GENERAL ISSUES ABOUT DESKPROTO AND RAPID PROTOTYING
I know nothing about machining: can I use DeskProto ?
Yes, you can: DeskProto has been especially developed to be used by CAD designers, not by CAM specialists (though of course for the last group easy-to-use is an advantage as well).
Currently we are using CAD software package "XXX": can this be combined with DeskProto ?
In most cases the answer will be Yes: any current 3D CAD system can export STL files. Do note the only prerequisite: it has to be a 3D system: DeskProto can not be used with a 2D drawing CAD system.
I thought that Rapid Prototyping was about stacking thin layers of material: how can DeskProto that uses CNC milling be called Rapid Prototyping ?
Some people indeed do define Rapid Prototyping as a technology to produce prototypes by adding material (Additive RP), which does exclude CNC milling as there material is removed (Subtractive RP). However, in our opinion this definition is incorrect: Rapid Prototyping is about creating a physical prototype: (1) from 3D CAD data, (2) Rapidly and (3) Automatically. The actual process used does not matter and will be a kind of black-box to the designer.
How does Rapid Prototyping using DeskProto compare to Stereolithography and other Layered Manufacturing Technologies (LMT) ?
Both available Rapid Prototyping methods, LMT and CNC have their specific advantages and disadvantages. As a result both have their preferred application areas as well: for CNC these are Concept Models and Styling Block Models, for LMT Functioning Prototypes.
See the publication
"CNC versus LMT" (PDF/ 426 Kb) on the
articles page of our website.
Can you supply a turnkey Rapid Prototyping system, including a CNC milling machine ?
Yes we can and most of our dealers can so as well. Do look at the
Contacts pages of this website, and for every dealer (and for Delft Spline Systems as well) you will see which machines are available.
FILE FORMATS
Can DeskProto import all STL files ?
Yes: DeskProto understands the complete STL definition, both the binary and the ASCII format.
STL stands for STereo Lithography (sometimes also explained as Standard Triangle Language). Stereolithography was the first addittive RP system. It's supplier defined the STL file, and luckily all other RP suppliers followed that definition. The file describes the outer surface of a part as a very large quantity of triangles.
Can DeskProto import invalid STL files ?
Yes: where layered manufacturing systems need a true solid geometry, DeskProto accepts incomplete solids as well. So small defects like gaps, cracks, orphan surfaces etc are no problem: as long as the gaps are so small that the cutter cannot make a visible hole.
Can DeskProto import all DXF files ?
No, DeskProto only understands a subset of the DXF format definition. DXF for instance can also contain a 2D drawing with dimension lines, which for DeskProto is useless information. DeskProto only can import the DXF entities 3D FACE and POLYFACE MESH (which are the same triangles as present in STL files). For instance all DXF files form 3D Studio are OK for DeskProto.
The 2D Operation in DeskProto can read 2D DXF files, in that case also only a subset of the entities is supported (Line, polyline, circle, arc)
DXF stands for Drawing eXchange File, and is a file definition created by Autodesk for its AutoCad software. As many other suppliers followed that definition it is now widely used. Some care is needed as Autodesk changes the DXF definition with every new version of Autocad.
Can DeskProto import all VRML files ?
In this case the answer is 'Almost'. DeskProto accepts both VRML version 1 and 2, including hierarchy and transformations. Only certain standard objects are not supported. Information on color, lighting and texturing is of course discarded. Do note that the standard file-extension for VRML files is .WRL
VRML stands for Virtual Reality Modeling Language, and has been created to use 3D geometry in an Internet web environment, along with HTML files.
Can DeskProto import IGES files ?
No, IGES files can not be used with DeskProto. Reason is that the IGES format is far more complex than STL, which typically will result in conversion problems. Geometry conversion from system X to system Y using IGES files in many cases does lead to incorrect results and the need for retrying. STL on the other hand guarantees smooth conversions. IGES is in fact only needed in case the geometry must be remodelled in the second system; for "downstream processes" like prototyping and moldmaking STL is fine. Do note that theoretically speaking using IGES results in a better surface quality (as the real surfaces are transferred, not a polygon approximation). In practice there is no difference, as in any CAD system the accuracy of the STL file can be freely chosen.
IGES stands for Initial Graphic Exchange Standard. It is an official standard, defined by an international committee of specialists. It can describe a wide variety of 2D and 3D entities.
I cannot open my 3D geometry file: how can I find it in DeskProto ?
