Choosing a Mandrel

Deciding which mandrel is best for you is a tough job, especially if you are new to call making, calls, lathe tools, and such.  Our suggestion is to visit some of the various forums or online pages to get feed back from other call makers on their likes and dislikes for the various designs available.  Keep in mind, that people are bound to have several different opinions, and in the end it will be up to you do decide which mandrel you want.  The most common mandrel these days is an expanding mandrel.

 Here are some details that may help you decide which mandrel is best for you.

 - Expanding mandrels are available with a #2 Morse Taper and straight shank (for use in a collet chuck) in 1/2", 5/8" and 3/4" and with a #1 Morse Taper in 5/8".  If you have a different mount on your lathe, you will either need to find/make an adapter that will work, or look at a different style of mandrel.  To help identify your Morse Taper, this link has the specifications for the various tapers to compare to yours.  A collet chuck will mount to the spindle and a collet installed in the chuck will hold the mandrel.

-  Mandrels are chosen by the diameter of the bore they are intended to hold.  If you have a stepped bore,  you will use a mandrel that fits the smallest diameter of the blank, and then make a support bushing that has an ID that matches the mandrel and an OD that matches the bore of the blank.   Since the mandrel does not expand at the back, that is where the bushing will go and support the blank - while the end of the mandrel actually holds the blank at the end.

-  Expanding mandrels only expand about .020-.030" safely.  So you CAN NOT use a 5/8" mandrel for a 11/16" hole for example.  It will not expand that large and remain centered - as well it most likely will be bent after that much beyond its limitations.  Expanding mandrels are not a "one size fits all" setup - they are a "one size fits one size up to about .015" oversize" type deal.  The expansion range is just not there.  In addition, the non expanding section of the mandrel that is closest to the shank, is the size listed, so if the bore is larger than the size listed, the blank can wobble on the mandrel since it is only "held" at the end with the expanding plug or screw.   Remember, most drill bits used on the more common call making equipment will NOT drill a perfectly on-size hole.   It is nearly guaranteed that your hole will be LARGER than the size of the drill.   If you ever have issues with the mandrel not holding tight - its likely the hole being too large rather than something wrong with the mandrel.

- The MVS and PLS are not designed to be used without the tailstock in place.  If you require an unsupported end on your mandrel, neither the MVS or PLS are mandrels you will want to use.  You will want an Expanding mandrel or use a stub version of the PLS.   (Note:  These style of mandrels have fallen out of the mainstream years ago...  while we may still have one or two in stock - they are not the mandrel of choice these days.)

- The Expanding mandrels are available in various sizes and configurations.  Custom sizes are possible, as long as there is a mandrel on the site that is larger than the size you want, and that the expansion screw is not larger than the size you want.   For example, the EXM500 can be cut down to about .425", the EXM625 mandrel can be cut down to accommodate about .600" and the EXM750 can be cut to about .700".

- The Expanding mandrels with Morse tapers require the customer to build a "Draw Bar" to secure the mandrel in the headstock.  A draw bar is in essence a long bolt that goes from the back of the headstock into the actual mandrel and is used to "draw" the mandrel into the taper very securely and hold it there.  The threads in the back of the Expanding mandrel are 3/8" - 16tpi for the #2 MT mandrels and 1/4" - 20 for the #1 MT mandrels.

- Turning on the face of the call (mouthpiece and end face) is possible with most of the mandrels.  The expanding mandrel will require you situate the blank hanging off the end of the mandrel and can only work on end at a time. The MVS, PLS, and Stub PLS have recessed cuts spaced to allow end work and "bell mouthing" on both ends without moving the blank, but they require a very narrow tool to allow access to the inner wall without touching the mandrel.  But be careful doing this - no matter what mandrel you are using!  Flying call parts is a very real danger if a tool grabs at the wrong time.

-  MVS and PLS mandrels require a very accurate hole.  Drill bits are NOT good at giving accurate holes, they are not designed to be extremely actuate.  Chucking reamers and boring bars are meant for bore accuracy.  It is strongly recommended that you drill your blanks 1/64 undersize, and then use a chucking reamer to open up the bore to the proper size.  One way of looking at it, is if you don't already know why you need an MVS or PLS... odds are, you probably will be better served with an expanding mandrel.

 In the end, it really comes down to 'you', the customer.  We can suggest things until we are blue in the face, but what is truly important is that you are happy and the only way to achieve that is for you to decide what would work best for you - for the way you plan on turning calls.  We strongly suggest that you read the manuals on the Downloads & Manuals page, familiarize yourself with how they operate, and compare that with your current style.  Or if you are new to call making and have no current style, get on some of the forums and see what others have to say about the styles of mandrels they use and why they like or dislike them.

If you are like many people that just want a recommendation, maybe this will help...  We pretty much use expanding mandrels anymore, and strongly recommend expanding mandrels for beginners.  So, the short of it is, our recommendation is a collet chuck, with straight shank expanding mandrels.

 Happy Turning!