Building Help for Technic Noobs!

[Bob De Quatre]

Hi guys, I'm back with more noobs questions!

I'm working on a small 6-wide monorail that uses one stud wide brickbuilt rails. I've come up with simple design (inspired by Psiaki's) and tested it with relative success. Since the monorail is supposed to run during a convention, I'm wondering if the motor will overheat and if I'd need to put a white coupling gear in there, and if so how?

There are two yellow rubber bands that can't be shown in this LDD screencap:

[Jeroen Ottens]

You don't need a white clutch gear. These are used to prevent the motor from stalling when too much torque is required. In your case you already have a torque limiter because the pulley wheel relies on friction to transfer the torque to the wheel.

Whether or not the motor will overheat will depend on the friction & load when driving. I assume the yellow bands are used to connect the frontwheel to the backwheel? If so, this will introduce quite some friction. If the train can run without the rubberbands I would definitely recommend to remove them. The other thing to pay attention to is the bracing of the axles. Each axle needs to be braced at two points preferrably, close to the position where the gears are. So the small wheel is braced properly (allthough it can be better still if the #6 connectors would be restricted in rotation by something else than the axle going through it).

[Bob De Quatre]

Each rubber band connects the pulley wheel and the two half bush on one side.

Thanks for your advices. I can't see a way to get rid of the rubber bands and to drive the wheels with gears. 

I've updloaded a LXF file here

[Jeroen Ottens]

Ah, now I see, of course...

Still, no clutch gear needed. The rubberbands will act as a torque limiter. If you want to get rid of the rubberband you can see if you can make the pulleywheel (or another wheel with an axle hole) drive the little wheel (like I wrongly assumed first). That way you have both a torque limiter and no rubberbands... But it does require a big wheel in the centerline of the structure, which is not so easy to couple to the motor.

One other remark: The M-motor turns relatively fast, the pulley-wheel to half-bush will increase that speed even more. Have you tried this in real life? If it is too fast you can use half bushes instead of the pulleywheels, that should slow the whole thing down considerably.

[Bob De Quatre]

Oh and now I see why you thought the pulley wheel driove the wheel directly 

I did try it yesterday, and using a pulley wheel made it run a bit fast, but using half bushes instead made it a bit too slow, and worse, the rubber band wasn't stretched enough and slipped a lot. I'll experiment more this week end!

[Mantarri]

Hi.

I'm working on a Unimog U400/4000 C Model for The MB Arocs 42043

Now, I need some help with the front axle

It needs to be 19/17 Studs wide (including the 3 stud wide wheels that come with 42043), I'm wondering if there are any axles that can fit steering, power, suspension, and homeade portals axles in 19/17 studs?

I've come up on my own with either a 19 stud powered, steered, suspended axle, without port axle,

or a 19 stud non-powered, steered axle with portal axle.

Edited January 22, 2017 by XtremeBuilder
Clarifying things a bit

[Captainowie]

9 hours ago, Bob De Quatre said:

Oh and now I see why you thought the pulley wheel driove the wheel directly 

I did try it yesterday, and using a pulley wheel made it run a bit fast, but using half bushes instead made it a bit too slow, and worse, the rubber band wasn't stretched enough and slipped a lot. I'll experiment more this week end!

Another way to reduce the speed would be to swap out the gears at the motor for an 8t and a 24t crown gear. That's how we did it back in the old days, before this newfangled studless nonsense. :-)

Or you could use a PF train controller to make the motor turn slower.

Or you could use a battery box with two 'dummy' batteries in it.

As far as the motor burning out, if you can lock the wheel and remove the motor and turn the axle with your fingers (i.e. so that the rubber bands are slipping) without having to really grip the axle, then your motor should run all weekend without trouble.

Owen.

[Mantarri]

including

On 2017-01-20 at 1:32 PM, XtremeBuilder said:

Hi.