In DeskProto the Open button and Open command enable you to open a DeskProto Project file (DPJ), which does contain all settings for an existing project. In case you start with a fresh geometry, you need a NEW project, in which you can import your geometry using the 'Load Geometry' button or command.
I cannot open my 2D drawing file: how can I find it in DeskProto ?
As DeskProto is mainly aimed at 3D, 2D is a bit hidden. You have to first add a 2D Operation (in Edit Part Parameters) and then edit the 2D Operation Parameters. One of these is the 2D file to be used: Browse to open the file that you need.
VARIOUS WINDOWS VERSIONS
I cannot install DeskProto on my (older) Windows 95 system.
The first version of Windows 95 that was released (called OEM Service Release 1 or OSR 1) did not yet support OpenGL and COM, both of which are needed by DeskProto. For Win95 no Service packs are available, so you have to install both: OpenGL see the README2 file on the DeskProto CD, COM by installing some more recent Microsoft software like Explorer 3 or newer, Office 95 or newer, etc.
I cannot install DeskProto on my (older) Windows NT system.
In order to install the FULL version of DeskProto on Win NT you need to have Administrator privileges (not needed for the free trial version).
The first versions of Windows NT 4.0 did not yet support OpenGL and OLE, both of which are needed by DeskProto. For Win NT you need Service Pack 4 (SP4) or later, that is available from Microsoft without cost.
I cannot install DeskProto on my Windows XP system.
The error message says: "C:\WINDOWS\SYSTEM32\AUTOEXEC.NT. The system file is not suited for running MS-DOS and Microsoft Windows applications."
This error is caused by the InstallShield software that uses some 16 bit code. It means that from directory C:\Windows\System32\ one or more of the following files are missing: Ntvdm.exe, Autoexec.nt, Config.nt, Command.com. Restoring these files from the original Windows XP CD will help.
Also see the support information on:
the InstallShield website
the Microsoft website
I cannot install DeskProto on my Windows XP-64 system.
The new 64 bits version of DeskProto is not yet supported by DeskProto. The program itself is compiled in 32 bit mode, so does not access the advantages of 64 bit. In addition, no 64 bit dongle driver is yet available, and also the current setup program contains some 16 bit code (see previous question) that does not run on Win64.
MACHINES AND POSTPROCESSORS
The CNC machine that we have/want to buy is not listed in DeskProto: what to do ?
In DeskProto it is easy to add a machine: you can do so yourself in the Library of machines (Options menu). A second step needed is choosing/creating
the postprocessor for the machine. If already available just select it, if not you can create one in the Library of Postprocessors. The easiest is just to copy an existing postprocessor that is almost right and then to edit it. Most machines accept G-code variations: in that case start with a copy of the postprocessor "ISO plain G-codes" and change that until it runs OK.
Obviously in case you are new in CNC machining it will be unclear what to edit: so the easiest way is just to ask us for support: we are happy to create a machine definition and a postprocessor for you, without charging any cost.
The CNC machine that we have is listed in DeskProto, but without the Rotation axis unit that we have. Can we change this ?
In DeskProto it is easy to change your machine definition: you can do so in the Library of machines (Options menu). Adding a Rotation axis can be done by checking the box "Available". In the Edit box "Centre level" enter the distance between the rotation axis and the machining table. Do NOT check "A-values may exceed ..." unless you are sure about this. After pressing OK (twice) the rotation axis functionality will be available in DeskProto.
I cannot change the postprocessor to be used.
In DeskProto it is indeed impossible to directly choose which postprocessor to use for a certain project. Selecting a postprocessor is a two-step process: first you have to edit a machine-definition (Options menu) to connect the postprocessor to a machine, then you have to select that machine (Parameters menu).
What in fact is a postprocessor ?
The postprocessor is a part of the software that translates the resulting NC program file to the correct format that is needed for the selected machine. It is in fact the same as in Windows a printer driver, only in CNC machining the common name is postprocessor. Each printer comes with its own printer driver, and so for every machine an special postprocessor will be needed as well. Note that an ISO standard for NC programs has been defined (G-codes), however in practice all machines that do conform the standard does still show small differences.
We have a five-axis CNC machine: can we use DeskProto ?
Yes, you can, however without using the fourth and fifth axis: A and B remain at angle zero, so the cutter keeps having a verical orientation. DeskProto only generates 3-axis (X, Y, Z) toolpaths.
It is also possible to generate five different three-axis programs, to machine a part from five sides: vertical cutter from above, horizontal cutter from front, right, back and left. For an example see the
Gallery project on "five axis machining".
