I'm not familiar with the design of this particular sawboard but another advantage* of having the suboard - the bit the base of the saw runs on is that its possible to position the board well behind the work at the start of the cut. Basically you can run the saw along the suboard, say for 6 inches before you actually start cutting into the wood, In which case you need a sub-board of sufficient thickness as can support the saw and keep it level as you make that 6 inch approach to the cut. The same applies at the other end at the end of the cut, You want the saw to travel on past the work underneath to get a clean exit, and again the sub-board needs to be of sufficient thickness to support the saw.
Basically the length of sawboard you will need - depending on size of blade you're using will need to be sufficiently long to give you a good run in at the start of the cut and a good exit at the other end for your longest planned cut,
I suspect that what I mean by sub-board is what you mean by the "bit underneath". Hardboard is unlikely to support the weight of the saw either at the start end or end of a cut. The principle behind the sawboard is sound, so theres no reason to skimp on materials. The biggest waste of money is always on gimmic tools IME.
I don't think you really need to support the saw. With the first one mentioned above, I have the guide part project beyond what you call the "suboard" at the ends. This means that if you line up the beginning of the sub-board with the beginning of the work, you can rest the front of the sole plate of the saw on it, which prevents "roll" misalignment, and push the edge of the sole plate against the projecting guide to prevent prevent "yaw" misalignment. "Pitch" misalignment doesn't matter, since the plane of the blade will be correct and as soon as you move forward the pitch angle will correct itself. The advantage of doing it like this is that you don't have to fiddle with trying to get the lower guard of the saw to rest on the sub-board -- I tried it like that (ie with the sub-board projecting too), and faff of lifting the lower guard only to have it spring back off the sub-board when I put my hand back on the grip convinced me to do it the other way.
Sure
The argument here is more convincing, (not least because the chance of your sawboard being exactly the right length is negligible), but with the hardboard I didn't notice a problem, probably because the weight of the saw was still supported by the back of the sole plate on the part of the sub-board resting on the work even when the saw had cleared the cut.
Seems likely.
It's not a matter of skimping: until I try with the 6mm sub board, I'm not going to know whether break-out is a problem.
That might depend on the weight of the saw. The AEG saw I use for cutting
18mm MDF sheets was bought years ago for cutting 24mm thick birch ply for worktops and the like. It can cut to 3in. is quite a big lump and weighs quite a lot. When I've finished the jig tomorrow, the one with the groove and the runner I'll be taking some piccies for my records - pictures with automatic dates are so much easier than bothering with a diary or notes - and I may post one on tinypic.
You've lost me. If you're keeping the saw straight and tight against the guide fence, and the guide fence is parallel with the edge of the sub-board then the lower guard will rotate backwards as soon as it comes into contact with any part of the leading edge of the sub-board and will eventually trail behind on the top of the sub-board. That's if you're keeping the saw tight to the fence. While the blade of the saw will be in close contact with the parallel edge of the sub board. At all times. Before, during, and after the actual cut. There's simply no room for the lower guard to spring back. Not if you keep the saw tight to the fence. First running the saw along the sub-board should eliminate all problems with the lower guard which should be already out of the way of the spinning blade before the blade starts cutting into the wood.
There should never be any need to change your hands.
The only time you need to worry about getting the lower guard out of the way manually is when you're doing plunge cuts starting in the middle of a board. As you would need to do for instance, if you wanted to saw a board in half in a vertical position - i.e with it leaning against a wall. (Something I forgot to mention when descibing that option last time . When sawing by hand you can start from the top but not with a circular saw. Oops!)
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One possible solution for top side breakout is to deep score the line first with a Stanley knife blade or similar. If you use a straightedge to deep score on top of your pencil line and then align the sawboard with that, that may be the best solution to your problem. Or score using the edge of the sub board taking care not to actually pare any wood off the edge - maybe by part taping the blade. There are plenty of other solutions such as taping the line before sawing. So I doubt sawboards are a definitive answer in every case as things usually aren't quite that simple.
