Hi all,Please take it easy with me as I am at a very early stage of an AutoCAD 2014 course. I will surely be asking more questions but here is my first.I am just quickly brushing up on a drawing exercise that we were given on my course. In layperson terms (as that is what I am), please can I ask what type of circles are the ones on the attached drawing, I have put red arrows pointing towards them. Sorry for the naive question but hopefully over the next three years my questions should be....less 'basic'.Thank you in advance,Bhttp://i199.photobucket.com/albums/aa214/craigten/AUTOCADDRAWING2.jpg

If it is a whole circle then it's a......circle.If it is a partial circle it is an arc.Whole circles can be trimmed with crossing geometry to produce arcs or one can use the ARC command.  Note that there are several options (various ways to create an arc) available.  I'd suggest trying each so you are familiar with the results.  That way, in the future, you'll know what option you want to go with.Does that answer your question?

Maybe this will help.

Well thank you so very much John, I really appreciate it. However, the 'circles' that I have indicated really are not perfectly round, if you zoom in and look, there is a difference between the 'perfect' circles on the left hand side of the page and the ones I have put arrows to. I can draw all of them in circles just fine, it is the ones that I have put arrows to that confuse me. Does this make sense at all?

Take my word for it they are a closed plane curve every point of which is equidistant from a fixed point within the curve.  In layman's term that whole description can be summed up with one word: CIRCLE.If they were ellipses they would have both their major and minor diameters indicated which is not the case in the diagram you posted.One last observation.  If they weren't circles how could I have reproduced the objects precisely as shown yet all I used were circles not ellipses?Time to move on Bob.

John Connor2014-03-01 12:09:59

OK...I took a closer look at the diagram and I think I see what may be the cause of your confusion.It appears that the circles on the right are constructed from a series of very short lines.  In other words they appear to be polygons.  This could be due to the program that was used or the resolution of the screen when the image was taken.  HOWEVER, since the author used the diameter symbol followed by a number just as he did on the object to the left he fully intended for the geometry in question to be circles.  There is no sense in belaboring the point.  Period.

[QUOTE=John Connor]Time to move on Bob.[/QUOTE]So at least you see that I wasn't going crazy then? Thank you JC, much appreciated. As stated previously, please try to understand that I am just learning so my questions will be extremely primitive....but given time I will get there. If you think that this forum is too advanced for my naive questions, I honestly don't mind if you can point me towards a more appropriate forum....but this one looked, to me, ideal.Thank you again.

Some times our eyes play tricks on us.  We have to look at the totality of all the information provided.This forum is not too advanced.  Maybe the only downside to this forum is the number of active members.  The key word there is "active".  It's nice to boast that a forum has tons of members but when you compare active members to total members you'll see the percentage is pretty small.  Maybe that's true of all forums.  Some people join just to ask one question and never come back.

I understand, thank you for that. I am here for the long term and as I am looking to change my career from being a Welder to working in AutoCAD. I am in my first year of night school but plan on studying for three years minimum. My only concern is that for the first year or so I will be just asking questions but hopefully in time I can contribute too.By the way, off topic, I have a 6ft acrylic poster of Arnie for T3....girlfriend wants me to throw it out but I never will!

Your girlfriend will throw it out at the first opportunity when you aren't looking.  Tell her to chuck it over the pond.  I'll be waiting.What are you studying that will take another three years?Funny.  I want to learn welding just to say I tried my hand at it (not as a career move).

Yes, she has just verified that she will, I'll have to keep watch. Also, I have a motorbike (only a TS185 for the local woods) and my friend and I share the joke of 'Say...that's a nice bike', I'm sure you recognise that. Well, without checking, I think the first year is basic AutoCAD, second year more advanced and third year is a 3D course. Only one evening per week, unfortunately.Welding - Any particular method? Mig, Arc or Tig? I have many, many DVDs on it if you ever want copies(Could even Dropbox some of them).I Mig weld for a living but have done courses in Tig. Tig is cleaner and more skill needed. Arc is tough, I found.

I ride street now but I started out in the dirt on a Honda SL125.  I think everyone who rides a motorcycle should learn in the dirt.  That way when things get a little dicey you keep a cool head and don't end up launching yourself over the handlebars.That is a damn long time to learn AutoCAD.  Too long in my opinion.  In that time span several new versions will have been released with new commands, etc.  There are better ways.Mig welding to start.  I have a book about welding (all types) in work that I am reading right now.  We have our own welding shop and I'm sure if I asked the guys might give me a lesson or three.

