A new rule of thumb for me. Is your tab thick enough?

I've been thinking about replacing my finger tab.  It's never quite fit me comfortably and the leather is too thin/floppy.  My fingers get sore after about 30 minutes of shooting.  I asked the knowledgeable Chris Hill what he recommends, and regarding the thickness of leather, here's the rule of thumb he suggested:

For each 10# of weight on the fingers, 1mm of tab thickness.  20# on the fingers? 2mm thick tab leather.  30# on the fingers?  3mm thick tab leather.  This is a guideline I think I can remember.  Just in case I can't though, at least it's here on the old blog.

A great video on recurve aiming

I saw a link to this video on YouTube by ArcheryWinchester.  It describes proper recurve aiming and some potential issues people may encounter. 

I'll be incorporating this into my own shooting and when I give advice to others.  Good stuff!

3D Printed Sight-Mount for Cartel Clicker

Several years ago while helping with my daughter's JOAD team I got the crazy idea to make a 3D printed mount to attach an inexpensive Cartel Magnetic Clicker to a sight extension.  It's a similar concept to the excellent AAE sight-mounted clicker, but the idea was to make it cheaper and also keep the option of mounting the clicker directly on the riser if desired.  The AAE works great, but you can't move it to the riser if you decide to go that route - you'd get to buy a new clicker.

After a few rounds of prototyping I came up with something that I even tried making molds of and casting myself.  Let's just say that worked, but only barely.  I discovered that these initial attempts had a flaw - the kids would rotate the clicker so that it aligned with the sight bar when they took their bow down, thereby making it impossible to return the clicker to the exact spot next time they assembled it.  Having a look at the Cartel Magnetic Clicker (Midas) the base has a unique shape, which I used to make an inset in the mount.  This inset makes it impossible for the clicker to be rotated on the mount, so as long as the mount is in the same place on the sight extension, the clicker will always be in the same location.

This design works really well.  It's also not terribly expensive when ordering from Shapeways.  Shapeways uses SLS machines with nylon, and the print quality and tolerances are really great.  The problem is, the cost is still a bit higher than I had wanted it to be.  It's about $12 as of this writing (Dec. 2017) to get from Shapeways, plus shipping.  Many have been ordered through Shapeways by myself and others over the past couple of years.

Fast forward to 2017.  I needed three more of these and wanted to find a way to bring the cost down.  Printing these on a more common FDM type 3D printer would make these considerably less expensive.

The design I came up with has portions that cannot be printed on a FDM 3D printer without support structures.  Many people have access to these types of printers at schools or libraries or they may even own their own machine.  The cost of printing something like this on a FDM machine would be a lot lower, so I did a little re-thinking.

By removing just a few parts and re-orienting the insets for the captive nuts (used for providing metal threads), I was able to make a modified version that can be printed on a FDM printer.  In my area, the library has a Lulzbot Taz that you can order 3D prints from at very minimal cost.  I didn't know for sure if it'd work, but I sent it off to be printed.  It successfully printed* and cost a whopping $0.68!  That's more like what I had originally hoped.

Here's a summary of the Shapeways printed version versus the Library FDM printed version,

Shapeways Version

• Very high print quality
• Very good tolerances
• Wide variety of colors
• Lightweight material
• Reasonable turnaround time
• Unfortunately, more expensive than I had wished, but not outrageously expensive.

Library FDM Printed Version

• Tolerable print quality, but not great.  It's usable, but definitely visible layering and some artifacts are always present.  In some cases, the first few layers printed spread out horizontally and are thinner, resulting in deformations that must be dealt with using sandpaper and sharp blade carving.
• The material is much harder than the nylon used by Shapeways' SLS machines.
• The cost is very, very low.
• Turnaround time can be slow.  I've had it take 3 weeks on parts before, but hey, it's really cheap!

I find that the FDM prints are usable, provided you don't mind the print quality and doing some cleanup to deal with the distortions.  The Shapeways SLS prints are of vastly better quality, but I think the plastic used in the Library's FDM machine (PLA plastic) might be a little stronger.

So here's the interesting part.
While these have been available to order from Shapeways for some time, I've decided to make the STL file I used for the FDM printer available to download.  If you have access to a FDM printer and want to try one, the link to the STL file is below.  The units are MM.  

https://drive.google.com/open?id=1A3abQLRj_yXJMcxNRn80CvQuP6ioPCX3

Licensing 

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

This means you can make them, modify the design, and share the modified design with others, but you cannot use it for commercial purposes (sell them).

Choices
So, if you want to try one of these, you have two choices now:

1. Order one from Shapeways if you want the much higher print quality
2. Print one yourself using the STL file if you don't mind the look and possible distortions.  

As I said, I find that the FDM print has vastly inferior print quality but it's still totally usable and is very, very, very cheap.  You decide what's important to you.  

Here are some photos to help you decide.  The Library FDM print is on the left, and the Shapeways SLS print is on the right.

