Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: HimyKabibble on October 27, 2009, 11:07:34 AM
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Below is a spreadsheet I've created to help with drive design. It supports both steppers and servos, allowing you to enter component parameters (motor voltage/current/inductance, drive reduction components, screw type, etc.) and it calculates such things as optimum supply voltage for steppers, overall reduction ratio, step size, steps/unit, axis thrust, required step rates, etc.
At this point, I can't guarantee it's 100% complete or correct, but it is to the best of my knowledge. If you find any problems, or see anything that should be added, please let me know.
Regards,
Ray L.
Updated spreadsheet 10/27/2009 12:15 PST to correct errors in metric conversion, and thrust calculations.
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Hi Ray,
This is cool !
When I select Cont. Torque I get this pop-up for Inductance.
Is this right ?
Russ
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BTW - The user should ONLY enter values into the green cells. All others are doing calculations, and should not be modified.
Regards,
Ray L.
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Hi Ray,
This is cool !
When I select Cont. Torque I get this pop-up for Inductance.
Is this right ?
Russ
Russ,
Nope, that's a oopsie. Now fixed. Just download the file again.
Thanks!
Regards,
Ray L.
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Nice job Ray,
Should come in handy for a lot of users.
There are programs out there that go into great depth for evaluating a drive system.
But yours is additive to them since you get some basic values for intial motor tuning.
RICH
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Ray,
This certainly will come in handy for many.
I think we need to put it in the Members Docs. when all is done, maybe even make it a "sticky".
It answers many questions that arise when setting up a rig and will be great to direct users to.
Could also be a good idea to inset a link to it in the Mach set-up pdf.
I'm sure it will get many referrals.
NICE work.
Russ
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I've revised the spreadsheet to fix a couple of errors:
Thrust calculations were not correct.
Metric conversions not always correct.
Re-download to get the corrected spreadsheet.
Regards,
Ray L.
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Hi Ray,
very nice spreadsheet you have made :)
However there seems to be some errors still. Motor power at target feedrate both stepper and servo and thrust at target feedrate for servo. I'm working on correcting the formulas even if I'm not familiar with the new versions of excel.
Edit: This is for the metric version. I havent checked the Inch version.
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Hi Ray,
very nice spreadsheet you have made :)
However there seems to be some errors still. Motor power at target feedrate both stepper and servo and thrust at target feedrate for servo. I'm working on correcting the formulas even if I'm not familiar with the new versions of excel.
Edit: This is for the metric version. I havent checked the Inch version.
You're right! I fixed the max calculations, but not the target. I'll get that fixed shortly.
Thanks!
Regards,
Ray L.
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B30*B49*B22*6140/B27
This is the formula for the thrust at target feedrate for the stepper at metric mode.
Edit: The 6140 constant is replacing PI and pitch conversion.
More edit: I think this works for both metric and inch: B30*B22*B49*6,14/B29
Yet more edit: It certainly does not work for both!
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Here is the formula for the thrust at target feedrate for both metric and inch: IF(B6="Stepper";IF(B3="Metric";B49*B30*B22*6280/B27;B49*B30*B22*0,392/B27);"")
Edit: I think...... ;)
More edit: Changed the constant "6140" to "6280"
Yet more edit: Changed the constant "0,384" to "0,392"
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Ray, a couple questions, I'm not very familiar with excel, is it possible to make the "white" cells read only? It is easy to accidentally remove the formulas in those cells. Of course, if not saved, you can reopen the document to recover the lost formulas but it would be better if you couldn't erase the cells in the first place.
I like the "drop down" list. How do you make one? I couldn't find this function.
Steinar
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Ray, a couple questions, I'm not very familiar with excel, is it possible to make the "white" cells read only? It is easy to accidentally remove the formulas in those cells. Of course, if not saved, you can reopen the document to recover the lost formulas but it would be better if you couldn't erase the cells in the first place.
I like the "drop down" list. How do you make one? I couldn't find this function.
Steinar
Steinar,
I don't know of any way to protect individual cells, but I'm no expert either.
To create a drop-down, create the list of values you want to allow (they're at the bottom of column A in my spreadsheet), select the cell you want to have the drop-down, then select Data->Validation, and in the drop-down in the dialog that pops up, select "List", then put in the range of cells containing the allowable values.
Regards,
Ray L.
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Ahh, many thanks Ray :)
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Ray, a couple questions, I'm not very familiar with excel, is it possible to make the "white" cells read only?
Steiner, unlock the green cells and then protect the sheet as follows:
Select a green cell(s), right click, select Format Cells.. > Protection and remove the check from the “Locked” box.
Repeat for all green cells.
Go to Tools > Protection > Protect Sheet..
Check the “Protect worksheet and contents of locked cells”.
It’s OK to leave the password entry blank.
In the bottom window uncheck everything except “Select unlocked cells”.
Now excel will only let you select the green cells.
Al
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Ray,
have you updated the spreadsheet yet?