10ER Speed Changer Knurled Nut

[jsburger]

The 10ER speed changer came originally equipped with a 1 1/2" long set screw and a knurled nut. The set screw replaces the set screw in the head stock that secures the motor bracket post. The 1 1/2" set screw is long enough to pass through the hole in the center of the speed changer bracket. Then the knurled nut is put on. This allows the speed changer to slide with the head stock as it is moved.

4 of the 5 10ER's I have here came with speed changers but only one had the long set screw and knurled nut. I bought a speed changer on eBay for the fifth one and the seller had the long set screw and nut. You rarely see speed changers on eBay with the long set screw and nut.

The set screws are readily available and of course you could use a plain 3/8 hex nut but I wanted something closer to OEM. I have looked long and wide for one that came close to matching the original with no luck. The original is aluminum. You can't use just any 3/8-16 knob because if it is too big it will interfere with the floating sheave arm. The closest I could find was a steel one from Grainger. It is the same thickness but larger in diameter. It works perfectly.

The picture shows the original and the Grainger substitute. One face of the Grainger knob is stepped as shown. The other side is flat.

[reible]

My speed changer is still in the shipping bag but I'm pretty sure it does not have any of the mounting parts. From the drawing it looks like it will need the set screw and a couple of washers, jam nuts and this nut. Does that sound about right?

Anyone know how long the set screw can be if need be to accommodate thicker nuts etc. (I gather it is a 3/8"-16 tpi)?

How large is the original knurled nut, diameter wise?

I pulled the bag (with speed changer and belts) out of storage and hope to have a look at it tomorrow. I did look at it when it arrived to make sure it wasn't damaged but have no idea of the actual condition it is in bearings wise but I guess I should get started on it in case I need to order parts..... bushings anyway.

Ed

[rpd]

The 10ER speed changer came originally equipped with a 1" long set screw and a knurled nut. The set screw replaces the set screw in the head stock that secures the motor bracket post. The 1" set screw is long enough to pass through the hole in the center of the speed changer bracket. Then the knurled nut is put on. This allows the speed changer to slide with the head stock as it is moved.

4 of the 5 10ER's I have here came with speed changers but only one had the long set screw and knurled nut. I bought a speed changer on eBay for the fifth one and the seller had the long set screw and nut. You rarely see speed changers on eBay with the long set screw and nut.

The set screws are readily available and of course you could use a plain 3/8 hex nut but I wanted something closer to OEM. I have looked long and wide for one that came close to matching the original with no luck. The original is aluminum. You can't use just any 3/8-16 knob because if it is too big it will interfere with the floating sheave arm. The closest I could find was a steel one from Grainger. It is the same thickness but larger in diameter. It works perfectly.

The picture shows the original and the Grainger substitute. One face of the Grainger knob is stepped as shown. The other side is flat.

Thanks John, great information.

I'll be needing to get these (and a set of belts) for my recently acquired Speed Changer. (and fortunately we have an Acklands-Grainger here in town)

My speed changer is still in the shipping bag but I'm pretty sure it does not have any of the mounting parts. From the drawing it looks like it will need the set screw and a couple of washers, jam nuts and this nut. Does that sound about right?

Anyone know how long the set screw can be if need be to accommodate thicker nuts etc. (I gather it is a 3/8"-16 tpi)?

How large is the original knurled nut, diameter wise?

I pulled the bag (with speed changer and belts) out of storage and hope to have a look at it tomorrow. I did look at it when it arrived to make sure it wasn't damaged but have no idea of the actual condition it is in bearings wise but I guess I should get started on it in case I need to order parts..... bushings anyway.

Ed

I just checked the one of mine that came with a speed changer. The set screw is 1 1/2" 3/8-16 tpi , and it just has a plain old hex nut, so not original, but there is no interference the arm.

Mounted on the 10ER, note this set-screw is longer than required.

SCnutsetscrew1.JPG (273.66 KiB) Viewed 6545 times

and loose on the table.

SCnutsetscrew2.JPG (256.62 KiB) Viewed 6545 times

The parts list shows two washers, mine did not come with any, no lock nuts are required.
When installed the knurled nut is only snugged up finger tight, over tightening risks breaking the casting.

[jsburger]

As with all things SS there are variations.

I made a mistake in my original post which I corrected. The set screw is 1 1/2" long 3/8-16.

