What is the size of the thread of the Crank shaft of the LA-15?
Scott(needs as much help as I can get) Riese
Scott(needs as much help as I can get) Riese
Scott Riese
LA-15 help
Stuka Stunt Main Forum · 38 of 38 known posts recovered
>What is the size of the thread of the Crank shaft of the
>LA-15?
>
>Scott(needs as much help as I can get) Riese
7/32-32
Dennis
>LA-15?
>
>Scott(needs as much help as I can get) Riese
7/32-32
Dennis
Scott and Dennis,
I expected it would be a metric standard size!
The guys at the local ACE Hdwre are getting used to me wandering in with some wierd engine and testing the loose metric nuts and bolts stuff.
Seems most of the metrics in the major chain hardware stores are better grade than the US standard stuff, unless they also carry higher graded pieces.
I expected it would be a metric standard size!
The guys at the local ACE Hdwre are getting used to me wandering in with some wierd engine and testing the loose metric nuts and bolts stuff.
Seems most of the metrics in the major chain hardware stores are better grade than the US standard stuff, unless they also carry higher graded pieces.
\BEST\LOU
>What is the size of the thread of the Crank shaft of the
>LA-15?
>
>Scott(needs as much help as I can get) Riese
5mm
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCT52&P=Z
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBY15&P=
Terry
http://www.dustersrcclub.com/
>LA-15?
>
>Scott(needs as much help as I can get) Riese
5mm
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCT52&P=Z
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBY15&P=
Terry
http://www.dustersrcclub.com/
Ron B.
F4Fguy
I think you'll find it's a #12-32. Hold on to your hat when you try to buy a tap! The best price I could find was $19.00+ at McMaster-Carr. Most places around here say, "you want a what"??!!
Ron B.
RON....I just went to the Hardware Shoppe that I go to. They say WE have every thing! They had the tap.......$63.97 SAY WHAT?? 
Scott Riese
>RON....I just went to the Hardware Shoppe that I go to. They
>say WE have every thing! They had the tap.......$63.97 SAY
>WHAT??
Did you tell them that you just needed one tap and not the whole set?
If it is 5mm, that's not that un common, but is it is a fine thread, that is what is making it difficult.
Good luck and have fun!
Dan McEntee
>say WE have every thing! They had the tap.......$63.97 SAY
>WHAT??
Did you tell them that you just needed one tap and not the whole set?
If it is 5mm, that's not that un common, but is it is a fine thread, that is what is making it difficult.
Good luck and have fun!
Dan McEntee
Type at you later
As Ron says it is indeed a 12-32 UNEF thread. The listed major diameter is .216 and the basic minor diameter is .1777.
It is of course a standard thread however the taps are considered "specials" because of very low production. My catalogs show a low of $23.00 and a high of $72.00.
Don't break many!
It is of course a standard thread however the taps are considered "specials" because of very low production. My catalogs show a low of $23.00 and a high of $72.00.
Don't break many!
Randy C
Brett Buck · Feb 13, 2007 03:59 PM
#8 source>
>Ron B.
>F4Fguy
>
>I think you'll find it's a #12-32.
Oy Vey! Why in the world would they do a silly thing like that, when a perfectly good not-oddball metric size would do?
Brett
>Ron B.
>F4Fguy
>
>I think you'll find it's a #12-32.
Oy Vey! Why in the world would they do a silly thing like that, when a perfectly good not-oddball metric size would do?
Brett
Brett,
Actually I think most non-technical Americans consider any metric size "oddball". This was likely a "marketing decision". After all all of their other LA engines have American threads on the shafts.
10-32 was likely not considered strong enough and obviously .250-28 was too big for the shaft. Viola 12-32.
Actually I think most non-technical Americans consider any metric size "oddball". This was likely a "marketing decision". After all all of their other LA engines have American threads on the shafts.
10-32 was likely not considered strong enough and obviously .250-28 was too big for the shaft. Viola 12-32.
Randy C
Brett Buck · Feb 13, 2007 05:47 PM
#12 source>Brett,
>Actually I think most non-technical Americans consider any
>metric size "oddball". This was likely a
>"marketing decision". After all all of their other
>LA engines have American threads on the shafts.
