and see you in the near future to buy some gear i will give you a ring in the next week or 2 .
johno
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rethinking i have worked out that you are just cramping the whole lot including the bearings from the ends , not clamping the wheels between the bearings . ok so it took a while for the penny to drop , doing to many projects at once at the moment , good thing is though it gets me 2 posts in the forum .
johno
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For mine I made the inner spacer closest to the bearing with a grub screw to lock it on the shaft so when I tightened the end nut I wasn't loading the bearing. The inner of the bearing is locked on the shaft with a grub screw anyway but this way I keep everything away from the bearing, I was also concerned about water working its way inside the spacer to the bearing, this way the spacer and bearing are well away from each other, I thought originally that if water was creeping along the shaft I might put a disc to sling the water out and away but it hasn't been necessary.
Thats a bit of a rambling post, get back to me with any questions, I will catch up later when I have time.
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I used shaft collars, they are easy to use, you can put enough pressure on them and then tighten the grub screw and it keeps everything tight and spinning in the right direction.
Philip
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good idea thats what i might do make up some stainless steel collars with couple of grubs screws in each . the collars will act as a slinger to throw the water off . only thing is it wont clamp the wheels together very tight along the shaft , i dont know how tight they need to be until i use one . last time i used a cab grinder was in 1972.
johno
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In the same way as rusted, i use a shaft collar at each end of the wheels so that i am not putting any pressure on the bearings at all. First i line up my inner most collars and tighten them up then put on the wheels and spacers and then using the outside end collar i put pressure on the wheel / spacer group and tighten the grub. I found that i need a relatively strong amount of pressure to keep the wheels from slipping. I need the two collars because i have 4 bearings on the device, two in the middle and then one at each end. I had to do this because i designed it to take 10 x 8" wheels and the length of the shaft (over 1m in length) would have caused it to bend under the weight and potentially become dangerously unstable once it was spun up to speed. If you are using a long shaft you will need to support the ends but if it is just for 4 or 6 wheels (i.e. 2 - 3 each side of the center bearings) then it will be fine.
Philip
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i was thinking 4 in the middle between the bearings then 2 on each end outboard . might not get all 8 wheels at once may only get 6 to start me off then see what others i need or would like .
1 1/5 inch wheels and 1 3/4 inch gap between them will work for the shaft i have here .probably only go 6"wheels i think cos i have not won lotto yet .
johno
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while i have your attention what speed do people run the 6" wheels at , i have a 1400rpm motor dont know if i should step the revs up with pulley size or not .
johno
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This is mine. Thought i had a pic of the solenoid manifold on the back but can't find that is the gallery. I have right hand threads on each end, put a spanner on each end and squash it all. Never moved, slipped or come loose. 1200mm stainless shaft. Can't remember the rpm but it looks in the pics Ive stepped it up to probably1600-1800rpm.
(https://aussielapidaryforum.com/forum/gallery/albums/Misc/Dir_1/medium_main_7041.jpg) (https://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=7041)
(https://aussielapidaryforum.com/forum/gallery/albums/Misc/Dir_1/medium_main_7042.jpg) (https://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=7042)
(https://aussielapidaryforum.com/forum/gallery/albums/Misc/Dir_1/medium_main_7083.jpg) (https://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=7083)
(https://aussielapidaryforum.com/forum/gallery/7/medium_5704-040415131059.jpeg) (https://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=7326)
(https://aussielapidaryforum.com/forum/gallery/7/medium_5704-040415130940.jpeg) (https://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=7325)
(https://aussielapidaryforum.com/forum/gallery/7/medium_5704-040415130841.jpeg) (https://aussielapidaryforum.com/forum/index.php?action=gallery;sa=view;id=7324)
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WOW! Magnificent set-up.
Congratulations on a great job.
Ghost.
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Thanks mate, it's needing to start being used to grind rocks again. I'm using it more for grinding metal atm, motor shafts, sharpening lathe tools etc.
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They are also great for sharpening drill bits. Although Mrs Flash has banned me doing this on HER machine >:(, so I have to use the old tub machine or my faceting machine.
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Get one of those cheap small Chinese bench grinders from Bunnings or wherever, chuck the crappy wheels, mount a worn out diamond faceting lap on each end and you have a magnificent sharpening machine, I have a 600 at one end and 180 at the other it does a fantastic job at sharpening drills, knives, chisels, lathe tools etc.
Worn out for rocks still does magic for tool steel and carbide tools.
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Never thought of that, could use the crappy wheel as a backer and bolt the lap against it.
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You are both a fountain of good ideas.
I now have an excuise for buying a cheapie grinder.
beers
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That is one really sweet setup MakkyBrown !