How to build a portable target frame

For optimal performance with the ShotMarker, your target frame should be rigid and stable. The sensor mounts should be square and in plane. A target that flexes and shakes in the wind will not be as accurate as one that doesn't move.

You don't have to follow these directions word for word, but I find this 28" square frame (17" shooting area) ideal for a portable, personal frame that can fit in your car, and will provide optimal performance from the system.

However you proceed, be careful about "good enough". More screws and stronger materials is probably worth the trouble.

​Materials
  • 2x10, 44" length x 1 (A)
  • 2x6, 28" length x 4 (B, C, D, E)
  • 2x6, 8" length x 2 (F, G)
  • 2 1/2" wood screw x 48
  • 1 1/4" wood screw x 18

Advice: measure and pre-drill all your holes with 1/16" bit. It helps.
​Step 1 - Base

Start by measuring a position for the lower frame (B) on top of the floor (A). It should be centered in both directions. Attach with three screws on each side, from the underside of (A) as shown:

Step 2 - Sides

Next, place the frame sides (C) and (D). Verify that they rest flat on the floor (A). Secure each to (B) with ​four screws from the front (leaving space in the middle where the sensor bracket will go).

Secure the sides (C) and (D) to the floor (A) with three screws each.

Step 4 - Top

Attach the frame top (E) to the sides (C) and (D) with four screws from the front.

Step 5 - Side Supports

The side supports (F) and (G) will prevent the frame from flexing back and forth. Cut the corners to fit nicely if you wish.

Secure each side wall with six screws as shown. Be careful that the screws do not intersect other screws already installed.

​Secure the side supports to the floor (A) with four screws through from the bottom each.

​Step 6 - Sensor Brackets

Install the brackets with the correct color in each corner as shown in the photo below. The bottom brackets should have 1 1/2" clearance to allow the sensor cable to fit.

The sensor brackets should form a rectangle. Ensure:
  • Width on top equals width on bottom
  • Height on left equals height on right
  • Two diagonals match
  • Top and bottom are level horizontal
  • Left and right are level vertical

Measure carefully. Accuracy of 1-2 mm is ideal. A rule of thumb is that the shot errors will approximately match the target frame errors. If one sensor is 1/4" out of square, then reported shots near that sensor might be shifted as much as 1/4". You will calibrate to ensure the center is correct, but shots near the edges of the frame are the ones that will suffer.

Step 7 - Measuring width and height

You will need to enter the sensor width and height into the system. Measure from center to center, or left to left, or right to right (these are all the same).
​
If your two measurements differ by an acceptable amount, use the average. Write the numbers in millimeters on the target frame so you will remember.

Finished!

You should add some feet, depending the type of ground you shoot on. The target rocking back and forth in the wind is the fastest way to kill accuracy, so ensure it is not able to wobble.

The Sensor Hub should tuck nicely along the bottom edge of the frame. If you are afraid to shoot it, lay it down or move it to the side. It can go anywhere; wireless range is a non-issue for medium distances.

This frame has a 17" square shooting area. Use cardboard or coreplast as a backing for your target paper, not plywood or any solid object. Staple the backing to the sides, not the top/bottom, since the sides are in plane with the sensor brackets.

Aim near the center to avoid shooting the frame. Remember, with electronic marking, you can reuse a single aiming mark. The system will record every shot in sequence even if they keep going through the same hole, and you can clear and save separate strings as often as you like. Ideally, adjust your elevation so that you can aim slightly low while your shots go through the center. This way you avoid obscuring your sight picture with bullet holes.