LEGO Boost interactive motor shaft

[vxhall]

 I wonder if anyone could help me to find the 3D model of the shaft of the interactive motor in LEGO Boost(17101). The part number of the motor is 6181852. Mine is broken. I bought a new motor but I'm looking for a way to repair the broken one. If I can find the 3D model file of it I may have it printed and make the motor working again.

[JopieK]

Boost is relatively new so I doubt it exists. You could use TinkerCAD to make it yourself. I would use (digital) calipers to take measurements of the originals. You could of course also return the item to LEGO service although they probably don't like the fact that you opened the motor.

[RohanBeckett]

I agree.. with @JopieK Boost is too new - you could very well be the first person in the world to break that bit, and need to recreate it!  so the challenge, and glory can be yours! ;)

 

Maybe if you can supply accurate measurements, @efferman might be able to help?

https://www.eurobricks.com/forum/index.php?/forums/topic/91294-effermans-custom-parts/

 

Edited August 3, 2018 by RohanBeckett

[vxhall]

Thanks guys. I think Boost has been out there for nearly a year... anyway I can try to measure it next week and see if I can figure it out.

[doug72]

It might be the same part as used on other PF motors.

[JopieK]

There are already some basic parts available: https://www.thingiverse.com/thing:2153994

[Tommy Styrvoky]

I could model it, if you had a caliper, that would be helpful to get a few base dimensions, though othwise you could take some top down photos of the spindle with a mm scale or ruler laid at the same height. The only other dimensions that would be needed of the side profile are the, spline thickness, collar thickness, and height of the connector for the axle to the collar. Also the diameter of the collar and axle connector.

 

The PF m motor spindle is different, as it goes directly to a planetary reduction.

Edited August 3, 2018 by Tommy Styrvoky

[dr_spock]

If there is an existing STL of the PF one, you could try to modify it.  Replace the bottom 3 pins with the star shape and make disc smaller.  MeshMixer might be a good tool to combine parts. 

 

[Tommy Styrvoky]

12 minutes ago, dr_spock said:

If there is an existing STL of the PF one, you could try to modify it.  Replace the bottom 3 pins with the star shape and make disc smaller.  MeshMixer might be a good tool to combine parts. 

 

Stls suck for modifying, as nothing is ever square or parallel. And I already looked in the ldraw library it would only take like 15min to model it up.

Edited August 4, 2018 by Tommy Styrvoky

[Tommy Styrvoky]

Done with the basic shapes, just need correct dimensions of the spline, collar and axle connector. 

[vxhall]

 

4 hours ago, Tommy Styrvoky said:

Done with the basic shapes, just need correct dimensions of the spline, collar and axle connector. 

Wow you are so fast! Well I need to find a caliper next week. And because the shaft had broken, so the measurements might be not that accurate. But anyway much much appreciate to what you’ve done.

[vxhall]

Just got a caliper and did some measures.

[Tommy Styrvoky]

Here's an updated drawing, I just want to make sure that the diameter of the edges of the splines are 1mm and the depth of the axle well is 7.8mm, as everything else is corrected now. From some of my previous prints the tolerances were within ±.05mm so it should work just fine if all of the measurements are correct. I used @efferman's dimensions for the axle hole, as those are slightly different from yours.

 

replacement spindle for Lego boost motor Drawing by Tommy Styrvoky, on Flickr

If everything checks out, then here's the link for the part on Shapeways.

https://www.shapeways.com/product/ZS3TT7SKG/boost-motor-spindle-replacement?optionId=67504149&li=shop-inventory

Edited August 9, 2018 by Tommy Styrvoky

[vxhall]

Thanks @Tommy Styrvoky , that looks amazing! Well as to the detail measurements, the diameter of the spline is quite tricky but I think 1mm is correct, and the axle depth I got is 7.9mm and I think that difference is not a big deal. And for the dimensions for the axle hole, the difference might due to my measure not very accurate or the distortion of the hole after I splice the broken pieces. But comparing the dimensions in your model and the cross axle(https://bricks.stackexchange.com/questions/9406/what-are-the-dimensions-of-a-technic-axle), it should be fine. Anyway I will give a try and let you know. 

