Understanding plans.

[JasonBModerator @jasonb]

Dave as I tend to make most of my crank pins with a shoulder and smaller dia threaded section that screws into the web this also ensures that the pin pulls up square to the web. Not that either of us would produce wonky work to start with

[Alastair HamParticipant @alastairham63197]

Jason that’s awesome thank you! If you’ve just made that can I have it?? Seems much quicker to describe what I need and let you make it 😂😂 I’m obviously kidding, I appreciate the help and guidance so much!

[duncan webster 1Participant @duncanwebster1]

I'd just use bright bar for the 3/16" axle, it is plenty round and parallel enough for little steam engines.

[Alastair HamParticipant @alastairham63197]

Hi guys, it’s been a long time since I’ve managed to get on here. Suffice it to say I haven’t plucked up the courage to try out the various methods you all suggested, the main reason is the lack of material I have in case (or perhaps when) I make a mistake, I’m trying to build up my collection of offcuts so that I can try and try again before committing to the project proper.

Anyway I feel I have finally made a useful tool that I needed. I bought a second hand 4 jaw chuck without a key, an Allen key worked on 3/4 screws but number 2 seemed more worn than the others so the key wouldn’t grip. The inside shape was also square rather than hexagonal.

I started the hole central on the outside cylinder but as I increased the drill side I think it drifted slightly. I also have not been shown how to tap and thread yet and my first couple of efforts weren’t good so I decided to try to make it press fit and use loctite. In the same vein knurling is a brand new concept but I decided to have a go, it wasn’t perfect and hardly improves the grip but aesthetically it didn’t detract too much.

I realise most seasoned engineers would simply grind a square from an old Allen key or something but I wanted to practice some techniques. Feel free to commen and please don’t be too harsh with the criticisms to come

[Alastair HamParticipant @alastairham63197]

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Alastair Ham on 15/10/2018 19:26:53:

.

I think you may find it helpful to look through this thread, Alastair: **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=103028&p=1

You're not the first, and won't be the last, to struggle with posting images here !

MichaelG.

[Alastair HamParticipant @alastairham63197]

[Gary WoodingParticipant @garywooding25363]

Posted by SillyOldDuffer on 02/09/2018 12:17:42:

Finally, 'What it looks like from the front, what it looks like from the side, and what it looks like in plan view.' is itself multi-choice – for example, is plan view from above or underneath? Older British and European practice was to draw plans 'First Angle'. The Americans spotted advantages in drawing plans in 'Third Angle', and this is now the preferred method world-wide. (The advantage mainly appears in complex drawings.) In my experience, the difference between First and Third Angle is rarely a problem. However, getting First Angle and Third Angle confused might mean certain features are made as mirror images of the designers true intent.

Dave

Unfortunately, whilst your example shows a 3rd angle drawing, the projection symbol (the little cone) depicts 1st angle. Or am I confused?

[Alastair HamParticipant @alastairham63197]

By the way thanks MichaelG! In this day and age that seems an unnecessarily complicated way to post a photo. Oh well

[fishy-steveParticipant @fishy-steve]

Posted by Gary Wooding on 16/10/2018 09:42:09:

Posted by SillyOldDuffer on 02/09/2018 12:17:42:

Finally, 'What it looks like from the front, what it looks like from the side, and what it looks like in plan view.' is itself multi-choice – for example, is plan view from above or underneath? Older British and European practice was to draw plans 'First Angle'. The Americans spotted advantages in drawing plans in 'Third Angle', and this is now the preferred method world-wide. (The advantage mainly appears in complex drawings.) In my experience, the difference between First and Third Angle is rarely a problem. However, getting First Angle and Third Angle confused might mean certain features are made as mirror images of the designers true intent.

Dave

Unfortunately, whilst your example shows a 3rd angle drawing, the projection symbol (the little cone) depicts 1st angle. Or am I confused?

I was thinking the same thing. The end view has been flipped the wrong way.

Steve.

