Upgrade Cowboy CB3200 Edge Guide - Modification

Upgraded Edge Guide

I was having a real problem with the Cowboy CB3200 edge guide.  I believe it was designed for the CB4500 which has a slightly different casting in the cylinder arm.

The problem:
The thumbwheel tightens from the bottom and the thumbwheel comes into contact with the cylinder arm casting which limits the edge guide to about 1/2".  I usually set my edge stitching from 1/4" - 5/16".  The edge guide comes with a wing nut which allows for a closer setting, but is extremely hard to tighten; one of those things that you need three hands for and it also hits the cylinder arm casting.

The Solution:

Replace the threaded post and thumbwheel.

Replacement Parts:

T-Slot Bolt (M6X1 Thread), 5/16" washer, thumbwheel (M6X1 Thread)

Bronze sleeve bearing (1/4" ID, 3/8" OD, 1/4" Length).  You will need to lap the bushing from 1/4" to 21/128".  I used 80 grit sandpaper. This took about 10 minutes.

Procedure:

3/8" hole is too large for new T-slot bolt which allows too much play.

 After lapping the sleeve bearing, tap it into the 3/8" hole until it is flush top and bottom.

Place the spring washer in its original position.

The 5/16" washer was one that I had and it fit inside the stepped hole (slip fit).  It compresses the spring washer when the thumbwheel is tightened.

Insert the T-slot bolt from the bottom through the slotted keyway and thread the thumbwheel from the top.  The T-slot bolt has a flattened side which rides along the keyway and keeps the bolt from turning when tightening the thumbwheel.

Note that the guide bearing can be adjusted right up to the front walking foot without the T-slot bolt hitting the cylinder arm casting.

I also added a washer above the guide bearing to reduce the clearance from the needle plate to the bottom of the bearing.  This helps keep thinner materials from sliding underneath the bearing.

I couldn't find a 1/4-28 threaded T-slot bolt so the 6 mm - 1 pitch was substituted.

Parts Source:
McMaster-Carr

• 2868T1 - Bronze Sleeve Bearing, for 1/4" Shaft Diameter, 3/8" OD, 1/4" Length
• 92770A111 - Machined Neck T-Slot Bolt, M6X1 Thread, 25MM Long
• 90368A300 - Stainless Steel Round Knurled Thumb Nut, M6X1 Thread, 24MM Head
• I had the 5/16" washer 

Works perfectly now and is very easy to adjust.  Total cost: about $25.  The guide can be swung 180º and left on the machine for normal sewing.

Hope this helps,
Mike

Adding A Custom Pedal and Stand Modification For A Cowboy CB3200

 I am setting up a new leather shop and recently purchased a Cowboy CB3200.  I upgraded the stand (Cowboy 441 stand) but found that I couldn't comfortably sit and work.  I decided to redesign and relocate the pedal and move the machine support column closer to my chair.

I'm very happy with the changes and can now comfortably sit at the machine with my right foot applying the gas and in a comfortable position.

Hopefully this will provide a solution if you use one of these commercial stands, but would like to work from a sitting position.

This is a post about the process:

Completed modification with machine support column moved forward
and the redesigned foot pedal installed.

Original pedals and support column position.

The column is mounted centered front to back which makes the machine hard to reach from a seated position.  Also, the legs on my chair would hit the metal base preventing me from scooting up to the machine.  Note that the presser foot pedal is operated by the right foot and the gas pedal is operated by the left foot which is awkward... probably due to driving a car.

The machine had to be supported to remove the base plate for drilling.  Here, a couple of 1 x 4s span two saw horses.  The 1 x 4 nearest the support column had to be notched for the bolts protruding through the bottom of the table.

Clamps were used on the 1 x 4 nearest the support column to compensate for any weakening due to the notches.  Shims were also used to keep the board flat and square to the table.

I used paint stir sticks to left the machine just high enough to get the weight off the casters, then unbolted the base plate and slid it over one set of holes to the front.  

I also needed to drill holes for the pedal.  Blocks were used to support the machine support column.

Using what were the front holes to bolt down the back of the column, the column was moved forward about 4 1/2 inches.  A tri-square was used to square the column to the base and then a drill about the same size as the column base holes was used to mark the new front hole centers.

All holes drilled and tapped.

This machine used 10mm 1.5 thread pitch bolts to secure the column to the base.  Irwin has a tap and drill set for about $6.00.  The drill that came with the tap is an R (8.5mm).

Column Reattached

Before taking the stand apart, I took some measurements of my foot position, angle, and distance from my chair and designed a top-hinged pedal.  It is constructed from plywood.  If anyone is interested in the plans, let me know and I'll post them.  It took about two hours to build.  

The pedal is secured to the base using two 5/16-18 bolts.  This requires a 17/64 drill bit.  Don't forget to use oil while drilling and tapping the holes.  I had some 3-in-1 oil which worked fine.

Here is the project finished and placed back in the shop with the chair.

Yours truly comfortably sitting and operating the foot pedal
and the machine in a much better position.