[HELP] Generic Building Help Topic

[lcvisser]

On 2/3/2022 at 1:16 PM, heyitsdisty said:

This is perhaps a little off-topic, but I thought it best to post here instead of starting a whole new thread for it.

Does anyone have any tips for identifying light grey vs light bluish grey for 12-tooth bevel gears? I'm usually fairly good at distinguishing the two colours on most parts, but for some reason I find it really difficult to tell 12-tooth gears apart.

 

I don't have experience with the bevel gears per se, but I struggle in general with distinguishing old grey from LBG (color blind doesn't help). For me it helps to take a photo next to some parts of which I know they are LBG. The screen on my phone are easier (for me at least) to distinguish.  Sometimes illuminating the parts with the bright LED on my phone (flashlight) is also sufficient (again, next to some known LBG parts).

[Hrafn]

I am struggling with the a-pillars on my 15-wide car, as the length isn’t a multiple of a half stud, and the angles are not standard ones (divisible by 22.5 or 15 degrees.). Has anyone come up with good  solutions besides those identified in this thread:

I have experimented with “bar holder with clip” and “bar holder with handle” but nothing has quite worked.

In my case I also am limited to white parts.

Edited February 5, 2022 by Hrafn

[TechnicRCRacer]

@Hrafn I see three options: white axles, soft axles, or rigid hoses. Rigid hoses are the thinnest and are ideal because they can be bent (and stay bent), cut, and stuck through axle holes at precisely the desired length. I have used rigid white axles in the past.

[Hrafn]

2 hours ago, TechnicRCRacer said:

@Hrafn I see three options: white axles, soft axles, or rigid hoses. Rigid hoses are the thinnest and are ideal because they can be bent (and stay bent), cut, and stuck through axle holes at precisely the desired length. I have used rigid white axles in the past.

Thanks!  I will take a look at the rigid hoses, I have never used those.  The a-pillars in the vehicle I am modeling are very straight and thin so that sounds like a good solution.

[Lipko]

Hi all,

What application would you suggest for Technic design on a phone? I tried Mecabricks but it doesn't have all the newest parts and it's very inconvenient to use.

Any suggestions welcome! 

[Jurss]

Why?! :)

Maybe some remote desktop to some windows machine, if it is really so critical.

[Lipko]

2 minutes ago, Jurss said:

Why?! :)

Maybe some remote desktop to some windows machine, if it is really so critical.

Me-time at a proper computer is an unobtainable luxury for me.

[Jurss]

Only proper option is that mecabricks. If other apps, then really some remote desktop, f.i. chrome remote.

Maybe option is some windows tablet. LDD could work on some older ones (not so expensive).

[Gray Gear]

I don't know what you are trying to build, but imo the screen of any phone or tablet will be too small for any serious MOC anyways. I myself bought a 32" display for my PC a few weeks ago to improve working with LDCad.

[Hrafn]

I am working on the steering motor configuration for a 15-wide vehicle (13 wide not including the doors).  The vehicle is very fast so I wanted return to center steering.  I also wanted the steering motor assembly to fit more or less in the dashboard/glove compartment area.  My first design uses a PF-M motor and a hockey spring; it works very well but since it relies on stalling the motor, it drains a lot of current that could be going to the drive motor.

Front view:

 

Back view:

 

The second design uses a servo, but the four bar linkage takes up a lot of space, and the linkage sometimes jams:

 

So now I am thinking about abandoning return to center steering, maybe using a design like this (obviously this is just a proof of concept):

 

Any thoughts or suggestions? Thanks!

[whitepen]

1 hour ago, Hrafn said:

I am working on the steering motor configuration for a 15-wide vehicle (13 wide not including the doors).  The vehicle is very fast so I wanted return to center steering.

Is this the infamous pop-up headlight car?

[Jurss]

4 hours ago, Hrafn said:

maybe using a design like this

there can be pretty big delay, slack (?) in that connection between worm gear and that small gear. Not good for steering, especially in fast car.

[Hrafn]

7 hours ago, Jurss said:

there can be pretty big delay, slack (?) in that connection between worm gear and that small gear. Not good for steering, especially in fast car.

Good point.  Also, getting the car to go straight would be difficult.

Maybe I just need a different RTC mechanism that requires less power to overcome, so when the PF-M stalls, the stall current isn’t too great.  Maybe the one that uses two 2x4 L-shaped liftarms.

A servo solution would be even better if someone can figure out how to make it compact enough.

[Carsten Svendsen]

On 2/25/2022 at 3:51 AM, Hrafn said:

A servo solution would be even better if someone can figure out how to make it compact enough.