>10-32 was likely not considered strong enough and obviously
>.250-28 was too big for the shaft. Viola 12-32.
Heh! It's a lot easier to find a standard metric than a 12-32!
Brett
>Actually I think most non-technical Americans consider any
>metric size "oddball". This was likely a
>"marketing decision". After all all of their other
>LA engines have American threads on the shafts.
>10-32 was likely not considered strong enough and obviously
>.250-28 was too big for the shaft. Viola 12-32.
Heh! It's a lot easier to find a standard metric than a 12-32!
Brett
Ron B.
F4Fguy
Brett,
I think it's the attempt by O.S. and other Japanese companies to cater to the U.S. market by making the shaft threads compatible with American standards. What obviously was left out of the equation was the fact that the #12 size was originally developed to allow re-tapping a stripped or worn #10, not as a "normally used" size.
You're right, of course, a 5mm x 0.8 would be a more logical choice.
Ron B.
Ron,
I've heard this theory about #12 threads before but in fact Fed-Std-H-28 simply treats #12's as the next logical size consideration in unified threads after the #10.
At Raytheon we actually use a fair number of the things. Weight/strength considerations usually determine design when size/weight gets into the "nitpicking" area as it often does in Missiles.
Cdertainly they are not generally common hardware store items although most good ones carry them.
Were I designing a series of engines like the LA's I doubt that I would make all the shafts American threads except one. That doesn't seem like a logical decision.
Still the shaft probably could have been made to accept a .250 thread without a lot of weight penalty.
I've heard this theory about #12 threads before but in fact Fed-Std-H-28 simply treats #12's as the next logical size consideration in unified threads after the #10.
At Raytheon we actually use a fair number of the things. Weight/strength considerations usually determine design when size/weight gets into the "nitpicking" area as it often does in Missiles.
Cdertainly they are not generally common hardware store items although most good ones carry them.
Were I designing a series of engines like the LA's I doubt that I would make all the shafts American threads except one. That doesn't seem like a logical decision.
Still the shaft probably could have been made to accept a .250 thread without a lot of weight penalty.
Randy C
Deleted out of embarrassment.
Howard Rush
Howard Rush
Tower Hobby's links (posted by Terry) say it's a 5mm thread...but I wonder. I'd check an official OS website for specs. The .15 FP is 7/32-32, that's a fact, and a 12-32 would be really close, but AFAIK, there's a 12-28...and no 12-32. OTOH, we've got some 1/4-100's at work, for some special project, in the dim dark past. Point is, you can get any tap you want, with only two problems: $ and time.
Why don't you "single point" the threads, Scott? I single pointed 1/4-60 internal thread (microphone adapter) at Boeing, and had to make the cutter myself.
Steve
Steve Helmick
Renton, Washington
USA
Why don't you "single point" the threads, Scott? I single pointed 1/4-60 internal thread (microphone adapter) at Boeing, and had to make the cutter myself.
SteveSteve Helmick
Renton, Washington
USA
Howard Rush · Feb 13, 2007 11:45 PM
#15 sourceRight. I used to have one of these taps. I think you used it to make the prop nuts for The Bomber, sportily mounting each on the tap while machining the outside. It must be here somewhere in my crew-chief's kit.
Howard Rush
Howard Rush
Thanks all. I ordered 5mm x.08 and 5mm x.05.
A club member found the 12 x 32 for $2.79 at Brownells firearms
A club member found the 12 x 32 for $2.79 at Brownells firearms
Scott Riese
>Tower Hobby's links (posted by Terry) say it's a 5mm
>thread...but I wonder. I'd check an official OS website for
>specs. The .15 FP is 7/32-32, that's a fact, and a 12-32 would
>be really close, but AFAIK, there's a 12-28...and no 12-32.
>OTOH, we've got some 1/4-100's at work, for some special
>project, in the dim dark past. Point is, you can get any tap
>you want, with only two problems: $ and time.
>
>Why don't you "single point" the threads, Scott? I
>single pointed 1/4-60 internal thread (microphone adapter) at
>Boeing, and had to make the cutter myself. ;@ Steve
>
>Steve Helmick
>Renton, Washington
>USA
Ron B.
