How to start 1-Axis really simple design

[Timbersmith]

So we run a timberframe mfg shop. We design in 3d with AutoCAD and a 3rd party app cut on a 4-axis Hundegger macjhine. We want to start cutting the very simple stud frame components as well but don't want to spend the $100k for a Hundegger SC1 machine or the like.

All we need is a simple 1-axis stop block for a chop saw. Something like this:
http://exfactory.com/seelit.aspx?ima...cnum=SO-010173

Even at $14k it seems like most of the money is going into the controller but I can get all that for free if I use a PC instead of their custom interface.

And If I built a simple 1-Axis machine i could be onthe road to designing and building a 2/3 axis plasma cutter next.

Instead of the extruded alum fence, I'm thinking about a simple 6x6 angle iron as the fence with a smaller angle mounted off of it for mounting the rack.

Can anyone point me inthe right direction?

[ger21]

Seems like you're already heading in the direction you want to go. Do you have any more specific questions?

[andy_ck87028]

Originally Posted by Timbersmith All we need is a simple 1-axis stop block for a chop saw. Something like this: http://exfactory.com/seelit.aspx?ima...cnum=SO-010173 Even at $14k it seems like most of the money is going into the controller but I can get all that for free if I use a PC instead of their custom interface.

At $14K, I reckon most is going in someone's pocket.

That solution should be up and running from scratch for no more than $1K.

Would you be using the 1 axis for auto positioning and manual use of your chop saw .... or can I see the need for a second axis?

Andy

[lerman]

What is the total length you require? What tolerance would you like to cut to? How fast do you want it to be when moving from one end to the other?

How would you like to set the length? Keyboard, turning a crank or knob, switches?

Would you like to have some stored standard sizes (think of it as speed dial)?

Ken

[lgalla]

I will be following this one.I have used Tiger stop and it is cool.Stored sizes would be good.
Since the stop is low weight I imagine a stepper direct drive on a rack&pinion would be cost effective.Supported round shaft should be enough for linear guide.
Computer control?..Don't know much of that field.
Larry

[Timbersmith]

Thanks for the help.

Length should be able to handle 18'.
Tolerance +/- 1/16"
Speed of the should be 2ft/sec min if possible.
The "cut-list" data comes from our 3d building model. I've got the piece data in any number of formats- xls, mdb, comma delimited, or proprietary hundegger, randec or mitek.

Other considerations;
Guys will be hitting the stop with the material. It need to be able to withstand some abuse.

Information that need to be conveyed to the operator:
Qty. Length. Thickness. Width. Wall#. Piece#
I need some sort of software that will control the stop block. Ideally it will be a list based format that would allow the operator to advance to the next piece after he's cut the required number of pieces.


I'm sure I'll think of more.

Any ideas of what software I should be looking at? How big should the motor be? Standard sizes of rack and pinion gearing? How much power will I be looking at? If I can get an idea of how big the required componentry is, I can start working on rough design.

[ger21]

You might want to look at driving it with an acme screw. Bumping it with an 18' long piece of wood might move the rack and pinion, and you'll then lose position.

You want it to move automatically following your cutlist? Hmmm. Not sure what's available to do that.

[deerhunter]

18' long lead screw man that thing would whip at those speeds, my suggestion, servo drive or encoder on stepper to move a belt or pinion and then add a brake to the rail to withstand the abuse

[jdell42]

Originally Posted by ger21 You want it to move automatically following your cutlist? Hmmm. Not sure what's available to do that.

How about writing some simple GCODE with a dwell or tool change (any command) that would require mach or emc to have a user hit a button.

If you had a cut list in CSV or XLS you could quickly write a macro in Excel to convert to GCODE inserting the "Pause" command of choice and calcuating the x jog.

If you got smart you could put a limit switch such that when the chop saw was actuated it would trigger the controller to move to the next line of gcode.

[lerman]

OK. We have some good info.

1 -- Lists of parts/wall/etc. You need a real computer. With a real display -- LCD, of course. Maybe put a touchscreen on it; if not, a custom operators panel.

2 -- I would use a screw drive. Probably about four feet long. The drive would move a long slide that had five solenoid (or motor, or pneumatic) actuated stops at four foot intervals. So positioning will involve moving the screw less than five feet and dropping the proper stop. Servo drive will be more reliable than stepper drive, I think.

3 -- I'd probably build it out of 8020 or some other aluminum extrusion system.

4 -- I'd run it on linux using some of the HAL real-time components from EMC.

5 -- You might want a label printer on the system to automatically print a label that could be applied to each piece of stock as it was cut.

6 -- The table should probably have rollers on it so that the stock can be easily slid on it. An alternative would be an HDPE surface.

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Question: How wide is the stock? i.e. How wide does the table have to be.

[dannystooblue]

You could use an acme shaft if you turned the nut, this would remove the whip. if you use the rack and pinion I agree that a break would be a good option, it could be as simple as an air cylinder driven mechanism locking into the rack itself.

I would think a simple cnc software could be used with notes added and M00's between sizes. it would read something like this.

G0 Z15.5 (QUANITY = 15); THIS WOULD BE A 15-1/2" LENGTH
M00;
G0 Z176.25 (QUANITY = 3); THIS WOULD BE A 176-1/4" LENGTH
M00


Danny


Danny

[lerman]

Put a stop every foot, actuated electrically or by air. The table they are mounted on is fixed.

Move the saw blade a foot to set the actual length.

Advantages:

1 -- The moving mass is fixed and independent of the length of the table.

2 -- The motion distance is only a foot. This should be pretty easy to do.

Disadvantages:

1 -- Need good guarding over the blade since it will change location. Interlocks must be provided so that the blade must be stopped and its guard in place before indexing to the next position.

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Questions: Tell us more about the saw. Diameter, motion (does it just pivot down, does it slide horizontally, does it do both). Is the saw motion done automatically, or does a hand guide it? Does the saw do miters? Compound miters? How are the angles set?

Ken