Thread: saw problems

I really feel for ya buddy!

I find cutting mitres on my $1500 CMS a bloody nightmare..... to get totally accurate mitres (ridiculous I know) I use one of those $35 mitre saws with the wide blade saw mounted in it.

at least I get some added arm-exercise

David,
first off place a straight edge across the fence to check that it is straight. Then use a square to check that the blade is square to both the fence and the table. Also using a larger square make sure that the travel on the slide is square to the fence as well. You'll probably find that some of these settings are a smidgeon out. Adjustment of these settings varies from saw to saw. Once you've got it all square you also need to check that when you lay the saw over to do bevel cuts that it is really at 45deg. There will be an adjustable stop somewhere for this. The other thing to check is that there are no bits of sawdust between the stock and the fence as this can throw things out as well.

Mick

Sometimes if the stock moves during the cut, it can also cause what looks to be like a bow in the middle. Make sure that stock is clamped down firm and check the blade is on nice and tight. The blade itself could also be a little bowed giving an inaccurate cut... speaking of which... what type of blade are you using? The standard 40 tooth is probably a little rough for finer mitre joinery. An 80 tooth might give better results, although these suckers cost some big $$

Which model Ryobi? Does it have just one, or two slides?

My neighbour has a single slide Ryobi and there is a bit of play at full extension. In use, it is easy to let the play in the system allow the cut to go offline. That could be the reason for your "bow in the middle".

Is the "gap" you talk about caused by the cut not being exactly 45 degrees so that you don't get a true 90 degree joint? If that can't be corrected as per a previous post then one way to compensate is to make the cuts from different sides of the saw blade without moving the blade across. You will have to flip the work piece over, top to bottom, to achieve that

eg - If your saw cuts 44 degrees when the work piece and the blade are to the left side then it will cut 136 degrees when the work piece is to the right side and the blade is to the left side. That translates to 46 degrees when you flip the work piece back. Provided you can achieve that safely then the total angle will be 90 degrees, despite the inaccuracy.

:eek: One word of warning :eek: . Cutting with the work piece coming from the right, motor, side of the blade can be awkward. Keep your fingers out of harms way and don't cross your arms. Do a dry run and use clamps to hold the work piece in place if you feel at all uncomfortable.

Items cut at 44 and 46 will not be the same length across the cut, making further issues to deal with. I guess it depends on what is being mitred here - if it's an internal architrave that can be easily fudged, then that would be fine I guess, but if it's an outside corner of a cabinet's header mould, then it could be a problem.......and for what it's worth, I love the older homes where the architraves have corner blocks, enabling all cuts to be at 90 degrees.

You are right Steve. It is a question of which is the lesser of the two evils.

As to corner blocks, I saw an example of that just yesterday. A local doctor has converted an old house into his surgery and, thankfully, has retained the old, ornate skirtings. At every corner there is a corner piece, about 65 mm square, that rises above the level of the skirting and has a carved top.

It looks wonderful but, oh boy, can you imagine the cost of doing it today.

The room I saw was all internal corners. How would you do it for an external corner?

g'day again - not sure if you mean architraves or skirting boards in part of your post, but the cost of the "right" corner blocks is around $20+ each, which sure adds up! The there’s the cost of everything else! Will eat lunch and post again some of the stuff we are doing here….

Can you explain further what youre referring to (skirting boards? Room panelling?) when you mention inside and outside corners?

Thanks

Originally Posted by seriph1

g'day again - not sure if you mean architraves or skirting boards in part of your post, but the cost of the "right" corner blocks is around $20+ each, which sure adds up! The there’s the cost of everything else! Will eat lunch and post again some of the stuff we are doing here….

Can you explain further what youre referring to (skirting boards? Room panelling?) when you mention inside and outside corners?

Thanks

By skirting, I mean the horizontal board at the base of an internal wall. Also called kick board, I believe. It is the piece that gets marked by brooms and vacuum cleaners and, these days, is generally about 100 mm high off the floor, made of MDF, and has a rounded, bull nosed, top.

An internal corner is a conventional corner where the walls meet at 90 degrees. By an external corner I mean the 270 degree corner you get when the skirting comes around something that protrudes into the space. You see the latter in old house where there is an archway in a passage and, sometimes, when a fireplace protrudes into a room.

I work in an old building, 106 years since the foundation stone was laid, and it has 450 mm high skirting boards made of jarrah. They did some renovations to the place a few years ago and, in the process removed and scrapped some short pieces. Somehow, they found their way into the boot of my car. That is the nicest, clearest jarrah I have ever seen. The skirting boards in that place would cost, today, about the total value of my house.

David. Sorry to take over your thread. If this goes any further I will start a new thread. I hope you get something useful from the comments.

David

If you are trying to acheive a 90 degree angle to fit in with the corner of a wall you should measure the angle first as most walls are not exactly 90 degrees. You may be trying to fit an accurate 90 degree join into a 95 degree corner.

If you are doing fine furniture then one way to get the mitres spot on is to use a shooting board or a donkey's ear depending on the type of mitre you are trying to make.

This can be a bit time consuming and involves using a handplane but once you get into it the time flies and the results are rewarding. This method is probably not suitable for large building renovations but if the job has to be spot on then perhaps it might be worth investigating.

- Wood Borer

The Ryobi with the single slide is very easy to pull out of alignment. It's essential that the height of the saw is at a point where you are not reaching for it in an awkward manner. When you are standing to one side of the saw (as you have to do) if it's too high you will tend to pull it toward the side you are standing. The single slide and even most double slides are not rigid enough to stop you doing this if the height of the saw is not perfect.
Are you using the slide function when you don't need to? You should also think about using it as a drop saw rather than a slide saw. The less movements you have to perform, the less there is that can go wrong.
Also, the trigger and handle mechanism is not the best ergonomic design I've seen. I use my Ryobi on my bench but I have found that the only time I am comfortable using it is when it's on the floor. My hands are on the small side and the thickness of the handle means that I have to adjust my grip as I pull the saw down and that can make me change the attitude of the saw.
Having said all that, most of the above can be negated by just going a little slower. The saw is so imprecise that you have to be a little more circumspect in its use.

If you have a table saw you might want to think about building yourself a sled with 45° guides to do your mitres.

Just as an aside, I noticed that everyone was using 'deg' instead of '°'.
Have a look at http://www.coloryourprofyle.com/phade/alt.html and you will get all the alt codes for inserting things like that.

I have a Ryobi SCMS, and use it mostly as a drop saw (it paid for itself in constructing my deck). I can do basic mitres, say for architrave around a window or door frame, but it's a piece by piece process.

For really fine mitre work I use a sled on my tablesaw - I can now do fantastic picture and mirror frames using my croscut mitre sled. I got the design for it out of a few different sleds that were inllustrated in the Fine Woodworking "Methods Of Work" collection.

Cheers,


Justin.

By "sled" do you mean something that is adjustable and fits in the groove on a table saw?