What do 380 pilots have in common?
Drum roll please
Not one of them can fly!
Okay, we'll admit; that was a BAD JOKE.
Today in Tech Notes, we're talking about the pilots you use day in and day out in your machine shop.
Why? Because without a quality pilot that's on size and the right one for the job, your finished product will be sub-par.
Most of you have looked at the Goodson catalog or the Goodson website. You've noticed there are pages of pilots. Three full pages of pilots. Plus other specialty pilots on other pages. Yup, we counted 'em. There are 380 pilots stocked by Goodson listed in the catalog and on the website.
So how do you know which pilot to use for which job? Keep reading to find out.
Solid Tapered High Speed Steel Pilots
These are your every day pilots. Goodson offers them in 4 top sizes — .297", .375", .385" and .437". A few other top sizes (.390" and .406") have been made in the past, but there is little demand for them anymore.
All of these pilots are designed to remain stationary in the guide bore, allowing the tooling to turn around it. Goodson recommends these pilots for valve guide and valve seat work.
Solid tapered high speed steel pilots are also available in an Extended Length version. These were designed for deep-set valves such as those in diesel applications. Sometimes the seats are set so deeply that the standard pilot doesn't extend beyond the deck far enough to support your tooling.
Solid Tapered Carbide Pilots
A step up from High Speed Steel Pilots, these carbide pilots have less deflection under stress. They are available in two top sizes — .236" and .375". As with the high speed steel pilots, these are used primarily with guide and seat work.
Another popular pilot variation is the Expanding Pilot. Every expanding pilot is good for a range of guide sizes. For instance our 5.5mm, .375" Top Expanding Pilot will fit guides in a range from .213" to .233". With standard pilots, you would need several individual pilots to cover the same range of sizes as a single expanding pilot.
BUT don't use expanding pilots with multi-angle valve seat cutting systems such as the Goodson 3-D Fast Cut. They will deflect too much and not yield a good finish.
Every expanding pilot has three parts — the body, the collet and the expander. All pieces are included when you purchase the pilot (at least they are when you purchase from Goodson) but replacements are available.
Be sure to check out our tech tip on Setting Expanding Pilots.
Straight Carbide Pilots
The last type of pilot we're going to talk about here is the .375" Top Serdi-Style Straight Carbide Pilot.
These pilots are also known as live pilots which means they turn with tooling. They are available in 42 different stem sizes, from 3.99mm to 9.52mm.
A Few Last Words
- Take care of your pilots.
You have a substantial investment in these tools and they need to last. Be sure that you are keeping them clean and properly stored to prevent damage. Always clean your pilots when you are done with a job so they're ready when you need them next.
- Remember pilots wear out - and pilot tops wear more than bottoms.
A good habit to get into is to mic your pilots before using them to be sure they are on-size and concentric. You don't want to complete a job only to find out that your pilot was out of round so all of your hard work is down the drain.
- Use the right pilot for the job.
Goodson carries a lot of pilots for a reason. If you're not sure which pilot to use, call a Goodson Techxpert to get some advice.