I let DeskProto send the NC file to my machine, but nothing happens.
In most cases this is due to a misunderstanding about what DeskProto does. DeskProto generates an NC file with toolpath information. DeskProto does NOT control a milling machine: it can for instance not generate step and direction pulses over the parallel port. It also cannot set the machine's workpiece zero point. For this funtionality Control Software is needed. See the article
An Introduction to CAM Software on the
articles page of our website.
DeskProto's option "Send NC program to machine" can be used only for certain machines that function without Control software (for instance Roland machines) or have it built in the machine's controller (industrial machines like Fanuc and Heidenhain). Still for the latter is is preferred to use the special communication software that came with the machine, as in most cases that contains error checking on all communication.
PROBLEMS WHEN USING DESKPROTO
My computer screen shows strange behavior (invalid icons on buttons, 'textured' surfaces, etc).
We have heard this problem a few times, related to using other Open-GL based applications. The problem could always be solved by downloading and installing the newest drivers for the graphics card. Do note that the installation of an OpenGL based application possibly can damage/overwrite a driver that did function correctly before.
The graphic windows of DeskProto show strange behavior (missing or repeated lines).
This is an old DeskProto problem, that we could not reproduce nor fix until in Sept 06 we found a PC that showed the error. It should be solved in builds dated Sept 06 or newer.
The problem is related to the Vertical Synchronization of the display, and it may also be solved by switching that Off: Open the Display Properties dialog, tab Settings, button Advanced, tab "Your graphics card". For NVidia GeForce: menu "Performance & Quality Settings", check "Show advanced Settings", Select "Vertical Sync", uncheck "Application controlled" and next select Off.
After running DeskProto in Windows 2000, I get an error message "The memory could not be read".
The full error message is "The instruction at '[address]' referenced memory at '[address]'. The memory could not be read. Click OK to terminate the program." This is a bug in Win 2000: see
support.microsoft.com (Article ID: 262490). Can be solved by installing a free Win 2000 upgrade.
DeskProto refuses to recognize the parallel dongle on my printer port.
The dongle is needed to prevent illegal copies of the DeskProto software. Two types are available: for the parallel port and for a USB port.
The parallel dongle is known to give problems when used with older drivers (DeskProto dated before 2003) on a new PC (say above 2 GHz). This can happen when an existing DeskProto user upgrades his PC to a newer machine. The problem can be solved by downloading a free bugfix version (email us for download instructions). Note that a reboot is needed after installing this bugfix version.
On the DeskProto CD a directory 'dongle' is present, with two programs: ddlook.exe to find the dongle, and setupdrv.exe to (de)install the dongle drivers. For deinstalling use "setupdrv /ufull".
I have inserted my USB dongle before installing DeskProto, and now the dongle is not recognized.
When inserting the dongle, the New-Hardware-Found Wizard starts searching for appropriate drivers. As DeskProto was not yet installed these were not yet present, so perhaps Windows uses incorrect drivers. You can check this in the Control Panel, System, at the Device Manager (for some Windows a Tab, for others a button). The USB dongle is listed as "USB Security Key" under "Software Security Token". After opening the Properties for this device you can check and if needed change the drivers. Do not forget to reboot afterwards.
The rendering on the screen shows black parts in the surface.
Black parts in the rendering indicate that the backside of the surface is visible. Sometimes just for one triangle, sometimes for larger parts or even for the complete geometry. STL files do contain information about which side of the surface is the outside and which is the inside of the object, and obviously normally the inside is completely invisible: it needs not be rendered and/or machined. In some cases this information is incorrect, indicating invisible parts as being on the outside. In DeskProto you can correct this in the Project Parameters dialog (parameter menu): see the help information at that point.
I cannot see any picture on my screen
After loading an STL file the geometry is not drawn on the screen. When I move my mouse it briefly flashes, not more.
Only for Windows Vista users: this is a problem that Vista has with Open GL software. It can be fixed by changing some display settings in Vista, see the description at the end of the
forum page on this subject..
QUESTIONS ON HOW TO USE DESKPROTO
I have chosen a different machine/cutter, however the resulting NC program file does not change.
In the past we have seen some users that tried to change the cutter or machine using the DeskProto Options menu. In that case nothing will change indeed, as the Options menu is only meant to change the machine- and cutter-definitions. To indicate which of the machines/cutters must be applied, you have to use the Parameters menu. For the Machine the Part Parameters dialog, for the cutter the Operation Parameters dialog.
I rotated the geometry, however the toolpaths appear to be for the original rotation.
