Stevo Posted February 26, 2014 Share Posted February 26, 2014 I'm looking to design a thickness sander for balsa and other associated modelling timbers. I'm not looking to do wide strips of balsa, I'll buy them like that! Perhaps doing something like thinning a 6x6 strip to 6x4 or other internediate sizes. I have an oscillating sprindle sander that I can base it around. Anyone designed or made one? I had some designs from KC on here which have helped, but I want to take it to the next level up. Ta Steve Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted February 26, 2014 Share Posted February 26, 2014 As a woodworker, I think you're going to find issues with attaining the correct feed speed and the required pressure on the timber, i.e. how to raise or lower the drum. Ideally you'd need a powered feed system feeding the wood either over or under the sanding drum/belt. If this feed stops or slows down then it will damage the wood. I don't envisage that an oscillating spindle sander would work with this idea with a speed feeder, as the original idea with an oscillating sander has the timber held flat on the table, and you use hand pressure to push the piece against the drum. Unless, you use some kind of non-slip feed belt that has more resistance than the abrasive, I believe that the oscillating drum will just damage the piece. All table sanders use a rotating belt and the spindles do not oscillate, and the table is adjustable for pressure. I don't doubt that it is doable, but I think the work behind it far exceeds the cost of a small planer/thicknesser sold by Axminster or even Screwfix. I believe Proxxon do a small thicknesser for modellers. I'd like to see the design you speak of, it would be interesting. I use a large stand alone planer/thicknesser bought from Axminster, and I really cannot rate it's worth enough. I don't mean to knock the idea, but IMO it'll be less of a headache buying a small thicknesser. Quote Link to comment Share on other sites More sharing options...
kc Posted February 27, 2014 Share Posted February 27, 2014 I would suggest something like a router table - that is a fence either side of the bobbin sander one to run the balsa along so it just rubs the bobbin, and the other adjustable to push the balsa against the other fence & abrasive. In other words just like a saw bench but with the bobbin sander where the circular saw blade ( or router cutter) would be.I suppose a false table with the fences could drop over the bobbin spindle and be clamped down onto the sander table.There is a good book about making a router table from wood, I think it's called Router Jigs and Techniques by Patrick Spielman, published by Stirling in USA. This might suggest some ideas.Rather than make the machine infintely adjustable it might be easier to use multiple packing blocks of 1/16 and 1/8 to adjust to any thickness between 1/16 and 3/8 inch. ( rather like the SLEC stripper ) Just my crazy ideas...... Quote Link to comment Share on other sites More sharing options...
kc Posted February 27, 2014 Share Posted February 27, 2014 There is a very simple thickness sander shown in one of the magazines years ago.It was a block with sandpaper attached, on top of the sandpaper were two runners ( strips of hardwood ) which went either side of the work.( A sort of tiny sledge or toboggan with sandpaper underneath) You just sand down until the runners touch the bench. When they touch the bench the work is exactly same size as the runner thickness. I suppose you make one for each size you need. The runners are ontop the sandpaper so it cuts exactly to the runner thickness.I would suggest a piece of Permagrit sheet would be better than the sandpaper and work faster. Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted February 27, 2014 Share Posted February 27, 2014 The router table idea would work. Mount the bobbin inside a heavy ply box, make an adjustable fence either side of the bobbin, and make a smaller fence in front of the bobbin which is also adjustable but shorter in length of the main fence. This will give you the following: The in feed fence will be 1 or 2mm further back from the leading edge of the sanding bobbing, the fence in front of the bobbin would be set with the out feed fence to the required finished dimension. These three fences will provide stability of keeping the piece steady and at a set distance and stop the bobbin sanding more off than required, and the smaller front fence would provide the pressure as you feed it through. Then again, you can just do the same with a router table and two feather boards! Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 Hi All... KC - your suggestion regards the Hardwood Runners idea is how I sand all my stuff - it's a must, as it keeps it all square! It would be great to see how SLEC & Co. do it. Daz - The idea regards the 'router' was how I envisaged it to work - you read my mind! Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted March 1, 2014 Share Posted March 1, 2014 Stevo, I've been thinking more about this, and the bobbin effect is what worries me, in regards to how you are going to keep the piece from being pushed and pulled as the bobbin is, er, bobbing! Can you remove the bobbing effect? Unless you make the fences to also include height adjustable fences to keep the piece from moving, as in the use of feather boards perhaps? Have you ever watched the New Yankee Workshop with Norm Abram? He inspired me to start working with wood all those years ago, and he invents all kinds of jigs etc. Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 The Bobbing effect cannot be disconnected I'm afraid. However we laugh in the face of Bobbing. I may take get a good quality sanding drum, and drive it with a motor - and use the routing effect you describe. And as for feather boards and New Yankee workshop... "I'll just apply some GERLOOOOO...." I have the red check lumberjack shirts and the 'Norm stick on beard" too... Love the programme. Edited By Stevo on 01/03/2014 11:38:42 Quote Link to comment Share on other sites More sharing options...
Braddock, VC Posted March 1, 2014 Share Posted March 1, 2014 Ask alan whitaker, he has a formidable intellect when it comes to designing items like this. What I did with the three 60 cm long bits of strip that I wanted thinning was to put a sheet of glass from a greenhouse on my building board then stack up strips of A3 card cut with a manual gullotine (the slide one) until almost enough stuck up above the glass and then razor planed it with the sheet of glass preventing the razor plane from cutting too deeply. I finish sanded it with one of those big permagrit blocks. Quote Link to comment Share on other sites More sharing options...
