Newbie, trying to understand the finer details of slide design using turcite b

I am reaching out to understand the finer details of slide design using turcite b as described below. I hope that my descriptions are complete enough to understand what I am trying to describe. Many thanks, to those of you in advance, for your vast knowledge, and I hope you will share your wisdom. The application is a simple repeating pattern cut in 6” dia. Schedule 40, PVC pipe. This pattern goes all the way thru, using a 5/8” dia. ex-long end mill, single rough pass and finish cut. This is cut on custom router, with very short “y” axes (4” actual cut) x “z” axes of 7” and “x” axes of 8' to 10'. My hope is to flush out the small details as well as understand the concept well enough and have a true appreciation of what would be required to get to this level of equipment that has built in a method to maintain high accuracy and durability.

The specific part of interest is the bridge assembly “y” and “z” axes of bridge type of router. This needs to be sized to allow a 2nd spindle (at some point in time). The thinking is to use a “square cross section” carrlane (this link has all the shapes in 1 place)V Cast Sections | Carr Lane for the “y”. This square would be rotated 45 degrees so it is like a diamond (setting on edge, the thinking is like on a lathe the “v” style of bed is desirable, as to be self locating) with an additional “V shaped cross section” of dura bar, sized so an additional “V shaped cross section” will fasten around (both sides) the “square cross section” and to allow between the inside surfaces of the “V shaped cross section” a thick section of turcite b. The “V shaped cross section” are orientated left and to the right, so the split is top and bottom. At this split is a shim (top & bottom) that is designed to allow for ware in the slide to be compensation for. This I have read can nearly be “zero clearance” when freshly assembled.

For the single spindle design a “T cross section” would be fasten to one of the “V shaped cross section” to create the “z” axes. This “T cross section” will have generous contact area, underside of the “T” so the slide will have plenty of life between service/maintenance, to allow for the ware, as it cycles. This surface as well will have shims built in to allow for ware. The edges of the “T” require a gib type of method, to maintain the fit. My thinking here is a wide cross section as practical. The gib side of the “T slide” will have a turcite b attached to a long wedge shaped part that allows a method to fasten to the “T slide” during partial fabrication of the “T slide” so both can be cut parallel in one setup, this will be with the slide not fully assembled, so access will be easy with conventional equipment. See question 5 below.

Naturally, be sensible to the sizing of the servos, as well as the rest of the assemble, that are used because they will be part of the weight that will be in motion. This needs to be light and balanced.
So the question is to start with sizing of the “y” axes “square cross section” of dura bar and “z”axes “T cross section”. This “y” axes will have a short travel (4” max, actual cut length), as not to cut thru side wall of PVC. The “T cross section” will need close to 7” of travel, needs to clear the PVC.

So the questions are:
1) The ratio of size of slide to length of contact with slide (length of “V shaped cross section”); my thinking 3 to 1 (slide 2” square x 6” long)? Is there a rule of thumb that is relative?
2) Thickness of turcute? Use small brass flat head screws with epoxy to attach turcite.
3) The underside of “T” (for the “z”axes) at least 1” per side x 6” long. Maybe not use duro bar “t section” but use 1” x 4” tool steel, fasten to a bracket between the back side of “V shaped cross section” and the 1” x 4” tool steel bar.
4) If you start with a ground surface (either cast iron or heat treated tool steel) it appears I need to flake the surface of cat iron but not the tool steel?
5) Not completely clear how to make pressure oil supply to the gib side of “z” axes, the ( the edge of the ”T” ), If the gib was thick enough to (drill & tap) oil from the end of the gib with drill in from turice side to connect, maybe.
6) Should all oil supply lines be completely independent, so control is obvious, and when were is allowing too much oil to restrict that location. I'm thinking that a slide close to maintenance time, may allow the bottom of “V shaped cross section” to have all the clearance (say in the up, non cut mode) and if all oil were one supply, maybe most of oil goes to where all the clearance is.
7) All slides should have matching wiper seal, so there is a controlled film of oil left on the slide? Is there a pocket of oil trapped between the wiper and the end of turcite that allows a film to be lay-ed down as the slide is operated. My thinking is the “z” axes, when a lot of full travel motion is required, and that it is in the vertical position would make this desirable or is the oil groove in the turcite enough. The gib sides of the slide are going to ware the most because of the smallest contact area, and this is were the question of lubrication is most critical, is my thinking.
8) To control the ball screw contamination a boot or the spring steel that slides inside itself as it changes length should be incorporated. Are there other options? Maybe a convoluted rubber tube/boot?
9) In addition to the turcite being bonded to the slides (the moving part) a oil relief (1/3 of the center needs .005 deep) and oil groove (“Z” in shape) to be cut 80% deep of total thickness of turcite). This is for each surface in question.
10) Is there an acceptable way to apply a surface treatment to say cold or hot rolled steel that is all ground to size? Thinking about the sub zero (cold treatment) or like in the fire arm industry that may work for the application?

Many thanks!

Lets see some pictures/models of what your trying to make. It'll be easier to ask questions and give answers with. Right off the bat, if your machine is to only cut PVC pipe, any objection to using linear guide rails? What kind of tolerances are you hoping to obtain?

Corey

Many thanks Corey!
The issue with a ball contact is point loading w/o any way to service it after ware is set in. Ball contact is what I think you are describing. If you were talking of roller (as in cross roller type of system) as I understand it, in the vertical position the rollers creep a small amount and w/o a stop or pre-loading they don't work well. A key part is the way to address the ware or serviceability of the assembly.

Please understand that my interest is in knowing the parts that I currently don't know and keeping the most sensitive parts of the business strategy somewhat confidential. Please understand I have others that are involved in the project and I need to honor my confidential agreement. If I have over extended welcome, with this need to know, or there is some info not complete, please point that out or if there is suggested reading please point me in the correct direction.

many, many, thanks, any help would be warmly welcomed!

Once you find the price on those cast iron V's you will go with linear rail. Might as well just get to it. Modern VMS's use them.

You will be using high feed rate cutting plastic. Better to go with linear rail. Round section (cheaper, crude) or "square" is your choice. If you type mebfab into youtube you can see the plasma cutter I am working on. Building a router as well but not on youtube yet.

Let's get my credentials out of the way: I have a BS in Mechanical Engineering and have spent the last decade doing custom machine design. I currently do new machine development for a machine tool builder that makes million dollar machine tools which are 6 axis machines capable of sub-micron work.

They are all linear way machines.

Without trying to be a jerk or crush your dreams: the machine you and your buddies are designing most likely already exists. That's not to say you can't build a good one too, or that you don't have a novel application for this type of machine, but as I tell anyone who comes to me wanting me to help them with their awesome, genius, million dollar idea: Google it. Google is the great meat grinder of dreams, once you know how to look.

And if you have found a great, undiscovered machine tool, I'd give some serious consideration to bringing in some outside help who is familiar with the business. This market is brutal, and knowing the how and when to save money on these machines is critical if you want to be cost competitive.

Good luck!

Many thanks for all the wonderful help!!

I appreciate the thoughts and see others are in agreement! Could someone help me with the thinking about flaking on cast iron vs. just ground cast iron surface. And using heat treated steel that is ground w/o flaking, or is it just the hardness of the steel makes shore the wear it to the turcite.


many thanks!