Any reason you're using 14 tooth gears instead of more robust 12t? The servo option was basically made for steering, does it really have to go in the glove box? How much space have you got? Normally the servo is put in line with the chassis and either a gear rack+pinion or just direct drive. I'm sure you could figure out a way to get the steering wheel hooked up to it somehow.

[Hrafn]

7 hours ago, Carsten Svendsen said:

Any reason you're using 14 tooth gears instead of more robust 12t? The servo option was basically made for steering, does it really have to go in the glove box? How much space have you got? Normally the servo is put in line with the chassis and either a gear rack+pinion or just direct drive. I'm sure you could figure out a way to get the steering wheel hooked up to it somehow.

I was experimenting with the 14 tooth gears because when using 2 gears, if the gears have a number of teeth divisible by 4, you get an angle between thee input and output shafts (15 degrees if using 12z gears.). With a servo, this is undesirable because when the servo is in a neutral position, the steering shaft is not.  The 14z gears can be oriented to avoid this issue.

I ended up finding a compact solution using the PF-M and Sheepo’s recommended return to center steering solution; it works well in isolation but I haven’t tested it integrated with the rest of the vehicle yet.

The steering doesn’t _have_ to go in the glovebox, but I wanted to see if I could make it work so that there was room for a full interior.  At this scale a servo would be too large to really look like a center console.

Edited February 28, 2022 by Hrafn

[aminnich]

I am modifying 2legoornot2lego’s lowboy trailer to move a heavy load. I am having an issue with the suspension on the axle not being nearly strong enough. All axles bottom out right away. In my opinion there is no reason to have suspension if it is just going to bottom out like that. 
 

I’m wondering if anyone has recommendations to stiffen the suspension to handle the load. 

[TechnicRCRacer]

I mentioned a year ago that I was going to build a dark green supercar. The chassis is done and works well, so I am starting the bodywork. I am struggling to find a way to fill in the two large holes on each side of the back. Should I fill them or not, and what would be a good way to fill them?

[Lipko]

15 hours ago, TechnicRCRacer said:

I mentioned a year ago that I was going to build a dark green supercar. The chassis is done and works well, so I am starting the bodywork. I am struggling to find a way to fill in the two large holes on each side of the back. Should I fill them or not, and what would be a good way to fill them?

Option three: incorporate the gap into the design, like in some recent hypercars.

 

[TechnicRCRacer]

@Lipko That's a great idea, thanks!

[technicfanatic]

Hi Everyone, I'm aware of 32054 to attach an axle and give it friction. 

Is there anything that can be added to the middle of an axle to add friction? I have a structure with an axle I want to add friction to, but in order to use 32054 I would have to modify the structure in a way that annoys me. It would be much more convenient to be able to add something in a pinhole in a link arm the axle is going through.

Thanks!

[Jundis]

Can you show the specific case? It's hard to judge without seeing, what assambly you are building... ;-)

[Gray Gear]

You could add a 12t gear on the axle, connected to a 12t gear with a friction pin

Also, at the very top of the Eurobricks Technic Page there is a thread named Generic Building Help Topic. It was created to avoid a new thread for every little problem someone might encounter. But its little use if people just ignore it and make a new thread anyway. Please keep that in mind next time you have a question 

[technicfanatic]

12 minutes ago, Gray Gear said:

It was created to avoid a new thread for every little problem someone might encounter.

I've seen that thread. I find it very hard to extract information from it. A FAQ type page would be more accessible than a multi-year thread with digressions. I find it much easier to have separate threads that have clear thread titles that are easily findable, especially if there are tags.

16 minutes ago, Gray Gear said:

You could add a 12t gear on the axle, connected to a 12t gear with a friction pin

Yes, that could work. Even better would be a shift up to increase the opposing torque. This does add more axles and more axle supports.

Ideal would be a bushing with through hole, but I guess that doesn't exist?

[Gray Gear]

Great, so you didn't miss that thread but decided to just ignore it and open a new thread anyway? Great... You just made sure I will not be answering any "Help" requests outside of the correct topic ever again. I don't want to encourage behaviour like this. 

Edited March 21, 2022 by Gray Gear

[technicfanatic]

27 minutes ago, Gray Gear said:

Great, so you didn't miss that thread but decided to just ignore it and open a new thread anyway? Great... You just made sure I will not be answering any "Help" requests outside of the correct topic ever again. I don't want to encourage behaviour like this. 

Ok. Please tell me if some one forces you and I will come to your aid.

1 hour ago, Jundis said:

Can you show the specific case? It's hard to judge without seeing, what assambly you are building... ;-)

Not sure if this is clear. My super-structure is built to support the axle from the inside, and I'd have to add a lot of structure to support the circled axle from the outside so that I can use a friction bushing. Thanks.

Edited March 21, 2022 by technicfanatic