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Using Constraints
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* July 19, 2016, 01:27:14 AM
Is there any constraints video or tutorials on the web, have seen the basic constraints video from turbocad
but I'm looking for examples that cover basic testing through motion of an object that rotates about an axis.

Where I need to test clearances between objects that are joined by ball joints and linkages.

I did see that Kai Sannes shared a video of basic constraints ( crankshaft and piston movement ), is the tcw file
available?

Darryl

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Daz
TCW V21, 2015-2019 PP, Animation Lab V5.2 & Redsdk enabled, LightWorks rendering mostly.


* July 19, 2016, 01:39:17 AM
#1
If you have two circles and a constrained line at the top of each circles quadrant and another line that runs
vertically in either circle, the the goal is to rotate the circle by the vertical line to check for clearance between other objects.

Has anyone performed this in tcw?

Thanks

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Daz
TCW V21, 2015-2019 PP, Animation Lab V5.2 & Redsdk enabled, LightWorks rendering mostly.


* July 19, 2016, 01:55:50 AM
#2
Does anyone know if Kais video can be downloaded or is it on youtube?

Thanks

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Daz
TCW V21, 2015-2019 PP, Animation Lab V5.2 & Redsdk enabled, LightWorks rendering mostly.


* July 19, 2016, 03:49:42 AM
#3
hi,  Can you please post a 2d file of what you require (easier than guessing).

If you have never used constraints before, I posted the original v10.5 guide in another thread, http://forums.turbocad.com/index.php/topic,11428.msg69137.html#msg69137 the first part is just the help file, then there is a small tutorial of using constraints with the calc palette, its not what you require but may get you started with using them,  EXCEPT pro plat has 3 more constrained which were not available back in v10.5, horizontal, vertical and mid point.

As to Kai's video, I haven't seen it on you tube, just what Kai posted on here which is on his TC-Norway site, hopefully Kai or Torfinn may be able to help.

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* July 19, 2016, 06:27:44 AM
#4
I have talked with Kai, and he dont save this *.tcw's when he was finish to make the animations
If you dont alredy have seen them, there is some examples her :

http://forums.turbocad.com/index.php/topic,9651.0.html

Torfinn

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* July 20, 2016, 01:30:21 PM
#5
Was wanting to use tcw constraints to prototype a simple test to confirm that there were no problems with clearance for the model below. Can the the constraints be aligned and joined to mimick a solution for this?

I was attempting to join constrained circles, horizontal and vertical lines, but I failed due to my lack of know how with constraints. The image is just link rods, balljoints, pivot points parts, pawls, ratchets, a solenoid and a micro switch.

see clearance by constraints below.png

Thanks

Darryl

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Daz
TCW V21, 2015-2019 PP, Animation Lab V5.2 & Redsdk enabled, LightWorks rendering mostly.


* July 20, 2016, 01:55:22 PM
#6
Was wanting to use tcw constraints to prototype a simple test to confirm that there were no problems with clearance for the model below. Can the the constraints be aligned and joined to mimick a solution for this?

I was attempting to join constrained circles, horizontal and vertical lines, but I failed due to my lack of know how with constraints. The image is just link rods, balljoints, pivot points parts, pawls, ratchets, a solenoid and a micro switch.

see clearance by constraints below.png

Thanks

Darryl

Darryl, can you clarify what parts move in what direction(s)? The .tcw would be helpful.

Henry H

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* July 20, 2016, 02:58:20 PM
#7
To my eye, the solenoid needs to be able to pivot on an axis parallel with the crank link's, normal to its slug.  Do people still call them slugs?

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* July 20, 2016, 05:37:24 PM
#8
To my eye, the solenoid needs to be able to pivot on an axis parallel with the crank link's, normal to its slug.  Do people still call them slugs?

To my eye, too, Murray. (I call them plungers.)

Henry H

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* July 21, 2016, 01:13:21 AM
#9
Andy H, Henry, Murray &  Torfinn

Red arrows point to the small holes in the linkage (ratchet and pawl) that is held under about 20in/lb tension when the springs are fitted. (springs not designed yet).
Green arrows refer to direction of travel for the linkage components, therefore any shaft rotates in a CCW direction under load.
Orange arrow point to M6 balljoints (5 in total).
Purple points to the first linkage part (rollpins not shown inside any linkage as yet).
Blue arrow is the direction of motion for the solenoid.

How it works.

Where the blue arrow from the solenoid means the direction of travel when 24v is applied (energized, this works in reverse from a normal solenoid it's from a marinised Deutz IIme engine).

Therefore as 24v is applied to the solenoid this pushes down thru the linkage in turn moving the link (purple) in a downward motion thereby acting on all other linkages to overcome the spring tension. Thereby lifting vertically the ratchet and pawl from a normally locked/engaged position, permitting the silver shaft (black arrow) to rotate other objects.

