|
|
Post by lostaussie on Apr 15, 2017 22:29:37 GMT -5
Hold on!!! That gives me an idea... I know that MB is picking up my general idea... but... we still need some type of XY table to hold the cutter. If the wheel is moving then we are back to square one. If the drill bushing is used and fixed in a vice could you spin the wheel using cheap drill press. This could take care of moving up and down the wheel. Then as VK mentioned you could use an adjustment screw to progressively adjust the depth of the cut by moving the cutting tool just on one axis. VK I would think most groups would probably have somebody who already owns a cheap drill press. Not sure when doing your $100 number you would need to include that or include even a hand drill if you used that to spin the rod. |
|
|
|
Post by Vitamin K on Apr 17, 2017 21:21:09 GMT -5
Hold on!!! That gives me an idea... I know that MB is picking up my general idea... but... we still need some type of XY table to hold the cutter. If the wheel is moving then we are back to square one. If the drill bushing is used and fixed in a vice could you spin the wheel using cheap drill press. This could take care of moving up and down the wheel. Then as VK mentioned you could use an adjustment screw to progressively adjust the depth of the cut by moving the cutting tool just on one axis. VK I would think most groups would probably have somebody who already owns a cheap drill press. Not sure when doing your $100 number you would need to include that or include even a hand drill if you used that to spin the rod. I think almost everybody has a hand drill. If we could find a simple way to provide linkage for one to the end of the rod, that would probably be sufficient. micro: Can you give me a rough idea of materials cost and time involved in turning down a rod that was 1/4" diameter around the shaft and then ~0.098" at the tip for mounting the wheel? I'm thinking that with 3 shafts of slightly varying tip diameter you could accommodate most BSA wheel bore sizes. |
|
|
|
Post by Vitamin K on Apr 18, 2017 13:29:04 GMT -5
Ok, so the bad idea machine is still churning. Here's a new idea for you guys to shoot down.
Let's start with a motor with an ER11 collet chuck on the end. We have a whole bunch of 1/4" diameter delrin rod blanks. Stick a delrin rod into the chuck and then use the cutting or sanding tool to bring the end of the rod down to .097" diameter (or whatever it is we need to hold the wheel). Then stick your wheel onto the newly turned mandrel and work the outside with your cutting/sanding tool.
If you need to change the bore size of the wheels you're going to work, cut/grind a new Delrin mandrel. I doubt you'd spend more than $0.25 apiece for each piece of Delrin you'd need. And, theoretically, the runout should be axed by the fact that you're not removing the mandrel from the collet after you grind it down.
|
|
|
|
Post by micro on Apr 18, 2017 14:01:42 GMT -5
I was going to get some 3/16 precision ground drill rod and play around with that..the first idea. I think that is the cheapest. I thought we were going for cheap?
|
|
|
|
Post by Vitamin K on Apr 18, 2017 14:09:45 GMT -5
I was going to get some 3/16 precision ground drill rod and play around with that..the first idea. I think that is the cheapest. I thought we were going for cheap? I am all about the cheapness.  What does it go for? |
|
|
|
Post by micro on Apr 18, 2017 14:16:58 GMT -5
Three dollars for a piece? Would need a few of them. I am just curious about how well they fit in the bushing. I have to piece meal my way through a puzzle. I have no idea what I am doing. Baby steps for an idiot like me.
|
|
|
|
Post by Vitamin K on Apr 18, 2017 14:27:03 GMT -5
Three dollars for a piece? Would need a few of them. I am just curious about how well they fit in the bushing. I have to piece meal my way through a puzzle. I have no idea what I am doing. Baby steps for an idiot like me. Are the bushings a standard part? So the idea would be buy the drill blank and the standard bushing, and then turn down the end of the blank into the wheel mandrel? |
|
|
|
Post by micro on Apr 18, 2017 15:03:48 GMT -5
Yes, the bushings can be ordered, a standard part. I am thinking that if successful the part that is turned down is precision ground at the same time as the end is made...it would have to be made at the same time, as again sticking in a perfectly ground drill rod into a lathe will be near impossible to get it to run true to be able to turn the end to 0.97 or so. I do have an e-z zero collet nut, so I could in theory get it fairly close, just not sure if that would be better..both would need to be made on the same piece at the same time. I am not sure how well if I just turn a part would fit in the bushing. I would need to get a larger stock piece as I only have 3/16 stock and that is smaller than .1875 so too much play to start with.
Sorry, random thoughts jumbled. An actual machinist would laugh at this don't show BSB this thread ok. I just start walking in one direction, stop and look around and see where the road leads.
|
|
|
|
Post by Professor Moriarty on Apr 18, 2017 15:25:45 GMT -5
Ok... I told myself that I would give myself a little break from this riddle... but I too... cannot help myself...
There has got to be a rod that mates near perfectly with a bearing... They are probably sold together that way.
Toss that thing into a collet and how far could it be off by turning down the end to .097"?
|
|
|
|
Post by Vitamin K on Apr 18, 2017 15:34:44 GMT -5
Yes, the bushings can be ordered, a standard part. I am thinking that if successful the part that is turned down is precision ground at the same time as the end is made...it would have to be made at the same time, as again sticking in a perfectly ground drill rod into a lathe will be near impossible to get it to run true to be able to turn the end to 0.97 or so. I do have an e-z zero collet nut, so I could in theory get it fairly close, just not sure if that would be better..both would need to be made on the same piece at the same time. I am not sure how well if I just turn a part would fit in the bushing. I would need to get a larger stock piece as I only have 3/16 stock and that is smaller than .1875 so too much play to start with. Sorry, random thoughts jumbled. An actual machinist would laugh at this don't show BSB this thread ok. I just start walking in one direction, stop and look around and see where the road leads. Sometimes you have to ignore the common sense. BSB is knowledgeable, but he doesn't think much outside of his regular boxes. He threw a lot of shade on Big Jimmy's wheel turning setup, but then had to admit that the finished product was a pretty good wheel. |
|
|
|
Post by Vitamin K on Apr 19, 2017 7:01:43 GMT -5
Ok... I told myself that I would give myself a little break from this riddle... but I too... cannot help myself... There has got to be a rod that mates near perfectly with a bearing... They are probably sold together that way. Toss that thing into a collet and how far could it be off by turning down the end to .097"? Well, you can buy turned rods of standard diameter, as well as bearings of standard ID and OD. For holding the bearing, maybe something like this?  That particular block accommodates a bearing with an OD of 8mm. You could mount a pair of bearings with an ID of 5mm and OD of 8mm, which means it would take a 5mm shaft. Would just need to figure out a locking solution (they make collars) and motor linkage solution. |
|
|
|
Post by Vitamin K on Apr 20, 2017 7:28:00 GMT -5
Well, my spindle came in...  I haven't fired it up yet. I need to cannibalize a 3-prong cord to hook up to the included power supply. Unit feels really solid, though. No play in the shaft when I wiggle it. Obviously, that tells me nothing of true value, but hey, it's what I got right now. Will need to get it mounted and then throw a dial indicator on that puppy to see what kind of runout I'm working with. |
|
What does it go for?