F4Fguy
#12-32 isn't just close, that's what it is. It's a standard National thread, #12-32UNEF.
Read replies #4,5,7,and 11.
Ron B.
>thread...but I wonder. I'd check an official OS website for
>specs. The .15 FP is 7/32-32, that's a fact, and a 12-32 would
>be really close, but AFAIK, there's a 12-28...and no 12-32.
>OTOH, we've got some 1/4-100's at work, for some special
>project, in the dim dark past. Point is, you can get any tap
>you want, with only two problems: $ and time.
>
>Why don't you "single point" the threads, Scott? I
>single pointed 1/4-60 internal thread (microphone adapter) at
>Boeing, and had to make the cutter myself. ;@ Steve
>
>Steve Helmick
>Renton, Washington
>USA
Ron B.
F4Fguy
#12-32 isn't just close, that's what it is. It's a standard National thread, #12-32UNEF.
Read replies #4,5,7,and 11.
Ron B.
Scott
Oddly enough the OS instruction sheet says 5mm, and a check with pitch gage on my NIB LAS 15 shows 0.8 ... the 32 pitch will be close 0.8 is 31.75, but the dia will be off with the #10 or #12 size...
Jim
Oddly enough the OS instruction sheet says 5mm, and a check with pitch gage on my NIB LAS 15 shows 0.8 ... the 32 pitch will be close 0.8 is 31.75, but the dia will be off with the #10 or #12 size...
Jim
>Scott
>Oddly enough the OS instruction sheet says 5mm, and a check
>with pitch gage on my NIB LAS 15 shows 0.8 ... the 32 pitch
>will be close 0.8 is 31.75, but the dia will be off with the
>#10 or #12 size...
>Jim
I guess that is what is meant when they say You can lead a horse to water but you can't make him drink. The shaft thread is M5.
Scott
I bet Parkrose True Value on Sandy Blvd has the size your looking for if you have never been their you should check them out. Winks hardware would be another place that would have them.
Terry
http://www.dustersrcclub.com/
>Oddly enough the OS instruction sheet says 5mm, and a check
>with pitch gage on my NIB LAS 15 shows 0.8 ... the 32 pitch
>will be close 0.8 is 31.75, but the dia will be off with the
>#10 or #12 size...
>Jim
I guess that is what is meant when they say You can lead a horse to water but you can't make him drink. The shaft thread is M5.
Scott
I bet Parkrose True Value on Sandy Blvd has the size your looking for if you have never been their you should check them out. Winks hardware would be another place that would have them.
Terry
http://www.dustersrcclub.com/
TERRY...WINKS were 69 bucks
Park rose..where out of stock 34 bucks
Tacoma Screw..SAY WHAT??
Enco...Out of Stock
McMaster-carr...18 bucks
two beers and a slice of pizza....priceless
Park rose..where out of stock 34 bucks
Tacoma Screw..SAY WHAT??
Enco...Out of Stock
McMaster-carr...18 bucks
two beers and a slice of pizza....priceless
Scott Riese
The Enco 2006 catalog shows a m5 x 0.8 tap (Cleveland) at $7.09 or the cheap charlie version for just under $3.00.... FWIW
Jim
Jim
I got 5 mm x.08 through ENCO. Great people. FREE SHIPPING TOOOOOO!
Scott Riese
johnnyarcana123 · Feb 14, 2007 08:12 PM
#23 sourceI have an ENYA .15 (in my Perky) that I purchased on Ebay. The engine runs great but some adz-hoe chased the metric threads with a 1/4 NC die!
John McCollum
johnnyarcana123 · Feb 14, 2007 08:17 PM
#24 sourceP/S:
I can hardly believe that there is more than ONE ANSWER to Scott's question!
Did someone chase the threads with an oddball die? Or, I should ask, different LA-15s with different dies?
I can hardly believe that there is more than ONE ANSWER to Scott's question!
Did someone chase the threads with an oddball die? Or, I should ask, different LA-15s with different dies?