As you've probably worked out for yourself, there's never any problem with breakout when sawing along the length of a sheet from top to bottom as the grain runs that way on both sides. So it can be useful to try and plan to have any really critical visible edges cut down the length of the sheet rather than across where breakout can be be more of a problem.
Having looked at the picture - one other thing to look out for when planning the saw board is to leave enough room i.e. make it wide enough, so that any clamps you're using don't foul the underneath of the motor when the motor is in its lowest position: i.e. when cutting the thickest material you're likely to encounter. Ideally the guide/straight edge should be thicker than the sub-board, much thicker IMO 12mm at least and so there's no reason why the 12mm factory edge guide can't be fairly narrow and the sub-board continuing out to the right to take the clamps. That in itself will reduce the height of the clamps by 6mm in relation to the underside of the motor.
Thats got to be a 230mm ish bladed saw, no wonder its tiring. Must weigh 5 or 6kg.
I use a Makita 5604 with a 165mm blade, cuts 54mm, weighs 3.6kg. I never need to cut over 50mm so 3mm ply is ideal for sawboards.
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If you make the sawboard out of 6mm ply with a 12mm guide you have a potential 18mm loss in cutting depth - depends on the clearance of the motor, you might have to adjust the saw to clear the batten.
I find the simplest way is to make double edged sawboards e.g. batten in centre, cut down both sides, leaves more than enough room for clamps.
Just out of curiosity 1 stone exactly according to my digital bathroom scales - I actually had to weigh myself first, and then when holding the saw - which is
6.36 kg according to my pound shop calculator.
When cutting up full sheets as this is, there's no weight involved as such anyway. As this is all taking place on the floor which means shuffling along on my knees. Which is what makes using a conventional single straight edge or sawboard all the more difficult. Its very hard to get a purchase with your knees on a smooth board so theres always the temptation to try and straighten up and use the sole of your foot. Plus my eyesight isn't what it was - its ok for driving or reading books etc but even with glasses I can only align edges or make out separate mm on a ruler from about a foot or less away. Which can be a pain. What's tiring is the being on your knees etc and then straightening up and having to squint to see stuff. Plus not letting the bugger wander off line as your knees slide across the board. IME its still the only way to cut a full sheet though, unless you have the sort of facilities which I don't have. If you want to do-it-yourself at least. And I'm cursed with the tight gene so I'd never ever buy cut boards on principle.
With the groove and runners I've found I can almost push the saw along with my foot. Or use a broom handle.
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here's the pix. Its just the one 1024 x 768 jpg with five images. Clockwise from the top left. 1) The saw in the first groove which I cut with the router using straight edges both sides. 2) The underside of the saw showing the runner. 3) The jig made for the router allowing it run in the last groove and cut the next groove. 4) What I ended up with 3 grooved boards of various lengths plus a template board for cutting more grooves if need be. And finally
5) The very costly, state of the art dust collection system I had designed at great expense and have fitted to the router. Like expanded polysyrene foam, MDF seems to double in volume as soon as you cut it. The shorter boards look ideal for crosscutting as its simple a matter of fitting a cross piece at right angles across the back for the work to butt up against. Using both the saw and router in the grooves really is a piece of cake as its possible to almost walk along just slightly bending down
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This thing looks like it was primarily intended for building sites. At the time there wasn't that much available and I knew of the reputation of AEG motors from another area. I used to invert it for use as a table saw as well. I had a big heavy bench which I made with drop-in inserts for a saw and a router. I've still got the legs in the shed although its never been assembled for yonks I've got a smaller Bosch saw which I use for cutting out thin stuff for jigs etc which I use in the normal way. On a bench made up of a 4 x 2 sheet, of chipboard ATM, bolted onto the top of an old B&D Workmate. You need the jaws underneath wide open for stability I found. But anything much bigger than 4 x 2 and its away with the Workmate and back down on the floor.