[QUOTE=John Connor]I ride street now but I started out in the dirt on a Honda SL125.  I think everyone who rides a motorcycle should learn in the dirt.  That way when things get a little dicey you keep a cool head and don't end up launching yourself over the handlebars.That is a damn long time to learn AutoCAD.  Too long in my opinion.  In that time span several new versions will have been released with new commands, etc.  There are better ways.Mig welding to start.  I have a book about welding (all types) in work that I am reading right now.  We have our own welding shop and I'm sure if I asked the guys might give me a lesson or three.[/QUOTE]Totally agree with you on the motorbike handling comment.I see what you mean about three years being a long time, let me check and get back to you on what is covered during that three year period.Welding- Mig is so easy that I say to people that even my mum could do it. I guess it's the same as everything, practice, practice, practice.Quick question, if I may:In the drawing I posted, (in layperson terms here), I see that the 30 Diameter circle's 'highest point' is higher than the centre point of the 50 Diameter circle but in the image you posted, the highest point of the 30 D circle is level with the 50 D circle's centre point?

I'll have to take a look later.  At the moment I am in chef mode.  Mixing up some chocolate chip cookie dough.

Damn it, that sounds good!! No rush at all.

By the "highest" point I assume you mean the quadrant of the circle?  In the diagram you posted it may appear to be higher but where it actually falls is based on the dimensions given.  I did not keep the drawing I made so I cannot check it.  The best I could do is repeat the exercise but that isn't going to happen soon as I am still working in the kitchen.  I have fresh salsa to make then I'm whipping up a batch of mango lassi to go with our butter chicken, basmati rice, and peshwari naan dinner this evening.  I love cooking as much as I love CAD.  The only thing that beats both is being out on my motorcycle, 1985 Honda Nighthawk 700S, on a cool fall morning slicing down a two lane road through the middle of some very unpopulated and heavily forested portion of the state.  You know the feeling.  It makes you smile.

Yes, I know EXACTLY the feeling. Some of the happiest times of my life have been on long windy forestry lanes up in the hills of Wales where I was brought up. My favourite days were the cold frosty mornings when you can smell the mixture of the woods and the fumes coming from the exhaust of my bike and going some place I have never gone before. I haven't been on my bike there for over two years since I moved out but my friend told me last night that he started my bike with the first kick and it's ready to go so it's penciled in for this coming Friday. I hope I manage it.I understand now what you mean about the drawing. The quadrant is definitely higher on the drawing and after I drew it to the dimensions given....so now I'm just plain old confused.  :o(Here is the link for the 'checked' drawing:https://www.dropbox.com/s/nht5p7hiw8os6m0/TRIM%20COMMAND%20CHECKED%20FOR%20JC.dwgPS- I Googled your bike....say, that's a nice bike.

OK....I checked the original diagram you posted and the top quadrant of the circle with the 30 unit diameter is 5 units higher than the centerpoint of the circle with the 50 unit diameter.My bike is pretty good at what it was made for.  I used to have a 1982 GS850G Suzuki before the Honda.  I took many a long trip on that bike as I set it up for touring.  I used to go on camping trips with a couple of friends and my brother.  Traveled all over the New England region and up into Canada.  The Nighthawk really isn't suited to that kind of use.  I mainly ride it on weekends for a couple of hours mostly on Sunday mornings when there is little traffic to contend with.  I have a half dozen favorite routes I like to take and somewhere along the way I stop at a roadside diner for a cup of coffee and maybe an egg and bacon breakfast then I return home.I miss my dirt bike too.  Loved to get all muddy, wet from going through stream crossings and blasting around on dirt trails.  After most rides I'd have to strip down to my undies before entering the house.  I usually came home a mess but a happy mess at that!  LoLSorry, I forgot to look at your drawing.  I got carried away with the bike talk.  I'm not on my CAD computer at the moment.  I'm back and forth between this website and the website with the cookie recipe.  I promise I'll take a look at your drawing later today.
John Connor2014-03-02 17:51:15

OK...I looked at the drawing quickly and it appears that the top quadrant of the smaller diameter circle is located correctly relative to the center of the larger diameter circle (i.e. - 5 units higher).  That's what your concern was right?

