Custom Jig Questions Explained...
Here is a little more information on the questions we ask and why they are important...
If you don't own a decent set of calipers or, better yet, an arsenal of metrology equipment - we suggest you start with at least a good set of calipers and a gauge pin or two and a gauge ring to verify the caliper and quasi-calibrate it as it ages. If consistency is your goal - there is only one way to get there! Be consistent with every thing you do and that means being able to measure it accurately!
Call Making Glossary - Click Here Should you not be familiar with some of the various terms used on our website, hopefully the glossary will help out!
1.) Length of your sound board from tip to back of cork notch.
This is to help verify pricing - if your tone board is too long to fit on our pre-prepped jig blanks, its going to impact not only cost but turn around time. If you are unable to measure this, you are welcome to send your prototype in and have us check it out and get back with you on pricing details. Please let us know ahead of time that you are sending it, and want us to do the measurements and get back with you on pricing.
The easiest way to measure your tone board length is to grab your calipers, and measure the OAL (overall length) of your keg, exhaust face to tip of the board and measure from the exhaust face to the back of the cork notch and then subtract the cork notch length from the OAL and tadaaaaa.... you have the length of your tone board.
Our blanks are ≈2.4" long, and will have AT LEAST a .200" pedestal (distance from back of jig to back of cork notch) - which leaves a maximum possible tone board length of ≈2.2" - which will fit a huge majority of the tone board designs out there.
2.) Desired jig blank bore diameter.
Again, this helps verify pricing due to the blank you require for your jig. If its not a bore diameter we have on hand, its going to add cost and turnaround time. 98% of the jigs we make have been from our regular .6235-.626" bore jig blank. If you don't know you need a different bore size, odds are good that the normal blank will be just fine.
The better the tenon fits the jig, the more repeatable it will be... but that puts the bulk of the focus on the tenon diameter, and that's all you baby! Worrying about a few thou is likely not worth the added cost... But, for example, if your tenons are going to be .605-.609" day in and day out and have no intentions of increasing the tenon to .620-.623" - you would likely benefit from opting for a .610 (39/64") jig blank. But to each their own! You know your call, yourself, your equipment and its your money... You pick what makes the most sense to you!
3.) If you have a preferred cork notch height, feature, or length. - please let us know specifically what you require. Or if you want us to just measure your current notch and average out the thickness to make a uniform cork notch. (Side note: one of the most common cork notch heights for the standard 3/16 cork many vendors sell is .165" - which is the height of ALL of our public and flat jigs - it is NOT a 3/16" cork notch - a 3/16" cork notch is .188" and will be extremely loose when used with 3/16 cork). If you want the cork notch to be tapered (we have seen an increase in this over the last few years) or anything other than the notch being a specific height, and parallel to the sound board surface under it - please say so! We will make the cork notch parallel to the sound board if not told otherwise. If we don't know about it, we cant do it.
If you are not having us measure and average your cork notch, we need you to specify the desired dimension of the notch (in thousandths of an inch preferably). Telling us you want a "standard notch" does not tell us what size you want, we do not know what your idea of "standard" is, or how that correlates to our "standard" of .165" tall - this is why we require an actual dimension. If you want your cork notch to be the same as one of our Public of Flat jigs, please let us know which model of jig to reference. They are all .165" tall - but some are longer than others. If you want a length alteration as well, please notate the length of cork notch desired and that it is an alteration from what ever ends up being measured, otherwise we will default to matching your existing cork notch length. If you don't know or don't care, just tell us to measure your notch and average it.
PLEASE BE DESCRIPTIVE!!! Using words like "standard", "uniform", "about", "a little bit", "like a normal jig", etc do not help at all - our machines do not have a "little bit" or "standard" button on the keypad :-D. Use specific dimensions in decimal form and use words or phrases like: Parallel to the tone board, up-slope, tapered up, tapered down, parallel to the center-line axis, add .xxx" amount, etc... Everything about a jig is bringing it to dimensions... So anything and everything will need to be described in a measurement. For those that are not aware, to get to a decimal number from a fraction, one just needs to divide the top number by the bottom number. ex: 5/8" = 5 ÷ 8 = 0.625"
4.) Do you want to locate off of the back of the jig? This is sometimes used to speed up the process of locating the keg in the jig - but it requires very accurate replication of a couple dimensions for it work as anticipated. (only suggested if you have a shoulder style keg - NOT RECOMMENDED AT ALL for anyone using a taper lock design - and at that, for it to actually work like planned, the tone channel has to be the same depth in relation to the location of the shoulder)
CONTACT US FIRST - If you want your jig made to use the back of the jig as the "stop" and DO NOT want a spacer - we will have to go through the details PRIOR to making payment on the jig, as we will have to see if the added length will allow the profile to fit on the standard pre-prepped blanks. Keep in mind, the blanks are prepped and hardened - so we are unable to move the set screw location without creating a new custom blank and having it heat treated (which will add significant time and cost to the process).
Using a spacer
Locating from the back of the jig is something that some folks like to do to speed up the process of locating the keg, and thus the tip of the tone channel in the jig in the correct location. This only works if the length of the tone channel is always the same distance from the shoulder of the keg to the tip of the tone channel. This is usually accomplished by using a drill stop on your drill AND making sure that the distance from the exhaust face of the keg to the face of the shoulder is exactly the same every time - which is not always an easy task.
