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South Bend 9A UMD Gears 18DP ? Who Makes them?

owlshop

Plastic
Joined
Jan 17, 2008
Location
asheboro nc
I got a picture from SWELLS that shows 18DP for the change
gears. I checked Boston Gear and no 18DP gears listed ?
Does anyone know who may be making any 18DP gears in 44,56,100
tooth? I'm trying to setup to cut metric 1.5 M thread for a
ER40 collet chuck. There was an artical in Machinist workshop
feb./mar 2015. Tells what gears he used but does't say what the
DO is on the gears. Thank You for any words of wisdom.
OWLSHOP !
 
no one in the US is making them as off the shelf gears, although many outfits will make them, very expensive though.

there are many alternatives.

I suggest you retitle this thread- "M1.5 thread on 9A" or something like that,so it will catch the attention of a particular member.:)
 
I had forgotten that there were actually three different Pitches used throughout the years on 9's. We make the Twin Gears upgrade kit, and those are 20DP, but some of the 9's used 18DP, some used 16DP, and some still came with 20DP, as well. If MebFab doesn't have the ones you need, we have made them for others in the past and have the 18DP Hobs to make them still. Time for more coffee...
 
no one in the US is making them as off the shelf gears, although many outfits will make them, very expensive though.

there are many alternatives.

I suggest you retitle this thread- "M1.5 thread on 9A" or something like that,so it will catch the attention of a particular member.:)

Hah- I saw it this morning, but did not have time to post.

Please tell us what gears you have on your machine now, and if you have the gearbox (model A).

allan
 
Somehow I knew you would be on it.:)

as just a sanity check,assuming a "9A" workshop, quick change box and standard gearing wouldn't a 26 or 52 tooth stud gear and the box set at 22 or 44 TPI come silly close to M1.5??
 
Somehow I knew you would be on it.:)

as just a sanity check,assuming a "9A" workshop, quick change box and standard gearing wouldn't a 26 or 52 tooth stud gear and the box set at 22 or 44 TPI come silly close to M1.5??

SB 9" CL344ZD 3 1/2' #49004nkr9
QC is chart #1
on the lead screw it has a 56 tooth gear with outer 40 tooth
idler is an 80 tooth.forgot to check stub gear.
 
SB 9" CL344ZD 3 1/2' #49004nkr9
QC is chart #1
on the lead screw it has a 56 tooth gear with outer 40 tooth
idler is an 80 tooth.forgot to check stub gear.

They are 20DP gears (20degree? 14 1/2degree?)I placed a gear on the print in
the Boston gear book but I can't tell! I asume 20 degree. OWLSHOP
 
Ok, you have lots of options: if you think you might want some other pitches later, I recommend getting a couple gears. Per this post I made years ago: Cutting a 2 mm pitch on an imperial lathe - Page 2 which I will paraphrase here:

You can buy a 54 and an 80 tooth gear from the normal 9B/9C set. There are almost always some of these on ebay. If you remove the current 20 and 56 tooth gears from the end of the lathe, and replace with 54 and 80 respectively, you will turn the gearbox at 1.89 times its normal speed. This will make your 8tpi leadscrew act like it is 4.233 tpi. This happens to be 6.00075 mm, which is 6mm with 0.0125% error.

Now, your gearbox can be used to cut 11 metric pitches.

mmpt gearbox
0.25 192
0.30 160
0.50 96
0.60 80
0.75 64
1.00 48
1.50 32
2.00 24
3.00 16
4.00 12
6.00 8


If you are sure that you only want 1.5mm, I'd suggest just cutting 20tpi (1.27mm, 1.6% error), it's close enough for the short engagement of a collet nut. If that error spooks you, another option is to replace the 20 tooth stud gear with a 26 (as suggested by Chad), and you'll get 3 metric pitches with .06% error:

mmpt gearbox
44 0.75
22 1.50
11 3.00

Hope this helps
allan
 
Oh, and your gears are not 20DP, unless someone swapped them. They should be 18DP, 3/8 face width, 9/16th bore, 14.5PA. Give us an OD and a tooth count of one of them, just to be sure.

allan
 
Oh, and your gears are not 20DP, unless someone swapped them. They should be 18DP, 3/8 face width, 9/16th bore, 14.5PA. Give us an OD and a tooth count of one of them, just to be sure.

allan

Thank You All for the information!!!!
40 tooth gear od.2.330 off the lead screw. OWLSHOP
 
there is a MAJOR terminology disconnect going on....can't type now...fill him in guys!!

Owl shop- look closely at this- it is the standard gear train- note that there are 20DP AND 18DP gears....you are only concerned with the 18DP ones.


http://www.wswells.com/data/howto/paula_stephens/9_10K_geartrain.jpg

I understood that we were talking about different gears. I was refering to the tandum gears on the lead screw/QCGB. OWLSHOP
Again THANK YOU TO ALL FOR THE INFORMATION B I G H E L P!!!!!!
 








 
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