- 80/20 mill build
-
08-12-2009, 01:47 PM
#161
Gold Member
Just a minor update here. A few weeks back, I was having some real trouble with my machine. It was oddly missing steps on the Z axis. Well, tried lots of things and the last was an upgraded motor. I removed the belt drive on Z and installed a 1200 oz nema 34. It worked great.
Then a bit later, the exact same thing started happening to X. I swapped everything including computers and controllers. The spindle was also loping up and down during the cut, but not when sitting idle. Tried different Bobs, spindle speed controls, etc. Took the mill table apart to check and clean everything.
Thats when I installed a new aluminum way cover. That worked nice, but still had some issues mentioned.
Well, until I actually swapped out the motor, it still happened. Miraculously it all cleared up after that. Everything............except the missing steps. What!
I tore it back apart and pulled the ballnut off. I had bought two sizes of replacement balls quite awhile ago. I only found very little trash inside, but at least one ball was sheared in two. a few of the balls seemed to have some flat spots, so I replaced all the balls alternating one large, then a smaller.
Put it all back together and now finally it's like a new mill again.
Man o man. It sure ain't no fun when stuff don't work right.
Aparently there were at least two issues with this. Intermittant fault with my X axis stepper causing the other motors in the system to foul up. Bad balls in the nut.
Anyway, back in business.
-
-
12-26-2009, 12:00 AM
#162
Registered
Hey Lee, can't tell you how much I appreciate this thread. I've been through it form the beginning about 4 times since I discovered it about 3 weeks ago. It's given me plenty of ideas to use down the road. Eventually I plan to have a machine with similar capabilities. Probably will be a while but I'll keep heading towards it.
I wanted to ask you, I hope to be able to route some aluminum soon and wanted to stock up on some router bits. Are there any endmills you'd recommend I get? I'm thinking the deepest I'd machine in aluminum would be about half an inch. I've been looking around and there are just so many to choose from. I was hoping you could point me in the right direction to start off with.
-
12-28-2009, 08:12 AM
#163
-
12-28-2009, 07:22 PM
#164
-
02-17-2010, 07:06 PM
#165
Registered
Coolant
Hi Lee, I just finished reading this thread all the way through, very impressive machine.
I've actually been building a machine of my own using 4"x1.5" extrusions similar to yours, i opted for a gantry design with a fixed table. I have to do a writeup on it at some point to ask for some advice from more experienced people on this forum.
However, before i do that i have a couple things i need to finish up, one of those is the actual spindle/motor/coolant setup. I think i basically have the spindle/motor stuff figured out except for the size of belt i should be aiming for, i'd like to cut at anywhere between 500-5000 rpm, with a 3hp motor. Logically the high rpm means smaller belt while low rpm means thicker one for more torque . But is there a general size that would work for that range. I'm going to use a toothed belt, likely going to buy it from mcmaster.
Also, i see that you use coolant in your setup, did you buy a kit for it? with the pump/strainer/hose or did you piece together the parts? Do you have any recommendation in this department?
Thanks
-
02-18-2010, 09:27 AM
#166
Gold Member
I would recommend what I have been using. I use a 1/2" belt for the spindle.
I bought it at SDPSI.
Mcmaster is okay, but I think the prices might be a little higher there.
As for coolant, I used a parts washer that I bought from harbor Freight.
Modified a bit, but most of the parts were there.
It works great. Perfect size pump for my needs. Mine is steel, but the new ones I have seen are plastic. Should still do a decent job though.
Let me know if I can help further.
-
02-19-2010, 11:44 AM
#167
Registered
wow that sdpsi website is awesome, great prices and really good selection. I actually think they have a WAY better selection of pulleys than mcmaster, by far.
-
02-19-2010, 12:03 PM
#168
-
02-19-2010, 12:17 PM
#169
Registered
hm, looks like choosing a timing belt isnt' that easy, do you have any suggestions as to the type of belt is best for a 3hp motor at roughly 6k rpm, specifically what material and tensioning member are best.
Also i'm assuming that pitch of the belt is the gap between teeth, and that has to match the pulleys i choose, however pitch length is the overall length of the belt, right? and obviously number of grooves is pitch length divided by pitch.
Thanks
-
02-19-2010, 12:52 PM
#170
Gold Member
They have a calculator there that will help with this. Once you determine what ratio pulleys you want, you put those in the calculator along with the distance from pulley center to center and viola. It spits out the size belt to order. Length wise.
I have been getting the aluminum pulleys and 1/2" wide belts. I have had zero issues with a 2 HP DC motor and that setup.
Somewhere in this thread I think I gave what ratios I used.
Don't have time right yet to look it up. It may have been close to 2 to 1.
-
03-07-2010, 03:54 AM
#171
Registered
I have one more question if you don't mind, I just received my X2 r8 head, but it looks like SDP/SI doesn't sell timing pulleys for the size of shaft of the spindle on this thing, it looks to be like a 1 1/8 or 1 3/8 (haven't really taken the time to measure yet as sdp/si doesn't even have anything over .75")
Which pulley did you order for the spindle side? Or did you just buy a big pulley and then custom machine it to the bigger bore?
Thanks
-
03-07-2010, 06:24 AM
#172
Gold Member
I think it was 30 mm, but you would need to double check that. Been awhile.
I just used the regular pulleys from them and opened up the bore on the lathe. The centers were aluminum. Took all of about 5 minutes on a little 7/12 lathe.
I think I logged what tooth count the pulleys had on here somewhere.
Whatever it was, it has worked perfectly.
-
03-07-2010, 06:32 PM
#173
Registered
ah, okay, too bad i don't have a lathe, i'll need to see if i can find someone around here who can turn it for me.
-
03-07-2010, 10:24 PM
#174
Registered
a drawing for r8 mini mill spindle can be found here..
http://www.littlemachineshop.com/pro...7SpindleR8.pdf
timing pulleys i get from misumi
-
03-08-2010, 06:00 AM
#175
- 80/20 mill build
Tags for this Thread
Posting Permissions
- You may not post new threads
- You may not post replies
- You may not post attachments
- You may not edit your posts
-
Forum Rules