Indeed. Putting the clamp on the running board rather than the guide will save 12 mmm and not just 6mm as I mistakenly said. You can see why I take so long marking stuff out anyway. My spacial reasoning ability has never exactly been one of my strengths.
If you have a batten in the centre then both edges of the batten can't be factory edges unless you know where you can buy very tall and narrow sheets of plywood. So isn't that against the rools ? On the other hand I suppose if you often change the blade from tungsten to plain there would probably be a difference in the width of the teeth and so a two sided job would come in very handy in such a situation providing it was properly marked up.
Is it not possible to add or adapt something without totally spoiling the look of the thing ? The first things that came into my mind there were a broom handle and gaffer tape. Maybe not those specifically but something along those lines.
I suffered from terrible backache at one point, a combination of sitting slumped forward in chairs for years on end without giving it a thought and a sagging mattress. As a temporary expedient I put my woodwork skills to good use by cutting out an appropriately sized sheet of ply, which together with two camping rolls were put in a duvet cover on top of the existing mattress. The morning it happened it was real Hunchback of Notre Dame stuff. I couldn't straighten out properly until about mid-day; luckily it was at the weekend. I also had to wear a tight belt and brace my back with another piece of wood for the rest of that afternoon. No problems since though at all. I knew about the board stuff from someone I knew years ago who'd injured their back lifting car gearboxes or something. The only thing I remember is that they'd had to sleep on a board for months on end.
I remember when computers first became popular, every second week there seemed to be an article from a physiologist or ergonomist or similar explaining that the ideal position was for the middle of the computer screen to be just below eye level. While the arms should be horizontal to the keyboard. Something like that anyway. Otherwise you'd strain your neck and do all sorts of long term damage. Then laptops come along - which are easier for retailers to store and sell - just the one box - which totally breach those rules. And while admittedly portables do have advantages in some situations, all the ergonomic stuff and resulting dire warnings were all quickly forgotten about. So presumably there'll be an epidemic of neck problems in 20 years time with everyone walking around in neck braces and support collars. But there again at least they won't all be overweight if they've been paying proper attention to that all that dietary information on the food labels.
I don't think that would work with one of my 3mm ply sawboards, the saw would be far to heavy. With a lighter saw you can easily start on an 'overhang' of the sawboard. Also it is easier to control, no real need for any effort to hold it against the guide.
My local timber merchant charges 50p a cut & do it with great precision, well worth the money IMO.
With a lightweight saw like my Makita its entirely possible to hold the sawboard down & not use clamps.
You are missing the principle of the sawboard. You can take any old scrap offcut of ply & glue a batten roughly in the middle. The saw determines the straight edge, you don't need a factory edge. Its exactly parrellel & at exactly the right distance - because the edge was cut by the saw.
Granted if you change blades it would be different, but using cheap/scrap material you can make several sawboards for different blades or indeed saws, for next to nothing.
Anywho. I've just sent an e-mail to DeWalt, Makita & Bosch asking why the motor is on the left. We have digressed - your original point is a good one.
Sorry, I didn't explain enough detail. I was using that particular sawboard to cut lengths of timber. Doing this on a workmate I wanted to support both sides of the cut, so put the workpiece across the gap between the two parts of the top of the workmate. Unfortunately one half of the top of a workmate is only held in position by being pushed by the other, so to have a gap and have it both fixed, I put a bit of scrap each end of the gap in the workmate and tighten it up on that. Now, there's only just enough room for the blade between the first of these scrap blocks and the start of the cut. Sliding the saw on from the beginning of the sawboard would result in sawing through the scrap.
So the choice is between lifting the guard onto the sub-board, or not having sub-board in the way of the guard in the first place.
I think you misunderstand. There's no problem with breakout on the side of the cut that's up against the sawboard; it's the other side of the cut ~3mm away from the edge of the sawboard that the extra piece of hardboard is to prevent.
