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50,000 RPM Mill Spindle
- Thread starter JimDawson
- Start date
I had to mill some very fine slots in aluminum and had the same idea of fitting the Hf grinder to a bt40 holder. Did you try to use it for anything besides engraving or possibly measure the run out on the grinders spindle? I may have to look into doing this. Thanks
- Joined
- Feb 8, 2014
- Messages
- 11,176
I haven't had a chance to play with it since I ran the first engraving test. I haven't checked the run out yet, by eyeball it looked pretty good.
I have heard of others using this grinder for circuit board work, so it is probably up to some light milling.
For $24 (on sale) and a little time I would say it's worth checking out
- Joined
- May 7, 2014
- Messages
- 776
so simple I smacked my head! LOL .: 50,000 RPM Mill Spindle
Ken, LUV it! Duh- So simple and it's perfect. Awesome call! Going to HF!
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Frigg'n AWESOME Stuff gang! Going to HF tomorrow to grab the pen holder grinder and see what else they have. Jim, D thanks for always posting Pics! Very kind of ya Sir. And Kens post on his holder is just too easy to say no too. I'm embarressed if I do not at least make that setup. If I cannot, the wife can chuck the machine out so I'll come to bed again most weekends. ;-)
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I think this might be design to also put in a tension (spring) loaded setup as well?? Say 1/2" to 3/4" of V travel? I saw some neat tricks w/ that type of capability.
CG
Ken, LUV it! Duh- So simple and it's perfect. Awesome call! Going to HF!
- - - Updated - - -
Frigg'n AWESOME Stuff gang! Going to HF tomorrow to grab the pen holder grinder and see what else they have. Jim, D thanks for always posting Pics! Very kind of ya Sir. And Kens post on his holder is just too easy to say no too. I'm embarressed if I do not at least make that setup. If I cannot, the wife can chuck the machine out so I'll come to bed again most weekends. ;-)
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I think this might be design to also put in a tension (spring) loaded setup as well?? Say 1/2" to 3/4" of V travel? I saw some neat tricks w/ that type of capability.
CG
- Joined
- Feb 8, 2014
- Messages
- 11,176
I did a job today that gave me a chance to give the HF pencil grinder a real workout. I was starting to get a bit of chatter towards the end of the run, so I suspect the spindle bearings might be getting a bit loose. I don't think it was designed to run under a heavy load for 16 hours. The in-line air oiler doesn't seem to work, so I stopped to squirt a bit of oil in the line every so often. I will replace the regulator that I have on there now with a complete air service unit with filter and oiler.
I had to make 550 of these little guys out of 0.020, 260 brass. The endmill is a HHS, 2 flute, 10* taper, with a 0.005 tip. Because of the low power of the grinder, I found about 3.8 IPM was the best feed rate I could muster. My 5 HP air compressor got a pretty good workout also, it ran about 50% of the time, about a 2 minute on, 2 minute off cycle. I was running the grinder at about 70 PSI. Power cost for air for the run was about $4.00
The 10x24 brass sheets (2 req) were double-side carpet taped to pieces of 3/4 inch MDF. I used deck screws to screw that down to another piece of 3/4 inch MDF that was bolted to the T-slots with countersunk screws.
16 hours later, it's on the last column of parts.
I had a lot of time to work on cleaning up the shop while this was running. Still not done with the shop, maybe tomorrow.
To see the guts of this take a look here http://www.hobby-machinist.com/showthread.php?t=23186&p=205311&viewfull=1#post205311
I had to make 550 of these little guys out of 0.020, 260 brass. The endmill is a HHS, 2 flute, 10* taper, with a 0.005 tip. Because of the low power of the grinder, I found about 3.8 IPM was the best feed rate I could muster. My 5 HP air compressor got a pretty good workout also, it ran about 50% of the time, about a 2 minute on, 2 minute off cycle. I was running the grinder at about 70 PSI. Power cost for air for the run was about $4.00
The 10x24 brass sheets (2 req) were double-side carpet taped to pieces of 3/4 inch MDF. I used deck screws to screw that down to another piece of 3/4 inch MDF that was bolted to the T-slots with countersunk screws.
16 hours later, it's on the last column of parts.
I had a lot of time to work on cleaning up the shop while this was running. Still not done with the shop, maybe tomorrow.
To see the guts of this take a look here http://www.hobby-machinist.com/showthread.php?t=23186&p=205311&viewfull=1#post205311
That is awesome Jim. Really slick stuff there. And that is one tiny end mill.
The slop in my old Millrite would snap that end mill in a New York second. But, I'm hoping that I can pull off a decent Pentograph engraver. Thats what I'm building right now. Bought the plans of the Pentograph from Joe Pie and am about 80% complete. And have my new die grinder like you have. So I'm hoping I can pull off some basic engraving. But, I know ( or think? ) before I even tried, that my mill has way too much slop to pull off using a end mill that small.
Very cool stuff Jim.