Planetary Reductions: Reasonable Prices

12p3phPMDC

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I picked up a planetary reduction for $30 from these guys:

http://matexgears.thomasnet.com/

output shaft $8 dollars
input coupling $22 dollars.

Rated to 5000 rpm

3.1 : 1 reduction (lot's of other reductions available)

110 in-lb rating.

Also available in 300 in-lb ratings for approximately double price.

246 g weight.

12mm shafting....

Requires a housing.

Awesome!!! 8)
 
Hi,

12p3phPMDC said:
I picked up a planetary reduction for $30 from these guys:

http://matexgears.thomasnet.com/

3.1 : 1 reduction (lot's of other reductions available)

Requires a housing.

You can combine the units for even greater reductions.

I decided Matt's drive is a better (for me) option because:
1. Belt first stage is quieter (not sure how noisy the Matex is but I'm sure belts are quieter).

2. The difficulties of providing a housing and lubrication

3. The issues in connecting the motor to the Matex and the Matex to a chain.

Please let us know how it works.
 
Well, unfortunately, I can't see how to make it work for the trike. But, that's ok.
It's just for experimentation at this point. But a reduction with no belts or chains
is awesome. Neuspeed makes compound reductions on high rpm, 5000 watt motors. But, Matt mentioned to
me that they probably wouldn't take the axial loads and that the high rpm motors are loud. Plus the neuspeed stuff is expensive, but looks fantastic.

But, if you have to build an assembly anyway, then you can pick the bearings that'll take the loads.
I'm on a planetary kick right now anyway. You guys are probably sick of it already. But, wait,
I'm not the only OCD person here.

:wink:
 

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Hi,

12p3phPMDC said:
Neuspeed makes compound reductions on high rpm, 5000 watt motors. But, Matt mentioned to
me that they probably wouldn't take the axial loads and that the high rpm motors are loud. Plus the neuspeed stuff is expensive, but looks fantastic.

A show-stopper with the Neu (for a lot of installations) is the reduction unit is about 2" long plus the length of the motor plus a sprocket and chain...
 
Planetary reductions are very slick. I'm a huge fan of them. If the gears have a high helix, they can run very quietly, but at the cost of sideloading friction resulting in lower efficiency. If they don't have a high helix, it's a tight little compact package that you can easily apply sound dampening material around. By shareing all the axial loading to sum the sideload forces to zero on symetrical gears. I also love how they tripple-up (or way more than 3) on the smaller gears to cut down on the torque loading, and the friction and stress on any single gear. Inherently very strong and compact designs.
 
Hi guys.

Liveforphysics - i'm looking at using a Rino Mechanical PGC23 40:1 Planetary Gearbox with my 2700w outrunner. Using a HTD 5m 15mm belt and pulleys from motor to gearbox, gearing will be around 30T/60T to keep the input rpm below the 5000rpm max. It won't be cheap but with a nominal output torque rating of 60NM and max output torque of 90NM - 120NM, it should handle the power no worries. Body size is: L 80mm x H 65mm x W 65mm - quite compact for the rated output.

Paul :)
 

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Yea, looks identical to what I just received @ 1/3 cost. :x
 
Hi Paul,

Timma2500 said:
Hi guys.

Liveforphysics - i'm looking at using a Rino Mechanical PGC23 40:1 Planetary Gearbox with my 2700w outrunner. Using a HTD 5m 15mm belt and pulleys from motor to gearbox, gearing will be around 30T/60T to keep the input rpm below the 5000rpm max. It won't be cheap but with a nominal output torque rating of 60NM and max output torque of 90NM - 120NM, it should handle the power no worries. Body size is: L 80mm x H 65mm x W 65mm - quite compact for the rated output.

Paul :)

Looks nice!

Do you know about how much it costs?

Is it quiet? If you are running a belt anyway, and if its not as quiet as you like, you might want to do something like 20t/80t to further reduce the input RPM.
 
I've also been running the planetary thought through my head for some time. I purchased a 13.5:1 planetary from these guys http://andymark.biz/am-0270.html. It's of rather good quality and should be on my bike within a week or so. I'll be running a hyperion 5025 motor on this in a cyclone style setup. Total gear reduction will be around 54 or so. Should be some stump pullling power in low gear!
 