Good points. I've made a quick addition to the Wiki page to that effect, but maybe you could copy your whole paragraph in there?
Eh ? The edge of the baseplate follows the batten. If the batten is out of true i.e crooked then the saw will saw a crooked line on whatever you've glued the batten onto.
Yes exactly parallel to a batten which may well be crooked.
That's the reason for the emphasis on the factory edge. That's the only piece of timber or guaguing device most people will ever get their hands on which is both 8 ft long and perfectly straight.
Surely the motor is on the left because most people cut to the right of a drawn line? As in that way you saw away the waste including the dust in the kerf and are left with the exact drawn dimension. If you're sawing to the right of the line then the work is on the left and this is where the base plate of the saw and the weight of the motor need to fall.
You don't want the weight of the motor on the waste, do you ?
I'm having trouble visualising this or answering specific points as they arise. Based on your mention of using a worknmate and breakout on the bottom surface.
If you have a Workmate the best plan is to make a sacrificial top (ST) for it - sacrificial in the sense that after you've made a few hundred saw cuts in it you can throw it away, The easiest way to fix this to the workmate is to fix a wide batten underneath and clamp this in the jaws. Make the ST of as thick a material as you can afford but for which you also have clamps. Good quality G and F clamps will last you a lifetime. Make this in either chipboard or MDF. It would be criminal to use plywood for this. The size of ST you can use - stability wise will depend on the exact model of your work mate. But don't make it much bigger than the footprint.
Clamp any jigs sawboards etc to this firm, flat surface. Bottom edge breakout is greatly alleviated if you make as shallow a cut as possible. If you visualise the angle of the blade as it cuts the bottom surface, the shallower the angle the more it pushes the wood along the horizontal into itself rather than outwards. You really need to do test cuts on scrap pieces until the wood is only just cut. This also saves wear on your ST. Using the finest blade possible - the greater number of teeth will also help. The nature of the wood can make a difference as well. To do crosscuts i.e presumably cut off the same length repeatedly you need to make yourself a cross cut jig, Which you can mount on your ST. Designing your own jigs and bits is half of the fun. But you can't do that just on the jaw tops of a workmate.
I've just read down. If you're cutting 3mm ply then your saw needs to be cutting 3.1mm and no deeper. That figure is out of the air, but what I mean is keep raising the blade of the saw on test strips until there's no breakout. The easiest way is to simply set the saw on its baseplate on the edge of the
3 mm ply with a thin sheet of cardboard under the baseplate and the blade hanging over and adjust the blade until its touching the surface below.i.e. to the side Which is exactly 3mm plus the thickness of the cardboard away.
I was cutting up 3mm play myself yesterday with my small Bosch saw. No sawboard just the right depth. Impossible to tell from the cut edges which were down and which were across the grain.
Yerbut, I don't & never have used the factory edge of a sheet of ply. In fact the original sawboard design didn't use one either, it seems to have been added when the design was included in the DIY Wiki.
This is close to the original - which has sasdly vanished from the interweb.
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use a piece of pine stripwood 4mm x 36mm
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is perfectly straight, prolly more so than the edge of a sheet of ply & also allows you to make double sided sawboards.
I'm totally confused now, didn't your OP take the opposite view?
"The Medway Handyman" wrote in message news:gDKHm.1164$ snipped-for-privacy@text.news.virginmedia.com...
