Re: STL files for metric change gears


Roger Bickers
 

Excuse me Allan and Doug, do either of you know where i can get a "Series O" apron for an "old wide 9" like Doug has?   Im looking for the gear in the saddle as well. Roger


On Wed, Nov 21, 2018 at 7:59 AM, m. allan noah
<kitno455@...> wrote:
I think the gears are 18DP, 14.5PA, .5" face width. But, you should
measure to be sure.

Assuming you have the gearbox that covers the range of 2 to 112 TPI,
you'll have a 48 tooth gear on the stud.  Replacing that gear with a
34 tooth gear will turn the gearbox 0.7083 times its normal speed.
That will make every pitch that much finer, and a few of them will
line up well with a metric pitch. A list below:

QCGB  MMPT    %ERR
3.0  5.9972  0.04630
4.5  3.9981  0.04630
6.0  2.9986  0.04630
9.0  1.9991  0.04630
12.0  1.4993  0.04630
18.0  0.9995  0.04630
20.0  0.8996  0.04630
24.0  0.7497  0.04630
36.0  0.4998  0.04630
40.0  0.4498  0.04630

A couple common fastener pitches are not in that list, so we'll need
to make another gear (33 teeth) to pick them up. The % error is
higher, but still good enough for fastener use:

QCGB  MMPT    %ERR
3.5  4.9893  0.21429
7.0  2.4946  0.21429
10.0  1.7462  0.21429
14.0  1.2473  0.21429

Other, less common threads will need yet more gears.

allan


On Mon, Nov 19, 2018 at 11:04 AM dar1095 via Groups.Io
<dar1095=yahoo.com@groups.io> wrote:
>
> Allan
>  A list would be great. If I can get the specs for the 34 tooth gear I can make a STL file to print it. I will make the STL file and your list available to the group.
>      Thanks
>          Doug
>
> --------------------------------------------
> On Mon, 11/19/18, m. allan noah <kitno455@...> wrote:
>
>  Subject: Re: [SouthBendLathe] STL files for metric change gears
>  To: SouthBendLathe@groups.io
>  Date: Monday, November 19, 2018, 9:13 AM
>
>  It is generally the same as the
>  10L single tumbler, but they both
>  suffer
>  from lack of a slotted banjo. There is no place to put
>  the
>  traditional transposing gearset. A
>  decent alternative is to replace
>  your stud
>  gear with a 34 tooth gear. That will let you cut a number
>  of
>  very close approximations of metric
>  threads. I can work up a list if
>  you
>  want.
>
>  allan
>  On Mon, Nov 19, 2018 at 8:46 AM dar1095 via
>  Groups.Io
>  <dar1095=yahoo.com@groups.io>
>  wrote:
>  >
>  > Allan
>  >  I have a single tumbler gear box. I
>  thought it might be the same as a 10 inch single tumbler.
>  >    Doug
>  >
>  --------------------------------------------
>  > On Mon, 11/19/18, m. allan noah <kitno455@...>
>  wrote:
>  >
>  >  Subject:
>  Re: [SouthBendLathe] STL files for metric change gears
>  >  To: SouthBendLathe@groups.io
>  >  Date: Monday, November 19, 2018, 7:56
>  AM
>  >
>  >  'wide bed
>  9A' is somewhat ambiguous. Do you
>  >
>  have a single tumbler
>  >  gearbox, or
>  loose change gears? The
>  >  former uses
>  18DP gears and is
>  >  harder to convert
>  for metric. The
>  >  latter uses 16DP
>  gears, and is
>  >  easier, perhaps with
>  the gears you
>  >  already have.
>  >
>  >  allan
>  >  On Mon, Nov 19, 2018 at 7:37 AM
>  dar1095
>  >  via Groups.Io
>  >  <dar1095=yahoo.com@groups.io>
>  >  wrote:
>  >  >
>  >  > Group
>  >  >
>  I am looking for STL files
>  >  for
>  printing metric change gears. I have a early wide bed 9A
>  >  lathe. I do not have a printer but I can
>  print some gears at
>  >  work when no one
>  is looking.
>  >  >      Thanks
>  >  >
>  >  Doug
>  >  >
>  >
>  >
>  >
>  >  --
>  >  "well, I
>  stand up next to a mountain-
>  >  and I
>  chop it down with the edge
>  >  of my
>  hand"
>  >
>  >
>  >
>  >
>  >
>  >
>  >
>
>
>  --
>  "well, I stand up next
>  to a mountain- and I chop it down with the edge
>  of my hand"
>
>
>
>
>
>
>


--
"well, I stand up next to a mountain- and I chop it down with the edge
of my hand"



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