ROY DAVIES 1 Posted March 1, 2014 Share Posted March 1, 2014 I had to fix drum and bobbin sanders years ago as part of my job. Most bobbin sanders have rubber hubs with expander in the hubs and when they spin they expand some more - not evenly. The drum sanders (2 drums for a coarse and fine paper) were belt fed and had machined drums with knurled pinch rollers to hold the abrasives sheets on. the abrasive sheet were quite coarse to avoid clogging and good dust extraction was essential for that as well. If the feed system stalled or failed you would burn the surface irreparably. I think we used 80 and 120 grit Aloxite type papers for their anti clogging properties as do the timber industries and until a few years ago so did I on my sanding blocks, you just knocked them on the bench and they would self clean - lasted for years. I would think if you can get a suitable drum for a router table set up using a box to guide the stock, you would have to push and then pull the strip through to complete the trimming but you may waste some at the start and maybe at the end too. I cut triangular stock on a wooded 'v' tray on my band saw, you have to extend the tray through the blade via a cut to give the wood support , try that method. Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 Movin' on Does anyone know where I can get a 100W (ish) 1500RPM 240V AC motor from? Even looked on ebay. Nothing. I plan to get a decent sanding drum and drive it with.. something.... Quote Link to comment Share on other sites More sharing options...
kc Posted March 1, 2014 Share Posted March 1, 2014 Mains electric motors are scrapped all the time - washing machines, dishwashers, food mixers, vacuum cleaners etc that there should be something available free. I reckon the small electric motor that washing machines have to drive the waste water pump might possibly be worth looking at. Otherwise an older Black & Decker type drill is 315 watts and 900 or 2400 rpm at the chuck.Edited By kc on 01/03/2014 16:47:25 Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 Indeed Kieth...! Where do I find one? SHMBO won't be too happy if I nick her washing machine motor Quote Link to comment Share on other sites More sharing options...
kc Posted March 1, 2014 Share Posted March 1, 2014 I have got all the old motors from ours in the shed! Did you see see my additional edit about B&D ? Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 Does the Mrs. know? Must be a very quiet kitchen you have there.... B&D? Quote Link to comment Share on other sites More sharing options...
kc Posted March 1, 2014 Share Posted March 1, 2014 I edited my comment just as you posted yours.... In years gone by Black & Decker drills powered their sawbench attachment etc so may be a suitable power source. Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted March 1, 2014 Share Posted March 1, 2014 Norm is God. Enough said! "Be sure to read, understand and follow all the safety rules that come with your power tools. Knowing how to use your power tools properly will greatly reduce the risk of personal injury. (ALL TOGETHER NOW.......) And there is no more important safety rule than to wear these........... SAFETY GLASSES!" I love the way he says "Gerlooo". They've just started a new series on Discovery Shed channel, think it was on Wednesday around 9pm. I have around 100 old episodes still on VHS kept safely in my loft. A hoover or washing machine will be too powerful if you only want 100w, but with a small blender/food processor, you get a variable speed switch as well, and they tend to start at around 100w. Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 Yep that made me giggle... I have a series link on my Virgin Box. Not to mention the 'BAYENDSAH'.. or the 'ROUDER'... If in doubt, Norm, put a Biscuit in there. Or use the 'MORDISAH'... And just where does all that dust go? That's some efficient extraction system he has there. Or he will be working on his latest 'PRAHJECT'... Yes he is god... Anyhow, I put a posting on our sister forum, (Model-engineering) and some kind soul round the corner is going to give me a 0.25HP 1500rpm motor... what a gent... Quote Link to comment Share on other sites More sharing options...
David Tweddle Posted March 1, 2014 Share Posted March 1, 2014 Hi Stevo have you seen this blog on there. David Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 Yes David I have... Not sure how a supercharged V12 would run my sander though Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted March 1, 2014 Share Posted March 1, 2014 Nice one Steve, keep us updated with your progress mate. Some years ago I went to Boston on holiday, and had tried to arrange a visit to the NYW through the American TV company WGBH that does the show. At the time (mid 90's) you could have a workshop visit. Unfortunately the dates I was there was when Norm was away on his holidays! Quote Link to comment Share on other sites More sharing options...
Luther Oswalt Posted March 1, 2014 Share Posted March 1, 2014 There is a small tool company that has a thickness sander named Micro-Mark. Their URL is: www.micromark.com. Here is the sander: http://www.micromark.com/microlux-drum-thickness-sander,8599.html I have no real knowledge about this product so I cannot comment on it. Leo Edited By Luther Oswalt on 01/03/2014 20:55:44 Quote Link to comment Share on other sites More sharing options...
Andy48 Posted March 1, 2014 Share Posted March 1, 2014 All the above sounds a right faff. A Proxxon circular saw will accurately cut a couple of mm off a piece of balsa. Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 1, 2014 Author Share Posted March 1, 2014 Posted by Martin Phillips on 01/03/2014 21:25:56: All the above sounds a right faff. A Proxxon circular saw will accurately cut a couple of mm off a piece of balsa. I expect it would. But it wont cope with 4" wide stock... and I'm also after shaping T.E. stock too. And I haven't go £400 for a proxxon thicknesser, nor £120 for a circular saw... and as an engineer, we love making our own... Good call Leo, I've downlaoded the manual. Edited By Stevo on 01/03/2014 21:34:16 Quote Link to comment Share on other sites More sharing options...
Stevo Posted March 2, 2014 Author Share Posted March 2, 2014 Managed to get two motors, 1500rpm, 0.25HP A compton and a hoover Now, anyone have any thoughts on a power feed mechanism? and a suitable drum... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.