Systeme de tension pour scie a ruban (subtitles en, fr)

Systeme de tension pour scie a ruban (subtitles en, fr)


A while a go I started building Matthias Wandell bandsaw Most of you probably know him. This bandsaw is almost entirely made of wood with the exception of all the part that can’t be made of wood, that is : the blade the engine… Matthias made a whole series of video on the topic I wouldn’t want to repeat what has already been said but I thought that I would make a video on a specific part of the saw, that is the little frame here You can move it up or down like that which tighten or loosen the blade I’m not sure you can see but if I turn the crank the frame goes up or down, which in return lower or rise the wheel and tighten or loosen the blade This frame here must be really sturdy to withstand the blade tension and consequently the joints in its four corners as well I made a rabbet joint, which means that in the long sides I carved a shoulder in which the short sides fit thus increasing the contact surface between the 2 elements to be glued Additionaly I made these little triangle here. I think they are called splines which greatly strengthen the whole joint. The first step is to cut and plane down lumber to the dimension we need Next step is to cut the rabbet in the long sides I did that with a grooving blade (I’m not sure this is the right word in english), we’ll see what it is in a moment You just need to cut, move your piece a little bit, cut and so on. Sawdust is flying around because I think I forgot to turn on the dust collector but the result is not too bad A grooving blade is different than a standard blade because it has flat teeth and when you make a few parallel cuts like here, the bottom of the cut stays flat. With a standard blade the cut would have been much more irregular Now that everything is rabbeted, cut and planned down We can check that everything fits well together and since it does we can go ahead to the next step : the glue-up. Nothing really scary here. Some glue here an there. Laying down everything flat. 2 Clamps along the frame. 2 clamps across the frame. One important thing to check however, is that the length of the diagonals are the same.
And since in my case it was not I added a clamp in the diagonal to correct it Once it’s dried up, the result is not too bad. The next step is to make the splines but before that I would like to say a few words on how these spline works actually. A general rule is that you can not really glue wood this way or this way. or this way because wood fiber soak up the glue and the joint doesn’t hold. Now it is true that with modern wood glues it is not so important anymore,
but the basic principle is still true and that’s the reasons why hundreds of different wood joint have been created. This one is just one of them. So first we make a slut across the joint like that and we then insert and glue a spline in it The spline works like a middleman in the joint because as we said the 2 pieces of wood doesn’t hold to each other well but they hold very well to the sline. This is due to the fact that wood fibers are connected by their long side and not by their end and the wood joint is much stronger To cut the slot in the frame, I built myself this litle jig mounted on the table saw rails with which you can cut the frame with a 45 deg angle. The interesting thing is that with only 2 setup of the jig we can cut all the 16 slots in the frame. That is 8 cuts per setup which is quite effective To make the splines I first cut thin strips of wood with the same thickness than the slot. And since I didn’t succeed on the first try I sanded the strips down to the right thickness I then cut them down into triangles. I got a whole bunch of them And i glued the 16 most beautiful into the frame 🙂 Nothing complicated here. You just need to be careful that the glue get in the slots to have a good contact between the triangle and the frame Once it’s dry we still need to cut the triangles flush with the frame I used a straight bit with a top bearing. The bearing move along the side of the frame and the blades that are flush with it remove everything that sticks out. With a chisel I removed dried glue from under the bearing so that everything is flush And then everything went well The last part are the guiding rails As before I used a grooving blade for that Since the frame is symetrical, we can make a cut, flip the frame make another cut. move the fence a few millimeters away, make a cut and so on… The frame is now finished. It is kind of useless wihtout the bandsaw but I htought it is worth to make a video about it just to show the differents techniques used in its realisation. I hoped you liked it because that’s it for today. Thanks and bye bye 🙂

5 Replies to “Systeme de tension pour scie a ruban (subtitles en, fr)”

  1. C'est clair et bien expliqué, quand on débute on ne comprend pas forcément le principe des clefs, expliqué comme ça c'est limpide 🙂 Perso j'avais réalisé le bloc tendeur d'une seule pièce dans du massif après m'être cassé les dents à essayer de le faire comme toi sans y parvenir (il me manquait le chariot à 45° et j'avais pas trop envie de le réaliser spécialement pour ça 😉

  2. Encore bravo pour cette vidéo super didactique…. tu nous serais pas un peu débarqué de l'éducation nationale, toi ?
    Non, je plaisante. mais elles sont très bonnes, tes vidéos. Continue….

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