Re: Diy brushless spindle
Quote:
What's the easiest way to accurately drill the holes for mounting the motor without any sort of indexing head/table anyone?
errrr? i did a bit of a hatchet job on my first one (not having cnc at that point)
scribed a line with a centre finder square... dot punched my first two holes then used my vernier calipers (one tip in the dot) and scribed a circumfrence from both dots trail and error style :)
it got me there (just)
make sure you mark and drill the face that is going to sit on your motor just in case your drill wanders.... i find it really easy to forget stuff like that :redface:
Re: Diy brushless spindle
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Originally Posted by
njhussey
Well I was thinking of either buying one of these
http://www.rdgtools.co.uk/acatalog/PROTRACTORS_ETC.html or drawing the bit in CAD, printing it out and sticking it on and centre punching the holes before drilling on the pillar drill, think I'll go the first way as the second seems a bit crude!!
No need to buy those... as Mark said all you need is dividers. Scribe a circle, or lightly touch the lathe tool to it whilst in the lathe to make a circle then use dividers to divide that circle equally - centre punch then a quick swing on the pillar drill. Equally nothing wrong with printing out a template and sticking it on - printers are pretty accurate.
If you've got access to a milling machine then just put it in the vice, center drill (or spot drill) in mill and mark out the holes with that. Zero the X/Y dials in the center, noting in what direction you zeroed them so you can compensate for the backlash by always turning to that point in the same direction. Move it the correct distance using CAD program or simple trig to find the distances.
There's many more ways to do it sufficiently accurately without buying anything.
Re: Diy brushless spindle
Well I've ordered the ER16 collet from fleabay http://www.ebay.co.uk/itm/ws/eBayISA...EOIBSA:GB:1123 and have had a go a boring the bearing housing. However my boring tool (went for the 10mm brazed tip boring bar http://www.rdgtools.co.uk/acatalog/B...ring_Bars.html) needs alot of grinding to get it to not rub...might see if I can grind one from scratch as we have a few lengths of tool steel lying around...still got probably 3 weeks to do it in before my ER16 collet arrives on these shores :smile: Thinking of which my bearings should be here from the US within the next week :tongue:
Re: Diy brushless spindle
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Originally Posted by
Villacherman
Anybody have an idea if these type motors will deliver decent torque at 500 RPM?
Not unless you either rewind the motor to get a lower kv, or use belts, which you are doing. Still 500rpm is pushing it with one belt reduction. I think you'd need two. My brushless motor spindle is a big 12 pole motor, so it's quite slow - but still 6000rpm on the full 50V. Eleven to one reduction isn't happening with one belt, but 3:1 to get max 2000rpm would probably be fine with that motor. You would only get about a quarter of the power out of that motor, but a quarter of 6kW or so is still plenty!