[Gerald_D]

After seeing the horrid prices that BWC and Hepco charge for their rollers and rails, we went the home-made route...

First we did hardened wheels:



http://www.mechmate.com/Forum/messages/11/594.html

those wheels ran on rails made by a milling machine:
http://www.mechmate.com/Forum/messages/11/1932.html


This weekend I grabbed an angle grinder:

That picture was just the start, here are more pics showing the use of the grinder to get the bevels as well:
http://www.mechmate.com/Forum/messages/11/3790.html

It actually turned out fairly good - definitely good enough for a big board cutting router.

[Switcher]

Will the rails be hardened?

Are you going to grind a bevel on the rails?

.

[Gerald_D]

We have chosen a big enough wheel so that our rails don't need hardening - we have run a set of "soft" rails since 2005 without signicant wear. If you follow the links above, you can see the bevelling process.

[Switcher]

Is that rail that is being cut on the bandsaw, the same rail you mentioned in your last post?

since 2005 without signicant wear

http://www.mechmate.com/Forum/messages/11/2546.jpg

Is that the only reason you cut the rail (worn)?



.

[Gerald_D]

A little bit of suspicion about why a blue rail is being cut only 4 months ago? Some history........

http://www.mechmate.com/Forum/messages/329/646.html

In the background of some of the pictures on that thread you can see another CNC router in a dust room. The base and X rails of that machine are original ShopBot, running size 2 BWC wheels on 3/16" angle iron, unhardened, since end-2000. Those angles have not been replaced yet, but they are significantly deformed where the rollers run (The tips of the rails are still original/unused).

Mid 2005, the gantry of the ShopBot was replaced (hence the lighter colour). The 1/4" rails were welded to the new design of gantry, and the whole gantry was put into a Gray planer/grinder to shape and finish the rails true & parallel. At the same time a second longer gantry was welded and the rails formed & ground. From this point on, the equivalent of BWC size3 wheels were used.

About Dec/Jan 05/06, a big table was built for the long gantry, but that table needed 12 ft rails which couldn't fit into the local planer grinder. So Gert made me a set of X-rails on his bandsaw and milling machine, but no photos were taken then.

In Dec 06 I started building current machine no.3 and I asked Gert for pics this time. The blue in his pics is Engineer's Blue from a spray-can, used for marking. The short 1 meter rail I made today was purely to prove it is viable with only an angle grinder.

To summarise, we have a y-axis running on "soft" rails since mid-2005, and an X and Y axis running on these rails since very early last year. None of these rails show significant wear - you can't see that the unused tips are any different to the working portions.

[Switcher]

I bet a low cost fixture could be made, to make a handheld grinder, bevel the long rails, just take a bunch of light passes.

On your cnc machine, do you run the X & Y axis, direct drive on the R&P (like you do the Z-axis)?

If all axis are direct drive, how do you like it?

I would like to build something like you have, would you recommend gearing the motors (or not)?



.

[Gerald_D]

The Z axis actually has a geared motor 3.6:1 ratio (bigger detent to hold the heavy spindle up in case the gas spring was mismatched and it was a motor that was lying around). X and Y are direct 1:1. I know that gearing the X & Y will make it better, but we are getting pretty adequate performance now. Adding some gearing/belts is quite low down on the To-Do list.

[BobWarfield]

Gerald, very nice work making up the v-rails. I suspected this could be done fairly efficiently and economically in a home shop and now you've shown how.

Cheers,

BW

[P.Passuello]

Hi Everyone

Thought I would share this jig I built to bevel the rails for my router.

It consists of a $2 grinding wheel (can't event remember why I bought it) and a few offcuts of MFD
I first cut a base out of MDF about 12" x 6"
I then cut another piece 7" x 12" which I then cut down the center to give 2 piece 3.5" x 12"
Screw one of these permanently down to the base and the other is screw into one of 2 positions depending on which side of the angle iron you are grinding.
The Grinding is done with a small 2 1/2" x 1/2" grindstone attached to a drill press.
The photos tell the story so I won't bore you with to many details.
I also include a picture of home made Vee Bearings. Each one has 2 skate board bearings in it.
How to use:
Set drill press speed to about 1200RPM The faster you got the more heat you generate.
Set Jig on drill press table and ensure no more than 1/2" of of the stone covers the angle iron when cutting.
Put angle iron in jig and set height if grind wheel to the required height but only make small cuts.
Push angle iron into the wheel and hang on. The wheel will drag the steel through the jig so wear gloves. The steel does not need to be held down but apply downward pressure on it anyway just to make sure.
Did I mention Hold on to the steel. The wider the area is the more it will pull the steel through. You will not be able to feed the steel backward against the rotation of the grind wheel.
Make many small cuts not one big one. The cuts are very fast 4 foot in about 20 seconds but if you don't hold it it will pull the lot through in about 1 second. You have been warned.

HOLD ON TO THE STEEL.

[Mike Everman]

! That's very, very creative!

[Gerald_D]

Here is the latest on the moving "skate" grinder for long rails:

http://www.mechmate.com/forums/showthread.php?t=730