LDraw.org Discussion Forums

Full Version: Form Technic Axle Flexible with liftarms
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Hi all,

Would there be a way to achieve the following:

I have 2 Technic Flexible Axles connected by a few 3 long liftarms.
The flexible axle is then formed / curved.
I'd like to position the liftarms like in the attached image below.

I have now rotated and placed the liftarms manyally and visually, but was wondering if one could position the liftarms along the path of axle to be more precize?
And thus be able to bent the axles in a more complex way while still moving and placing the liftarms accordingly too.

[attachment=7904]

Thanks.

Jaco
Tricky...
I'd try to create segments of flexible axle parts duplicated (to make both rails), a special segment with beam+2 axle segments, then create a special LDCad template using those segments. But imho it's worth the trouble only if you have many similar bent parts to do!
Hmm…can you combine static and deform placement in the same template? I would try making two custom donors: one with the liftarms plus some straight 20 LDU flex segments inside the outer two holes; and a second with side-by-side flex segments for the space in between. Use static placement for the first and deform placement for the second…??

Another option is separate path parts with identical path points. Once you have the flex axles formed, duplicate the path points in a new file and replace the flex segments with static liftarms. This has the advantage of letting both components take color 16.
(2022-05-17, 13:29)Philippe Hurbain Wrote: [ -> ]Tricky...
I'd try to create segments of flexible axle parts duplicated (to make both rails), a special segment with beam+2 axle segments, then create a special LDCad template using those segments. But imho it's worth the trouble only if you have many similar bent parts to do!

Ah yes, OK. I think I know what you mean.
The thing is I have a model that has quite a few more of these constructions in all sorts of forms and curves and even more complex, twisted too, like a DNA streng, if you know what I mean.

In the model if have in mind there are even more liftarms on the axle and those are actually closer to eachother so you get a very nice curve, if you can get the idea.
On the ends of the axle there are half pins so you can connect to other technic beams and elements with pin holes.
(2022-05-17, 14:09)Jaco van der Molen Wrote: [ -> ]Ah yes, OK. I think I know what you mean.
The thing is I have a model that has quite a few more of these constructions in all sorts of forms and curves and even more complex, twisted too, like a DNA streng, if you know what I mean.

In the model if have in mind there are even more liftarms on the axle and those are actually closer to eachother so you get a very nice curve, if you can get the idea.
On the ends of the axle there are half pins so you can connect to other technic beams and elements with pin holes.

This have to be a custom flex object. Have a look at the Tower Bridge or Silver Champion OMR models to see what I've done in the past. I may have done it for the Ideas Treehouse but I don't remember.
On my way home I thought about adding snap info to the axle segment?

I want to achieve something like these, purely illustrative, no where near the real model.

[attachment=7905]
[attachment=7906]
[attachment=7907]
(2022-05-17, 13:32)N. W. Perry Wrote: [ -> ]Hmm…can you combine static and deform placement in the same template? I would try making two custom donors: one with the liftarms plus some straight 20 LDU flex segments inside the outer two holes; and a second with side-by-side flex segments for the space in between. Use static placement for the first and deform placement for the second…??

Another option is separate path parts with identical path points. Once you have the flex axles formed, duplicate the path points in a new file and replace the flex segments with static liftarms. This has the advantage of letting both components take color 16.

Thanks N.W.
Orion too for looking into it.

I will have to try some things too, but I am just beginning to understand how templates and donors work.
(2022-05-17, 15:02)Orion Pobursky Wrote: [ -> ]This have to be a custom flex object. Have a look at the Tower Bridge or Silver Champion OMR models to see what I've done in the past. I may have done it for the Ideas Treehouse but I don't remember.

There are numerous applications for this.
Also elements around flex tubes, etc.
It would be interesting to be able to generate these kind of things?
(2022-05-17, 15:22)Jaco van der Molen Wrote: [ -> ]On my way home I thought about adding snap info to the axle segment?

I want to achieve something like these, purely illustrative, no where near the real model.

