Need a superlong X-axis?

[MechanoMan]

Hypothetically speaking, if it were possible to make a superlong X-axis (like 36" travel), would you be interested in such a product? Replacing the existing table with one of the same basic design but a longer table, dovetails, and leadscrew.

I know cuemakers already place a very long plate on the X-axis just to hold the work, but they don't get any more than the original 12" of travel and have to reposition.

It may be possible as long as the mill is bolted down (so it doesn't tip over when the axis and work is extended to one side) and the X-axis speed may need to be limited because there could be a span of 3ft of leadscrew between stepper and leadnut (or 3 ft hanging off the leadnut) and we don't want that wobbling into a "jumprope". Accuracy may (or may not) be reduced slightly as the table is extended because a 3ft long span of leadscrew has some flex to it in compression. It's a stiffness issue. Cuemakers do not need extreme accuracy to begin with. There will surely be some practical limits to how much work mass can be added before the Y-axis ways have too much torque on them from an off-center mass to move smoothly.

If you have long-stock projects, it sounds like a godsend, and doesn't sound that mechanically difficult of a design per se (actual production of such a beast is another issue). It could do jobs that some people might otherwise have to buy a $3000-$5000 wood router for. And a wood router typically wouldn't do a rotary axis for a cue for example even if you did get one. Production of such an axis would require a certain volume of users here.

[fretsman]

This is so weird as I just emailed Craig at Taig asking about a longer table (24') and matching screw. Unfortunately there isn't a setup like that available.

And now you bring this up........

Dave

[fretsman]

I may just end up making a longer subplate and getting a long good quality 1/2-20 screw.

Dave

[MechanoMan]

Actually I brought it up with Craig today. We're talking about official "Taig" parts with the same suppliers.

He was going through some reasoning over the phone in regards to setup costs and technical difficulties and how many he might have to sell to break even and all (and it could be like a hundred, or several, at Taig-ish prices). I added that it may also sell more mills so it's not entirely about the table itself. The difficulty is really in redesigning a table with quality ways. If you just need a long leadscrew compatible with the Taig leadnut, ask him about that, but the ways will be a problem for you.

He seemed interested in the idea, of course the market needs to be there.

[fretsman]

Hmmm, that's pretty funny, he was probably thinking, "what the hell are these guys up to?", lol! What timing!

Well, we could always do what Marty is doing and just join 2 X tables together. The ways, I would assume, would have to be lapped together unless there's a chance that they're all pretty close to each other.

Dave

[MechanoMan]

OK, I'm not familiar with Marty's effort- please gimmie linkey to that thread.

I did mention the joining of tables. Which, well, the alignment issue is a secret to neither of us of course. The proper gib pressure may not be the same from one table to another either, in normal production there would be no need for the ways to be of a precise width from one table to another, only that it stay consistent across a single table.

There may need to be a bearing block on the tail of the leadscrew. Right now it kinda waives around when the axis is all the way in, with 12" of free screw cantilevered off the leadnut. With 24" or 36" of free screw it may wobble enough to hit the underside of the table, especially since that problem could be amplified by motor resonance at certain frequencies.

[Jeff-Birt]

Marty used a couple of 2017 'X' tables to make his X (I only know as I sold them to him ). He did a lot of other things to to brace things up and make it stiff enough for the increased travel. I think he talked about a lot of them in this thread: http://cnczone.com/forums/showthread.php?t=72563.

[macdarren]

while you are at it (and I know it would add weight especially on the longer tables) but a wider table would be nice too. just a couple inches would be handy.

[MechanoMan]

Well a wider table could be had just by adding a larger work plate. The difficulties in making a large workplate are way less than making the axis' table to a different size.

So it'd probably be far simpler to go over to http://www.hightechsystemsllc.com/ and see if they'll make a plate to your desired size.

[awerby]

Originally Posted by MechanoMan Well a wider table could be had just by adding a larger work plate. The difficulties in making a large workplate are way less than making the axis' table to a different size. So it'd probably be far simpler to go over to http://www.hightechsystemsllc.com/ and see if they'll make a plate to your desired size.

[I don't want to rain on your parade, but what use is a wider workplate if you don't have the axis travel to cover it? If it hangs off the inside edge, it will bang into the Z-column when you try to machine something towards the outside edge. Yes, you can hang over the outside edge, but that doesn't mean you'll be able to reach it with the cutter.

The Taig was well-engineered to do what it does, and it does it pretty well, but it's not going to work as well if you extend it into infinity...]

Andrew Werby
www.computersculpture.com

[MechanoMan]

True. Widening the table in the Y-direction does not increase the Y-travel.

However, currently the 5.5" Y-travel does exceed the 3.5" table size. Without a larger workplate, the plate won't be under the extremes of Z-travel. Which, technically you can often mount the work in the center and let it hang off the table.

I personally REQUIRE that the table not be any larger. I have stock I need to machine which is thin but nearly 6" tall. When I mount an L-bracket on the table, I can clamp it onto the side of the table and get an extra inch before the work touches the XY saddle. There is still 2" of Y-travel past the table to use. The only problem is that darn post in the middle of the saddle.

If the table were larger, I would not be able to use this mill. So I'd say get a work holding matrix plate and not widen the table in the Y-direction.

[fretsman]

The only problem is that darn post in the middle of the saddle.

I still don't see why you just don't tape off the ways to protect them from grit and take a dremmel cutoff wheel to it like I did.

Dave