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Removal of motor shaft allen screw

Posted: Sun Aug 18, 2013 8:04 pm
by hitekcntry
Hi guys,
Does anyone have ideas on removing a stripped bolt on the end of the motor shaft. Whomever put it back together must have stripped the allen screw, as I have never found the right allen to remove it. I am trying to replace the spacer behind the fan sheave (???). Thanks in advance for your help.
Hitekcntry

Posted: Sun Aug 18, 2013 8:45 pm
by wa2crk
If I remember correctly the fan sheave is held in place by a set screw that is behind the sheave and in front of the motor. If the motor is still in the motor pan it can be reached from the bottom of the of the motor pan by putting the 5/32 allen wrench through the hole to engage the screw. They can be very tight. If you are referring to an actual bolt or a nut that is in the end of the motor shaft that is an earlier version that I have not worked on. Have you removed the spring from the shaft yet? Be careful that spring stores a lot of energy!!
After you remove the screw the fan sheave may be difficult to move but be patient. Penetrating oil and patience are the best tools.
If you can post a pic it would be helpful.
Bill V

Posted: Sun Aug 18, 2013 9:51 pm
by billmayo
The nut on the end of the motor shaft is a left handed nut and must be turned in the opposite direction. When I find that a set screw hex hole has rounded out, I use a Screw Extractor (Easy Out) that I can drive into the hole. You need a minimum set of 5 easy outs to cover most size holes. I have the drill bits needed to drill holes in broken bolts that these will remove most times. I find I have to use any extension on the easy out for the motor fan sheave set screw. The worst case is having to drill out the set screw which will damage the fan sheave to where you will have to replace it. There are left handed drill bits that I operate in reverse with a slow rotation hammer drill. I have used them to remove a few stuck set screws without damaging the set screw threads in the hub. A good machinest shop may be able to accomplish this task if you are unsuccessful. I have the equipment and tools to acomplish these tasks if you are interested.

The Speed Control Handle set screw is the one I find that rounds out much more than any other set screw.

Posted: Sun Aug 18, 2013 11:56 pm
by JPG
Let us be clear what we are referring to. A nut on the end of the motor shaft will only be on a 3/4 hp greenie motor.

All versions have a 5/32" hex set screw securing the fan sheave to the motor shaft.

There are two versions of the retaining ring secured spring. One has a cup and the later version has a washer.

The spring(etc.) must be removed to remove the fan sheave(etc.).

Since the set screw is torqued very tight, a very good allen wrench is needed to remove the screw. The correct size is 5/32"(sound familiar?). Make sure the hex hole is cleaned out thoroughly so the allen wrench can be inserted fully. An impact driver(will help). Penetrating oil(Kerosene) will help. Long(twisty) allen wrenches are not helpful!

Sticky bolt

Posted: Mon Aug 19, 2013 12:57 am
by hitekcntry
What I am having trouble with is the bolt in end of the motor shaft, not a set screw. It holds the big spring on. Just seems odd that such a big bolt has such a small allen wrench in it. It is tapered such that you can not use vice grips to get a hold of it. Anyway, I need to get it out so I can put the spacer in behind the fan to keep it from hitting the motor case.
Thanks for all the responses. Looks like a have an old 500 upgraded to a 510. No pictures tonight....
Hitekcntry

Posted: Mon Aug 19, 2013 1:58 am
by JPG
hitekcntry wrote:What I am having trouble with is the bolt in end of the motor shaft, not a set screw. It holds the big spring on. Just seems odd that such a big bolt has such a small allen wrench in it. It is tapered such that you can not use vice grips to get a hold of it. Anyway, I need to get it out so I can put the spacer in behind the fan to keep it from hitting the motor case.
Thanks for all the responses. Looks like a have an old 500 upgraded to a 510. No pictures tonight....
Hitekcntry
There ain't no 'bolt' on the outer end of the motor shaft.

The older 3/4 hp Greenies have a 'nut' that has a left hand thread(righty loosey, lefty tighty). No allen head. Just a hex nut.

Are you sure you do not have a retaining ring on the end of the shaft. There will be either a washer or a cup between the spriing and the retaining ring.

Regardless of what you have, the spring tension must be controlled and the spring allowed to expand slowly. That means the spring need be held slightly compressed away from the nut/ring as it is removed.

Be very careful. That spring is under considerable tension.

You need a way to hold the spring compressed.

Have you watched the saw dust session?

http://www.shopsmithacademy.com/SS_Arch ... rn_Pt2.htm

About 8:00 is of interest.

Posted: Mon Aug 19, 2013 3:58 am
by billmayo
hitekcntry wrote:What I am having trouble with is the bolt in end of the motor shaft, not a set screw. It holds the big spring on. Just seems odd that such a big bolt has such a small allen wrench in it. It is tapered such that you can not use vice grips to get a hold of it. Anyway, I need to get it out so I can put the spacer in behind the fan to keep it from hitting the motor case.
Thanks for all the responses. Looks like a have an old 500 upgraded to a 510. No pictures tonight....
Hitekcntry
How about a picture as we are having a hard time with your description. Thanks.

Posted: Tue Aug 20, 2013 12:00 am
by hitekcntry
With more light, stronger glasses and a brush to clear off the saw dust, I have found the magic retaining ring! When I figure out how to suppress the spring I will try and figure out how to use the ring pliers in the board to suppress the spring.....lol. Many thanks for helping this ole man see the light, uh more light!!!
More to follow.
Hitekcntry

Posted: Tue Aug 20, 2013 12:34 am
by JPG
hitekcntry wrote:With more light, stronger glasses and a brush to clear off the saw dust, I have found the magic retaining ring! When I figure out how to suppress the spring I will try and figure out how to use the ring pliers in the board to suppress the spring.....lol. Many thanks for helping this ole man see the light, uh more light!!!
More to follow.
Hitekcntry

I use a 1x3 about 1 foot long(maybe more). It has a counter bore large enough for the washer(or cup) to nest in(about 1/2" deep), and a 3/4"(maybe 7/8") through hole. The hole etc. is in from one end a distance that allows the end to slip under the headstock casting. That end becomes a pivot point. The 1x3 is placed over the motor shaft, rotated in under the headstock casting and the other end is pushed. That moves the washer/cup and compresses the spring. While holding the spring compressed, the retaining ring is removed. You need real good pliers to ensure complete removal of the ring in a short period of time. Then slowly release the board to allow the spring to expand. You may have to slip the pivot end out from the casting to expand the spring fully.

'Assembly is the reverse'.;)

I do not have access to my stick or I would give more exact dimensions.