HPGL file to X-Y Motion

  • Thread starter Kelly McFarland
  • Start date

Thread Starter

Kelly McFarland

Hello List,

Here is a project that us woodworkers have probably thought about...

I have a client who is looking for vendors that have a servo amplifier or stepper motor driver system that accepts Autosketch CAD files. They want to build an industrial X-Y plotter for a cabinet shop router application. In my experience, their budget is somewhat light for this---$5000 (US).
They want to build a gantry style table and plan on using the plotter pen "up" and "down" feature to lower and raise the router into the material. They got the idea from watching an HP plotter operate and are looking for a powerful enough system to drive a 30 pound gantry carriage. Feed speed is around 60 to 120 inches per minute and want to use a table that is large enough for 4 x 8 ft sheets of 3/4" veneer plywood.

Has anyone developed/used any products that they can recommend?

I have searched my usual sources and they don't have anything in this price range that directly accepts the plotter file.

Kelly D. McFarland
Automation Specialist-PLC
Tulsa Technology Center
Business and Industry Training
918-828-5417, [email protected]

Davis Gentry

$5000 is way light, unless they have someone in house who can write the code themselves. We did something similar (for in company use only, sorry) using Delta Tau PMAC control boards sitting in a PC, interfacing with amps from (depending on exact machine) Lenze, Kollmorgen, and most lately Performance Controls. Assuming fairly slow motion they could buy the amp(s),
motors, cables, and PMAC card for about $5k... Still lots of stuff left to purchase, though.

Davis Gentry
Carpenter Company

Ramer-1, Carl


You might try researching the saw drive mechanism used by the clothing manufacturing industry. They run a fabric cutting saw to cut
pattern pieces in a stack of fabric about 6" thick. I have no idea whether the drive accepts CAD file input, but the applications are very similar except for the blade up/down command. It may be easier to adapt from that process than develop a new one.

Carl Ramer, Engineer
SGS Controls & Protective Systems Design
Kennedy Space Center, Florida

Brandon Ellis


If you are seeking a complete system consisting of a two axis controller (I assume you will need
the ability to perform circular interpolation), two drives, motors, cables, actuators, and/or
gearheads for $5000 or less, then that is going to be very hard to come by. If, however, you are
looking for just the two axis controller which can accept CAD drawings (i.e. .dxf files), then I
would recommend you check out Galil Motion Control. Their URL is www.galilmc.com
Galil offers a software package called CAD-TO-DMC that will translate a .dxf file to the Galil
DMC Language. Cost will be approx. $3200.

Let me know your thoughts,
Brandon Ellis

Daniel Christadoss Newcor

Please check abilitysystems.com

They have the software which can do this

It is called indexerLPT and runs off the paralle port of a pc

One can easily build a xy router within $5000

Dan Christadoss

Guy H. Looney


I very seriously doubt you will be able to accomplish this application with your client's budget. I have been very successful in doing 2 axis gluing applications at multiple locations. I have successfully taken CAD files (DXF format) and used them to generate the 2 dimensional path for the glue head. There are several motion control companies who have such a utility (Parker Compumotor, Galil, Camsoft, to name a few). As far as HPGL goes, Parker Compumotor is the only one I know of; the others mentioned support DXF and DWG formats.

However, the control system alone will cost between $2,500 and $3,000. That doesn't leave a lot of money for the motors, drives, mechanics, limit & home switches, and assembly. Based on my experience, a system with 600mm x 800mm travel would cost around $13,000. That cost includes
controller, software, motors, drives, linear encoders, couplings, motor mounting flanges, operator interface, limit & home switches, light
curtains, and precision ball screw tables. That does not include the z axis (customer supplies their own pneumatic cylinder). That system is
running at a speed of about 100mm / second along the path.

Your system requirements call out half the speed of what we're running. You could probably get by with lower grade ball screw tables, no linear
encoders, no light curtains, and possibly cheaper motors & drives. However, you'd still be looking at $8,000 to $10,000 for the system.

Hope this helps,

Guy H. Looney
Sales Engineer

Regan Controls, Inc.
475 Metroplex Dr.
Suite 212
Nashville, TN 37211
phone: (615) 333-1940, ext. 322
fax: (615) 333-1941
[email protected]

This is a fairly easy task, we started with a quick basic program to open the *.plt file created by AutoCAD and parsed the file for geometry, min/max X and Y coordinates, line colors, etc. This was then spit out as another file with X, Y and Z commands that could be loaded directly into a Delta Tau PMAC motion controller. The line colors are assigned a
plunge depth at the user interface. This has been expanded to a full blown VB app now that allows all manner of scaling, reverse image
engraving, variable feedrates, program buffering (for files larger than PMAC memory) etc. We are working on a DXF input filter for it now.

I know this has been done by several different people for a variety of apps. Again, it was not a difficult undertaking and the basic parsing
engine took less than 2 hours to write, it was the scaling, flipping, spindle control, line color / plunge depth, etc. code that took the time
to make user friendly and robust.

Best Regards,

Ken Brown
Applied Motion Systems, Inc.

Where does the USD$5,000 start and end. If they intend to do the lot electronics, gantry, etc for $5,000 and you achieve it give me a yell, I think I could sell a few even at the current exchange rate :).

If its for the electronics, then it could be achievable (in principle) by using an old flat bed plotter that can handle the AutoCAD file format. Strip it down and keep the computer interface. From here on it would be a scaling exercise via analog or digital means, since the driver cctry would expect a table of a given size which will be different to the "new" product
size. Beef up the driver capacity, connect it to the steppers and your done. Simple Saturday afternoon job for a hobbyist (I wish).

