import X,Y data table from Excel

[J-J]

Good morning,
I tried the import point function but nothing happens when I select the xls file in the dialog box.
I wanted to import a gear tooth profile calculated in excel.
Thanks for any hint. (win7-64)

[Husky]

Hi J-J,

Thanks for any hint. (win7-64)

You are more looking to figure out how the excel import works or do you just in need of a gear in QCAD?
I can't help you with the Excel file but if you just need a dxf gear what you can use in QCad - I have a simple gear program for a task like that ....

[J-J]

Hi Husky,
Ok, I'm always willing to learn other techniques, I'll be happy to try your program. I guess one can do many smart things with QCAD scripting, but I have no experience with it.
Thanks

[Husky]

Hi,
Just to be clear - I'm not trying to sell a program (it is not mine - just a program what I use) but I'm offering to design the gear for you with this program and send you the dxf

You are looking for something like this?

J-J gear.dxf

(97.69 KiB) Downloaded 32 times

PM is OK!

[J-J]

Hi,
In fact, I need to cut 3 wheels that will match the worm screw on my lathe. The way I figured it initially was to calculate the involute curve by small increments and then feed the x,y points in QCAD. So it is not a standard situation in which you'd have a given ratio and center distance...The pitch of the screw is 3mm and the 3 wheels are 28, 30 and 32 tooth gears.
here's my attempt:

pignons Z28-30-32-&assy.dxf

(198.29 KiB) Downloaded 27 times

[Husky]

First try - close enough?

Tooth spacing (Center tooth along Pitch diameter): 3 mm
Contact angle (pressure angle): 20°
Addendum: 0.250 mm
Slop: 0

Check it out and give me a hint what has to be changed.

pignons Z28-30-32-&assy.dxf

(341.04 KiB) Downloaded 29 times

[J-J]

Hi Husky,
Thanks for your efforts. Quite close indeed. Major difference is mostly on tooth height and depth, probably because I used different formulas for OD and foot diameter. The profile you propose is certainly stronger, but no power is transmitted in this case...

[Husky]

Hi J-J,

Ok, last try

pignons Z28-30-32-&assy-new.dxf

(792.16 KiB) Downloaded 29 times

[J-J]

Hi Husky,
This looks perfect to me, thank you very much for your time.

[Husky]

You are welcome!