scale interlocking concrete block form

prusaprinters

Update: includes a .stp file of the base block and form, and allowed remixes in the license of the model, so you can modify the design for your block idea. Please do a remix if you upload your model.Update: New blocks 240x80x80 and 120x80x80 added upon request. The large 240cm form features the possibility to insert and glue into place a 10mm stiffening rod (aluminium rod or steel pipe).Describtion:Scale retaining wall interlocking concrete block form for RC-truck and construction machine playing landscapes and driving parcours.The base model is a 160x80x80cm standard block in 1:8 scale.Scale to whatever model scale you require:1:6 133.3% (use M6)1:8 100% (use M5 threaded rods for assembly)1:10 80% (use M4)1:12 66.7% (use M3)1:14 57.1% (drill to 3 mm and use M3)1:14.5 55.2% (drill to 3 mm and use M3)1:16 50% (use M2.5)For smaller scale it might make sense to print the blocks directly, you can find them here:https://www.printables.com/model/234941-interlocking-concrete-block-modelIt includes full, half- and quarter-block, slope, hinge and foundation block. Feel free to suggest any missing variant you would like to see. Print recommendation:Recommend gyroid infill and PETG to achieve a form that will be chemically stable against concrete additives and form separation oil.Ideall print orientation is laying on the side (as provided) as it will be used for casting later also. (L-shaped footprint on the print bed).0.4 mm nozzle for fine finish with a minimum of postprocessing (or 0.6 mm + arachne).1.2 mm wall thickness recommended (3 perimeters with 0.4 nozzle, 6 bottom and 6 top layers of 0.2 mm layer height) Casting concrete tipps:My concrete mixture: (be sure to scale your incredients to the power of 3 as volume shrinks with 3 dimensions)full block (160x80x80) 100% scaled: 480 ml water, 5 g PP fibers, 13 ml platicizising agent, 4000 g concrete premix (0-4 mm grain size).for the other blocks, estimate the concrete amount needed based on the volume (2000 g premix per liter) and modify accordingly. I usually ad 500 g concrete to be sure it will fill all forms that I prepare and do ~10-12 kg in one go. That ammount can be mixed well in a bucket by hand.For smaller scale I would suggest to leave the fibres away, to ensure propper filling of the form.Use a flat steel sheet as base (bottom side of the cast will be the visible side surface of the block)Form oil is recommended (I have not tried it without).Minimizing the water content in the mixture is important (use plastizising agent).Use vibration to remove air bubbles (oscilating multitool or similar).The top surface should be sweeped to the desired finish after the concrete beginns to set. Best time I found is ~2 h after cast. Keeping the surface wet continously helps to maintain a good finish (cover with a cardbord or platic lid that does not touch the wet cast)The form can be stripped after 24h but the block is still soft and will take 2+ weeks to cure and reach nominal hardness. I keep the blocks fully submerged in a bucket of water for a few days to ensure maximum curing hardness.