I have two speed changer manuals and they differ for these parts. One manual just lists the set screw and a hex nut. The other one lists the set screw, two flat washers and the knurled knob. So either configuration can be considered OEM. The manual with the knurled knob is dated 1953. The other one has no date but it must be earlier and how the speed changer was first shipped.

The OEM knurled knob is 3/8" thick and 11/16" diameter. The replacement knob I found is 3/8" thick and 1" diameter.

As far as set screw length and thicker nuts, the nut thickness is the critical dimension. The first picture shows the speed changer set to 0. If the nut is any thicker than about 1/2" the arm will hit it (first and third picture). The arm will not hit the set screw but the pulley will if the set screw sticks past the main casting more than about 1 7/8". Also if the nut is more than about 1" in diameter it will hit the lip on the bottom of the main casting (second picture).

[rpd]

As with all things SS there are variations.

I made a mistake in my original post which I corrected. The set screw is 1 1/2" long 3/8-16.

I have two speed changer manuals and they differ for these parts. One manual just lists the set screw and a hex nut. The other one lists the set screw, two flat washers and the knurled knob. So either configuration can be considered OEM. The manual with the knurled knob is dated 1953. The other one has no date but it must be earlier and how the speed changer was first shipped.

The OEM knurled knob is 3/8" thick and 11/16" diameter. The replacement knob I found is 3/8" thick and 1" diameter.

As far as set screw length and thicker nuts, the nut thickness is the critical dimension. The first picture shows the speed changer set to 0. If the nut is any thicker than about 1/2" the arm will hit it (first and third picture). The arm will not hit the set screw but the pulley will if the set screw sticks past the main casting more than about 1 7/8". Also if the nut is more than about 1" in diameter it will hit the lip on the bottom of the main casting (second picture).

Thanks for the update.

One might speculate that they changed from the regular nut to the knurled nut to prevent people (gorillas ) from over torquing, and breaking the casting.

[jsburger]

As with all things SS there are variations.

I made a mistake in my original post which I corrected. The set screw is 1 1/2" long 3/8-16.

I have two speed changer manuals and they differ for these parts. One manual just lists the set screw and a hex nut. The other one lists the set screw, two flat washers and the knurled knob. So either configuration can be considered OEM. The manual with the knurled knob is dated 1953. The other one has no date but it must be earlier and how the speed changer was first shipped.

The OEM knurled knob is 3/8" thick and 11/16" diameter. The replacement knob I found is 3/8" thick and 1" diameter.

As far as set screw length and thicker nuts, the nut thickness is the critical dimension. The first picture shows the speed changer set to 0. If the nut is any thicker than about 1/2" the arm will hit it (first and third picture). The arm will not hit the set screw but the pulley will if the set screw sticks past the main casting more than about 1 7/8". Also if the nut is more than about 1" in diameter it will hit the lip on the bottom of the main casting (second picture).

Thanks for the update.

One might speculate that they changed from the regular nut to the knurled nut to prevent people (gorillas ) from over torquing, and breaking the casting.

Yes, that is my guess also.

[reible]

Do you recall the shipping cost? I have a company I deal with called zoro and they want $3.86 plus $5 shipping and for me tax. Just wondering if I should go that way or the other?

http://www.ebay.com/itm/Z0285-Locknut-K ... 3641.l6368

Ed

[jsburger]

Do you recall the shipping cost? I have a company I deal with called zoro and they want $3.86 plus $5 shipping and for me tax. Just wondering if I should go that way or the other?

http://www.ebay.com/itm/Z0285-Locknut-K ... 3641.l6368

Ed

The Grainger bill did not break it down. I bought them from the local Grainger outlet and delivered there but they don't stock them so there was a shipping charge and tax. They did give me a military discount. I bought 4 and the bill was $31.31. That is $7.80 each so you are right there.

[jsburger]

Further update on the set screws. Grainger has them but they don't sell them individually. You have to buy a box, 50 or 100 I don't remember. I did not check the local Fastenal outlet but I suspect the same thing. I checked a local outlet called Nut & Bolt Supply. Nothing over 1". Again you have to buy a box.

I had already checked Home Depot and Lowes specialty drawers. No luck. The closest Ace Hardware changed hands and is now a local company called North Fork Hardware. Lots of specialty bins like Ace but no luck.

We do have an Ace outside Hill, AFB and we go to the base all the time. It is just the wrong direction going and returning. So lets check there. Bingo, Ace always comes through.