John McCollum
5mm x.08 is the correct one
12x32 IS so close it will work also
12x32 IS so close it will work also
Scott Riese
I did some more research at work, where my machinist's "Bible" is. There is a 12-32NEF. There is also a 7/32-32NEF. For what reason, I have no idea, as they are almost the same. The major diameter is a tad different, so the PD is also a tad different. I would expect them to essentially interchange, with tolerances & clearances overlapping. I found no evidence of there being a 5mm x anything other than .8mm, which was a surprise, even though we aren't real heavily into metric stuff.
Wot I would suggest (and should have, last night) would be to check the major diameter of the crank. If it's 5mm, it should be just a bit under .1968". If it's 7/32, it should be a bit under .2187", or if it's a #12, under .216". I have both metric and inch pitch gauges, but (fortunately?), I don't have a .15LA or FP. There is NO evidence that the thread would be a 12-32, while there is some evidence, that it might be a 5mm x ? and it's entirely possible that it is the same as the FP, which the factory literature says is 7/32-32.
The specs I found on the .15FP said 7/32-32, back during the B-17 project. I didn't actually make the spinner nuts, as Howard seems to think, but I did modify the OS factory option spinner nuts pretty significantly, to look like a B-17's prop hub. The reason was that the best price I found for a 7/32-32 tap was $40, so it was both cheaper and easier to modify OS parts. If Howard once had one, he's still got it!
Steve
EDIT: PS: If OS is so helpful as to make the threads in a stupid SAE thread for us Yanks, why the heck don't they make the hex SAE also? I throw them away, and replace them with 1/4-28 Gr.8 hex nuts from the local Nut Store...buy a box full, cheap. Probably made in ChiCom.
Steve Helmick
Renton, Washington
USA
Wot I would suggest (and should have, last night) would be to check the major diameter of the crank. If it's 5mm, it should be just a bit under .1968". If it's 7/32, it should be a bit under .2187", or if it's a #12, under .216". I have both metric and inch pitch gauges, but (fortunately?), I don't have a .15LA or FP. There is NO evidence that the thread would be a 12-32, while there is some evidence, that it might be a 5mm x ? and it's entirely possible that it is the same as the FP, which the factory literature says is 7/32-32.
The specs I found on the .15FP said 7/32-32, back during the B-17 project. I didn't actually make the spinner nuts, as Howard seems to think, but I did modify the OS factory option spinner nuts pretty significantly, to look like a B-17's prop hub. The reason was that the best price I found for a 7/32-32 tap was $40, so it was both cheaper and easier to modify OS parts. If Howard once had one, he's still got it!
SteveEDIT: PS: If OS is so helpful as to make the threads in a stupid SAE thread for us Yanks, why the heck don't they make the hex SAE also? I throw them away, and replace them with 1/4-28 Gr.8 hex nuts from the local Nut Store...buy a box full, cheap. Probably made in ChiCom
Steve Helmick
Renton, Washington
USA
>I did some more research at work, where my machinist's
>"Bible" is. There is a 12-32NEF. There is also a
>7/32-32NEF. For what reason, I have no idea, as they are
>almost the same. The major diameter is a tad different, so the
>PD is also a tad different. I would expect them to essentially
>interchange, with tolerances & clearances overlapping. I
>found no evidence of there being a 5mm x anything other than
>.8mm, which was a surprise, even though we aren't real heavily
>into metric stuff.
>
>Wot I would suggest (and should have, last night) would be to
>check the major diameter of the crank. If it's 5mm, it should
>be just a bit under .1968". If it's 7/32, it should be a
>bit under .2187", or if it's a #12, under .216". I
>have both metric and inch pitch gauges, but (fortunately?), I
>don't have a .15LA or FP. There is NO evidence that the thread
>would be a 12-32, while there is some evidence, that it might
>be a 5mm x ? and it's entirely possible that it is the same as
>the FP, which the factory literature says is 7/32-32.
>
>The specs I found on the .15FP said 7/32-32, back during the
>B-17 project. I didn't actually make the spinner nuts,
>as Howard seems to think, but I did modify the OS factory
>option spinner nuts pretty significantly, to look like a
>B-17's prop hub. The reason was that the best price I found
>for a 7/32-32 tap was $40, so it was both cheaper and easier
>to modify OS parts. If Howard once had one, he's still got it!
