A sliding limit block that can be attached to your existing steel ruler. Incorporates an easy to use thumb cam lock with positive snap shut to ensure the ruler does not slip once held. Allows you mark-out / scribe dimensions simply & repeatably. The wide face of the block helps to keep square up against the object.

To avoid too many variations, this listing is intended to capture the most common sizes for LARGE steel rulers, usually around 400-600mm (16-24") long rulers. Most of which fall in the range of 28-30mm wide. For other ruler widths click on the below links to listings:

• SMALL Steel rulers, 15-20mm wide (Most 100-200mm / 4-8" Long Rulers)
• MEDIUM Steel rulers, 25-27mm wide (Most 300mm / 12" Long Rulers)

Simply measure your rulers width and thickness and pick the Print Profile with the nearest dimensions in its title.

Tip: this is made super easy if you are measuring with digital calipers, and just round down/up any decimal places……examples below;

• if your ruler measures 28.2mm wide x 0.85mm thick, you would chose the “Rulers upto 28mm x 0.9mm” profile.
• if your ruler measures 28.9mm wide x 1.10mm thick, you would chose the “Rulers upto 30mm x 1.0mm” profile.

To assist with selection I have uploaded an Excel file in the Documentation (bill of materials section). It is titled ‘Limit Block Size Checker’ and will do all the math to let you know the best profile to chose…..or let you know if there isn't currently a suitable profile available.

Fasteners: For these limit block sizes you will need 2x M3 fixings which act purely as strong pivot axles to the cam lever. Optimally these would be 16mm long but you could also use any M3 fixing down to as low as approx. 8mm long.

Assembly:

• Insert the CAM lever into the Housing. Tip: Insert with the level in the closed / horizontal position as this is the angle it slides in easiest.
• Insert M3 Fixings. Tip: The fixings should pass though the limit block housing holes unhindered, but then will need lightly screwing into the CAM lever handle hole which has been deliberately sized so as to require some tightening without to much force. (Remember these are just acting as pivot points, no need to tighten down hard, but equally the fixing should not want to fall back out either.)
• Insert Ruler: Top Tip: The ruler is far easier to push in from the front (through the small slot in the block). This is due to the mechanics of the CAM.
• Enjoy - your sliding limit block is now ready to use. Note: The first few engagements of the thumb lock may be a little hard but should ease up slightly after a few uses. If not you could try printing a smaller CAM lever from another Print profile of the same width.

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