14 replies to this topic

[88high]

Hello everyone! Happy Easter!  You might recall my super car project topic from a few weeks ago. I have made some progress in the whole suspension and engine parts if the model, but I have now run into a "brick wall" when I have come to the frame.  I have built the connections, and they seem pretty strong. I also made an AWD-RWD switch behind the front axle. I now want to put in a gearbox, probably 2-4 speeds. I can do a 2-speed right now, but if I want a 4-speed, I need to figure out my trade with vyprynsall. I was thinking of using my compact 2-speed gearbox from my Kamaz 4911 , but, it might be too simple, or not compace enough. What do you think? I also am having trouble with steering. I am using the axle from Sheepo's MPS system. I have a 8tooth gear going through the axle. I would like to connect a moving steering wheel to that and Some type of M-motor powered steering up front... How can I do that compactly though?

So, as you can see, I am kinda stuck and I need your helps and opinions on how I should do this. I will post a video of my progress of the super car in my YouTube channel. (see below)

Thanks, and I really appreciate your help.

-88high

[GuiliuG]

Why do you make a new topic if you have already started a topic about your project? How do you want we help you without same seeing one picture?

I don't want to be rude, but your posts seem all similar and useless. It's impossible to help you simply with your explanations...

Edited by GuiliuG, 08 April 2012 - 06:40 PM.

[AndyCW]

When I'm stuck, I take a break and will cruise the interwebs for sometime.  The input of new ideas combined with the absense from building usually help me solve the problem or to figure out a work around.  Sometimes I end up rebuilding in another manner so the original problem doesn't even come into play.  Either way without an idea of your specific problems (pictures) we will be of little help.

v/r
Andrew

[captainmib]

I understand your problem of a "brick wall" but i like to go with GuiliuG - post your question in the thread you made of the MOC.

And just keep trying. Maybe design something else to get new insights or creativity. Look at other MOC's or just simply go read instructions from lego.

[DLuders]

Here is 88high's original topic about his Supercar project.  There were no pictures of his car there either.  

[88high]

GuiliuG, on 08 April 2012 - 06:40 PM, said:

Why do you make a new topic if you have already started a topic about your project? How do you want we help you without same seeing one picture?

I don't want to be rude, but your posts seem all similar and useless. It's impossible to help you simply with your explanations...

Well, my older post was just on starting my super car and how should I go about it, now I am stuck and asking for help, instead of posting replies to my topic, I made a new one which more people would read

Updates: I have made the gearbox very sturdy, and well built. I can power it one of two ways: RC buggy motors or PF XL motor. I put in the RC motors hoping for some good speed, and sufficient torque, but when I did put them in, they did not even have enough power to even drive! They are using the weaker input, so I might have to use the last one, with more torque. But will it be enough?!? Also, the video is uploading still. I can't post pictures on here much, because my apple iPod won't let me "upload pics" I will try and reply to this topic later with some...

Thanks for your patience

As for the steering, I did a wormscrew gear steering, with the M-motor in the front

Pics will be in a video on my channel soon

[DLuders]

@ 88high:  On Philo's "LEGO 9V Technic Motors Compared Characteristics" webpage, Philipple Hurbain wrote, "The [RC Buggy Motor's] innermost shaft hole is geared up by a 23/17 factor. Only the outermost output is tested below."  The RC Buggy Motor has a "stalled torque" of 12 Newton-centimeters (N.cm), which the Power Functions XL Motor has a stalled torque of 40 N.m (over 3 times greater).  To get that torque, (with no load) the PF XL Motor only rotates at 220 rpm while the RC Buggy Motor rotates at 1,300 rpm.  

  

Perhaps you should consider getting Crowkillers' (Paul Boratko's) Transmission Instructions (via his website or eBay) -- "2 sets of Instructions Available for both the 5-Speed and All Wheel Drive with Reverse Versions with Full Parts lists for both Models.  You will get both sets of instructions with Parts list for only $10":



"Instructions were Prepared by Eric Albrecht." (Blakbird)  

"These Transmissions will make great conversation Pieces, perfect for demonstrating how Gearboxes work, or even installing into your very own Custom Lego Supercar!