>:@ Steve
>
>EDIT: PS: If OS is so helpful as to make the threads in a
>stupid SAE thread for us Yanks, why the heck don't they make
>the hex SAE also? I throw them away, and replace them with
>1/4-28 Gr.8 hex nuts from the local Nut Store...buy a box
>full, cheap. Probably made in ChiCom.
>
>Steve Helmick
>Renton, Washington
>USA
Ron B.
F4Fguy
Steve,
Logic notwithstanding, I have, in hand, Several O.S. .15s of various vintages. All measure .2160" dia..
I also have two, in original package, O.S. shaft nuts. The one marked part #10453(as in the Tower ad) is a #10-32UNF, and fits all the O.S. .010s I have, as well as several Fox .15s and early (rear rotor) McCoy .19s,and is marked for the O.S..10FSR. It will not fit any of the O.S. .15s.(nor will it fit any of my Enya.010s, which are 5mmx.8)
The other one, marked part #21510003, is marked for the .15, .15FP,and .15FPS. It fits all the O.S..15s and is definitely a #12-32UNEF.It will screw onto a 5mmx.8 metric, but verrrry loosely, as it's almost .030" oversize.
Ron B.
Edit for dumb thumbs. Left the "2" out of 0.216!
Also,while it may be available as a bastard size, I can find no reference to a UNIFIED NATIONAL STANDARD 7/32"-32UNEF in either "Machinery's Handbook", or in "Marks'Standard Handbook For Mechanical Engineers".
R.B.
>"Bible" is. There is a 12-32NEF. There is also a
>7/32-32NEF. For what reason, I have no idea, as they are
>almost the same. The major diameter is a tad different, so the
>PD is also a tad different. I would expect them to essentially
>interchange, with tolerances & clearances overlapping. I
>found no evidence of there being a 5mm x anything other than
>.8mm, which was a surprise, even though we aren't real heavily
>into metric stuff.
>
>Wot I would suggest (and should have, last night) would be to
>check the major diameter of the crank. If it's 5mm, it should
>be just a bit under .1968". If it's 7/32, it should be a
>bit under .2187", or if it's a #12, under .216". I
>have both metric and inch pitch gauges, but (fortunately?), I
>don't have a .15LA or FP. There is NO evidence that the thread
>would be a 12-32, while there is some evidence, that it might
>be a 5mm x ? and it's entirely possible that it is the same as
>the FP, which the factory literature says is 7/32-32.
>
>The specs I found on the .15FP said 7/32-32, back during the
>B-17 project. I didn't actually make the spinner nuts,
>as Howard seems to think, but I did modify the OS factory
>option spinner nuts pretty significantly, to look like a
>B-17's prop hub. The reason was that the best price I found
>for a 7/32-32 tap was $40, so it was both cheaper and easier
>to modify OS parts. If Howard once had one, he's still got it!
>:@ Steve
>
>EDIT: PS: If OS is so helpful as to make the threads in a
>stupid SAE thread for us Yanks, why the heck don't they make
>the hex SAE also? I throw them away, and replace them with
>1/4-28 Gr.8 hex nuts from the local Nut Store...buy a box
>full, cheap. Probably made in ChiCom
>
>Steve Helmick
>Renton, Washington
>USA
Ron B.
F4Fguy
Steve,
Logic notwithstanding, I have, in hand, Several O.S. .15s of various vintages. All measure .2160" dia..
I also have two, in original package, O.S. shaft nuts. The one marked part #10453(as in the Tower ad) is a #10-32UNF, and fits all the O.S. .010s I have, as well as several Fox .15s and early (rear rotor) McCoy .19s,and is marked for the O.S..10FSR. It will not fit any of the O.S. .15s.(nor will it fit any of my Enya.010s, which are 5mmx.8)
The other one, marked part #21510003, is marked for the .15, .15FP,and .15FPS. It fits all the O.S..15s and is definitely a #12-32UNEF.It will screw onto a 5mmx.8 metric, but verrrry loosely, as it's almost .030" oversize.
