Nice video. I’ve been trying to solve this problem, and so far have been using winding sticks and referencing the sides of my bench. Aligning the rails is especially difficult when your bench top is 100% not flat (like mine)! I’ll definitely try out the string trick.
It was nothing fancy. 3/4" straight bit. A smaller one would mean more passes; a larger one starts to get hard to handle, so I find that to be a good size.
@@WhatDennisDoes Thanks. That's actually exactly what I ended up using (started last night before getting your reply). This is a scary and slow process (scary because it does not leave a pretty finished surface and I'm hoping that I can get it back to that!)
@@trolltaker you'll have to sand it a bunch later but should turn out ok! If you have very figured wood a trick is to use a "2 flute spiral upcut carbide endmill" it's what machinists use on aluminum and since it cuts with a spiral action it has less tearout on wood
@@WhatDennisDoes Yup. Just got back from Menard's with 3 grades of course paper for my rarely used belt sander. 3/5 done with the routing. Sure am making a lot of chips! Maybe I should buy a couple of hamsters now that I have a lifetime supply of bedding for them. - Thanks for your help, Dennis.
@@WhatDennisDoes Got r done. Well, not the sanding part, but the router milling, and it went well. I found that going back over it in with a couple of finishing passes, one perpendicular, really evened out the scalloping.
Hi Denis great video- exactly the problem I am trying to solve. I know I sound dumb but I don’t get how the string make me it level. Surely you can make the strings ‘just touch even if they are on an angle. Doesn’t the whole thing really depend on you getting the rails perfectly straight and then getting the rail you put on first perfectly level with respect to the ground and also level with respect to the table....?
The only way the strings will just touch is when the rails are parallel to each other. Give it a try with pencils and string if you need to see why. You can get roughly the same result by checking for level in 3 places: the first rail, then across the rails at either end. The string is just a little more accurate.
What Dennis Does hi thanks so much for replying - quite a rare thing in RUclips these days. I’ve gotten some bits of roof batten and string and cans of beans and mocked it up on the kitchen table. It does work but only if you don’t touch your three fixed corners that you set up and the beginning, presumably with a spirit level or laser. Imagine your bench with corners going round it clockwise A B C D. A B is short, B C is long etc...A is diagonal from C on one string and B is diagonal from D on the other string. Now suppose for a moment you are perfectly flat and the strings touch in the middle. Happy days. Leave B and D alone - in other words just consider one string. Now raise A vertically 1 inch. The strings will not touch. In fact you will put a half inch gap in them at the crossing point. You can make them touch again by dropping C by the same amount (1 inch). This will close the half inch gap in the middle. Now you will have a touching string where BD is flat but AC is on a gradient of 2 inches over its length. The beams of wood are now defo not in the same plane. Of you leave three points for example A B and D fixed and only adjust C then it will work. So you set the first beam with a spirit level and fix it. Then you fix one end of the second beam with a spirit level. Then you are sorted.... but why not just go all the way around with a spirit level. Thanks so much for your help.
@@hermanmelville2029 OH yes you are correct. In your example though, when you lower C to make the strings meet again you are bringing the beams back to parallel, so the surface will be flat. It won't be level, but it will be flat. The plane shifted so it's now on an angle. You do need a level to make sure the surface is also level. Sorry if I didn't explain that part. Picture it this way, stretch a bed sheet so that it is tightly pinned to each end, A,B,C,and D. Any time AD is parallel with BC you'll have a flat surface. If one point is higher you'll get a warp. I hope this makes sense. Also, thank you for such a good comment. I love having productive discussions on my videos.
What Dennis Does by the way there are several RUclips vids out there on this ‘string’ topic that don’t make this 100% clear. If you upgraded yours or added a new video to explain it in serial that would be real unique content that you would have
question: i tried this with a 2 hp router (25, 000 RPM) and a 1/2 surfacing bit with 2" diameter (Binstak's CNC Spoilboard Surfacing Router Bit). It burned the heck out of my table. I'm a noob, hobbyist. What could be the cause? I feel at times I was taking too much off of the surface off but then it would still burn when I was taking just 1/16th of an inch.
What I didn't explain well is that it may not give you a level surface, it only ensures that both rails are parallel, which would result in a flat surface.
Nice video. I’ve been trying to solve this problem, and so far have been using winding sticks and referencing the sides of my bench. Aligning the rails is especially difficult when your bench top is 100% not flat (like mine)! I’ll definitely try out the string trick.
Funny you should have a video about something I was planning on doing soon. Good tip about the corner to corner string.
