Free Tube Cut & Mitre Block Generator
Free saw guide and cut block generator for round tube, box section, hex bar and extrusion, with mitre and bevel slots. Order it printed in NZ.
What It Does
Cutting a tube square by eye is difficult, and cutting one to an angle by eye is a waste of tube. A cut block holds the section exactly and gives the saw a slot to follow, so the cut is the angle you asked for on the first attempt and every one after it. This generator builds that block around the section you are actually holding, live in your browser, with nothing uploaded. Designing is free; we print the block and courier it anywhere in New Zealand.
The Section It Holds
Round tube, square and rectangular box section, hex bar, oval and aerofoil sections, D-sections, T-slot extrusion in the common series sizes, or your own outline typed in as a list of points. Presets cover frame tubing, stock sections and the bicycle sizes that come up constantly, from a 27.2 mm seatpost to a 36 mm stanchion. Measure the piece you have rather than trusting the label: extruded tube runs to a tolerance, and a block cut for the nominal size will be loose on some pieces and tight on others.
Fit
Slip, snug and clamp are the three fits, or you can type an offset of your own. Slip lets the tube slide through for marking, snug holds it for a hand cut, and clamp is meant to be squeezed shut on it. The right fit is a judgement about how the block gets used, not a printer setting, which is why it stays a control. A lead-in chamfer at the mouth of the cavity is worth keeping: it stops the block catching on the end of the tube and makes a snug fit far less annoying to use.
Cradle, Vee, Split Or Sleeve
A cradle wraps part-way round and is the quickest to use, since the tube drops in from above. A vee block holds any diameter over a range on two flanks and self-centres, which is what makes it the tool of choice when the diameters vary. A split block is two halves bolted together with a nut trap, so it genuinely clamps. A sleeve is a closed tube the work slides into, the most accurate of the four and the least convenient. The wrap figure controls how far a cradle reaches round, and relief slots let a clamp block flex where it needs to.
The Saw Guide Slot
Turn the guide slot on and set the mitre and bevel angles independently; the tool reports the true compound angle those two produce, which is rarely the number people expect. Blade thickness and kerf clearance size the slot for the saw you own, and the station position sets where along the block the cut lands. For anything you plan to use repeatedly, add the steel guide plate pockets: thin steel strips either side of the slot mean the blade rubs steel instead of plastic, and the block keeps its accuracy instead of slowly widening its own slot.
Holding It Down
Magnet pockets let the block sit on a steel bench or a vice jaw and stay put. Bench fixing holes bolt it down properly for production. Both are worth having on a block you will use often; neither is worth the plastic on a block for one job.