Loading an alternative Plotter Driver to AutoCad 2000

[Stanier]

Hi - I am running AutoCad 2000 and using the plot-to-file option to create a file for use with a basic home workshop CAM system. This CAM system has been designed to run with data created using the Hewlett Packard plotter driver HP7470 but unfortuneately my version of AutoCad 2000 does not list this driver as an option under the Plotter Manager/Add a Driver tab. Can anyone tell me how I can go about finding and downloading a copy of driver HP7470 in order that it may be added to the list of options in the Add a Driver list?

 

I have tried using some of the alternative drivers listed in but all appear to give inaccurate or spurious results. Any helful suggestions would be most appreciated. - Regards Reg

[ReMark]

Did you check on the HP website for HP7470 drivers?

 

What OS are you using?

[Stanier]

The operating system is Windows XP

[ReMark]

And my other question?

 

Never mind.

 

You might want to read this.....http://www.cnczone.com/forums/printing_scanners_vinyl_cutting_plotters/9159-hp_7470a_plotter.html

 

It's possible you'll run into the same problem.

[Stanier]

I have tried searching various sites but for some reason cannot find HP740 although in the process I have been offered so called similiar drivers. When I go the the HP website, they want to offer me a "driver tuner" which is not what I am looking for.

[Stanier]

Yes, thanks for the link to the article, very interesting. It would suggest that although a version of HP7470A is not available for Windows OS systems later than Win9x, it should be possible to use it fom AutoCad. Before I try and do this has anyone had any experience in setting up a custom plotter in Autocad 2000?

[irneb]

This is a pain. That particular printer is an old pen plotter, so my guess is that you won't find any windows drivers for it. It uses the old HPGL file format (note NOT the HPGL2 which is more for inkjet/laser). And most of these don't work too well through windows drivers, ACad should have an HDI internal driver for HPGL (even just using a similar plotter). The language tends to be the same for all plotters which use this, with only minor differences like settings, pen changes, and perhaps scaling issues.

 

Sorry, I can't remember 2000's driver's - I do remember there was an older driver library before HDI (Heidi). Not sure if that was in 2000 or not. The last time I used 2000 was more than 10 years ago. And the last time I used a pen plotter (some Roland model, not HP) was even long before that! So my memory might not be too great on this score.

 

So to try and help: I'd say try the built-in acad drivers instead of the windows driver. Start off by testing a generic one. I know 2000i came with a sHPGL (meant as a simplified driver, not specific for any particular plotter), perhaps you can get similar results with something else in 2000. If giving issues try another driver, try a model name as close to 7470 as listed and work outwards from there.

[Stanier]

Hi - irneb thank you, a very interesting appraisal. Since posting my initial query I have been trying out HP driver 7475A (not sure whether this is a HPGL or HPGL2) and have had some success in terms of my workshop requirements but which has in turn has raised a couple of interesting queries in their own right.

 

Query 1) With the Scale in the "Plot settings" set to 1:1 the PR(x,y) data (i.e Plot relative) written to file is coming out under size and to correct this I am having to custom the scale by an emperically arrived at correction factor of 1 inch = 1.021 drawing units to put things right. No problem here but it would be interesting to know why this is necessary.

 

Query 2) This is more of a problem. I have discovered that when drawing for example a simple sequence of straight lines as a continuous operation i.e. without pressing ENTER, the PR(x,y) data written to the plot file is rational and as would be expected.

 

However, when the same set of lines is drawn by selecting ENTER between individual lines (Object Snap ON) then the corresponding PR(x,y) data written to file contains spurious values inserted between the valid set of values. This spurious data appears to take the form of a recursive step followed by a forward step before proceeding with the expected data. In practice, this means that it is not possible to amend a drawing without introducing these unwanted pairs of data.

 

All very confusing Any thoughts or ideas on the matter would be much appreciated

[Stanier]

Error in my posting above, reference Query 1) - The Plots are coming out oversized, not undersized - hence use of the correction factor.

Regards Reg

[irneb]

Q1: That might be due to some special case in that particular model. I remember us having to do this size correlation ourselves too. It's actually quite par for the course with these pen plotters. ACad even has a calibrate function for just this purpose.

 

Q2: Sounds very strange indeed. Is your optimization settings turned on/off. Used to be necessary for line-end optimizations so the pen wouldn't need to jump from one line end to another on the other side of the page. Otherwise turn your lines into PLines so it forces one continuous figure.