Eh ? That's plain sawn timber. All the timber you get in DIY sheds is plain sawn. That means they just slice the log hirizontally. As it dries out, the growth rings in all timber try to straighten out, depending on the humidity of the atmospohere in which its stored As a result even after planing boards or strips will warp bow or twist out of true or square. You'd be hard pushed to find a single piece of perfectly true softwood in any shed, except premium grade and even then its doubtful. The ideal is to have the growth rings running as parallel with the edges and faces as possible. This only occurs in the middle planks in plain sawn timber - which will be sold as premium grade, if at all, in sheds. Whereas quarter sawn timber which you'll never find in a shed is cut so to provide the growth rings running parallel to the edges and faces, and a much more regular figure on cut surfaces. And very little if any warping bowing or twisting. There's much more waste with qs timber and messing about rotating the log. Hence the much higher cost. In sheds the problem is made worse because the inside of the sheds are heated and so the humidity will be lower than it was when it was stored undercover outside. As it is in most yards. So unless you have an 8ft steel strightedge to hand I don't quite know how you're so sure its straight. This isn't an issue however as the stuff in sheds is primarily intended to be nailed to walls and the like
That is palpable nonsense
Plywood is perfectly stable in its overall dimensions. And will remain so indefinitely. An odd number of sheets of veneer are glued together with their grain running in alternate directions. Unless the glue gave way and the sheet split apart at the glueline its impossible for a plywood sheet to go out of true along its the edges. If a sheet gets damp on one side in storage - as happens in sheds - or an extra layer of decorative veneer is later placed on one side only, then the sheet as a whole can warp. But the edges will still be true. Even the poor grade stuff they sell in the sheds with holes not filled in the veneers so there are visible gaps at the edges, has edges which are perfectly straight.
If you don't believe me, you could always try asking at the information desk about the difference between plain sawn and quarter sawn timber, and all the different grades of plywood, the next time you go into Wickes.
Nope. I said exactly the same thing before. You saw to the right of the line. So the work is on the left and the waste is to the right. So the weight of the motor goes over the work, as there's usually more work than waste.
If on the other hand the work was much narrower than the waste, say in sawing off a narrow strip from a board, then you'd mark up to allow for the kerf - so a 25cm strip and a 2mm kerf would be marked up as 25.2 cm. And then again sawing to the right of the line you'd saw in the other direction. Admittedly crawling over the sheet.
The assumption however is that normally the work is wider than the waste.
I just remebered that in your previous post you said you use the sawboard without clamps ? Just by holding it. If the cut is that short, relatively speaking then that's more akin to a crosscut board. For that you fix another piece at right angles to your straightedge on the underside of the running board at the near bottom edge*, Then position the board on top of the work and butt the batten up to the edge of the work with your body weight. The first cut will then slice off all the batten to the right of the cut.
That's assuming that all the edges are square to straight with, of course.
michael adams
not necessarily right at the edge but it makes explaining easier.
I'm having trouble visualising this or answering specific points as they arise. Based on your mention of using a worknmate and breakout on the bottom surface.
If you have a Workmate the best plan is to make a sacrificial top (ST) for it - sacrificial in the sense that after you've made a few hundred saw cuts in it you can throw it away, The easiest way to fix this to the workmate is to fix a wide batten underneath and clamp this in the jaws. Make the ST of as thick a material as you can afford but for which you also have clamps. Good quality G and F clamps will last you a lifetime. Make this in either chipboard or MDF. It would be criminal to use plywood for this. The size of ST you can use - stability wise will depend on the exact model of your work mate. But don't make it much bigger than the footprint.
Clamp any jigs sawboards etc to this firm, flat surface. Bottom edge breakout is greatly alleviated if you make as shallow a cut as possible. If you visualise the angle of the blade as it cuts the bottom surface, the shallower the angle the more it pushes the wood along the horizontal into itself rather than outwards. You really need to do test cuts on scrap pieces until the wood is only just cut. This also saves wear on your ST. Using the finest blade possible - the greater number of teeth will also help. The nature of the wood can make a difference as well. To do crosscuts i.e presumably cut off the same length repeatedly you need to make yourself a cross cut jig, Which you can mount on your ST. Designing your own jigs and bits is half of the fun. But you can't do that just on the jaw tops of a workmate.