Ron B.
Edit for dumb thumbs. Left the "2" out of 0.216!
Also,while it may be available as a bastard size, I can find no reference to a UNIFIED NATIONAL STANDARD 7/32"-32UNEF in either "Machinery's Handbook", or in "Marks'Standard Handbook For Mechanical Engineers".
R.B.
Ron,
I would like to confirm what you said.
I measured one this morning with a set of precision thread gages and it definitely is within tolerance for a 12-32 UNEF thread and significantly out of tolerance for a 5 X .8 metric.
Don't know what else can be said. Let'em believe what they will...
5mm thread in a nut will probably be very easy to strip.
I would like to confirm what you said.
I measured one this morning with a set of precision thread gages and it definitely is within tolerance for a 12-32 UNEF thread and significantly out of tolerance for a 5 X .8 metric.
Don't know what else can be said. Let'em believe what they will...
5mm thread in a nut will probably be very easy to strip.
Randy C
Iskandar Taib · Feb 15, 2007 11:36 AM
#30 source>EDIT: PS: If OS is so helpful as to make the threads in a
>stupid SAE thread for us Yanks, why the heck don't they make
>the hex SAE also? I throw them away, and replace them with
>1/4-28 Gr.8 hex nuts from the local Nut Store...buy a box
>full, cheap. Probably made in ChiCom.
Send off to Fox for some of their Combat Special prop nuts.. they have a groove cut in the middle that should save you a few grams..
>stupid SAE thread for us Yanks, why the heck don't they make
>the hex SAE also? I throw them away, and replace them with
>1/4-28 Gr.8 hex nuts from the local Nut Store...buy a box
>full, cheap. Probably made in ChiCom
Send off to Fox for some of their Combat Special prop nuts.. they have a groove cut in the middle that should save you a few grams..
Royde26434 · Feb 15, 2007 02:02 AM
#28 sourceOK Scott. I just gotta ask. If a tap is what you needed, why not get another nut or proper nut instead of all the trouble you went to???
Roy (wonders what the heck?) Decamara
Roy (wonders what the heck?) Decamara
Roy DeCamara
Ron B.
F4Fguy
Roy,
That's precisely the question; what is the proper size. The O.S. part# shown above by Tower is not it. If you want to make an extension nut for a spinner or shaft extension you have to know the proper size to tap it.
Ron B.
I bought a nice little Thunder Tiger 15 last year
THEN I needed tap to make a shaft extender! I think the booklet said the shaft size was 7/32-32.
McMaster-Carr would not ship to the UK (Cited too much paperwork / US Customs regulations) so I had to get a friend in Boston to buy it and then send it to me. With all that, the #### tap cost as much as the engine! Ian R later told me I could have found a tap in the UK for about £5 - too late.
I too cursed the fool who didn't use a "standard" thread, metric or imperial. 5mm metric is dead easy to find - and cheap
Charles
PS
If you want to borrow mine, I'll post it to you
THEN I needed tap to make a shaft extender! I think the booklet said the shaft size was 7/32-32.
McMaster-Carr would not ship to the UK (Cited too much paperwork / US Customs regulations) so I had to get a friend in Boston to buy it and then send it to me. With all that, the #### tap cost as much as the engine! Ian R later told me I could have found a tap in the UK for about £5 - too late.
I too cursed the fool who didn't use a "standard" thread, metric or imperial. 5mm metric is dead easy to find - and cheap
Charles
PS
If you want to borrow mine, I'll post it to you
Royde26434 · Feb 15, 2007 04:22 PM
#33 sourceI see. Thanks. Knowing Scott personally, that generated my question. Cheers..............
Roy DeCamara
Bill Gruby · Feb 15, 2007 05:51 PM
#34 sourceScott;
This should get you your info:
http://www.osengines.com
Go to bottom of page and click on Engine Dimensions Chart, they are all there
Bill Gruby
This should get you your info:
http://www.osengines.com
Go to bottom of page and click on Engine Dimensions Chart, they are all there
Bill Gruby
Bill Gruby
>I see. Thanks. Knowing Scott personally, that generated my
>question. Cheers..............
