diy spindle

[ged]

if you have access to a decent lathe you can make your own spindle for 10000 rpm and down.Im going to use a 2.5 hp motor and power supply from a treadmill.Turn 2 step pulleys for a flat vacuum cleaner belt.I have purchased 10 dual race 11000 rpm bearings(1.55 odx.625 id,2900lbs dynamic load)for 10 bucks. (ebay)I used a 2" od,1.375" id steel tube for the spindle housing.Bored one end out to .001 smaller than od of bearing(4 jaw chuck)and turned od to clean 100%.turned around in 4 jaw and indicated for zero runout and turned and bored other end.housing length is 6 inches long.Next was the spindle itself.I used a 1" piece of sps(good grade of steel),12" long.centerdrill it in the lathe first then holding approx. 1\2 inch in chuck using center in tailstock,I turned down shaft starting at tailstock end..510 dia.(leaving .005 aside for finishing) and .750 long(for my holders which will be slip on and lock with setscrew)then I turned down 6" more leaving a .5" x1" shoulder at tailstock end.The 6" was turned down to .640 leaving stock to finish for the bearings.then the rest of the shaft was turned down to .5 for now so I could turn a .5"x20 thread for 2 lock nuts to take all play out of shaft.Once I threaded the shaft I turned down rest of shaft to the chuck to .437".after having a beer and letting it cool down I then proceeded to finish the shaft,turning down .500" and .625 diameters to exact tolerences.I then put .020 clearance on the .625 dia.in between the bearings to facilitate assembly.When I installed the two bearings in the housing I used a small propane torch to heat and expand the housing slightly and installed the bearings.When the housing cools it is a snug fit.Then I installed the shaft using 2 round nuts with a washer in between.I checked the spindle runout and it is excellent(using a .0001 dial indicator).Hopefully,I can find a treadmill this week.I hope this thread can help somebody !I know what it is like milling aluminum at 25000 rpm,Its insane.

[austin.mn]

i was able to find a treadmill for free on the local yahoo freecycle forum.

[Thazul]

Sounds great ged!

How about some pics?

Keep us posted on how it works!

[.xXACEXx.]

i love to hear about diy stuff!! and a diy spindle is a great idea!!..seems like 30,000 is pretty high for milling,i dont know,as i have ever done it! but that spindle idea is a great one...the "drive" motor for the spindle is another story,dave kush used a sewing machine motor on one of his spindles...(i hope you dont mind me mentioning your site dave ) i guess the hard part is finding a motor thats quiet but powerful enough to use a step pully on and still have speed and power for diffrent size tool bits..

[ged]

hey everyone I finally found a treadmill a few weeks back to finish this spindle.I got a place called rubberline products in Brantford ontario to make 6 kevlar 1/8 x 5/8 flat belts and it cost 10 bucks(cheap!)Anyway ,I used the power supply and controls from the treadmill and of course the 2 1/4 hp motor that came with it. I mounted it on a 1/2 x 6" x10" aluminum plate which will mount on the z axis.I did a 2 to 1 ratio on the 2 step pulleys and when I fired this thing up it ran at 11000 rpm full out with virtually no vibration.It is also very strong from low rpm to full out.Ill let you how it cuts soon and I will post a video or pictures soon but Im in the middle of replacing the thompson shafts on the x axis with 25mm hiwins which I purchased at a place called SNL in St George ONTARIO (northeast of Brantford for all you Canada builders)these guys are very cheap and have racks and racks of this stuff right in the shop and have no problem selling to the public.Anyway enough of my ramblings....gotta goooooo.....

[Thazul]

hey ged, good to hear your still workin on it
I can't wait to see it in action!

[.xXACEXx.]

ged ,
glad to see your still working on the spindle idea.i was afraid you gave up .what type material do you intend to cut with your spindle?you mention cutting aluminum at 25,000 rpm.also,is you machine a router,or mill ?

[ged]

actually I will only cut wood at 20000 rpm.this spindle uses the speed control from the treadmill so it runs from zero up to 11000 rpm because of the 2 to 1 ratio on the pulleys.(dc motor max is 5500 rpm,2 1/4 hp at 90 volts) I will hopefully be cutting aluminum around 2000-4000 rpm with approx 7ipm feed.I will take pictures once I get it mounted but this weekend I have to replace the tompson shafts on the x axis with 25 series hiwin rails.

[ged]

sorry about that,I forgot to mention that Im running a 48"x42" overhead gantry mill,g203s,500 oz,etc etc.

[ZipSnipe]

Wheres the pics?