Wednesday, February 27, 2019

Tilting Tables

For a mill, you either need a tilting head or a tilting table to cut angles.  I have a Sherline tilting table on which I can mount either the 2" Sherline milling vise or the three jaw chuck.  Fine, but it limits me to cutting odd angles in objects less than 2" across.

To hold bigger pieces, I use a montrosity that I call Frankenvise: it is a drill press vise.  I have squared the jaws and the bed as well as the outer edges where it aligns with the mill's table.  I doubt that anything produced on it will be .001" accurate, but for what I need, it works fine and can hold 4" wide pieces.  (And it is a bit easier to clamp workpieces in than the Sherline mill vise, which has a complicated clamping scheme intended to squeeze things both in and down at the same time.)

Here's the problem.  Frankenvise is 7" by 6.25" and will not fit into the tilting table.  (How it is held on the mill table is an esthetic crime, but it works using the same T-slot clamps as the Sherline vise.)  I really need the ability to put Frankenvise at a 30 degree angle for milling 30 degree angles in big pieces of acetal.  I really neither need nor want to invest the time into making a true tilting table.  I am contemplating building a 30 degree triangle which will use the T-slot clamps to hold the triangle to the mill table, and similarly to lock Frankenvise to the triangle.  Before I do this: Are there such triangles out there already made of aluminum or acetal?  I can mill a slot along the bottom of the triangle into which the T-slot retaining clips would go to hold it to the mill table, and then drill and tap holes for locking Frankenvise to the top.

Just to clarify: if I had a big bandsaw, I could put a 6.25" thick piece of aluminum in it, and cut a 30 degree angle.  But the chop saw that I have can't open that wide, nor would it be very happy cutting a piece that thick.  (Heat build up.)  I have been contemplating building something from sheets of aluminum bolted together into a triangle.

If one of you has a big bandsaw, and access to a piece of aluminum that could produce a base 6.25" x 6.062" with a 7" long hypotenuse, it would make sense to pay you to cut this rather than building this from parts.


  1. Perhaps one could be 3D printed.

  2. Which raises a thought: I see a benefit in the creation of a network of "tooling-equipped independent contractors" just for stuff like this. People who have documented competence with the machine tools in their possession and, for a nominal fee, will perform simple machining operations. UPS it to him/her, pay a few bucks, get it back in a reasonable time.

    A year or so ago I had a project that required either a LOT of precision hand saw work (which required long and precise cuts that were well beyond the capabilities of any master carpenter I've ever seen use a hand saw) or a few minutes with a much larger bandsaw than is commonly found. I eventually located a custom fabrication woodshop that had one (they do a fair amount of timber framing prep), went by and showed them how to set the job up to get the cuts I needed, and for $20, 30 minutes of drive time each way and 7 minutes of a quite competent band saw operator's time I had exactly what I needed.

    Might such a network exist already? If not, is there a reason for creating one? It could extend to emailing drawings or specs for a simple project and a money order, getting the finished product back in a week or two.

    Most areas have commercial machine shops, but their prices are substantial, and "quick simple stuff" is not really their ken.

    I see some complications with the "documented" part; there's no point in contracting with someone who has no idea what "Warner and Swasy" or "Bridgeport" mean but someone who has 400 hours hands-on with a Sherline, Grizzly or Erie could be eminently capable of medium complexity work ; perhaps a group/network web site with photos and specs of previous work.

    I also see a complication with the customer end - unsophisticated users may, even probably, would not understand the necessary requirements and complexities of some work, and/or submit incomplete drawings or specifications. What looks simple to Joe Shade Tree may involve cutting implements, equipment capabilities, task knowledge or setup time at or beyond the limits of a hobby machinist, and Joe may get upset if he gets responses indicating "this is a job for a local pro shop in your area." (In particular, I see issues with precise communication; average and below-average users are notoriously sloppy in precision descriptions.)