More Economic Gearbox options


#1

Hi there,
been struggling with a budget to build my foil, and since the Gearbox is one of the most expensive parts, been looking for alternatives in Aliexpress, since i saw one of the Factories of Neugart is based in China, i was betting there could be clones already at sale.

Found this one that looks like the Neugart PLE40: https://www.aliexpress.com/item/40mm-planetary-reduction-gear-ratio-4-1-planetary-gearbox-DC-motors-with-gearbox-micro-motor/32288271481.html?spm=a2g0s.13010208.99999999.270.nCrtXG

I will order one soon. The only thing is that since i don’t own an original one, i will not be able to tell the major differences.

Found also those other options if anyone doesn’t want to spend time looking:

https://www.aliexpress.com/item/PLE40-high-precision-planetary-gearbox-ratio20-1-output-torque-20N-m/1625382649.html?spm=a2g0s.13010208.99999999.277.nCrtXG

https://www.aliexpress.com/item/Helical-gear-planetary-gearbox-with-high-torque-and-low-noise/32620303533.html?spm=a2g0s.13010208.99999999.284.nCrtXG

All those Gearboxes can be ordered with the required gear ratio.

Hope this helps others.


#2

I did few comparisons with this “cheap” gearboxes few months ago. A lot of them are basically same factory, and those which arent, numbers seem very fishy. For an example, a lot of them have same/simmilar ratios and Nm outputs, same pictures same dimensions, same specs etc, however, whats not the same, is power rating. So for few “same” gboxes, u have 300, 1200, 3000 W etc. Very fishy.
I think i read here and on ES, some1 bought “afordable chinese” gearbox and it didnt last long.
Just a thought, not a putout :expressionless:


#3

Think about putting the motor in the hull and belt driving it. This way you can change the belt ratios easy. I’m using this gear box. https://www.amazon.com/Andantex-R3200-Anglgear-Universal-Mounting/dp/B00852JANI/ref=pd_cart_rp_2_3?_encoding=UTF8&pd_rd_i=B00852JANI&pd_rd_r=XYBNVRZQASV991NN93S5&pd_rd_w=94vUD&pd_rd_wg=oVjNz&pf_rd_i=cart-page-widgets&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=3529858822&pf_rd_r=XYBNVRZQASV991NN93S5&pf_rd_s=cart-page-widgets&pf_rd_t=40701&psc=1&refRID=XYBNVRZQASV991NN93S5

Buy these extrusions:

http://www.bcawnings.com/?o=modules&n=alum&f=alum&idinfo=899

Chris


#4

Got mine today from these guys: https://www.alibaba.com/product-detail/40mm-planetary-gearbox-for-extruder-grain_60688981587.html?spm=a2700.8443308.0.0.bYS9TY
Looks ok, so far, haven’t tested yet. What I figured out when searching for a Neugart PLE40 clone was that torque specifications vary and some only have a max torque of 6 or 7 Nm. Mine should have 16Nm but we will see. It was also quite time consuming to explain them what size I need an specify all the parameters (started in beginning of February with inquiry). They made a drawing according those specs and custom built that gear.


If I’d order again, I would change the diameter of the center line the output side M4 holes from 46 to 48 this would allow to use M4 screws from the back side of the square flange.
Price was 126US$ including shipping with TNT.


#5

Do you need a belt with that 90deg angle gear? You could run a long drive shaft down the mast and have a large diameter pancake outrunner in the board. The drive shaft would probably need some supports so that it doesn’t wobble in the mast. The nice thing, there is almost no size limit in the board with a vertical motor, you can go super low kv with massive torque. The downside is more motor noise/vibration, harder to cool and more weight on top, but I see no major showstoppers. Go build it. I think the 6063 profile might be a bit weak.


#6

Here is an idea I was thinking.
In NZ we have dagging plants. It’s a brushed motor that spins about 3000 rpm down through a flexible driveshaft to the handpiece to shear away the wool.
Dremels also use this system, and they are very robust.
You could mount what ever size motor on the board, run the flexible drive shaft down through the inside of the mast, and down to a prop on the bottom.

This would be lightweight and robust.

Pictures below for reference of the shaftimages%20(1)unnamed


#7

I’ve been at the end of one of them a few times on the olds’ farm. Great idea but don’t think you will get the torque we require though.


#8

How come the torque wouldn’t transfer? You would utilise a brushless motor with the kV range you need


#9

I see some pedal powered boats use them. But obviously much lower input speed, and if using a motor a sudden change in speed may cause problems on the flexy shaft?

And some other geared versions3535154737_ff5ec8082b

images%20(3)


#10

These pedal power boats! I never get why they push instead of pull with the propeller!


#11

It’s good to set te motor off to the side and timing belt drive it with a 5mm HTD belt. This allows you to change the pulleys easily to alter the drive ratio.


#12

I’d think the following would be an advantage of a pusher:

  • a bit more protection for the prop as the shaft may displace debris before it gets to the prop
  • water is more resistant than air, therefore having a pusher will push the blade onto the prop shaft vs pull it off.

#13

I think is makes sense. The water is traveling faster at the output of the prop, then it is in front of the prop. So with a pusher the frame work that holds the prop is in the slightly slower traveling water. The opposite would be true with a puller.