What size rails for these Bearing trucks

[planekrazie]

I have 4 THK HSR15 bearings and I am looking for some extra rails. All I need is 2 Rails at 6" for my z axis. What I am having a problem with is finding rails to match the trucks. If anyone has an extra rail at 12" or more, Or know what size and where I can buy. Let me know. I buy them from you or a company.
Thanks Steve

[snowshovelbmx]

I have a rail comming to me with two bearing trucks, but I do not need the rail its 12 1/4" long. Otherwise you would need the rails to be 15mm wide, but each rail profile is different for each model of bearing block and needs to be matched exactly.

[planekrazie]

What price do you want fot the rail.
YOu can call me at work at 1-800-929-0909 from 3pm till 11pm eastern
Steve

Originally Posted by snowshovelbmx I have a rail comming to me with two bearing trucks, but I do not need the rail its 12 1/4" long. Otherwise you would need the rails to be 15mm wide, but each rail profile is different for each model of bearing block and needs to be matched exactly.

[snowshovelbmx]

hi steve
how about 20 dollars plus shipping? let me know.
chris.

[planekrazie]

Sounds like a winner. PM me your address and Ill have the have the money right out. How much would you guess for shipping.? 10.00?
Steve

Originally Posted by snowshovelbmx hi steve how about 20 dollars plus shipping? let me know. chris.

[monte55]

I am building a 4' x 4' cnc table...............I understand x axis is where the tool would
move parallel to the tool rails and y axis is what the whole gantry moves on.....is this correct? Some posts I read indicate otherwise. I want to use 2 stepper motors, one on each side to drive y with leadscrews...........1 stepper to move the tool across the gantry and 1 for z. Every time I think I have it correct someone says something to make me think different.

[snowshovelbmx]

monte
You've got your axis right, however I'm not quite sure that you would need two steppers to drive the y axis, I have seen most designs with only one stepper motor in the middle of the table driving the entire gantry. I'm not positive but running two stepper motors on one axis could cause binding issues somewhere along the line, just an observation.

[monte55]

Originally Posted by snowshovelbmx monte You've got your axis right, however I'm not quite sure that you would need two steppers to drive the y axis, I have seen most designs with only one stepper motor in the middle of the table driving the entire gantry. I'm not positive but running two stepper motors on one axis could cause binding issues somewhere along the line, just an observation.

Thank you for your reply........the weight of the gantry is probably close to
25-30 lb now...it is being driven by 3/4 x 6 acme screws, one on each side.
I'm almost done with the mechanical part of the build. After I complete the Z
axis, I will probably drill lighting holes throughout the structure. All my aluminum is 5/8 thick plate. I have 4 linear bearings in cast iron mounts, 2 on each side on Y, 3 of the same bearings on X all riding on 1" shaft. This all starts adding up in weight. I'm thinking 425 steppers x 4 but what do I know? I should be getting my Lovejoy connectors today. I'm making my own 3/4x6
flanged screw nuts out of bronze. The tap cost $54 but as the nuts wear it
will be a cheap and easy replacement in the long run. After I'm done with the
assembly I will try to come up with a torque value at each leadscrew to move it plus actual pressure required to move each axis. I have a digital torque
meter that goes in between a socket and ratchet . Once I get that info
I'll throw it into the forum for advice on steppers and drives. Sorry for the ramble but since I originally decided to get a table then to build my own after
seeing prices and some negative reports on some I can't get this project out of my mind. It's been about 2 months now. I'll be glad when I'm done so I can obsess about something else. The mechanical part I'm ok with.....it's the computer and program stuff I'm worried about. Thanks again

[planekrazie]

I believe my Y is around 25 LBS+. I am using 200oz per inch steppers through out. Only three steppers total. My table is 4 x 6 with my z At 6"
I was going to use 3/4 rods and slide bushings for my Z but when I try to move it up and down with a small amount of pressure by hand against the tooling it binds. So thats why I want to get the extra rails for my z.
Oh well time will tell how good it will work and as for the software thing. same here. I think its gonna be a good challenge for me.
Steve

[ger21]

Originally Posted by monte55 I am building a 4' x 4' cnc table...............I understand x axis is where the tool would move parallel to the tool rails and y axis is what the whole gantry moves on.....is this correct?

The gantry travels along the X axis. The Z axis moves along the gantry on the Y axis. But you're free to call them whatever you want.

[monte55]

I have heard it two different ways on which is X and which is Y in the last couple of posts. Which one is correct?

[snowshovelbmx]

On a milling machine or VMC, from the front of the machine, the X axis is travels from left to right or vice versa, the Y axis is front and back and the spindle is up and down, but as ger21 stated you really are free to call them what ever you want on your router. Since there really is no actual front of the machine and you are the one building it, then it is really up to you.

chris.