I'm working on a Unimog U400/4000 C Model for The MB Arocs 42043

Now, I need some help with the front axle

It needs to be 19/17 Studs wide (including the 3 stud wide wheels that come with 42043), I'm wondering if there are any axles that can fit steering, power, suspension, and homeade portals axles in 19/17 studs?

I've come up on my own with either a 19 stud powered, steered, suspended axle, without port axle,

or a 19 stud non-powered, steered axle with portal axle.

Just to clarify, it needs to be 19/17 studs wide including wheels.

[Limga]

On 21.01.2017 at 0:32 AM, XtremeBuilder said:

Hi.

I'm working on a Unimog U400/4000 C Model for The MB Arocs 42043

Now, I need some help with the front axle

It needs to be 19/17 Studs wide (including the 3 stud wide wheels that come with 42043), I'm wondering if there are any axles that can fit steering, power, suspension, and homeade portals axles in 19/17 studs?

I've come up on my own with either a 19 stud powered, steered, suspended axle, without port axle,

or a 19 stud non-powered, steered axle with portal axle.

Is differential needed? Without differential it is possible to make 19 stud wide axle, including the wheels. I will try. 

[Mantarri]

7 hours ago, Limga said:

Is differential needed? Without differential it is possible to make 19 stud wide axle, including the wheels. I will try. 

Hi, thanks!

Differential is proffered, but I don't need it, thanks.

[Bob De Quatre]

On 21/1/2017 at 0:44 AM, Captainowie said:

Another way to reduce the speed would be to swap out the gears at the motor for an 8t and a 24t crown gear. That's how we did it back in the old days, before this newfangled studless nonsense. :-)

Or you could use a PF train controller to make the motor turn slower.

Or you could use a battery box with two 'dummy' batteries in it.

As far as the motor burning out, if you can lock the wheel and remove the motor and turn the axle with your fingers (i.e. so that the rubber bands are slipping) without having to really grip the axle, then your motor should run all weekend without trouble.

Owen.

I found a way to reduce the speed: adding weight to tow...

I made a test with the finished locomotive and a wagon holding the battery box. It runned perfectly on a straight rail, but it tilted on the inner side when on curved the rail, making the wheels slip. I know I don't have the right kind of tires, so I'll have to do more experiments. I also think I'll need to have a locomotive on each end of the monorail...

[Limga]

On 23.01.2017 at 3:15 AM, XtremeBuilder said:

Hi, thanks!

Differential is proffered, but I don't need it, thanks.

Here is the axle that is driven, steered and has differential, portal hubs and three-link suspension. There is no differential on photos because I could find a spare one, but it will fit:)
Unfortunately there is no gear reduction in portal hubs, because only two 8-tooth gears can be fitted inside the rim. And I am not sure that all those parts are available in 42043 but I think that it can be rebuilt with 42043 parts.
I have another idea with much robust portal axle that uses 8:16 gear reduction in portal hubs but differential cannot be fitted there if 19 studs of width are needed. 

[Bob De Quatre]

Hi guys,

I have a question regarding the white clutch gear. Should the motor be connected to the axle hole, or to another gear meshed with the clutch gear?

[agrof]

Given to the build-up, it should work both ways, check this link: http://www.technicbricks.com/2008/02/tbs-technugets-01-inside-technic-clutch.html

I don't know which is more effective, but usually gear meshing is applied, for rotation speed reducation and to increase torque.

[Bob De Quatre]

To be more specific, I have this mechanism:

The outputs are the axle that go through the 16 tooth gears. When I block them, the clutch gear doesn't slip... I'm thinking of replacing the clutch gear with rubber band(s).

[Jeroen Ottens]

Your setup is correct. When you say the clutch gear doesn't slip I assume you see the 8T gear also not rotating, right?

For the function of the clutch gear it doesn't matter if you drive the axle and get the output from the gearmeshing, or the other way around. What (obviously) doesn't work is to mesh with the motor to the clutch gear and then mesh with another gear also on the clutch gear.

