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Best way to generate gears in Alibre Design Expert ?

Discussion in 'Using Alibre Design' started by MikeD, Aug 17, 2008.

  1. RCH_Projects

    RCH_Projects Alibre Super User

    I see.

    The spacing can be checked or determined with the "TrimOffTeeth..." or "PitchCircleFace..." features (Edit Here, Edit in Seperate Window or using part configurations, within the assembly).

    Hey, did you know that if you use "Tangent outside" on opposing tooth surfaces ALIBRE ACTUALLY accurately reproduces the action of gears for the duration of actual tooth surface contact.

    What will ALIBRE think of next? :mrgreen:
  2. RCH_Projects

    RCH_Projects Alibre Super User

    I need a small expansion of the SpurGear_MAKER calculations. As needed I will probably first make gears from a 3D print service (close enough for prototyping!?).
    As I see it, I should have a minimal amount of play / backlash. This is such a great (and Alibre friendly) template I would like this addition but I am no Engineer.

    If anyone can post their own MAKER Mod or just the formula changes I will incorporate the change into my personal use modified version.

    Attached Files:

  3. RCH_Projects

    RCH_Projects Alibre Super User

    I needed simple internal tooth gears for planetary gears so I personalized SpurGear_MAKER further. Everything else out there cost a fortune, has to be exported, imported, copied, pasted and/or otherwise involves a lot of time and processing.
    It seems sufficient for my current needs.

    A little explanation of my preferences might help.

    B C - For a part like this, all Configurations unlocked allows changes such as tooth count to propagate to all configurations. This allows selecting a configuration in an assembly without opening the part to edit.

    B - The simple spur gear with variants on the display properties.

    C - A simple "internal" tooth variant.

    E - The "Equation Editor" is still flakey enough that I avoid direct access as much as I can (it is still SBD). I create a set of planes above the part to update and store what variables I can. It is important to note that in "design explorer" although the name of features are incorrectly grayed out, they are still active and editable as the icons colorization reflects (much as bold and highlighted features are still often in error).

    F - These are extra values only used in generating an internal tooth gear.

    G - This feature set is active when a simple spur gear is selected in configurations.
    If you select a "B, C or D" configuration in section B Configurations, you never need to suppress or unsuppress these features directly (and doing so in this section will mess up configurations).

    H - This feature set is active when a simple internal tooth gear is selected in configurations.
    If you select a "B, C or D" configuration in section C Configurations, you never need to suppress or unsuppress these features directly (and doing so in this section will mess up configurations).

    I - Here you can suppress or unsuppress the feature directly for a "tooth aligned" or "half tooth aligned" key slot. The selection here will reflect in all configurations. I could have moved this section just below section Ffor clarity.

    J - Again using "planes" I created a section where you can enter the "radius" from another gear in "Enter 2nd Gear Pitch Radius" and read the result in "Calc 1 and 2 Gears Offset" to determine, or just keep a record of, the axis offsets with another gear. This is a rare occasion, where to read the result, you will need to "edit" "Calc 1 and 2 Gears Offset" and select the "f(x), Equation Editor" to see the answer.

    The file is a bit large. But deleting redundant sections, for a new part as an example, actually "increases" the size from 2.59 MB to 8.4 MB :roll: . If you want a smaller part file without configurations or history you can export as a STEP(214) and import to bring it under 1 MB.

    Attached Files:

  4. RCH_Projects

    RCH_Projects Alibre Super User

    Having a planetary gear assembly I will post it up for "educational" example purposes with explanation.

    B - As loaded, you can drag the gears a short distance and observe the gears motion before Alibre loses the relationships. Then you can undo; or close without saving and re-open.

    A - Is constraints for the initial alignment of gears.

    If you have "Motion 1.x"; you can suppress the constraints in section B; go into motion and by adding and calibrating rotary actuators to each gear; create rotation but not actual simulation.

    Pitch circumference appears to be off in about the 5-6th decimal places. For a build I would inspect and correct manually if needed.

    Attached Files:

  5. RCH_Projects

    RCH_Projects Alibre Super User


    Attached Files:

  6. protarawizard

    protarawizard Member

    You have certainly taken this to another level :)

    I was intrigued and so tinkered some to try to work out how editing the Plane-like objects in the tree propogated to the EquationEditor ... so gotta ask.

