Jointer Retro-fit alignent pin question

[benush26]

Greetings,

New to this forum but bought a new 500 30 plus years ago and then sold it a couple years later (after a divorce and needing money), but now I'm retired and back in the fold.

I was lucky enough to get a good jointer cheap and it came with the Feather Retrofit (but not installed). The alignment pin has two threads 1/4 - 20 and 1/4 28 available. The 1/4 - 20 is included if the jointer was new enough to have the hole pre-drilled in the table at the factory. Mine is older so no hole.

I have the correct size drill bit and a 1/4 - 20 tap. Does anyone see any problem with me using that instead of going and buying a 1/4 28 tap for this one time only use? Yes, its' only 6 dollars, but I will never use the fine thread ever again and I'm not certain why the change. I'm not a machinist and have no real clue about the difference (except thread size).

Wisdom or even wild ass guessing advise would be appreciated.

Thanks

Ben

[SDSSmith]

Greetings,

New to this forum but bought a new 500 30 plus years ago and then sold it a couple years later (after a divorce and needing money), but now I'm retired and back in the fold.

I was lucky enough to get a good jointer cheap and it came with the Feather Retrofit (but not installed). The alignment pin has two threads 1/4 - 20 and 1/4 28 available. The 1/4 - 20 is included if the jointer was new enough to have the hole pre-drilled in the table at the factory. Mine is older so no hole.

I have the correct size drill bit and a 1/4 - 20 tap. Does anyone see any problem with me using that instead of going and buying a 1/4 28 tap for this one time only use? Yes, its' only 6 dollars, but I will never use the fine thread ever again and I'm not certain why the change. I'm not a machinist and have no real clue about the difference (except thread size).

Wisdom or even wild ass guessing advise would be appreciated.

Thanks

Ben

Welcome to the forum, Ben. Do you mean the stop pin (item 60E in the following diagram)? If so, you should be okay as long as the top of the pin is the same height from the table. If not, which pin are you asking about?

[ATTACH]18027[/ATTACH]

[wa2crk]

Ben
I believe that SS changed to the 1/4 X 20 screw size because so few people had the 28 thread tap. When I made the upgrade to my son's machine I broke the original stop bolt and used a 1/4 X 28 bolt as a replacement by grinding the head off. I see no problem with going with the 20 thread except that there will be a fewer threads to hold the bolt. Use a nut to hold the 20 thread bolt against the table. One word of caution, There will be no going back once the hole is tapped.
Bill V

[benush26]

[quote="SDSSmith"]Welcome to the forum, Ben. Do you mean the stop pin (item 60E in the following diagram)? If so, you should be okay as long as the top of the pin is the same height from the table. If not, which pin are you asking about?

Yes, 60E is the correct part.

Thanks for the reply.

[benush26]

Ben
I believe that SS changed to the 1/4 X 20 screw size because so few people had the 28 thread tap. When I made the upgrade to my son's machine I broke the original stop bolt and used a 1/4 X 28 bolt as a replacement by grinding the head off. I see no problem with going with the 20 thread except that there will be a fewer threads to hold the bolt. Use a nut to hold the 20 thread bolt against the table. One word of caution, There will be no going back once the hole is tapped.
Bill V

Thanks for the information, especially the nut against the table idea. I never would have thought of that. A friend who has tapped more holes will do the real work. I fix his computers and he helps me not screw up too much on all things mechanical!

We talked about using thread lock so with luck it won't vibrate out.

After that is done, it's time to clean and set up 3 (yes three) shopsmiths. Two are 500s and the newest is a 510. In the past couple months I found an older one cheap and then about a month later found one that was newer and in better shape (and had more goodies!) with the idea of getting it to a 510 (tables, carriage), but then found a reasonable deal on a 510 (again with yet more goodies), so now taking all the best and making one good set up and then selling the other two.

Thanks again SDSSMith and wa2crk for all the information and help.

Ben

[wa2crk]

A drop of blue Loctite would still be a good thing!!:D
Bill V