Free Tensioner Roller & Idler Generator
Free tensioner roller and idler pulley generator. V, U, flanged, crowned and twin-track profiles on a standard bearing. Order it printed in NZ.
What It Does
A roller is a simple part with two numbers that matter and a dozen that do not: the track the chain, belt or cable runs in, and the seat the bearing sits in. Get those right and the roller runs true and silently for years. This generator turns a profile and a bearing choice into a finished roller, live in your browser, with nothing uploaded. Designing is free; we print the roller and courier it anywhere in New Zealand.
Track Profiles
A vee groove is the chain guide and track wheel shape: the flanks centre the chain or the extrusion rail and the flat root keeps it off the bottom. A u-groove is for cable, where the radius should match the cable so the strands are supported all round rather than pinched at two points. A flanged profile keeps a flat belt where it belongs by walling both sides. A crown lets a flat belt centre itself, which it does naturally as long as the crown is gentle, so a millimetre or two of drop across the width is plenty. Twin track carries two lines side by side, and a plain profile is a chamfered cylinder for the cases where all you want is a smooth roller.
Bearings And The Seat
Pick a bearing from the table and the seat is sized to it: the common miniature series from MR85 upward, the 6800 and 6900 thin sections, and 608 skate bearings, which are the cheapest steel you can buy. The seat fit is a design decision and stays a control. A slight interference gives a press fit that will not walk out, while a slip fit and a retaining compound suit a roller that has to be serviced. Seat extra height lets the bearing sit flush with the face or recessed below it. Choose a plain bore instead and there is no bearing at all, which is right for a low-speed idler running on a bolt.
Hubs And Wall Thickness
A double hub carries a bearing each side and takes side load properly; a single hub is lighter and shorter for a slim upper roller. Whichever you choose, watch the wall over the seat, which the tool reports as you type. That wall is what stops the bearing pushing its way out through the side of the roller, and it is also the wall that has to survive being pressed onto in the first place, so thin is a false economy. The track root diameter is reported for the same reason: a deep groove in a small roller can leave almost nothing between the root of the track and the top of the bearing.
Curve Resolution
Draft, standard and fine control how many facets go round the circumference. Standard is smooth for a roller of 40 mm or so; go finer as the diameter grows, since it is the facet size in millimetres rather than the count that a running chain feels. The volume figure alongside is the solid volume, which is what the quote is worked out from.