ROY. glad to see your up and here with us.(MY THOUGHTS go out to you) I got a project, a customer needs a custom spinner nut and spool. SO I had to find the thread size. DO you think I could get on OS web page??? No.. The chipmunk I have has a broken leg and sometimes getting on a web page is a masterpiece......SO I came here and MADE everyone else look for me....lol
Thanks to all
>question. Cheers..............
ROY. glad to see your up and here with us.(MY THOUGHTS go out to you) I got a project, a customer needs a custom spinner nut and spool. SO I had to find the thread size. DO you think I could get on OS web page??? No.. The chipmunk I have has a broken leg and sometimes getting on a web page is a masterpiece......SO I came here and MADE everyone else look for me....lol
Thanks to all
Scott Riese
Copied and pasted from the OS website provided by Bill Gruby. The last numbers in the line is the prop nut thread.
.15 FP, .15 FP-S 1.3 0.57 2.22 1.57 2.49 1.56 0.98 1.21 1.98 7/32-32
.15 LA, .15 LA-S 1.3 0.57 2.22 1.57 2.4 1.56 0.98 1.21 1.91 M5
I think Scott is making the shaft extension for Ben Jones. But my recollection is that Ben wanted an extension for a .15FP, not a LA.
I have found catalogs with 7/32-32 taps, and 12-32 taps, but haven't found any specs on the thread tolerances, or if they aren't the exact same thing, for that matter. My Machinist's Handbook is not THAT one, it's some other, and it's not great, but at this point in my working life, I'm not at all interested in buying a good one (they're pretty expensive...also available in CD). I picked this one up in a 2nd hand store, and it's done ok for me in the 25 years or so that I've had it. I think I'll burn it, when I don't need it anymore. It's one 'book burning' that is socially acceptable, I hope. Steve
Steve Helmick
Renton, Washington
USA
.15 FP, .15 FP-S 1.3 0.57 2.22 1.57 2.49 1.56 0.98 1.21 1.98 7/32-32
.15 LA, .15 LA-S 1.3 0.57 2.22 1.57 2.4 1.56 0.98 1.21 1.91 M5
I think Scott is making the shaft extension for Ben Jones. But my recollection is that Ben wanted an extension for a .15FP, not a LA.
I have found catalogs with 7/32-32 taps, and 12-32 taps, but haven't found any specs on the thread tolerances, or if they aren't the exact same thing, for that matter. My Machinist's Handbook is not THAT one, it's some other, and it's not great, but at this point in my working life, I'm not at all interested in buying a good one (they're pretty expensive...also available in CD). I picked this one up in a 2nd hand store, and it's done ok for me in the 25 years or so that I've had it. I think I'll burn it, when I don't need it anymore. It's one 'book burning' that is socially acceptable, I hope.
SteveSteve Helmick
Renton, Washington
USA
Ron B.
F4Fguy
A #12 is a nominal 7/32" dia.. #12-32UNEF3A* major diameter=0.2160"/0.2100", 7/32=0.21875". The difference is, there's a Standard Unified Extra Fine #12-32Thread size. There is no standard 7/32" thread size.
The #12-32UNEF Fits all the O.S.15s I own, from a very early "steel fin" type to the FP and LA. All the shafts measure well within the #12 specs, i.e. 0.2100"-0.2160"
*#12-32 UNEF2A=0.2151"/0.2091" diameter.
Ron B.
P.S., Note: I didn't say you can't buy one, just that it's not a standard, anywhere.
F4Fguy
A #12 is a nominal 7/32" dia.. #12-32UNEF3A* major diameter=0.2160"/0.2100", 7/32=0.21875". The difference is, there's a Standard Unified Extra Fine #12-32Thread size. There is no standard 7/32" thread size.
The #12-32UNEF Fits all the O.S.15s I own, from a very early "steel fin" type to the FP and LA. All the shafts measure well within the #12 specs, i.e. 0.2100"-0.2160"
*#12-32 UNEF2A=0.2151"/0.2091" diameter.
Ron B.
P.S., Note: I didn't say you can't buy one, just that it's not a standard, anywhere.