Constraints

What I was hoping to achieve was to simulate the motion of parts by using connected constraints, I partially overcame this by just using circles for each shaft and connecting a line through the centre and extending it to th required height to simulate linkage length and confirming clearance. But I realised I did not have enough experience with constraint to connect all parts in this area. I'm thinking now that this might have been a bit over ambitious. In the end I just guessed that I had suficient clearance, lucky that I did.

Thanks for the creating springs in Turbocad.pdf it's awesome.

Andy H, Henry, Murray &  Torfinn, a big thanks for your help once again!

Darryl   8)
 :)
see clearance by constraints1.png

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Daz
TCW V21, 2015-2019 PP, Animation Lab V5.2 & Redsdk enabled, LightWorks rendering mostly.


* July 21, 2016, 06:57:06 AM
#10
"In the end I just guessed that I had suficient clearance"

Experienced designers do that more often than they're likely to admit ;-)

Henry H

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* July 21, 2016, 02:29:35 PM
#11
Hi Darryl,
I was sitting back looking at your mechanism, obviously I am looking from a distance without your design criteria in mind & what I am thinking may be totally wrong & not suitable for you?.
Firstly this is none of my business & I realize that & this is just an inquiry & a suggestion rather than anything else so please don't take this the wrong way as I am not interfering, it's your baby so to speak & I appreciate that!

Have you considered a simplified version of the mechanism.
Something to consider that maybe would not create long term issues or be as labor intensive & more cost efficient would be to remove the Solenoid Shaft, the shaft supporting Bush Blocks, the Leverage Arms, the Ball End Linkages, the left hand (looking at the picture) Lever Pivot Block & Lever, the left hand Ratchet & Pawl leaving only the Right Hand Ratchet & Pawl Mechanism.

If the Right Hand Pawl Pivot Arm was extended through the back of the Pivot Block, the solenoid could act directly onto it with a small linkage, the length of this lever would determine it's effectiveness.

The single Ratchet & Pawl mechanism maybe would want to be a little stronger to compensate.
This simplified version would be more reliable in the long run, more cost effective & very efficient.
Most times, good engineering is simplified engineering if you get what I am saying.

Just a thought?
Cheers
David

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* July 21, 2016, 03:51:02 PM
#12
Hi Darryl,

Sorry, I forgot to mention something that I noticed before.

On your existing design, In the picture it appears to have a Switch on the right hand pawl, so when it disengages it triggers a relay for the drive, is this correct?
If so you will need also a Switch on the left hand side as a fail safe.
When things wear especially with levers involved & with one switch on one pawl you could encounter a situation where the left hand pawl is still partially engaged creating issues.
If you have a switch on each pawl, you could have a small circuit that basically says Go or No Go with correct/incorrect disengagement.
Such as:

Switch 1               Switch 2             Relay On/Off
Triggered          Not Triggered              Off

Triggered            Triggered                  On

Could save headaches later on!

Cheers
David

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* July 21, 2016, 11:54:10 PM
#13
Hi David

No way would I ever take it the wrong way, for me anyway too many cooks just can't spoil the broth!


The single Ratchet & Pawl mechanism maybe would want to be a little stronger to compensate.
This simplified version would be more reliable in the long run, more cost effective & very efficient.
Most times, good engineering is simplified engineering if you get what I am saying.

I will have a look into that, space (this is a small machine with tightly engineered configurations) is my main issue here hence that's why initially I asked about trying to constraints.


Sorry, I forgot to mention something that I noticed before.

On your existing design, In the picture it appears to have a Switch on the right hand pawl, so when it disengages it triggers a relay for the drive, is this correct?
If so you will need also a Switch on the left hand side as a fail safe.
When things wear especially with levers involved & with one switch on one pawl you could encounter a situation where the left hand pawl is still partially engaged creating issues.
If you have a switch on each pawl, you could have a small circuit that basically says Go or No Go with correct/incorrect disengagement.

The switch is a micro switch only, giving feedback to the user as to the status of the lock mechanism either on/off state by red or green leds.

Thanks David, sometimes I need all the help I can get. Last four months full time drawing in Turbocad, prior to that zero experience.

Thanks


 

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Daz
TCW V21, 2015-2019 PP, Animation Lab V5.2 & Redsdk enabled, LightWorks rendering mostly.


* July 22, 2016, 01:39:28 PM
#14
Hi Darryl,

Ahh, now I see what the Switch is for!
I am not experienced with TurboCAD either & it's new to me as well.

Everyone looks at things differently & it's good sometimes to get opinions & suggestions on things, then you can weed out what you do & don't like.
Notice I said, sometimes, as at times other peoples input is a hindrance to your way of thinking & can throw you of course which I didn't want to do to you in this case.

Cheers
David












« Last Edit: July 22, 2016, 01:45:02 PM by willeng »

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* July 22, 2016, 03:13:07 PM
#15
All good David, hanks for the input!

Darryl

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Daz
TCW V21, 2015-2019 PP, Animation Lab V5.2 & Redsdk enabled, LightWorks rendering mostly.