ALVIN Compass Pro Speed Bow with Beam Bar 6" Model 205V Compass for Geometry and Engineering, Included Beam Bar Allows for Drawing Large Circles, Drawing and Architecture Tool - 6 inch

perfect and case good to store

Difficult to operate, but that's probably user error. I thought I could attach different writing utensils to this such as permanent fine liner pens but unfortunately I can not. It's the whole reason why I purchase it.

Lots of play between the compass arms, they squish around easily and it makes the measurements inconsistent. These are no better than the much cheaper variants out there which, for the price, is an absolute shame.

The 205V is made of a Tin Alloy (not Plastic) that is very lightweight, and is painted into a Silver color. The extender arm connected feels solid. The pencil adapter will help in multi-color circles. The speed adjust button plus micro adjust wheel work well. A few extra leads and one pin are included. The plastic case will protect the investment. No instructions, but I found an excellent video in the internet. I’m super happy with my purchase.

It's really hard to find a compass made these days like old school quality - this one isn't horrible but it's not that good either. I did a lot of online research looking for something good that wasn't a simple bow/divider type, and this looked like a decent bet. Most disappointing is that while still being made in Germany, it is about 95% plastic, and frankly the choice of plastic and some design elements makes it a weakness for all but the most gentle use on smooth surfaces. The legs are NOT metal, they are channeled plastic. The only metal pieces are the clamp nuts, center point, transverse screw, and the two screws holding the head/gears. The leg articulation is ridiculously unstable - I mean it's a really poor design that cannot be clamped tight enough to hold the legs in place (except for the most gentle non-pressure use and even then it's iffy) - if you attempt to overtighten them you run a real risk of stripping out the small and fine plastic threads. The same is true on the clamps for point and lead, and those don't look like they will last long at all..too soft, too fine, and the nut is super easy to cross thread (I have flipped the nuts upside down and that seems to be easier to get them started correctly, still clamps fine). I may carefully file some of the articulating joint surfaces so that I can have one or two "settings" where the legs have a chance of staying put - as it is, the surface is smooth and rounded, so contact of the clamp nut to the leg body is greatly reduced and just can't be tightened enough. Again, very poor design there. The beam is metal and seems stiff enough by itself - the universal clamp is nice and easily holds any normal pen and a few varieties of Sharpie markers. The plastic case isn't great either...nice for display but it won't open flat without raising/tilting it, and then the parts fall out of their holding places easily...have to slip in the transverse screw below the beam when you pack everything up (if you use the case for storage). I'm actually undecided as to whether I should return this or keep it but I feel a little duped and sorry I purchased it. Probably should have gone half the price with the $10 Mr. Pen model because this literally offers nothing better. So...not the worst compass and within usual drafting "light duty" application it should be mostly fine, but if you want higher quality it's probably best to look on ebay for old used instruments unless a metal machinist's/woodworker's model will work for you.

Excellent compass. Beautifully designed and easy to use.

Very nice design and feel until the pencil holder broke with very light pressure. I bought a metal pencil holder meant for another compass and it is working well. Since I use this tool only for pencil drawing, the fragile pencil holder is a major defect. EDIT: The compass appears otherwise well made and with the addition of a stronger pencil holder is a useful addition to my drawing instruments. I have ediited this review and upgraded it by one star to reflect consideration of those who do not need a pencil holder. Rated solely without the pencil holder, the compass would earn four stars.

I really love the quick-release buttons for fast adjustment of the arms. I have had other compasses that if you tried to draw two arcs of the same radius, the arms would move slightly between arcs, but I have experienced no issues like that with this compass. The only complaint I can think of with this is that when I tried to use a pen with this compass, the attachment holds the pen in the same plane as the threaded rod, so when I try to draw smaller circles, the pen often ends up hitting the threaded rod. This problem becomes even more apparent when the pen attachment is used with the compass extender. I think it could pretty easily be solved if the attachment held the pen at a slight angle to avoid the threaded rod. As long as you aren't drawing extremely small circles this shouldn't be an issue. As I am writing this I realize that the ends of the arm can bend at the ends, so that will probably fix the issue as well. Overall, I think this is a very quality compass and I would definitely recommend it. Edit 7/6/2018: A day after posting this, I experienced my first major flaw in the design of this compass. While trying to adjust the lead, I accidentally overtightened the thumb screw and it broke the plastic lead retention piece. I completely acknowledge my fault in overtightening it, but I personally think that this product could be dramatically improved by changing the design of the lead retention mechanism. I think that parts that are meant to be threaded and unthreaded relatively frequently should be made of a more durable material, especially since the piece is pretty thin in some places. I still maintain that this is a good product, I would just advise being careful with that particular piece. Hopefully the lead holding mechanism will be improved in the future, but for now, it's just something to be careful with.

Great product