how to make a proportional divider for drawing

how to make a proportional divider for drawing

WARNING! Power tools, including drills and saws,
are extremely dangerous and can cause injury or death!
Use at your own risk! Let me show you how to make a proportional divider. You want to use a piece of good quality wood. This is oak wood, but you can use maple, or any other good quality hardwood. Inexpensive pine wood tends to split, and is actually harder to work with. So, get a piece of wood like this. This one is at least 14 inches long. That’s how long our proportional divider is going to be. So, I will put a mark here, at 14 inches. This is where we’re going to take
our proportional divider from. And then the other thing I’m going to do is put a halfway mark at 7 inches. Then the next thing is to put a line down the center of this piece of wood, exactly down the middle. Really take your time on this and make sure that it’s a nice straight line right down the middle. So, I’ll put a little mark halfway and then take a straight edge. So now I have 14 inches marked off, the halfway marked off, and a line down the center. Now we’re going to drill holes on one half of that. So between here and here, we’re going to drill holes, like so, all the way through. And then, we’re going to put it on a table saw and rip off a couple of strips to make your proportional divider from. But it’s really important that these drill holes are exactly on the mark. And if you try to just drill them straight like that, the drill bit tends to walk a little bit and your lines won’t be straight. To start, I’ve got a small Phillips-head screwdriver. You could use a nail in place of that, but this little Phillips-head screwdriver works great. What I’m going to do is start about halfway, and move just slightly off-center, and that’s where our first hole is going to go. So really take your time, and make sure that that point is exactly on that line, stand it up, and just hit it with a hammer a couple of times. That is going to allow us to… When we start to drill, if we drill into that hole, it’s going to keep it exactly where we want it. Now that I’ve got that first hole marked, we’re going to put another mark about every half inch. So I’ll just make some marks. There’s where I need to put all the drill holes. Right on the line. Now that I have all those marks there, I’m going to use my drill and drill holes. Even though we’re only going to take two strips off, and we really only need to drill about that deep, just go ahead and drill all the way deep, and that way you can cut four of these strips and choose the best ones. Usually, the top one you’ll discard, because when you start the drill, it sort of tears it up a little bit. So, now we have all the holes drilled, and we’re ready to rip this this way. We’re going to use a table saw. You could use a hand saw if you don’t have a table saw, and just cut it by hand along a line, but that’s going to be really hard. So if you do have a table saw, you should use one, if you know how to use one safely. OK. So now let me re-measure and cut these exactly 14 inches long. Let me cut that real quick. Now I’ve cut these to 14 inches. The next thing is to put the screw through, and it doesn’t matter what hole we pick. I’ve got just an assortment of screws. This one is a little short, this is a wing screw, with a wing nut, and you can find these anywhere. The thing that will really help is if you can find one of these gasketed washers. Because what I’ll do is I’m going to first put a washer there, then I’m going to put it through one of the holes, and then I’ll put the gasketed washer on next, with the rubber facing out, and then put another washer on. And what happens is when you tighten this down, it will squeeze that gasket and it will grip the screw better. What that does is that it means when you tighten this down, it’ll stay tight. We can wiggle it all day long
and it’s going to stay tight. It’s not going to loosen up like this will do without a gasketed washer. So now I’ve got the screw in there, and that’s going to hold it dead straight so that these are exactly lined up. That’s why we want to go ahead and put that screw in. You can even tighten it down. It doesn’t matter what hole, but put it in one hole. Then the next thing is we’re going to take some masking tape and just tape the whole thing together. See how I’m pulling that real tight? So that doesn’t move. And you even could do it down here on this end. Now that that’s got the screw in it and we’ve got tape, now we’re going to cut these ends, or just sand them. And there’s two ways you can do that. One, we can just literally try to cut it, like that. So that what we’re going to do is cut a point, but that can be hard. The other thing to do, which takes maybe more time, but there’s nothing to it, is get the heaviest sandpaper you can find — maybe not the heaviest, but this is 60-grade — and just start sanding, like that. Do both ends. It’s going to take a long time, but when you’re done, you’ll have
a fantastic proportional divider. Just going to keep on sanding like that. The other way is to cut it, or use power tools or something. But this is the way that anybody can do it. And if you don’t even have any of this heavy sandpaper, or you don’t want to spend any money on it, then take this and go out on a sidewalk, on a concrete sidewalk, and just drag it on the sidewalk. It may take a long time, but eventually you’ll get a nice point, as you can see I’ve started to get already. And we’re going to put a point on both ends. I’m going to do a combination of the two. I’m going to cut it and then sand it. But you don’t have to,
you can just sand it all the way down. So I’ve taken a saw and just taken it almost to the point, and then I’ll do the rest with the sandpaper. So that’s basically done. Before you take your tape off you want to make sure that that point right there—
See if I split it apart? You want to make sure that one’s not longer than the other. So if that one’s slightly longer, then I’ll just sand on this side until it is exactly equal. It should round right onto the crease so that those are exactly the same length and have a nice, sharp point on the end. So don’t take this tape off
until you’ve examined that point and made sure it’s dead right. So that’s a good one there. It should have a nice, sharp point. Take your time on the sanding. That’s what’s really going to make
this a good proportional divider. Or not so good. Checking both sides… and we’re all set. Now we can take the tape off. So now all the tape’s off, and we don’t want to touch these points again. You can check and see how well they’re lined up. If you don’t like your point, then you can tape it again and sand it again. But don’t try to sand this without putting tape on it to hold it perfectly together like that. Then I can just very gently, without touching the point, just sand the rest of the edges. So there it is. There’s your proportional divider. Ready to go. This is the end you measure with, and that’s the end you plot with. Usually.