How can I be the first to comment, this has been up for a day?? Looks good. I wish I could see my bench top ;-)
Did I miss where you showed us the bit you were using? I'm going to need to do this soon and that's what I was hoping to learn from your video.
It was nothing fancy. 3/4" straight bit. A smaller one would mean more passes; a larger one starts to get hard to handle, so I find that to be a good size.
@@WhatDennisDoes Thanks. That's actually exactly what I ended up using (started last night before getting your reply). This is a scary and slow process (scary because it does not leave a pretty finished surface and I'm hoping that I can get it back to that!)
@@trolltaker you'll have to sand it a bunch later but should turn out ok! If you have very figured wood a trick is to use a "2 flute spiral upcut carbide endmill" it's what machinists use on aluminum and since it cuts with a spiral action it has less tearout on wood
@@WhatDennisDoes Yup. Just got back from Menard's with 3 grades of course paper for my rarely used belt sander. 3/5 done with the routing. Sure am making a lot of chips! Maybe I should buy a couple of hamsters now that I have a lifetime supply of bedding for them. - Thanks for your help, Dennis.
@@WhatDennisDoes Got r done. Well, not the sanding part, but the router milling, and it went well. I found that going back over it in with a couple of finishing passes, one perpendicular, really evened out the scalloping.
Hi Denis great video- exactly the problem I am trying to solve.
I know I sound dumb but I don’t get how the string make me it level. Surely you can make the strings ‘just touch even if they are on an angle.
Doesn’t the whole thing really depend on you getting the rails perfectly straight and then getting the rail you put on first perfectly level with respect to the ground and also level with respect to the table....?
The only way the strings will just touch is when the rails are parallel to each other. Give it a try with pencils and string if you need to see why. You can get roughly the same result by checking for level in 3 places: the first rail, then across the rails at either end. The string is just a little more accurate.
What Dennis Does hi thanks so much for replying - quite a rare thing in RUclips these days. I’ve gotten some bits of roof batten and string and cans of beans and mocked it up on the kitchen table. It does work but only if you don’t touch your three fixed corners that you set up and the beginning, presumably with a spirit level or laser.
Imagine your bench with corners going round it clockwise A B C D. A B is short, B C is long etc...A is diagonal from C on one string and B is diagonal from D on the other string.
Now suppose for a moment you are perfectly flat and the strings touch in the middle. Happy days.
Leave B and D alone - in other words just consider one string. Now raise A vertically 1 inch. The strings will not touch. In fact you will put a half inch gap in them at the crossing point. You can make them touch again by dropping C by the same amount (1 inch). This will close the half inch gap in the middle.
Now you will have a touching string where BD is flat but AC is on a gradient of 2 inches over its length. The beams of wood are now defo not in the same plane.
Of you leave three points for example A B and D fixed and only adjust C then it will work.
So you set the first beam with a spirit level and fix it. Then you fix one end of the second beam with a spirit level. Then you are sorted.... but why not just go all the way around with a spirit level.
Thanks so much for your help.
@@hermanmelville2029 OH yes you are correct. In your example though, when you lower C to make the strings meet again you are bringing the beams back to parallel, so the surface will be flat. It won't be level, but it will be flat. The plane shifted so it's now on an angle. You do need a level to make sure the surface is also level. Sorry if I didn't explain that part. Picture it this way, stretch a bed sheet so that it is tightly pinned to each end, A,B,C,and D. Any time AD is parallel with BC you'll have a flat surface. If one point is higher you'll get a warp. I hope this makes sense. Also, thank you for such a good comment. I love having productive discussions on my videos.
What Dennis Does great stuff - totally get it now cheers !
What Dennis Does by the way there are several RUclips vids out there on this ‘string’ topic that don’t make this 100% clear. If you upgraded yours or added a new video to explain it in serial that would be real unique content that you would have
question: i tried this with a 2 hp router (25, 000 RPM) and a 1/2 surfacing bit with 2" diameter (Binstak's CNC Spoilboard Surfacing Router Bit). It burned the heck out of my table. I'm a noob, hobbyist. What could be the cause? I feel at times I was taking too much off of the surface off but then it would still burn when I was taking just 1/16th of an inch.
weird, I haven't experienced burning from a router bit before. 2" is a really big bit. Maybe try turning the speed way down
@@WhatDennisDoes good idea, I'll try next time I flatten something. Thanks.
What bit did you use
I think it was just a 3/4" straight carbide bit.
Are you off the thickness of the thread
Probably, yes. But the movement of the wood itself is more than that.
I don't understand how that string would work. You can just keep taping one corner from the bottom string till the two strings meet and be way off
What I didn't explain well is that it may not give you a level surface, it only ensures that both rails are parallel, which would result in a flat surface.