Transmission #1 -- 5 Speed Transmission with Reverse:  This fully functional Transmission follows this Shift Pattern:

R 2 4
1 3 5

Gear ratios are as Follows:  
Reverse 1.66 : 1
1st Gear 1.11 : 1
2nd Gear 1 : 1
3rd Gear .66 : 1
4th Gear .60 : 1
5th Gear .40 : 1

Transmission #2 -- All Wheel Drive 5 Speed with Reverse: This fully functual Gearbox follows this Shift Pattern:

1 3 5
2 4 R

Gear Ratios are as Follows:
1st Gear 2.08 : 1
2nd Gear 1.60 : 1
3rd Gear 1.25 : 1
4th Gear 1 : 1
5th Gear .75 : 1
Reverse 2.25 : 1"

Edited by DLuders, 08 April 2012 - 09:32 PM.

[88high]

The video is now posted on YouTube, thanks for explaining the motors to everyone, (I already knew about philo) I think I will stick with my design of transmission because it fits perfectly in the already-small chassis

AndyCW, on 08 April 2012 - 07:17 PM, said:

When I'm stuck, I take a break and will cruise the interwebs for sometime.  The input of new ideas combined with the absense from building usually help me solve the problem or to figure out a work around.  Sometimes I end up rebuilding in another manner so the original problem doesn't even come into play.  Either way without an idea of your specific problems (pictures) we will be of little help.

v/r
Andrew

True :) also taking a break helps

[DLuders]

@ 88high:  On your silent YouTube video, you wrote a rhetorical question, "with dual RC motors, they don't have enough torque.  Should I go back to a [Power Functions] XL [motor]?"  Yes, you should because (1) The PF XL motor has over three times as much "stalled torque" as the RC Buggy Motor, (2) The PF XL motor does not draw nearly as much current as the power-hungry RC Buggy Motor does, and (3) The PF XL motor is far more compact.  

Edited by DLuders, 08 April 2012 - 09:59 PM.

[SNIPE]

I would suggest a 9v motor because they are small yst fast but they are not really compatible with PF, I don't know if you like using non lego stuff, I don't but if you do you can get PF to 9v converters.
If you don't then I would have a gear reduction using a 24 tooth gear on the steering axle meshed with a 8 tooth gear on the motor axle.
the motor for your transmission with be back to back with the steering motor.

As for the gearbox the best bet would be to use this:

It can have several 'gears' up to 8 (I think) so if you want 4 years then you could take some off to make it less wide, this is very small for a gearbox and has many features.
Note that next to the 14 tooth gears there is an axle with no gear on it, this is because you need two of these on each blank axle:

http://img.bricklink.com/P/9/4143.gif

The shift pattern for the wider gearbox is:

1-4-5-8
| | | |
2-3-6-7

The '-' and '|' mean bi-directional stick-shift movement, there is no neutral unless you take off a gear from the axle or something like that, there is no inbetween position for neutural between any of the above gear numbers as a result. the pattern is like that beuse the axles of the gearbox are close together, if you don't want it like that, move the axles out by 0.5 L, this will let you have a normal sticking pattern but it means it takes longer to move from gear to gear.

You just have to find a shift lever that works with the black clutches, I would use something like a technic 2 cross hole lever thin.
If you want the white clutch gear on just give me a shout, there is a tiny gear for high traction which improves grip and acceleration from a stationary joint too but I don't know if you want those.
As for reverse you use the H bridge in the motor and it is fast at switching and takes up no space in the model.
The long axles are the input and output shafts, here is another version which is less wide but has less features and has around 4 or 5 'gears'

http://i42.tinypic.com/66gj0m.png

Again put the gears I showed you on these blank axles too.

For the tutorial on setting up the gear synchronizations so that the lever does not jam or snag, or on using it as an automatic transmission and on the other features email me or for the LXF file for the less wide version , also email me

This series of gearboxes (PiT 12, 10 or 6) work by having different combinations of the clutches meshed which select the larger main gears to spin, not spin or float.
file here:
PiT-12.lxf

Edited by SNIPE, 10 April 2012 - 01:51 AM.

[88high]

DLuders, on 08 April 2012 - 09:11 PM, said:

@ 88high:  On Philo's "LEGO 9V Technic Motors Compared Characteristics" webpage,

>snip<

Gear Ratios are as Follows:
1st Gear 2.08 : 1
2nd Gear 1.60 : 1
3rd Gear 1.25 : 1
4th Gear 1 : 1
5th Gear .75 : 1
Reverse 2.25 : 1"

Hey Dluders. Thanks for your advivce on the transmssion. I don't really want to pay for instructions, its just not my thing... I think i have it covered though...I have my 2-speed design in the frame pretty well...If you do want to help me make a 3-4 speed transmission, i need it within these diameters: 7-studs wide-by 11-studs long (including XL motor). I would like to keep the frame pretty slim, so I can fit some seats and a moving steering wheel into the sides.