82 thoughts on “how to make a proportional divider for drawing

  1. Mar, my hubby is going to try making one because I broke two AccuraSee dividers already. He wanted to ask why it had to be 14" long. Was that just for "ease of hold" or did it have to do with the ratio measurements? thanks!!

  2. 14" inces is just a good length for the general artist. If I was painting murals, I would make it maybe three times as big.

  3. What size screw and drill bit did you use if you don't mind me asking? (if you remember) I don't think I heard it in the video. My apologies if you said it.

  4. I am getting ready to make the proportional divider. How thick are the strips, it looks like something near a wooden yard stick thickness on the video? I have listened to the video several times and I haven't heard that fact.

  5. maravilloso si no me ense帽as nunca me entero que existe que Dios te bendiga por tu inteligencia y generosidad al compartir tus conocimiento de coraz贸n muchas gracias amigo

  6. I have just made such a prop. div., and it worked well. Dont't try to saw the tips (as someone suggested) unless you have a very precise saw! I used a belt sander, which worked extremely well. I had some nicely formed tips within 10 minutes. My PD is 35 cm long, and the distance between the (5mm) holes is 1 cm. 1cm is a bit much. I tested it, and I would have needed a hole between 3 and 4. So maybe you try to make as many holes close together as possible…

  7. You may be interested in this: I used 5 mm screws, which is alright. But maybe it would be better to use smaller screws and holes closer together to get a finer variation!

  8. If you don't have a very precise saw (and few people have that!), don't try to saw that because it is to delicate! The nicest tool for that purpose is a belt grinder, which I happened to use abt. 1 hour ago. Worked really fine!
    And, by the way, there a many people who like to / need to measure and remeasure proportions in a painting. To me it happens frequently that I get doubts, and then it is the only thing to remeasure! Nothing to do with being "talented" or not.

  9. I made one of these yesterday and started using it today. Thank you so very much for the video. I made mine 18" because that is what was convenient at the time. I expect to make a larger one in the future. It is working perfectly. Once again, thank you so much 馃榾

  10. If you cant cut the wood I believe you can get some thick paint stir sticks at Lowes or a paint store or even a yard stick cut down. Thanks for posting this.

  11. Hi nice to meet you 馃檪 great tutorial…just wondered how thick is the wood you used聽
    thank you for sharing this great help appreciate it … keep up the great work 馃檪聽

    Have a nice day 馃檪聽
    magz 馃檪聽

  12. but how exactly are you planning ratios? You are putting holes at every half inch and starting just a little off center but wouldn't 1 to 1 be on the center? and how much enlargement does a half inch provide?

  13. Great video, as an amateur artist and woodworker聽made one the next day. One observation is that using regular 1 inch spacing will give you ratios that are not even. In order to get 1:2, 1:3,1:4 etc. hole spacing has to vary. A simple formula聽for hole spacing x ,length L and ratio R is that x=L divided by R+1聽 or written as聽x=L/R+1聽so for the 14 inch example and a ratio of say聽1:4聽 x=14/5=2.8 other side 11.2 for 1:3聽 x=14/4聽 and so on.聽Be careful trying to rip thin strips of hardwood on a table saw . Thanks so much.

  14. Hi Mark ,Got a piece of oak and made my first proportional divider. It works but looks like something from a medieval artifact museum. :}

  15. Hello,
    The second try on the proportional divider turned out better. Sometimes the trial and error way is the best teacher.:}

  16. i know this video is over three years old but you don't have to buy a piece of wood for the proportional dividers, you can go to a hardware store like Home Depot and go to the paint section and grab the wooden painting mix sticks, which are free.

  17. I like your video but i notice some thing you did no show in the video that you problem note all ready.well one is how thick to cut the strips when you fines drill the hole into the side of the bored.