Probably not much help, but it is food for thought.

Allan Dow

Embedded Systems & Solutions
Ph: +61-7-3879-9003
Fax: +61-7-3278-9158
Mob: +61-411-666-094
Email: [email protected]
Have you tried contacting any of the already existing CNC router companies. In the past I worked very closely with a company Anderson Router out of Charlete North Carolina. Jason Chen (not sure of last name) is the fellow that the technical expertesse of the company. Ph: 704-522-0823. This guy is a genius and I am sure he will be willing to help you out anyway he can.
While one might be capable of "easily" building a xy router within a $ 5000 budget, I would disagree that this could be a unit capable of cutting 4' x 8' x 3/4" plywood @ 60 to 120 inches per minute (these speeds are necessary to maintain cut quality and reasonable tooling life). Most industrial cabinet shop applications require; vacuum holdown, high quality ball screw
drives, high quality encoders, and extremely rigid frames and guideways, etc. These items are necessary to maintain the tolerances required for this type of application. When one takes the price of these materials into consideration, they will soon see that a $ 5000 cnc router is a pipe dream.

Respectfully, Tim Jones
Hi Kelly

You may want to consider Galil motion controllers (website: www.galilmc.com). I believe they have a DXF/HPGL to motion commands translator. Haven't used the translator before so I can't give you the details, but I have used their hardware products -- they are very good. The next thing is probably to look for suitable amplifiers and motors.

For US$5000, I think you may be able to scrap together the electrical parts. I guess you would have some reasonable-priced source for your mechanical parts?

Have you also looked at the XY-gantry robots to see if they can do the job? Brands like Yamaha, NSK, IA comes to mind. They also have attachments for the Z-axis.

Fong Kin Fui
Centre for Intelligent Control
National University of Singapore
Hello... Your clients may be much better sticking to existing CNC technology for this purpose. I say this for several reasons. The least important being their budget. I doubt $ 5000.00 US would be enough money for you to purchase the servo motors and amplifiers. The biggest reason I suggest they stick to established CNC methods is...
have you ever watched a plotter produce a plot of an ACAD drawing. You will find that there appears to be no rime or reason as to the order used when the lines of a plot are drawn. With a router in wood, or any material, a very special sequence must be determined then followed in order to remove the proper material at the proper time.

Best Regards... Rick Kelly

Chief Technician
Natural Cuts
Cheese Operations
Kraft Canada
(613) 537-8069 V
(613) 537-8057 F
[email protected]
$5000 parts cost on ebay.com if your lucky and have a few months to watch for the right stuff . . . + figure on donating labor (you are doing this for the thrill of it), next, plan on dedicating yourself to the project 99% of the time after it's built because you will be the
only one in the world who will know all the tricks and traps on how to get it working . . . and oh yeah, get ready for the re-design when the
only amp you have leaks a little smoke and you have to buy something completely different because you can't find that particular part again.

Realistically . . . any woodworker worth (his or her) salt wants to do quality work and use quality tools because they know that paying a
little more for the tool is well worth it in the long run. $5k for a cnc router?? plan on lots of frustration, headaches, inaccurate cuts and worn out mechanisms after a few weeks or months of hair pulling operation.

That will be $.02 please . . .

Ken Brown
Applied Motion Systems, Inc.

Julian Purcell

Try Galil servo boards. They wrote a file for me some time back to convert HPGL to DMC ( their native language ) HPGL can support a Z axis (Tech80 group I think.) Another route is to use the command for the 8 pens as levels in the Z
direction. We have altered HP plotters to do similar tasks as you outline, A0 Plotters are given away here in Australia!

Regards Julian PURCELL
Surveyor Resources
Canberra Australia

Tanweer Ahmed

IIEE (Institute of Industrial Electronics Engineering) had build exactly a similar device controlling 3-axes servo driven motors, a PC based
control system interfacing with CAD. They demonstrated it at an engineering exhibition.

Mr. Sadiq A. Rizvi
Institute of Industrial Electronics Engineering
ST-22/C, University Road, Gulshan Iqbal, Karachi-75300
Phone: +92-21-4982353

Tanweer Ahmed

Kelly McFarland

As usual, I have been very pleased with the "list" response. I have received several emails and one phone call on this and it seems this is a popular project for a variety of businesses. Lots of applications and data out there. At least three companies are offering the electronics
and driver software below the $5000 dollar mark. One company is offering a package with steppers for substantially less than this. As you imply,
I am a slightly skeptical about the ease of implementation and use of these systems and want to review additional information. My client is
basically a "mom and pop" operation with little or no CAD/CAM experience.

They are able to build the table and gantry. However, they are looking for a"package" for the motion and CAD side.

Kelly D. McFarland
Automation Specialist-PLC
Tulsa Technology Center
Business and Industry Training
918-828-5417, [email protected]
There are also a number of engravers that do exactly the same thing.

These are the type of engraving machine that produce the traffolite labels on many control panels (among other things) and anything up to a small engraved mimic panel.

CAD files are downloaded and the plate is engraved.

Similar machines are used by sign makers to cut vinyl.

I agree that $5000 for a self design machine is extremely light. This might be the purchase price of a manufactured machine (though it is unlikely - the controls alone could easily cost this much). The design costs could easily be more than ten times this.

How big an area must the machine cover? How heavy is the router? What accuracy is required?

Daniel Christadoss Newcor

MancNc makes a CNC router for less than $1000.00
and this can take CAd files
So we could make a router for less than $5000.00
by just scaling this
I think it is a myth that we have to pay more than $10000 for a router
Dan christadoss