[Mr.Chips]

For thoes of us still using Gas Pipe Rails and Roller blade bearings, we quickly find out just how flexible a 1" gas pipe is, and this limits construction to shorter lengths.

Here's a tip that you may already know, but I haven't seen it in these past few months on this forum.

Make a inverted "T" stand to fully support the gas pipe rails.
The trick is to cut a cove in the top of the support that fully contacts the surface of the pipe. A Table Saw is necessary to cut the cove.

I found this method of cutting coves in the Finewoodworking.com site. It's pretty neat, can be very useful for woodworkers.
Here's the link: There's a very good video.
http://www.taunton.com/finewoodworking/pages/wvt077.asp

Here's a drawing of the pieces. Please disregard the extra lines, not very good at using TurboCad.

Hager

[Blackhawk]

how do you make the cove round like that, on the site they are elliptical.

[ropewrench]

Clamp a the fence at 90 degree of the blade.

I have a friend who made rifle stocks. He made the barrel bed with a paddle bit reground to match the barrels and used his drill press with a fence.

[Mr.Chips]

In that link they show a "On line cove calculator" Click on it and it will open the software.


Quote from link:
Tilting the blade distorts and elongates a cove. To achieve the cut you want, you can draw your pattern on the end of the workpiece, sight across the blade, and, by trial and error, arrive at your blade-tilt and fence angle settings. Or, as shown in this video, you can take the guesswork of the process by using the Online Cove Angle Calculator

[ger21]

Or you can buy the closest size core box router bit and get it done quicker and easier.

Gerry

[cbcnc]

I just made a V cut in the top of the support. It's about 20° with the blade raised up 3/8" in 3/4" ply.
The pipe sits on about 2/3 of the thickness of the support. Make a little drawing and you will see where.
My X Rails are 46" long for a 32" cutting area.

Chris

[Mr.Chips]

Yep.
There's lots of ways of getting the job done, these are all good tips to improve the rigidity of gas pipe rails. Chose the one that works best for you and the tools you have.

Ger21's method doesn't require a table saw, only a router which you most likely have since your building a CNC.

CBCNC's method like mine requires a table saw.

Another advantage of the inverted "T" support on the "x" axis is that you can easily secure it with a couple of screws/clamps from the side while working on the alignment, and it will pretty much keep it's self upright.

Keep thoes rail tips comming.

What's your best rail tip?
Hager

[cbcnc]

I found that the gas pipe is kind of soft. I used 1/4-20 bolts up through the bottom. You can't torque too much on the bolts or they will strip the threads.
MrChips- It looks like in your drawing that you are using 5/16" or 3/8" bolts which I think is a better chouce.

Chris

[ger21]

Ger21's method doesn't require a table saw, only a router which you most likely have since your building a CNC.

A good table saw wouldn't hurt because you need to cut that support so it has two perfectly parallel edges or your Z height will vary. Although you could do that with a router and careful use of a straight edge.

Gerry

[Hobbiest]

Or for another idea, scribe a line down the edge of the pipe lengthwise. Drill holes every 6" or so, and tap for 1/4" NFT. Drill corosponding holes in the base of the machine, and insert a bolt. The bolt must have no shoulder. Put two hex nuts on the bolt, then thread into the pipe. Set the two ends to their height, then tighten the nuts to the pipe end, and the base end to lock in place. Go down the line and do this at every bolt, and you have a mounting system that is not only solid, but is infinately adjustable for absolutely true ways! Length is also not an issue, as the bolts run the entire length of the ways.

[Mr.Chips]

CBCNC
3/8" might be a better choice for tapping the gas pipe.
Hager

[ljoe1969]

chris,

i like the look of your machine. would get me another pic? this time pan up a little.

[mvaughn]

I agree, I'd like to see more of chris's machine as well.

[cbcnc]

Ok, I'll do a little photo shoot tomorrow. I just got a new digital camera so I gotta play. I'll put the pics in the photo section and let you all know.

Chris

[ljoe1969]

has anyone thought of using square tubing as a support?

[balsaman]

I would be worried about it rolling side to side from cutting pressure.

E

[arvidb]

Also, how would you fasten it to the table?

Arvid

[pminmo]

Originally posted by ljoe1969
has anyone thought of using square tubing as a support?

I think it might work if you took some 6061 aluminum plate Drilled a 1" hole in the 6061 and cut it to make a support for several places instead of the washer.

[owhite]

Originally posted by balsaman
I would be worried about it rolling side to side from cutting pressure.

E

Hit it with an arc-welder. If you dont have one, you could get it welded at a shop for reasonable $.

[balsaman]

I would think welding it will make it distort....not a great thing for router rails.

E