Sunday, December 6, 2015

Ball Chair Project Wheel Jig Is Completed!

It seems like a never ending procession of projects that pass through the workshop from one day to the next.  I finish one and another three show up at my door.  Not that I am complaining..... I love it!  That's what keeps me going and gives me more to write about here on the blog so it's a win for both you and I when I can keep moving forward with the projects that you see here. 
  Yesterday I was able to put the finishing touches on the jig that I will need for the Captain America ball chair project that I posted about recently.  This jig is a vital piece of equipment that I will need to create the chair and having figured out all of the pieces that I needed to create this jig was another feather in my design cap on top of it all.

This interesting part was one of the vital pieces that I needed to make for my drill press in order to start building the wheel jig.  It's a drill guide jig in itself that I 3D printed so that I could get perfectly center drilled holes through one inch wooden dowels. 
I printed two of these drill guides so that I could get the wooden dowel aligned properly with the 3/8th inch drill bit in my drill press.  Once I had drilled through one end of the dowel I placed a bolt through the guide and the new hole so that I could align another hole at the opposite end of the 40 inch dowel.  It was just a matter of taping the drill guide in place for the second hole and then placing it again on my drill press. It worked out perfectly to get the holes I needed for the mounting of the two dowels for the wheel jig.
Here are all of the parts that needed to be assembled and put together for the wheel jig.  The orange pieces that you see in the photo above took 16 hours to 3D print.  The black assembly that you will get a closer look at in this post is the roller assembly that I also designed and 3D printed for this portion of the project.  This added an additional eight hours to the 3D printing.  So the hours already have added up quickly and I haven't even started to putting the assembly together yet.
I did refine the design quite a bit when I figured out the mounting parts that I needed for the two one inch dowels for the assembly.  Originally I was going to have two solid 3D printed bars that would hold both dowels in place until I figured out that these would add an additional nine or ten hours of print time to the project and a whole lot of ABS plastic in the process.  As you can see I trimmed that way down to simple circular dowel mounts.  I only need eight of these small parts that only took around an hour to make.  A big savings in cost and time so it was well worth the effort to get this part of the assembly looking and working this good.
Once I had all of the dowel  and 3D printed parts for the base aligned and mounted properly I could breath a sigh of relief.  I had to take extra care not to mess up with the drilled holes for the large base and the smaller spacer boards that are just underneath of the orange 3D printed parts for the dowels.  Also the holes for the dowels needed to be aligned to everything as well so when it all dropped into place I just had to say " Man! It's like I knew what I was doing or something!"  Anyway the workshop gods were on my side yesterday when this part of the project worked out just as I had planned.
Next came the roller assembly that needed to be mounted to the wooden dowels.  These rollers will help with the rotation of the foam rings that I will be cutting or any circular wheel that I want to cut in foam in the future.  The wheels are some left over skateboard wheels that I had in the shop and they fit the bill nicely for the jig.  On the side of each of the mounts for the wheels is a small wheel to rotate a bolt to create a friction point for the roller assembly.  This was done so that when the entire assembly is tipped at different angles this roller assembly will not move out of position while creating a cut with the hot wire table.  The bar between the two roller mounts is just there to keep the mounts from rotating out of position around the shaft of the wooden dowels.
I had to take apart the dowel assembly in order to get the roller assembly mounted to the wheel jig. But this was just a simple matter of removing the end bolts from each of the dowels and then sliding the roller assembly into place. Once I was happy with that being done I reassembled the mounting bolts for the dowels.
Next came the lower mounts for the wheel jig platform assembly.  The large slot that runs down the center of the base of the jig assembly was made this way for easier mounting to the hot wire table.  This also provided easy access to installing the bolts for the lower mounts.  The bolts needed to be mounted with the heads being on the bottom of the assembly for clearance purposes when in use.
The upper mounts for the jig platform were slid into place next with perfect alignment to the lower mounts.  These parts I tried to created in wood but could not get the accuracy that I needed for the assembly so 3D printing them took a bit longer to create them but it saved me a lot of problems in the process. Plus the look and fit was perfect as usual.
Lastly the wheel jig platform is mounted to the upper and lower mount assembly using wing nuts.  This portion of the assembly is designed so that the platform can be loosened and tightened into position to get any size diameter Styrofoam wheel that I want to cut.  This along with the capability of being able to have this assembly mounted to my tilt bed hot wire table will also allow me to create any sort of angle I need on the outer and inner faces of the rings I need for the ball chair project.
Here is a computer image of how the wheel jig assembly will look once it is mated to my tilt bed hot wire table.  The blue arms of the table allow me to tip the hot wire table to any angle from zero to forty-five degrees.  I used this table extensively when I built my three section kayak and my motorcycle cargo trailer projects.
   When I use the wheel jig assembly it is just a matter of measuring the distance from the center pivot point of the wheel jig dowel to the hot wire and then rotating the Styrofoam to create the wheel or ring that I need for the project.  With the ball chair project there are six different rings that need to be cut ranging in size from 40.27" to 30.16" in diameter. So this jig will help me accomplish this task with the accuracy that I will need for the project and also give me another good accessory for my hot wire table for use in future projects.
The next step in the ball chair project will be to cut out the rings for the first section of the chair. Once again I will have to take great care in this process to get it right the first time. I have the materials on hand now and will have to check and recheck my setting on this wheel jig/hot wire table setup to get it all dialed in correctly.  I'll just have to take my time and hope the workshop gods are on my side once again.  Have a good one and stay tuned for further developments on this and other projects.

1 comment:

  1. I love your design for the hot wire table. Can't believe that I've missed seeing this one. Awesome job and thanks for sharing! I get a kick out of seeing practical things you design and build with a 3d printer.