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Your cart is empty.Safe-T 46110 mmArc Protractor Compass Plus - Pack of 1 - 15.8 cm long, Made of Clear Plastic with Bluish Hue, Semicircular side with rotating disc inset on one edge, Spinning and Accurate Protractor revolves easily within a groove, Creates Circles from 10mm radius to 120mm radius on 1mm radius increments, Allows direct view of vertex points, Straight Edge sides have inch/metric scales, Works well with Vis-a-Vis or other felt tip pens, Can be used with Rightstart Mathematics, Flat enough to use as a bookmark in a high school geometry or algebra text, Safe for Children, Dimensions 6.22 x 3.06 in x 0.06 in - The disc has holes at distances of 10 to 19 mm from its center. The rectangular part of the instrument has ten rows of ten holes, at distances of 22 to 120 mm from the center of the disc. To draw circles, one fixes the disc at the center, places a pencil or other writing implement at the desired radius, and rotates either the disc or the rectangle. The semicircular edge is divided to degrees and marked by 20s from zero to 180 in the clockwise direction and by 20s from 10 to 170 in the counterclockwise direction. The disc is marked: SAFE-T PROTRACTOR. It directs students to look at the upper, black numbers for angles facing left and at the lower, red numbers for angles facing right. A scale of 11 centimeters, divided to millimeters, is along one edge, and a scale of four inches, divided to 16ths of an inch, is along the other edge.
Jaime L
Reviewed in Mexico on October 19, 2020
Muy caro para lo que es. Plastico fragil, y la parte que deberia girar no gira libremente, hay mucha friccion y para los circulos mas pequeños es muy dificil hacerlo girar, al final por la dificultad de hacerlo girar, los circulos mal hechos.
Another you
Reviewed in the United States on July 21, 2018
I used it for about 10 minutes inside the 10-20mm radius and it started to stick and would not rotate without my pencil tip breaking or it catching and messing it up. will be looking for alternatives. however outside the 20mm radius still works fine for larger circles if you hold it down firmly. still not very happy overall
A. B.
Reviewed in the United States on June 8, 2016
There are a few problems with this item.Pros:Sort of does what it advertises.Small, easy to transport, no parts that stick outCheap-ish.Cons:Very difficult to get it to consistently and smoothy rotate.Paint wears off immediately, which is frustrating, because then you have absolutely no use for this.Holes are awkward and definitely need a more aggressive bevel or at least a big indentation. The size of the holes themselves aren't the issue, it's the bevel around them.My main problem with this thing, which I use for marking off circles on things for the lathe, is that it is hugely inconsistent. The interior circle seems to catch on the big rectangle in a few places during a full revolution. It won't do this unless you put it on a surface, though, so don't go spin yours and say "nope!". However, I also wouldn't be surprised if this was an issue with manufacturing tolerances.This means that often, when marking, I have to lift and free the compass. It's literally not possible to force it through the catch. I'm a fairly strong 6'3" guy and the only way I could force it over whatever bind it keeps hitting was to physically lift and unbind the compass. I purchased a second one from another internet store, and it was the same. I'm sure I could force it if I had leverage, but while it's on the paper your leverage consists of whatever lead you are using to mark the page. Even a steel tipped rollerball can't give me enough torque to move this thing when it gets stuck.The problem is that you have to put pressure on it to keep it steady, or the giant hole in the middle will jiggle around your center, or if you're holding the outside steady and spinning the center for small circles, you need to press the outside down. Either way, you end up constantly binding it even with the smallest pressure. But if you apply too little, it moves and your circle is now ruined if you need precision. If you apply too much, your circle is now ruined because you have to lift the compass, free it, and put it back down as closely as possible.Really not a fan of this item. Great concept, easy execution if done right, but terrible actual execution. They need to consider a harder, lower friction plastic for the contact areas so it doesn't bind so easily or maybe add some more tolerance in their specs to allow for a bit more freedom of movement.
kelsey
Reviewed in the United States on September 28, 2015
Works great. I wanted one of these for drawing circles for wood working. I had a traditional compass that was hard to use on a bumpy surface, and this one works much better. Many of the reviews focus on how the plastic circle sticks to its track and the circles come out very rough looking. This is easily fixed with a little graphite. If you have a tube of graphite, that works best. If you only have a pencil, try to draw along the creases in the compass and get some graphite dust in there. Spin the circle around a bit to spread the graphite around, and the compass will work perfectly.
Joy D. J.
Reviewed in the United States on February 11, 2015
Does what its supposed to and is what its supposed to be but should not cost 10 dollars! More like 4.99
Scott
Reviewed in the United States on June 18, 2014
Draw up to about 9.5" circles... device is in metric... I was able to get good circles each time... the little wheel that you hold stationary has enough play in it to cause inaccuracies... can't be helped.For the price, I wanted better build quality... the plastic seems thick enough, but the inner circle has play in it, and there's a 'bump' when operating, enough to create a little mark in the circle... overall, I'm please, and with free shipping it become a great deal.
Lmkaminski
Reviewed in the United States on May 6, 2014
I have bought a few of these combo protractor/compass tools lately for my geotechnical course. This is my favorite one. It is just the right size for drawing Mohr's circles and it isn't bulky in the backpack. It's also durable.
Femi Fatusin
Reviewed in the United States on November 27, 2014
This is a good tool that provides the ability to create circles based on the millimeter. It also has a ruler in the english and metric system and a compass. The only thing I dislike about it is the golden notch where the axis for all circles is located. It damages paper surfaces if it is pressed too hard and it's too wide. It also lacks increments for 20 mm and 21 mm radius measurements.
ian
Reviewed in the United Kingdom on October 30, 2014
Very good and useful. Many applications for art and technical drawing. Also used to liven up the bathroom wall with loads of different sized bubbles, good effect.
Annoyed
Reviewed in the United States on April 13, 2014
I bought this because I saw someone else with one and thought it was a very clever, useful, and compact tool. It really is ingenious. The only issue I have is that the inner circle goes up to 19 mm while the outer edge starts at 22mm, So this tool cannot draw 20 and 21mm circles which in my opinion is common enough that it should be there.It's inherent to the design, there's not much that can be done about it but it should be known.
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