FDM Printed Mount (left)

Shapeways SLS Print (right)

Shapeways SLS Print (right)

FDM Printed Mount (left)

ASSEMBLY INSTRUCTIONS
You will need: 2 #6-32 nuts, 1 #6-32 by 3/8" machine screw, and 1 #6-32 by 2" machine screw.

The nuts go into captive insets on the back of the lower adapter.  You may choose to put a dab of super glue in the inset prior to inserting the nuts to hold them in place.

The clicker goes in the inset on the front of the lower adapter.  Remove the rubber washer if you have one before putting the clicker into its inset.  Use a short #6-32 screw to hold the clicker in place.  If you need to, add washers so that the screw doesn't stick out the back so far as to interfere with the 2" bolt.

Insert the 2" bolt through both vertical holes in both pieces.  Attach the mount as seen in the photos.  Don't over-tighten the mount so much that it crushes the mount or your sight!  Just tighten it firmly so it won't move.

Aim small, hit small

This past week I had the privilege of running the archery range for two days at my church's annual girl's camp at Camp Batel, Wyoming.  The girls that attend these camps range in age from 12-18 years old and the majority of them are not experienced with archery.  In fact, a few have never touched a bow in their lives!

I had groups of 20 or so come through during the days, with most groups shooting for around 45 minutes.  About 150 girls in total shot at the range, I think.

I took up some standard 40cm targets and some balloons (about 8 inches) to shoot at as well.  The balloons had a little extra fun added - I put a bit of flour in each so they make a cloud when they pop.

In the afternoons and evenings the girls had free time and a lot of them chose to come down to the range and shoot some arrows.  Some girls were getting pretty competent, so I worked with those that wanted to improve a bit.

One girl was shooting very well with the camp's Polaris bows, so I offered her the opportunity to shoot the PSE Optima I own that I brought up.  She did much better with this Optima and acclimated to using a finger tab quickly.

The girls all wanted to shoot at some balloons, so I put some up.  The girl shooting the Optima immediately hit hers and asked for another.  As I was putting up the balloons I decided to give this girl a challenge.  I gave her a small water balloon to shoot at instead (~2 inches), placed right over the 10 ring on her target face.

The first response to this was "I can't hit that".  I told her that I was pretty sure she can.  She responded "No way.  I can't hit that.  I haven't even had one arrow fall in the yellow directly."  I again reassured her that I was positive she could hit it and asked her to try.  I told her the funny thing is, if you aim small, you'll hit small.  She was skeptical but agreed to try.

The best thing happened next.  She shot her first arrow after putting up the small balloon and the arrow went right into the X ring, popping the small balloon!  She was so excited . There was a lot of cheering and celebration.  It was really cool!

When shooting with the JOAD team, I regularly put up targets that have only the 7, 8, 9, and 10 rings (only red and yellow), but they're the exact same size as the 40cm targets' red and yellow rings.  A funny thing happens - the archers' aim improves even though the area they're aiming at is exactly the same size.  The removal of the distractions allows them to focus on what's important.

So, this experience at camp reminded me that when you allow yourself to be distracted by extraneous stuff, you may not hit your target.  This applies to regular life as well as archery.  When you focus on what's important, you're much more likely to achieve it, even if you think you can't.

It's been a few weeks now and I've made quite a few strings.  I've experimented with several methods of loop end making.  So, in this photo are three methods.  The one on the left: two-color loop.  The middle one: the method shown in Evans Performance Bowstrings (executed less-than-perfectly).  The one on the right: the method described in the Texas State Archery string making instructions.

The two-color method is definitely the most interesting looking and the most fun, but it results in large lumps of served string under the serving.  That's not an issue most of the time, but if you decide to put no-glove type devices on your string, you will destroy your serving.  I also don't like the multiple tag ends that can show.

The method in Evans Performance Bowstrings results in absolutely no bump of served string under the serving and is therefore very sleek, but it's very difficult to "weave" the transition at the base of the loop and have it look nice.  I suppose this improves with experience.  Plus, the tag ends are only visible at the very ends of the serving away from the loop, so a clean look.

The Texas State Archery method seems like a compromise between the two.  You get a bump from serving over some served string, but it's half as much as the two-color method.  You also get no visible tag ends on the loop, just one at the end of the serving if you do it right.  It's easier to do than either other method.

So, I think I'll probably be doing the Texas State Archery method for most bowstrings from now on.  It's clean, strong, minimal "bump", and quick.  Hard to argue with that!

Non-scratch clamp-able feet for Cartel CX-1 String Jig

As mentioned in yesterday's post, I recently got a Cartel CX-1 string making jig.  Overall I'm very happy with it, but I did have to do something about those feet it came with.  If you haven't seen one, here's what the ends look like, with bent aluminum bars as feet:

Cartel CX-1 Jig: End with bent aluminum feet

As you can see, the aluminum bar stock used for the feet has simply been cut off and then bent to form the feet.  This works, for sure, but the actual contact with your table is a fairly sharp edge.  This will destroy the surface of the table upon which you make strings!

Besides messing up the finish on your table, the jig is all-aluminum except the posts.  This means it's very light and will slide all over while you work (further scratching your table).  Clamping this thing down would be a nice option, right?