No problem, I appreciate it. All I want to know is have I done it correctly. Then I can move on to my next drawing. At the moment I am a little, as the Pilots phrase goes, 'behind the curve' with my college drawings and I am trying to catch up. We are on drawing 9 at the moment so I am trying to go through them all again to refresh my memory...that's where this forum comes in and I hate to put the pressure squarely on you, you see. I feel guilty as hell.Your description of what you used to do on your bike sounded wonderful, you have described how most of us feel and it is a good description of why we love it!!PS- Quick story- I used to have a little Yamaha DT 50 when I first started when I was 16 and I tried and tried and tried to get up this steep dirt track which lead to the top of a mountain but never could quite get there (I tried running alongside it and everything, used to get so hot and bothered). The joy I felt when I got a DT 125 and finally made it was something else, I will never forget that! It turns out there wasn't a lot up there...but that's not the point!

[QUOTE=John Connor]OK...I looked at the drawing quickly and it appears that the top quadrant of the smaller diameter circle is located correctly relative to the center of the larger diameter circle (i.e. - 5 units higher).  That's what your concern was right?[/QUOTE]Yes, that was it, thank God for that! Phew! I just couldn't see where I was going wrong with mine relative to yours, you see. What I really struggled with was that there (appears to me) is no stated point on either the 50 unit Diameter circle on the right or the 30 unit Diameter circle on the right for the line to start and end from, if that makes sense? (IE- It's not as if the line starts from the bottom quadrant on the 50 unit Diameter circle on the right)

Why do dirt bikers climb hills?  Because they're there.  That's all the excuse we needed.Honestly I don't mind helping you at all.  If you have a question come back and post.  Can't promise an instant response but I do check this particular website fairly often.Good luck with your drawings.Got to sign off for a while so I can actually get the cookies baked without burning them.  It's got to be about 5 p.m. where you are right?  Have a good evening.  I'll catch up with your down the road at some point.  Keep smiling.Adios amigos.

Too right about the hills!! Similar to what JFK said about why we chose to go to the Moon: 'We choose to go to the moon in this decade and do the other things. Not because they are easy, but because they are hard.'Yep, 5pm and I will plough on for a while with CAD and see how I get on, if I happen to post a question, don't feel you have to reply, take your time, I'm doing this course until the end of May so I'm sure I'll keep up with the guys on the course thanks to you/this forum. I've learned more in this last two days than in the last two months.If/when you come back, please try and explain why there (appears that) is no stated point on either the 50 unit Diameter
circle on the right or the 30 unit Diameter circle on the right for the
line to start and end from, if that makes sense? (IE- It's not as if the
line starts from the bottom quadrant on the 50 unit Diameter circle on
the right) I don't understand what anyone is supposed to do/where they are to start and end the line. To me, it surely has to matter?PS- I'm playing with the idea of some sort of head cam for when I'm on the bike in the summer. I want to store memories like those.Speak soon and good luck with the impossibly-nice sounding meal.

Common "points" on a circle would be the center and the four quadrants.  These can be "grabbed" with the aid of your osnaps.  After that you're probably looking at lines that are tangent (another osnap option) to some part of the circle.  This will vary depending on where your line starts to begin with.  Is that clear as mud?The cookies look awesome.  Smell awesome and taste....  Well let's just say that it borders on insanely good.  And washed down with a very cold glass of milk....it's heavenly.

Yep, I've got that, that is what I thought but I am still confused that, according to the drawing I posted, the line doesn't come from a quadrant or tangent, so it looks to me as if it is up to the student to decide. I'd prefer to 'know' than to have to decide myself, if that makes sense. Oh well, on to the next one. Thanks JC.PS- I now have an incredibly strong craving for home cooked cookies, I wonder why..  

The only other option, like I said is that the line is tangent to some point on the circle.  That is the only option that makes sense.  Anything else and your geometry will be wrong and while that may not seem like such a big deal now (barely see the error) it would make one hell of a difference if you try to JOIN the two lines or create a 3D model.  Errors like that will screw things up quicker that a fox running in front of a dirt bike.

Got it!!Thank you so much!!

[QUOTE=John Connor]Maybe this will help.Oops.  Diagram on the right.  Small 30 dia circle needs to move up 5 units.  My bad.[/QUOTE]