Search:

Does shellac on aluminum come out okay? Does it adhere well with no crazing due to material (thermal) differences)? Maybe a very thin film buildup is the trick (?)

-Chris

I'm about ready to send my gantry plans off to a waterjet service, to have my parts cut out of 0.472" 6061 or 6063.

Since I have very limited metalworking gear at home (basically, a drill press)...

If you have a servo motor moving your axis, and say you are cutting either metal or hard wood -- and for whatever reason the spindle (or router) stops -- what tells the servo controller to stop...

On my account (affordablehost), there is a setting that says "what do you want me to do with mail that is sent to xxx.domain-name.com, if a valid email account does not exist?" The choices are to...

My two entries. One Good. One Evil. :p

I think the trick on a large machine is to design it so the rails are on a substrate that is adjustable (using shims, as an example).

How do the 'big' CNC machine builders do this? Do they rely...

Yep, "that guy" knows his stuff!

If I'm not mistaken, that's our buddy Swede :)

-Chris

Here's my banner entry. It's animated, so if you have 7 seconds to spare, give it a click...

Here's my 1x3 sticker entry.

Hi Terry,
Try 'tools'->'toolbar layout' click on 'default', and make sure that Main1 and Main2 are selected, as well as Standard.

That ought to put you back to the default...

I noticed that most of these have a set screw which they claim "to lock the shaft". Would this be enough to prevent axial movement?

Here's an example:
...

...moved to sticker entry thread... :wave:

Lee, 90% of the people who hang out here (including me) haven't made it past the planning stage (yet) -- so if you are moving forward on building, the rest of us are going to be watching, and...

If you are using a traditional gantry design (sides of the gantry extend below the cutting table and are tied together underneath the cutting table), then it makes more sense to use a single,...

I bought brand new servos off eBay, and they came with encoders already mounted. Encoders are 1000 CPR, and my design calls for using 5 TPI screws. I want to jog at around 175 IPM.

Am I figuring...

This has got to be true about every DIY (or commercial) builder who uses aluminum plate as part of their design. Now I'm curious, since you aren't the first person here who has mentioned the...

Sounds cool...I'd just recommend that for anything that's any degree of subjective grading, it'd be nice if you could put up a "vote one time" thread to get an actual "people's choice" sort of...

IMO, if you've got a requirement for having a rigid, accurate machine then both the moving gantry or moving table designs give ample opportunity for problems :)

Personally, I like the idea of...

Hector, to use the equations for rack/pinion, you'd put in the lead for the pinion-to-rack ratio instead of the lead for a ballscrew. For example, if there is 2" of forward motion for every 1...

Jay,
It's useful...it agrees with my version, so the math looks okay (or we are both wrong :o )

It would really be useful as a robust web-based application, with context-sensitive help...

Swede: Thanks for all the great info. No way do I have (or know anyone) who has the tooling & skill to do this work at home, but you've given me great pointers for when I go talk to the machine...

I think they have a flanged version of their cheap square ball nuts...for $33 more than the plain version.

I'm still bewildered by by the end blocks at $311 each.

-Chris

Marc,
Thanks for the info & offer...yeah, NY to AZ is a bit of a trip!

I'll start hitting the yellow pages and probably take a couple of trips to local machine shops. Services seem to...

hmm...that's a good point...I wonder if there is anything that I could do myself to 'rough out' the portion I want turned, by grinding down the outer hardened surface.

My only metalworking tool is...

I'm working out the design of my hobby/woodworking router...and I've come to the point where I really need to understand how I'm going to mount my ballscrews to the frame of the machine & to the...

Jay,
It's not 100% complete. That's why I throw in a 2x 'fudge' factor. To really do this the right way, the set of equations should take into account:

1. the mass, diameter, angular...

Yes, for this machine you definitely ought to be looking at servos - especially at the cutting and jogging speeds you are talking about.

When you say an 8Nm motor -- wow, if that is constant...

Hector, the only calculation that has any importance is the force required to accelerate (and to stop) the gantry.

Here is how to work backwards to a motor size specification. I'm going to do...

I just looked at the x axis, as an example.

With a screw pitch of 20mm, at a screw rotational speed of 1016 RPM, you are moving the gantry at a rate of 34 cm per second (!)

That is a pretty...

Yes, you have the 'E' winding...even more torque sensitivity.

I'm not sure about the four brush configuration, maybe the motor was set up for some sort of switchable voltage / direction wiring...