Here's what I did.  I got a cheap wooden yardstick from my local big-box hardware store.  I also got some longer zip ties.  I cut a length of the yardstick for each end of the jig, zip-tied it to the jig with an extra portion of the wood sticking out for clamping, and then attached some self-adhesive felt pads to the bottom.  Problem solved!  No scratches on the table and I now have a convenient place to clamp.  Naturally, a photo is in order:

Cartel CX-1 String Jig with non-scratch, clamp-able feet

 
Having used this jig now to make close to 25 strings, the difference in usability from simply clamping it down is significant.  Plus, I am no longer "distressing" the finish on the table.  Cost less than $4 to do, so I call this a win!

Making Bowstrings ...

The back story: a buddy of mine has been volunteering as range master for an archery range at a Cub Scouts Day Camp.  It goes for several days, and as many as 200 Cub Scouts will be shooting (not all at once).  He has some inexpensive fiberglass bows that have been used for many, many years.  This year, they didn't come with strings.

I have been considering getting a string making jig for some time so I can help Boy Scouts with their Archery merit badges, so I figured now is the time.  I picked up a Cartel CX-1 string jig and a Bearpaw serving tool.  The jig can be seen to the left, including the modifications I made to the feet to keep it from scratching my table and allow me to clamp it in place (a big help).

I had limited knowledge of what I was doing, so I posted on ArcheryTalk asking for recommendations on string material, number of strands, and serving material for generic, low end bows.  A representative from Brownell Archery contacted me and helped me out with a bunch of materials!  I received a bunch of B-50 bowstring and #4 Nylon serving thread in an assortment of colors.

Now that I had the materials and the tools, I set about learning how to make some strings.  I watched a bunch of YouTube videos and read a lot of online tutorials.  The online tutorial that helped most at first was this one from Texas State Archery.

I've discovered that there are dozens of techniques and methods for building bowstrings.  It seems people find the way that works for them and use that.

After a few shaky attempts, I was getting something resembling a bowstring!

Starting and Stopping Spinning

The biggest trouble I had at first was the terrible instructions for the CX-1 jig.  They just don't clearly tell you how and where to start spinning the bowstring onto this jig.  Furthermore, the instructions tell you to do things that can't be done.  After some looking at YouTube videos, I settled on the following way to start and stop spinning the bowstring:

1. Wrap the string several times around the inner post of one end of the jig.
   
2. Spin the strands of string onto the jig. (Don't count the 12" part from the inner post to the outer post!)
3. Finish spinning by wrapping the string around the outer post on the same arm that was used to start in step 1.  Cut the string so you can get the spool out of the way. 
   

Making End Loops

I used two different methods for making end loops:

1. Serve a section to a particular length, then finish it and cut the serving thread.  Form the loop and serve the rest of the loop (sometimes in a contrasting color).
2. Use a continuous piece of serving thread as in this YouTube video by Evans Performance Bowstrings.

Method #1 has the advantage that you can use different colors for the loop and the rest of the loop serving.  I made all the Cub Scouts strings with a red upper loop, black serving and a black lower loop.  Also, if you mess up the loop closing serving, like we did installing no-glove string button devices, you can more easily repair the problem.

The problem with method #1 is that you get a lump at the base of the loop, which can be challenging to serve cleanly, and makes installing those no-glove string buttons nearly impossible without ruining the serving.  

After the experience of building over a dozen strings for the Cub Scouts using method #1, I have since switched to method #2 as shown in Evans Performance Bowstrings video. Although you can't mix/match serving colors like I did using method #1, the result is a much smaller and neater looking end loop.  I suspect it's probably a bit stronger too.

For my sanity's sake and for future reference, here are the serving lengths and starting points I used for making end loops using each of these methods:

Method #1

Upper loop: serve anywhere you like as long as you have enough room.  Serve a 4" length and finish it using a whip end.  Position the loop as desired after you rotate the jig arm back.  Serve the rest of the loop, starting so that you get a 1.5" loop.  I usually don't match up the ends, so that serving over them tapers a little.

Lower loop: rotate the jig arm 90 degrees on the end opposite that you just finished serving.  Measure 3.75" from on post (the jig arms are 12" apart on the CX-1).  Start serving there.  Serve for about 3.75" to 4".

Method #2

The video from Evans Performance Bowstrings says it all, except it leaves out a couple of things, like measurements.

Top Loop: Serve 3.5" before rotating the jig arm and aligning the ends of the serving.  This will give you roughly 1.5" top loop.

Bottom Loop: Mark the exact center of the bottom loop location.  You can use a marker as in the video or tie a small piece of serving thread at the exact middle on the post.  The serving for the lower loop should be about 2.5", and must be centered exactly on that mark.  This will give you roughly a 1" bottom loop.

Which Method?

Since I've mentioned two methods for making the end loops, you're probably wondering which I'll be using in the future.  I guess it depends.  If I want a flashy, multi-color served string, I'll use method #1.  If I want a sleek, potentially stronger string, I'll probably use method #2.  Either will work pretty well.