TPI Feeds X-Feeds: Generalized Excel file for your Lathe

[B2]

Hi @verbotenwhisky

I am moving our interaction to this thread. Since it deals with the TPI generating Excel Workbook, it is more appropriate here.

I finally had a chance to look at the spread sheet, you were correct, it is a bit off due to the settings on my lathe, I am trying to calculate some of the gearing but unfortunately

I understand busy. What discrepancy were you finding? Feed rates or threading? So much time has passed and because I was also helping others I have gotten a little confused about what I posted for you about your PM1230. I do recall that I made some other changes and then posted the PM1230 sheet, (not the PM1230T) in with the version that I posted for Larry$, the PM1440HD sheet. The Workbook name you should be using is:
"TPI Many Lathes add PM1236-draft and PM1440HD-draft N203_1048 Zipped.zip" which was posted at

I edited the PM1440HD-draft worksheet slightly above and deleted the attachment above.... and I am attaching the corrected version here. Still a draft. No changes to the PM1236 sheet.

In this version, I think I figured out all of your gear box ratios in the PM1230 .... with the concern about the knob#1 values being taken from the manuals Feed rates. See the attached table. When you have time if you check the first row for accuracy we will know for sure if the gear box ratios are correct or not. However, this says nothing about the accuracy of the feed rates.

By the way, there are 5 knob settings that all yield 12TPI. Maybe you can just scratch a thread and compare the one from A-1 to B-2 to see if they are the same.


Dave L.

 

[Provincial]

Dave, I made some progress on finding the gears for my Metal Max 1340. I posted on a thread here for Grizzly 12x36 lathes and a fellow responded with measurements for the 32-tooth gear Grizzly sells for their G9249 lathe. I'll have to enlarge the bore by 1 MM and deepen the keyway. Otherwise, it is a good fit.

I also have located a source in Florida for a the hubless 35-tooth gear that goes on the tumbler. It only will need the bore enlarged from 10 MM to 16 MM and a 5 MM keyway added. There are a lot of things to do before I get that far. I'll let you know how it works out.

I have done a spreadsheet on the Metric feeds that will be available. It is sorted by pitch, with columns for the four gear combinations and each lever position. Some pitches can be cut by more than one combination of gears and lever positions.

I really appreciate the help on this, from you and others. I will post my experience with this project in the Jet section, since that is where it will reach the most people that can use the information.

 

[B2]

Hi @Provincial
It is great to hear that things are working out for you. I'm glad to have been of some help.

The existing macros allowed you to search by any column or set of columns. Hope that helped.

I have also made a macro to enable searching the mmPerThread column. It was not hard to do as I just modified the Search for the TPI macro. I also made some other fixes for bugs and documented the results. I have a couple of other things to add/change. Maybe I can make one which will search a specified column rather than a fixed column, that way one can delete the unwanted columns and then still do a search. I would also like to have a macro which would delete the redundant lines, but that is harder. When this is finished and I hear back from @verbotenwhisky about the PM1236 sheet I will post the revised workbook here.

It is good that you post in the JET section. Maybe you can reference this thread so that others can also find the workbook?

By the way, I think it is a real pain that the gears on your lathe are not interchangeable. Would it be possible to just make them all have the larger diameter hole and make a ring to fit inside the gear when you wanted to use it at the smaller shaft? The ring could be discontinuous to allow the key to reach the key way. A key could be made with different thicknesses at the shaft and the gear sides if necessary. Just a thought!

I look forward to hearing how you come out.

Dave L.

 

[Provincial]

Hi @Provincial
It is great to hear that things are working out for you. I'm glad to have been of some help.

The existing macros allowed you to search by any column or set of columns. Hope that helped.

I have also made a macro to enable searching the mmPerThread column. It was not hard to do as I just modified the Search for the TPI macro. I also made some other fixes for bugs and documented the results. I have a couple of other things to add/change. Maybe I can make one which will search a specified column rather than a fixed column, that way one can delete the unwanted columns and then still do a search. I would also like to have a macro which would delete the redundant lines, but that is harder. When this is finished and I hear back from @verbotenwhisky about the PM1236 sheet I will post the revised workbook here.

It is good that you post in the JET section. Maybe you can reference this thread so that others can also find the workbook?

By the way, I think it is a real pain that the gears on your lathe are not interchangeable. Would it be possible to just make them all have the larger diameter hole and make a ring to fit inside the gear when you wanted to use it at the smaller shaft? The ring could be discontinuous to allow the key to reach the key way. A key could be made with different thicknesses at the shaft and the gear sides if necessary. Just a thought!