I believe this kind of snap capability (on skin segments as opposed to path caps) became available with the latest LDCad alpha 2.
(2022-05-17, 15:27)N. W. Perry Wrote: [ -> ]I believe this kind of snap capability (on skin segments as opposed to path caps) became available with the latest LDCad alpha 2.

I made a dual flex axle template that works well. Adding the fixed width beam segments is more tricky. Be able to adjust their separation distance is even more delicate... Perhaps the possibility to add connectivity as suggested by NWP would be the best solution Big Grin

...need to install alpha2, not tried yet!
(2022-05-17, 15:27)N. W. Perry Wrote: [ -> ]I believe this kind of snap capability (on skin segments as opposed to path caps) became available with the latest LDCad alpha 2.

OK, I added snap info to axlehol8 and now the beams actually snap to the ends of the flex axle, but not the mid section.
Since axlehol8 is used in the parts that make up the ends, I thought this should work.
Since axlehol8 is used in ldcFlexAxleMid.dat too?
(2022-05-17, 16:06)Jaco van der Molen Wrote: [ -> ]OK, I added snap info to axlehol8 and now the beams actually snap to the ends of the flex axle, but not the mid section.
Since axlehol8 is used in the parts that make up the ends, I thought this should work.
Since axlehol8 is used in ldcFlexAxleMid.dat too?
You have to make the middle segment static. I am currently experimenting, starts to work!
I can say it's OK now.
Attached the new files (donor with connectivity and new template) and the test LDCad file.
Drawback, file is huge...
(2022-05-17, 17:08)Philippe Hurbain Wrote: [ -> ]I can say it's OK now.
Attached the new files (donor with connectivity and new template) and the test LDCad file.
Drawback, file is huge...

Ah! You sir are one of kind.
How did you get the half liftarm around the axle? ;-)

I cannot get it to work. I've put the template in the templates folder and the dat in the donor folder.
My parts do not snap either.

I am missing something. Can you please share ldcFlexAxleDualEnd Cap, D, E, F and G too?
(2022-05-17, 17:36)Jaco van der Molen Wrote: [ -> ]Ah! You sir are one of kind.
I cannot get it to work. I've put the template in the templates folder and the dat in the donor folder.
My parts do not snap either.

I am missing something. Can you please share ldcFlexAxleDualEnd Cap, D, E, F and G too?
These files are in my previous post (zip file). Are you sure you're using latest 1.7alpha2? Have you restarted LDCad after donnor file update?

Quote:How did you get the half liftarm around the axle? ;-)
Tricky isn't it?   Big Grin
Actually, I used axle connexion to allow auto-orientation of part. A pin connection might work in non-twisted configuration, but otherwise it's better to use a part with axlehole and replace it later with a beam.
(2022-05-17, 17:57)Philippe Hurbain Wrote: [ -> ]These files are in my previous post (zip file). Are you sure you're using latest 1.7alpha2? Have you restarted LDCad after donnor file update?

Tricky isn't it?   Big Grin
Actually, I used axle connexion to allow auto-orientation of part. A pin connection might work in non-twisted configuration, but otherwise it's better to use a part with axlehole and replace it later with a beam.

Oops, my mistake. I worked with LDCad 1.6d. Blush

I have 1.7alpha2 too. That works better, but snapping is off sometimes.
Still, very promising. Thank you.

The only file in the zip is "twisted flex.mpd" BTW

[EDIT] Works good with axle holes, but then replacing with beams is difficult, since the center is elswhere.
(2022-05-17, 18:50)Jaco van der Molen Wrote: [ -> ][EDIT] Works good with axle holes, but then replacing with beams is difficult, since the center is elswhere.
Good point... We could use a single axle connectivity in the middle of axle segments.
(2022-05-17, 19:10)Philippe Hurbain Wrote: [ -> ]Good point... We could use a single axle connectivity in the middle of axle segments.

Do note snap info is only used when the source donor is placed statically.

Also with the 1x3 beams covering the axle deform might be unnecessary.