[SillyOldDufferModerator @sillyoldduffer]

Posted by fishy-steve on 16/10/2018 10:19:43:

Posted by Gary Wooding on 16/10/2018 09:42:09:

Posted by SillyOldDuffer on 02/09/2018 12:17:42:

Finally, 'What it looks like from the front, what it looks like from the side, and what it looks like in plan view.' is itself multi-choice – for example, is plan view from above or underneath? Older British and European practice was to draw plans 'First Angle'. The Americans spotted advantages in drawing plans in 'Third Angle', and this is now the preferred method world-wide. (The advantage mainly appears in complex drawings.) In my experience, the difference between First and Third Angle is rarely a problem. However, getting First Angle and Third Angle confused might mean certain features are made as mirror images of the designers true intent.

Dave

Unfortunately, whilst your example shows a 3rd angle drawing, the projection symbol (the little cone) depicts 1st angle. Or am I confused?

I was thinking the same thing. The end view has been flipped the wrong way.

Steve.

 

You might well be right – I didn't check. The tool used is FreeCAD. The 2D drawing was derived using the Drawing workbench from a 3D object defined with the Part Design workbench. The drawing and its information block,including the cone symbol, were generated automatically. I assumed (always a bad thing) that the cone would follow the selected projection type.

Just tried generating another drawing and FreeCAD creates the information block, including cone, before the projection is decided. It appears that adding the base object and then switching between first and third angle projections DOESN'T update the cone. Oh dear.

This might be a glitch in FreeCAD and it will be interesting to see what Fusion360 does with the same object. Very possibly it's my fault and the projection cone has to be changed manually to show the intended projection. If so, it's rich source of error!

In mitigation, I wasn't trying to show the difference between first and third angle, only that a number of views, usually three, may be needed to remove ambiguities from a drawing. However, I plead guilty to negligence in charge of a projection cone and can only hope the court will be lenient…

Dave

Edited By SillyOldDuffer on 16/10/2018 11:52:52

[SillyOldDufferModerator @sillyoldduffer]

Posted by SillyOldDuffer on 16/10/2018 11:50:04:

Posted by fishy-steve on 16/10/2018 10:19:43:

Posted by Gary Wooding on 16/10/2018 09:42:09:

Posted by SillyOldDuffer on 02/09/2018 12:17:42:.

…

Unfortunately, whilst your example shows a 3rd angle drawing, the projection symbol (the little cone) depicts 1st angle. Or am I confused?

…

…

Just tried generating another drawing and FreeCAD creates the information block, including cone, before the projection is decided. It appears that adding the base object and then switching between first and third angle projections DOESN'T update the cone. Oh dear.

This might be a glitch in FreeCAD and it will be interesting to see what Fusion360 does with the same object. …

In Fusion360 (October 2018 version) First Angle or Third Angle are set as a general preference that's picked up silently when the 2D drawing tool is started. My copy defaults to Third Angle.

When Fusion360 generates a 2D drawing from a 3D object, it does not add a cone symbol or any other indication as to the projection type. Unless I'm missing something, in Fusion, if you want a cone, you have to add it yourself.

Dave

[Enough!Participant @enough]

Posted by Gary Wooding on 16/10/2018 09:42:09:

Unfortunately, whilst your example shows a 3rd angle drawing, the projection symbol (the little cone) depicts 1st angle. Or am I confused?

Depends on whether the smaller circle shows one end of the cone or a hole along the axis

[Gary WoodingParticipant @garywooding25363]

Posted by Bandersnatch on 17/10/2018 17:22:33:

Depends on whether the smaller circle shows one end of the cone or a hole along the axis

Center line shown, but no hidden lines.

[Neil WyattModerator @neilwyatt]

Posted by Gary Wooding on 18/10/2018 18:55:44:

Posted by Bandersnatch on 17/10/2018 17:22:33:

Depends on whether the smaller circle shows one end of the cone or a hole along the axis

Center line shown, but no hidden lines.

What if it's a bucket?

[JasonBModerator @jasonb]

Posted by Neil Wyatt on 18/10/2018 19:55:29:

Posted by Gary Wooding on 18/10/2018 18:55:44:

Posted by Bandersnatch on 17/10/2018 17:22:33:

Depends on whether the smaller circle shows one end of the cone or a hole along the axis

Center line shown, but no hidden lines.

What if it's a bucket?

Can't be a bucket, where is the handle? bowl maybe

[Author]

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