I've just read down. If you're cutting 3mm ply then your saw needs to be cutting 3.1mm and no deeper. That figure is out of the air, but what I mean is keep raising the blade of the saw on test strips until there's no breakout. The easiest way is to simply set the saw on its baseplate on the edge of the
3 mm ply with a thin sheet of cardboard under the baseplate and the blade hanging over and adjust the blade until its touching the surface below.i.e. to the side Which is exactly 3mm plus the thickness of the cardboard away.
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When doing this when using a sawboard you will of course need to place the saw on the sawboard in addition to adding the cardboard. So its 3mm plus the thickness if the cardboar plus the thickness of the sawboard away.
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I was cutting up 3mm play myself yesterday with my small Bosch saw. No sawboard just the right depth. Impossible to tell from the cut edges which were down and which were across the grain.
General purpose timber in the sheds is usually low grade. Stripwood is a premium product.
Even the poor grade stuff they sell in the sheds with holes not filled
No it doesn't. Go and look at the ply in the sheds, they employ Stevie Wonder as a forklift driver, you would be lucky to find a sheet without a damaged edge.
You could do with actually looking at a piece of stripwood before talking rubbish.
Or you could just forget measuring kerfs - which is the benefit of the sawboard - and saw left to right with the saw supported. Or do you just enjoy making simple tasks complicated?
Oh what a revalation. This was discussed here a couple of years ago.
If I'm cross cutting a board 300mm wide or less I use a framing square & line up the mark with the notch in the saw base. If its a 450mm board for shelves in airing cupboards for example, you can just hold the sawboard. If its a door or larger I will clamp it.
No thanks I'll just carry on upsetting you instead. It's much more fun. I wonder how long it will be before you run out of playground insults ? Eh diddums ?
Because the people you do the work for are clueless, as otherwise they'd do it themselves so they won't notice any difference ?
So people who use straight edges are all mugs then.
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I get the 12mm birch ply I use for straight edges and jigs and other stuff from a proper timber merchant. If you want you can get one eight foot, one six foot, and two three foot, foot wide straight edges out of one sheet with a 6x2 piece left in the middle. That's from memory as you only need to buy a sheet every few years. If that.
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My saw is heavier than yours, for a start. Rememeber? I even weighed it. I do hope you don't think I'm being patronising again in pointing that out to you.
It would be surprising if it hadn't have been discussed at some time or other, I imagine.
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The disadvantage of a framing square though surely is with its being flat there's nothing to butt up against the work. You have to do it by eye. Whereas bolting a batten along one arm would be what, ten minutes work ? A couple of holes in a framing square would do no harm and the bolts and the batten could be removed in 20 secs.
No, patronising bollox you cut & pasted from somewhere. We are well aware of how timber is cut thank you.
Oh how sophisticated.
The old 'insult the business ploy'. I've run a successful handyman business through the worst recession for decades - and I've only succeeded by working for the clueless? Highly likely.
Are you Tanner OP or Unbeliever in disguise? Or just a new f****it?
Only you. You seem unable to tell if a piece of timber is straight or not by visual inspection.
It was patronising bollox because we all know perfectly well how plywood is made, we don't need a tosser like you to inform us. And plywood edges are not necessarily straight.
You seem to specialise in patronising bollox. Like explaining how to fix a sacrificial top to a workmate & how to adjust the depth of cut. People around here learnt that years ago.
Your problems are many. You have a saw too heavy for a wimp like you to handle, you are too thick to appreciate the many advantages of a sawboard, and you have never seen a piece of stripwood.
If you are using a saw with an 80mm depth of cut for 18mm ply you clearly have the wrong saw and can't handle it properly.
No, I just think you are a complete idiot who bought the wrong saw for the job.
Oh what a f****it. You can buy framing squares with or without a lip on the edge. Either way its a matter of seconds to line up, 100% accurate, no need for bolts or drilling holes or battens.
You really like making extra work for yourself don't you? Sign of a complete amateur educated beyond his natural intelligence.
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