Do note that DeskProto includes two different ways to rotate your geometry. One is for viewing only (mouse rotation, thumb-wheels, etc) which only influences the camera position, not the actual orientation of the geometry in space. The second is for 'real' rotations, and can be found in the Part Parameters. Do note the different behavior of the Orientator (the three axes in the left bottom corner of the screen): it does rotate when rotating the view, it does not rotate when rotating the part.
I cannot influence the datum point (zero position) of my geometry.
We see two possible causes. The first is that you interpret the Orientator (the three axes in the left bottom corner of the screen) as an indication of the datum point. This is not true: it only indicates the direction of the axis system, so it will never move (only rotate).
Secondly you might be confused by DeskProto's automatic translation: as a default DeskProto does translate you part, making the top-front-left corner of the bounding box (the material block) the workpiece zero point. This is OK for most cases, if not you can change the translation settings in the Part Parameters dialog (Translate tab page).
You can see the current position of the Workpiece zero point by checking the option "Orientator on workpiece zero point" in the Subjects in View dialog.
The workpiece zero point is different for operations with different cutters.
In most cases this is not an error but a misunderstanding instead. On the DeskProto screen you see two different black dots, one for each Operation. Each black dot indicates the start of the toolpath, not the workpiece zero point.
You can see the current position of the Workpiece zero point by checking the option "Orientator on workpiece zero point" in the Subjects in View dialog.
Still an error may be present: in some cases the control software performs an extra translation, shifting the zero to the extreme left-front point. For instance the control software PCNC: in the Parameters menu the command Misc... will lead to tab page
Misc. parameters (in German "Sonstiges"). Here for
Zero point in File ("Nullpunkt in Datei") the option
bottom ("links unten") might be selected. This is
not correct: it should be set to
origin of co-ordinates ("Koordinatenursprung").
I need a prototype that needs to be machined from all sides: how can I achieve this ?
As on a 3-axis milling machine the tool comes from one direction only (mostly from above, so from the positive Z-axis), you cannot machine the bottom of the part. Basically you have three options to create the complete model that you need:
1. you can machine two separate parts and attach them later (this is the easiest: see lesson 2 in the
DeskProto Tutorial),
2. you can machine one block of material from two sides (use the Two Sided Milling Wizard, or see lesson 3 in the Tutorial), or
3. you can use a Rotation axis device to rotate the part during machining.
How do I tell the machine where I fixtured the piece of material to be machined ?
This is in fact machine-dependant. Obviously the machine does not know where to start: you will have to tell by setting the workpiece zero point. DeskProto makes that easy by using the left-front-top corner of the material block as zero point. So on most machines you can just move your tool to that position and tell the machine to use that position as workpiece zero point. Please consult your machines manual or your dealer for more help on this subject.
I need both roughing and finishing toolpaths. How to achieve this ?
It is indeed common practice to apply a roughing operation first and then a finishing operation. Roughing means to remove excess material as quickly as possible, so using a large distance between the toolpaths and if possible a large cutter. The finishing operation that follows uses a small toolpath distance for a smooth resulting surface.
In DeskProto this can be done by using two operations for the part (to create a second operation press Add operation or Copy operation in the Part parameters). The first operation is for roughing, the second for finishing: you can use appropriate names for clarity. In the Operation parameters for the Roughing operation check "Use" on the Roughing tab page: now you can use the roughing options Skin and Layer height. See the Help for more information. The Finishing operation will remove the remaining skin of material: small cutting forces for a smooth surface.
When the same cutter has been selected for both operations, the resulting toolpaths will be saved in one NC file, otherwise DeskProto will save two separate files. Unless of course your machine has an Automatic Tool Changer (ATC).
I want to fine-tune the results of the Two Sided Milling Wizard. Is this possible ?
Yes, it is, and in fact we often do so as the wizard's settings are not optimal for every part. The changes that are needed most are:
-
Adding operations, for roughing/finishing. Run the wizard with the settings for the largest cutter (is needed to make your support blocks large enough). Afer finishing the wizard, create the finishing operation for each part, NOT by "Add operation", but instead by "
Copy operation" (in the Part parameters). This is needed to copy all settings that the wizard made in the operation.
-
Changing the cutting depth: when cutting a sphere the cutter does not need to go deeper than halfway down for each side. You can change the depth by editing the Z-min value of each Operations's subsegment.
-
Editing the support blocks, as these are not always put at optimum locations. Note that DeskProto stores these blocks at Part level, so you will have to make the same changes twice: for both parts !