What you could do is place the clutch gear below the wormwheel. You do not have the selfbraking property of the wormwheel anymore, but that might not be an issue for you.

[Bob De Quatre]

16 minutes ago, Jeroen Ottens said:

Your setup is correct. When you say the clutch gear doesn't slip I assume you see the 8T gear also not rotating, right?

No, when I try to block the 16T gears, the mechanism forces and still runs... That's why I thought I've put the clutch gear the wrong way. I'll take a closer look a what happens tonight.

37 minutes ago, Jeroen Ottens said:

What you could do is place the clutch gear below the wormwheel. You do not have the selfbraking property of the wormwheel anymore, but that might not be an issue for you.

Sadly I don't have the space needed to put the clutch gear below the worm gear.

[AkiyamaWataru]

Could it be, that your reduction is to high. You might just can't reach the torque needed to let the clutch gear slip. At this setup you have a 1:24 Reduction (one rotation of the worm gear turns the 24Z-gear a 1/24 of a circle and you have 24 times of the input torque)

[Limga]

1 hour ago, Bob De Quatre said:

Sadly I don't have the space needed to put the clutch gear below the worm gear.

You can change 24z gear below worm gear with the clutch gear. Or you can just swap 8z gear and clutch gear.

[John Daniels]

Unfortunately you can not have the clutch gear below the worm gear, and utilize its torque limiting function. Since the 16z gears and the worm gear would both mesh directly with the teeth of the clutch gear. Effectively turning the clutch gear into a normal gear. You would have to place a clutch gear and 24z gear on the same axle, that way you would separate the input and output drivetrains, allowing the clutch gear to perform as intended.

[Jeroen Ottens]

6 hours ago, John Daniels said:

Unfortunately you can not have the clutch gear below the worm gear, and utilize its torque limiting function. Since the 16z gears and the worm gear would both mesh directly with the teeth of the clutch gear. Effectively turning the clutch gear into a normal gear. You would have to place a clutch gear and 24z gear on the same axle, that way you would separate the input and output drivetrains, allowing the clutch gear to perform as intended.

Ouch, you are so right! I even mentioned it in my post that you should not mesh twice on the clutchgear

But it sounds like you need less torque to slip. Then indeed using rubberbands is probably the better way to go.

[Bob De Quatre]

Thanks guys. I did more tests and the clutch gear did slips. I tried with rubber band but with no success, so I kept the clutch gear, but swapped it with the 8T gear! I hope to show you soon what I'm building 

[Aventador2004]

If you need a 1:1 ratio just use in this order: 24t clutch, 8t. Worm, 24t reg

This may work

[Mechbuilds]

16 hours ago, JustBrix said:

Hi got a a noob question.

How many XL motor can i run on 1 AA battery box and also how many XL motor on 1 ir receivers? This is for off-road 6x6, so the motor will probably be under load.

Thanks.

• Servo - 150mA
• M - 150mA
• L - 225mA
• XL - 300mA
• Train - 225mA
  
  TLG recommends that you run a max of 800mA off of a single battery box.
  However if your motors are doing extreme heavy lifting, like stalling an XL motor, it'll probably suck most of the power out of the battery box.

[XG BC]

On 1/20/2017 at 1:13 PM, Bob De Quatre said:

Hi guys, I'm back with more noobs questions!

I'm working on a small 6-wide monorail that uses one stud wide brickbuilt rails. I've come up with simple design (inspired by Psiaki's) and tested it with relative success. Since the monorail is supposed to run during a convention, I'm wondering if the motor will overheat and if I'd need to put a white coupling gear in there, and if so how?

There are two yellow rubber bands that can't be shown in this LDD screencap:

if you have built a monorail please make shure that you post picures of it in the train tech forum in the crs monorail tread and if you need help designing it you are always welcome to ask any questions that you want.

XG BC