[vxhall]

ehhh.... it seems not very economic to order it on Shapeways since the shipping fee is about the same as buying a motor. I wonder if there is a way that I can pay to get your models digital file(for 3D printing) thus I can have it printed out locally?

[Tommy Styrvoky]

1 hour ago, vxhall said:

ehhh.... it seems not very economic to order it on Shapeways since the shipping fee is about the same as buying a motor. I wonder if there is a way that I can pay to get your models digital file(for 3D printing) thus I can have it printed out locally?

I will upload the file tomorrow,( 8 hours from now) and you can find a local place to do it for you, though depending on what method you decide to print it could determine if some changes may need to be done for the axle hole or splines.

[Tommy Styrvoky]

Stl file for it here. https://www.bricksafe.com/files/Tommy_styrvoky/Boost motor spindle.stl

 

[vxhall]

Thanks a lot! Will let you know how it works then.

[vxhall]

It works! The hole for the cross axle is a little tight but ok. Thanks Tommy and all of you guys. Now I have a spare motor and a few spare shafts(or say spindles).

[Tommy Styrvoky]

21 hours ago, vxhall said:

It works! The hole for the cross axle is a little tight but ok. Thanks Tommy and all of you guys. Now I have a spare motor and a few spare shafts(or say spindles).

Glad to hear it works, if it is cheap enough, I could increase the axle size by a 1/10th of a mm, as that's an easy fix. Also depending on the material, I think some polyamides can be dyed, so you could make it red if you want.

Edited August 18, 2018 by Tommy Styrvoky

[vxhall]

On 8/18/2018 at 8:31 AM, Tommy Styrvoky said:

Glad to hear it works, if it is cheap enough, I could increase the axle size by a 1/10th of a mm, as that's an easy fix. Also depending on the material, I think some polyamides can be dyed, so you could make it red if you want.

The price I paid for it is about 1/3 of a motor, I think I will go with the current spindles. Maybe you can modify your model on shapeways to make it more perfect for others who may need it:). 

[rob79au]

Brilliant, I have the same issue.

What precision do I need to print this part?

[vxhall]

rob79au, I didn't specify the precision when I printed it. I just use the default. If you wan to have a try, maybe you can ask Tommy if he can increase the axle hole size a tiny bit. The one I printed is a little tight for the cross axle.

[rob79au]

On 1/3/2019 at 1:37 PM, vxhall said:

rob79au, I didn't specify the precision when I printed it. I just use the default. If you wan to have a try, maybe you can ask Tommy if he can increase the axle hole size a tiny bit. The one I printed is a little tight for the cross axle.

vxhall, thanks mate. What printer are you using? I'll check the specs as I want to make sure I use one with similar µm resolution.

On 8/18/2018 at 10:31 AM, Tommy Styrvoky said:

Glad to hear it works, if it is cheap enough, I could increase the axle size by a 1/10th of a mm, as that's an easy fix. Also depending on the material, I think some polyamides can be dyed, so you could make it red if you want.

Tommy, I have the original stl. Did you  get a chance to increase the axle size? If so, can I get a copy of this stl?

[Tommy Styrvoky]

34 minutes ago, rob79au said:

vxhall, thanks mate. What printer are you using? I'll check the specs as I want to make sure I use one with similar µm resolution.

Tommy, I have the original stl. Did you  get a chance to increase the axle size? If so, can I get a copy of this stl?

Sure, I can do that tomorrow, also someone bought 2 of these from my shapeways shop, so I guess this is somewhat a common problem. Maybe I should increase the axle hole size by 5-10 microns, any idea how hard it is to insert/remove compared to a regular Lego one, as I recall from using FDM printed parts a difference of 10 microns made a large difference.

On 1/2/2019 at 8:24 PM, rob79au said:

Brilliant, I have the same issue.

What precision do I need to print this part?

You could probably do this with a FDM machine, thought it may need some tweaks to the stl file, and it may shear off the splines due to print orientation.

Edited January 6, 2019 by Tommy Styrvoky