Step-by-Step Guide to Adjusting the Clutch on a Summit Metal Lathe

Lathes are complicated pieces of modern machinery, but they all rely on basic parts. On a metal lathe, the clutch helps to control the speed of the lathe spindle. The clutch also performs a key role in slowing down the spindle, essentially working as a braking mechanism.

There are a few easy steps to follow in order to adjust the clutch on any of the Summit metal lathes. This approach will also work for most other metal lathes, but be aware that every individual lathe is different. Not all of the steps will line up exactly. 

Step 1: Set Your Spindle Speed

Start with your spindle in its second-fastest position. For a 2200-rpm lathe like the one in the video, that second position rotates about 1600-1800 rpm. This helps to give you a definite starting point for your clutch adjustments, as well as providing a bit of room to adjust the clutch either way.

Step 2: Warm Up Your Lathe

Once you’ve set your spindle speed, you can start warming up your lathe. Metal expands slightly when hot, meaning that adjusting a cold lathe will give you poor results.

Warm up the lathe by letting it run for about 30 minutes at the set speed. That will let the internal workings of the lathe get up to normal operating temperature.

Step 3: Turn Off Your Lathe

Once the lathe is warmed up, power it off. Be sure to remove it from the power source – follow your company’s lock-out tag-out and safety procedures.

Step 4: Access The Clutch

On many lathes you’ll find a small exterior access panel that will give you limited access to the clutch. You may also need or want to remove one of the larger panels on the engine housing to gain a bit more access.

Step 5: Verify The Clutch

Many lathes have more than one clutch – typically a forward and a reverse clutch. To verify which one you need to adjust, move the shifter handle. This should cause the clutch to shift, and let you identify exactly which part requires adjustment. 

Question: How Do I Know If The Clutch Needs Adjusting?

The easiest way to tell if you need to adjust the clutch on your lathe is to see how long it takes your spindle to get fully up to the correct speed. On a well-adjusted lathe, that time should be between 2-3 seconds. If it’s any longer, you’ll need to tighten your clutch.

It isn’t just a performance issue, either. Improperly adjusted parts will wear out more quickly and cause damage to the rest of the lathe.

Step 6: Find The Adjustment Pin

Once you’ve identified the correct clutch, look for the adjustment pin on the collar of the clutch. If you don’t see it immediately, manually rotate the clutch using the belts until you locate the pin. This pin should pop loose with some pressure from the head of a screwdriver. It won’t fall out, but should pop just out of place a bit.

Step 7: Turn The Clutch Collar

There will be a series of holes in the clutch collar. Begin to adjust the clutch by tapping it gently with the screwdriver. As you turn the clutch, the pin should fall into the next notch in the sequence.

Step 8: Adjust the Collar One Step At A Time

It’s often best to adjust the clutch by one notch at a time. The adjustment pin should reset at every step, requiring you to loosen it before adjusting it another notch. 

That’s all there is to it. Once the clutch is properly adjusted, carefully reassemble the outer cover and restore power to the machine.
The entire process sounds complicated, but shouldn’t take more than 5-10 minutes with a bit of experience. If you prefer to watch a demonstration, follow the instructions here!