  18. thank you. i am learning how o build Kentucky longrifles and pistols and the better guns that are more pleasing to look at always follow the golden mean. that means i need a set of proportional dividers set three to five. i was a blacksmith long before i started building guns, so taking your building technique and using steel instead of wood will be easy. so again, thanx. Mike Blair Kalapooia forge.

  19. made 3 of these (one for me, one for the wife, one backup) as a B-day present to myself last week! Really love using it! Thanks! check it out: I even got the same brass nut and thinned down some vandyke brown and stained it 馃檪

  20. Thanks Mark, i don't have any of your tools , but am going to tell a carpenter to make one for me, but what i didn't understand how can i use it , use this one we measure it and the other we blog with, sorry but this is my first time to see a proportional divider and don't know how to use it after i have it from the carpenter, please can you help me , thanks again.

  21. Thanks Mark for all what you give, i really appreciate it. I don't know how to use the proportional divider, am from Africa and this is my first time to use it ! you said one side of them is to measure with, also i don't know how, and you said the other one to …., I'll be appreciate if you make a Video on how to use it , thanks again.

  22. Now, now. Let's start from the beginning. 1) To get the perfect centre line, use a MARKING GUAGE. Reverse sides to make sure you're dead centre. 2) To evenly mark out perfectly equal divisions, use a compass with points only. 3) By using the "points" left by the compass (perfectly equidistant) you can use a bradawl to accent these. 4) Use a drill press with a square guide ; this way your holes are perfectly PERPENDICULAR. I'm only at 4:11 and I'm out. Sorry, this is just too amateurish. Your holes don't even line up. Plus, you have to stagger the holes to obtain different ratios. Look below for these ; some people give great ideas. Friendly advice : try to be 100% sure of yourself before making a video. You know, as they say: The road to Hell is paved with the best intentions.Good luck.

  23. Thanks for the video would please clear me that I have make hole every half inch from middle point 7 inches..?and how many holes …?

  24. hi, what's the brass screw and nut? how is it called? Im trying to look for that online and I need to know what to write

  25. Good ole' american system of my accidents are your fault. Thank god you threw in these additional tips, @ 4:23 otherwise you might have been liable for someone else's severed fingers. LOL. "But Mr.Mark told me to use the saw!! Its HIS job to pay for all of the hospital bills!"

  26. Would it be better to have the points flush with the inside edge of either arm and tapper on the outside like a compass? That might make it easier to expand angles. Not sure. Just wondering.

  27. omg so weird. A lot of unnecessary work. You can buy two wooden regular rules in dollar store and stick them the same way like here. That麓s all. Imagination is much better than a hard work.

  28. What a nice guy! I may just buy one from but I really appreciate the option to make one. I then can spend more money on other art supplies. I'm saving for his Geneva paints too. I have others but I want some Geneva!
    What a kind soul.

  29. I sure hope he can paint, because he doesn't know shite about wood working. His whole drilling was very poorly done, a cheap dowelling jig would have helped him a lot. I reckon if he had cut a couple of strips off a cheap polyethylene cutting board he would have got a better "prospect".

  30. Hi fellows. I think you need to take some time and take a fast tour on woodprix website to learn how to make it.

  31. I love how you not only sell things of great quality but how you also show how to make a "budget" diy version. Thank you so much.

  32. I'm using the sidewalk, sitting with it between my extended legs. Taking awhile but I'm getting there. 馃檪

  33. I just want to commend your kindness & freely offered generosity of your art skills, not only in drawing/painting, but in instruction for making your tools. So many creative people are craving quality instruction, & many cannot afford any fraction of the fine quality training you offer freely… I'm sure I speak for others in Thanking You & your Lovely Wife for this treasured gift. Can't get enough! PLEASE Keep them coming. 馃槃

  34. most wood stores have hardwood in smaller sizes. You can easily find maple or oak thats 1/4 inch thick and 1 inch wide.

  35. It never ceases to amaze me on here to see 'so called' intelligent and skillful people can be so 'dumb' in expecting viewers to just happen to have a table saw in their bed room, kitchen, garage or especially fitted out shed. Having used commercial table saws and know whzat they cost the space they need to be able to cut cleanly for such a short piece of wood is bloody stupid and expensive. Plus it takes great skill to drill perfectly perpendicular to ensure the dividers when angled slide exactly ensuring they don't twist. Also (which again astounds me) this artist has proven incredible brush and drawing skills for hair line accuracy but then shows us sand papering the 'so called' pointed ends which in truth more like bulbous large thumbs for purpose of placing a fine point. Mind not you not as bad as the little old lady making a cat flap door which included a virtual hardware store of precision cutting and electric tools , easily costing about $5000 so her cat could get in. Even so, stick to what you are a master of, a very good artist and don't insult us with 'making' wooden proportional dividers' please.

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