I look forward to hearing how you come out.

Dave L.

Dave,
That would be nice, but in my case, the 32-tooth gear is only useful on the QCGB end of the gear train, and the 35-tooth gear is only useful on the upper end. Gears are available both with and without hubs, and if the Grizzly gear is obsoleted in the future, one can be made from a stock 32-tooth "blank" with little more effort than modifying the Grizzly one. The "blanks" are about $5.00 cheaper, so it doesn't break the bank.

I needed an excuse to get my little AMMCO shaper running anyway. Cutting internal keyways is a good job for it.

I'll be sure to link this thread in the Jet section post. I'll also post something in the Asian machine section, since so many of the imports are similar, and people are always looking for parts and modification information.

 

[B2]

Hi,
@Larry$ @verbotenwhisky

Guys,
Please let me know. ( I have gotten a little confused about the status of the spread sheets that I supplied to you.)

I think that @Larry$ was content with the "PM1440HD" sheet, but mentioned some lingering question?

I think I was waiting for @verbotenwhisky to let me know if the Knob #1 position agreed with what he physically observed on the "PM1236". (not PM1236T).

The Workbook name you should be using is:
"TPI Many Lathes add PM1236-draft and PM1440HD-draft N203_1048 Zipped.zip" which was posted at

You will note that the file name has changed to reflect the new, N203_1048, date/time. "TPI Many Lathes add PM1236-draft and PM1440HD-draft N203_1048 Zipped.zip"

Please let me know. I would like to finish up these sheets and post the final version.

By the way, I have almost completed a new macro which scans the AllTPI sheet of possible positions for gear knobs and external gears and removes the duplicates and redundancies. I think that @Larry$ and @Provincial felt the sheet was too long to print out. This would make the table a little smaller and easier to use. I am also writing code to automatically scan the AllTPI sheet and find and extract ALL the " industry standard" UNF & UNC TPI values. I assume(?) these might be useful to folks as it is to me.

Dave L.

 

[Larry$]

I assume(?) these might be useful to folks as it is to me.

For sure. The raw spread sheet of all possible combinations is pretty overwhelming.

 

[B2]

For sure. The raw

So, unless I hear otherwise I will assume you are ok with the PM1440HD spread sheet and will take it out of the draft category.

If you will tell me exactly which external gears you wish to include for the upper (at the spindle) and lower (at the gear box) gear positions I will run the workbook and generate a AllTPI sheet and then reduced by removing the redundancies AllTPI . (I cannot recall exactly which gears you have where.) Then you can tell me if I have made mistakes in removing things etc. Feed back which I am in need of before I will know if the new macros work properly.

I will also prepare a sheet which shows which of the Common UNF & UNC TPI you can make with which gears. I could also do the same for the standard metric pitches. This would be a lot smaller than the raw sheet, but would not provide for pitches which are approximations.

I think the UNF & UNC TPI are: 80, 72, 64, 56, 48, 44, 40, 36, 32, 28, 24, 20, 18, 16, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4.5, 4

I think the standard course and fine metric pitches are: 0.2, 0.25, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7, 0.75, 0.8, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6

Dave L.

 

[verbotenwhisky]

Hi,
@Larry$ @verbotenwhisky

Guys,
Please let me know. ( I have gotten a little confused about the status of the spread sheets that I supplied to you.)

I think that @Larry$ was content with the "PM1440HD" sheet, but mentioned some lingering question?

I think I was waiting for @verbotenwhisky to let me know if the Knob #1 position agreed with what he physically observed on the "PM1236". (not PM1236T).



Please let me know. I would like to finish up these sheets and post the final version.

By the way, I have almost completed a new macro which scans the AllTPI sheet of possible positions for gear knobs and external gears and removes the duplicates and redundancies. I think that @Larry$ and @Provincial felt the sheet was too long to print out. This would make the table a little smaller and easier to use. I am also writing code to automatically scan the AllTPI sheet and find and extract ALL the " industry standard" UNF & UNC TPI values. I assume(?) these might be useful to folks as it is to me.

Dave L.

Sorry for the delay, I will try to get on this next week, I should be home then.

 

[BStrickland]

Thanks for these charts!

 

[B2]

Sorry for the delay, I will try to get on this next week, I should be home then.

I understand. I hat to keep asking. On the other hand do you know anyone else with a PM1236 (not a PM1236T) that could run this test? It should not take very long to scratch a couple of threads, but is pretty hard to do when you are not near the lathe!

By the way, there are 5 knob settings that all yield 12TPI. Maybe you can just scratch a thread and compare the one from A-1 to B-2 to see if they are the same.