We feel that this option is best suited for jigging CNC produced parts or if you are really good/disciplined at either making the critical dimensions repeatable and accurate - OR - you fully understand the relationships and adjust your drill depth/shoulder length as necessary based on changes in other dimensions. Committing to using the back of the jig (with or without a spacer) to butt up against the shoulder of the keg is more or less forcing you to be more accurate and repeatable with both the tone channel and the location of the shoulder in relationship to the tip of the tone channel.
If we were to recommend going with locating off of the back of the jig to a shoulder on the keg or not... the only way we would recommend it is if you were jigging CNC production parts or if you have the skills to be repeatable and accurate and/or have the tools necessary to accurately make adjustments to your tone channel drill based on the dimension of the location of your shoulder in relation to the tip of your tone channel.
If you want to utilize a spacer or locate based off of the back of the jig, please let us know if you...
A.) Us to make a spacer for you (specify making it out of Steel +$25.00 or Acrylic +$15.00).
B.) You will make your own spacer and just want us to supply the approximate starting dimension.
C.) Want us to make the pedestal thicker and not use a spacer (we typically do not recommend this as the set screw usually ends up on the o-ring groove - but occasionally we will see a prototype where this would in fact work out).
The absolute minimum distance for the pedestal (back of jig to back of cork notch) is .200" but may be made longer at your request - provided the blank is long enough. Our suggestion is to have your jig made with the standard pedestal, which is .200" - and then to use a spacer to locate the keg properly in relation to the shoulder of your insert. This does two things that are quite helpful: 1.) It keeps the set screw off of the o-ring groove - which is a common issue with making the pedestal thicker, and 2.) It gives you the ability to adjust the depth the keg sits in the jig. Since it is not an easy task to remove material from the jig, nor is it cheap to make a new jig, using the spacer allows you to make new spacers, or buy shims washers to make your adjustments rather than having to alter the actual jig. We strongly recommend this method if you must use the back of the jig to locate your keg in the jig. To measure the dimension for the spacer, you would measure the distance from the back of the cork notch to the face of the shoulder that would stop against the barrel or jig when assembled - and then subtract the thickness of the pedestal of the jig (typically .200" ±.001") - that will yield the approximate thickness of the spacer/shim. You can use the same trick we mentioned for measuring tone board length, above. We DO NOT recommend using the taper of your insert if you have a taper locking style insert, where it stops in the barrel/jig as a locating method in the jig. There are way too many problems that may arise from do this - especially if you are hand turning. We will do everything we can to talk you out of doing that. An example of one of the issues: If your taper lock up is a 1° taper (2° included angle) and your tenon diameter varies just .001" - the point of contact for the barrel bore to the taper will change roughly .050".
5.) How you want your tone board located on the jig blank - Option 1, Option 2, or Option 3? This deals with deck height and duplicating it or adjusting for a tenon diameter that is different than the prototype.
Option 1: Locate based off of the center-line of the keg - this usually works best for those who do not maintain consistent tenon diameters. This usually ends up with a deck height that is higher than the prototype unless the tenon is right on 0.625" and cylindrical. Using this method in essence corrects for the difference in diameter between the tenon and the jig bore from the prototype to the jig. Choosing Option 1 essentially results in a higher deck height so that if your tenon diameters vary, you wont end up with too shallow of a tone channel. This is the default choice if you do not specify otherwise, or do not have a preference. If you don't know why you would want option 2, then likely Option 1 is what will best suit you.
Option 2: Locate based off of the bottom of the tenon (i.e. bottom of the jig bore where the keg would sit) - this usually works best for those who have very consistent tenon diameters and desire a specific deck height. This does not account for the difference between the tenon diameter and the jig bore. This is generally the option chosen by those making large quantities of parts and/or with consistent tenon diameters that are are within .002" of the jig bore. Our most particular call makers choose this option, not because they are particular, but because they are good enough that they can be accurate and repeatable with their tenon diameters (and being straight cylinder) within a couple thousandths even when working by hand. Customers using CNC or metal lathe turned tenons or blanks may find this a helpful option, provided their machinist is accurate and repeatable. This is an alternate option, and must be specified when ordering your jig.
Option 3: We decide based off of what we see on the prototype and what you tell us about your end-goal tenon diameter. We'll just need to have the prototype here to inspect, and a little info from you in an email that describes what your "ideal" tenon diameter is or what you are striving for in terms of diameter. We'll base our decision on what your prototype is and what is your idea of a "perfect" tenon for your design.
All in all - if you are still not sure how you want the profile located on the jig blank after reading the above info - our suggestion is OPTION 1
6.) Do you intend on using the jig for adding grooves in the tone board (commonly called 'spit grooves') using a mill or drill press?
Jig blanks have some variance side to side with regard to the jig bore. The main focus when prepping the blanks is to keep the bore parallel to the bottom surface and to mitigate costs, less attention is given to the side to side location. If you are relying on the jig bore being centered for later operations using the jig, please let us know this so that we can use a blank that has the bore centered more accurately.
The "Do your thing" option:
There it is... just what we've been waiting for!!! You don't know, don't care, don't wanna know, or what ever... You can tell us, "do your thing" and we will make the jig as if we were making the jig for ourselves. No muss, no fuss - but there is one catch... What ever you decide to do, its yours. You left it up to us, so we decided, and we did it. Just a "fair warning" and a case of "cover our butts".
>>> PLEASE BE SURE TO INCLUDE THIS INFORMATION IN YOUR INITIAL EMAIL. It is the "meat and potatoes" of the whole shebang. :D