    How did you manage to link the likes of EquationEditor "InputPressureAngle" to (what looks like to me to be) an inserted Plane object in the project tree? The linked Plane object has name "Pressure Angle".

  7. RCH_Projects

    RCH_Projects Alibre Super User

    Hi Norman,


    It's great to have a real nice platform (SpurGear_Maker) that handles engineering issues that slow me down, to build on.

    Tonight I will do a new topic regarding your question titled something like "Banish the Equation Editor".

    Deepest respects,

  8. MKR

    MKR Member

    Hi Oldbelt

    Just what i needed 8)
    Thank you for sharing!

  9. fpirz

    fpirz Member

    having a problem generating mating gears

    I'm trying to use the SpurGear_MAKER RCH mod 1.0.AD_PRT to generate a pair of mating gears.
    for the internal gear, I've set module to .278 and # of teeth to 48 which gives me the desired internal
    pitch radius of 6.672 in.
    for the external gear, i've set the # of teeth to 12 and then "activated" the simple spur gear.
    examining the sketch for the gear I get a pitch radius of 1.668 as expected.
    I've used the same module and was expecting a set of gears that would mate.
    I made a circular backing plate on which the internal gear is constrained to be aligned
    with a hole 6.672 - 1.668 = 5.004 from the center as the shaft location of the spur gear.

    what am I doing wrong?

    Frank Pirz

    Attached Files:

  10. drof34

    drof34 Member

    I read in a book that the teeth of an external gear point away from the center while they point to the center on an internal gear.
    It may just be my opinion but I believe the tooth FORM of an internal gear should look more like the tooth SPACE on the matching external gear.

  11. fpirz

    fpirz Member

    thanks for the comment.
    the way this software works (for the internal gear) is to build a tooth for an external gear
    and then reflect it around the pitch diameter..
    if you download the RCH spur gear example you can examine the sketch profile and
    see both the internal and external profiles..

    my concern is that they don't mesh, even they have the same module and are located
    on the correct (i believe anyway) pitch diameters.. :-(

    Frank Pirz
  12. fpirz

    fpirz Member

    Modifying Internal Gears to reduce Interference

    Jim's comment got me to thinking about the interference question I posted. So I went in search of some commercial gear designs to see
    what I could find out. I located the QTC website
    where you can download .stp models of the KHK gears they rep. BTW the KHK website
    http://www.khkgears.co.jp/en/gear_techn ... _info.html
    has some easy to read guides on gear nomenclature and design.
    I downloaded models for si1-60 60 tooth internal gear and kps 1-15 external gear. note the interference, as well as the footnote on QTC's
    internal gear web page wrt interference.

    So I went back to the two gears I had designed and made changes in the designs. I'm running AD Personal Edition so I can't see the equations
    [or I'm not looking in the right place] but I made the following changes to the internal gear generated by SpurGear_MAKER RCH mod 1.0.AD_PRT
    with the settings # teeth - 48 and module .278

    and to the external gear generated by ParametricHelicalGearwheelTemplate.AD_PRT with the settings
    CONTROL_HeliAngle 0, CONTROL_Module 7.06 mm, CONTROL_Numb_teeths 12

    While I have yet to cut the gears, they now look like they should mate without interference

    Attached Files:

  13. fpirz

    fpirz Member

    Re: pix of mating gears

    Here is a pix of the gears (forum is limited to 3 so I had to put it here)

    Attached Files:

  14. Kunkmiester

    Kunkmiester New Member

    With the thread necromancy babbling...

    Looking this up, this seems to be simpler than some of the other stuff I've found on gear making. Will it be straight compatible with the 2017 version though?

    I'm looking at doing some prototyping with 3D printing, and later machining parts off the same models, so I'm only worried about them being compatible with each other.
    Alridley likes this.
  15. albie0803

    albie0803 Alibre Super User

    I can provide you DXF's of desired gears if you like. This is the 12-48 set from 3 posts up.

  16. MKR

    MKR Member

    If everything else fail, FreeCAD have a build-in involute gear designer.


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