If you have any furthur ideas, please contact me, or just simply reply here :)

SNIPE, on 10 April 2012 - 12:38 AM, said:

I would suggest a 9v motor because they are small yst fast but they are not really compatible with PF, I don't know if you like using non lego stuff, I don't but if you do you can get PF to 9v converters.
If you don't then I would have a gear reduction using a 24 tooth gear on the steering axle meshed with a 8 tooth gear on the motor axle.
the motor for your transmission with be back to back with the steering motor.
>snip<

Hello SNIPE! :D Thanks for your information and inspiration on your transmission designs, they look great for my purpose! However, i dont think they will work for me. I would like for the transmission to be more relatively linear, in line with the frame, to insture good suspension balance. I think that will come when we accomodate to make it have less speeds due to my parts count. Plus, I also only have 2 pairs of the red shifter parts. (I'm aquiring a few more soon) Do you have a transmission design along those lines that can use Something with 4 speeds and only two of those red shift catches? please contact me back soon< i think your way will work:D


I will have to tear out my simple 2-speed transmission from the close-to finished frame though. ugh. But I think it will be worth it!

Please Reply sooon

-88high

Edited by Rufus, 12 April 2012 - 04:43 PM.
Please don't quote the entirety of long posts.

[SNIPE]

Check out the transmission that the lego 8448 supercar uses :).

Dont use the reverse or 5th gear in your gearbox unlike the one in the 8448, this will mean using two red shifters only as requested.

Just put the gearbox motor in reverse it is quick and takes up no space at all.

I did not understand the following:

Quote

I would like for the transmission to be more relatively linear, in line with the frame, to insture good suspension balance. I think that will come when we accomodate to make it have less speeds due to my parts count

I'm guessing you meant?:
The technic connector pegs, there some either side connect it to the chassis which needs to have a 9L wide gap min (9 holes worth) for the transmission (assuming it is a 'PiT12-somethingsomething')  to sit. There would then be another higher up support for the gear stick to move around but not come apart.

If you have the some PiT10 model then the gap needs to be 8 holes wide.
For reference: technic studded bricks with the holes in them are 1L, so are some gears,wheels, liftarms etc

Edited by SNIPE, 11 April 2012 - 03:00 AM.

[88high]

SNIPE, on 11 April 2012 - 02:28 AM, said:

Check out the transmission that the lego 8448 supercar uses :).

Dont use the reverse or 5th gear in your gearbox unlike the one in the 8448, this will mean using two red shifters only as requested.

Just put the gearbox motor in reverse it is quick and takes up no space at all.

I did not understand the following:

Yes, later tonight I will look up instrutions for the 8448 Gearbox. Is it studless? i hope it is...

As for your second paragraph, I would like to keep my drivetrain on one technic beam hole in the center of the frame. it can go up/down, but i prefer not side-to side, because it throws off the balance of the car. It would be fine to go up/down

I'm guessing you meant?:
The technic connector pegs, there some either side connect it to the chassis which needs to have a 9L wide gap min (9 holes worth) for the transmission (assuming it is a 'PiT12-somethingsomething')  to sit. There would then be another higher up support for the gear stick to move around but not come apart.

If you have the some PiT10 model then the gap needs to be 8 holes wide.
For reference: technic studded bricks with the holes in them are 1L, so are some gears,wheels, liftarms etc

[SNIPE]

or try this sicne you want the normal stick pattern:

Now the black clutch barrels are three position, allowing you to change to another barrel when the gear lever is in the middle position, I took the barrels off so can see the axles they would still be there.
The gearbox in the 8448 s studded but you can put studless tiles on it and it is only the interior part where you might see studs unless you add tiles.

[88high]

SNIPE, on 12 April 2012 - 04:08 PM, said:

or try this sicne you want the normal stick pattern:

Now the black clutch barrels are three position, allowing you to change to another barrel when the gear lever is in the middle position, I took the barrels off so can see the axles they would still be there.
The gearbox in the 8448 s studded but you can put studless tiles on it and it is only the interior part where you might see studs unless you add tiles.

I havent gotten the chance to reply to this forum yet, but i made my own modified version of the 8880 4-speed gearbox. It works perfectly for my purposes. I guess the gearbox issue is closed now.

Thanks for your help. I should have looked at a Lego gearbox all along!