Here's another one: $9.50 each
http://www.allelectronics.com/make-a-store/item/PLG-360/PLANETARY-GEAR/1.html
Currie #BD-360. Planetary Gear Assembly for Currie Electric Bikes, scooters and US Pro-drive Conversion Kits. Fits 0.32" (8mm) diameter flatted bore on one side and splined 12mm bore on other side. 4.5:1 gear ratio on interior ring. 4:1 ratio on outer ring. 75mm outer diameter x 21mm thick. Eight 4.5mm mounting holes in outer ring.


height.500_width.500_modified.1238617878.6015.PLG-360_2.jpg
 
Those types of gear sets are so strong. Torque moments are balanced, axial loads balance, and you get 4x the teeth the share load. Inherently a very strong and thin design.
 
The supplier told me max input rpm was 5000 on the unit I bought.

The general trend on the data sheets is approximately linear reduction in output
torque capability vs. rpm.

data sheets are at matex...
 
That 8mm allelectronic one should slot right on to those cheap surplus Kolls.. how the heck would you hold it in place tho?
 
Hi,

vanilla ice said:
That 8mm allelectronic one should slot right on to those cheap surplus Kolls.. how the heck would you hold it in place tho?

It is supposed to be in a housing (another obstacle) with lubrication.
 
Ah so you would need two circles of ally and some gasket material to seal her up then. Knew there was a catch. Might be worth the trouble though.
 
Hi Mitch, yeah i got a quote from Rino for a PGC23 40:1 with a 10mm input bore instead of the standard 6.35mm - $325 USD. They mention 60db operating noise so hopefully it wont be too noisy, especially with the chain, belt and motor noise blending in! But yeah if need be it can be regeared to suit. I hope to order one in the next few weeks but wont have it running for some time yet. I'll let ya's know how it goes when i do!

Paul :D



MitchJi said:
Hi Paul,

Timma2500 said:
Hi guys.

Liveforphysics - i'm looking at using a Rino Mechanical PGC23 40:1 Planetary Gearbox with my 2700w outrunner. Using a HTD 5m 15mm belt and pulleys from motor to gearbox, gearing will be around 30T/60T to keep the input rpm below the 5000rpm max. It won't be cheap but with a nominal output torque rating of 60NM and max output torque of 90NM - 120NM, it should handle the power no worries. Body size is: L 80mm x H 65mm x W 65mm - quite compact for the rated output.

Paul :)

Looks nice!

Do you know about how much it costs?

Is it quiet? If you are running a belt anyway, and if its not as quiet as you like, you might want to do something like 20t/80t to further reduce the input RPM.
 
Here's an animation where by clicking on a button you can freeze either the sun, planets, or ring gear, you can see the effect on the various shafts rotations.

If we want to fabricate a two-speed transmission from off the shelf parts (its been done before, but a size we want may not be currently available in our desired configuration) I think its a given that the central small high-speed shaft should be the input. [edit, it can be done several ways from any of the three different elements][pre][/pre]

That being said, there's probably a couple of "home-made" ways to affect the planet carrier plate/shaft or the ring gear to get two speed outputs. Some kind of disc brake, a clamping band like an automatic trans,...must...drink...coffee...mmmm...beer?

http://www.mekanizmalar.com/transmission.shtml

Trans_Planetary.gif


"before you criticise anyone, you should walk a mile in their shoes...that way, you're a mile away when they realize that you have their shoes" -Jack Handey
 
Spinning Magnets,

you are finding some cool stuff !! 8)

Yea, a small band or disc brake sounds like a good idea.

But, from what I've read and experimented with so far, and the moped planetary trans you found,
that it maybe easier to fix the sun.

It's counter intuitive to me, but when you fix the sun in the animation, and drive the ring,
you get a reduction on the planet carrier because it is moving slower....right?
:| huh big gear drive small gear slower??? scratch head...But it's not the speed
of the planet gear but the speed of the planet carrier that matters.

So if you do a reduction from the motor to the ring gear like the moped trans...
then you get another reduction from the ring to the planet carrier if the
sun is fixed. 1st gear.
Then if you clamp the sun to the planet carrier, you get a locked planetary and a 1:1 ratio.
2nd gear.

You have to be able to tie the two clutches together. The sliding shaft has
the advantage of two clutches on one assembly.

Here's from Wikipedia

"In bicycle hub gears, the sun is always stationary, being keyed to the axle or even machined directly onto it. In this case the gear ratio is simply given by (S+A)/A where S is the number of teeth on the sun and A is the number of teeth on the annulus. The number of planet teeth is irrelevant"
 
I've seen a 3-speed bike hub used as a transmission for a 500W motor, and the builders goal was extreme range. He sounded happy with the improvement over a 1,000W motor on another bike with the same battery pack. The only drawback mentioned was he had to downshift and slow down on hills. The fat-motor 1000W bike could climb faster but had less range. Flat-ground accelleration was good on both.

Also, the 3-speed bike hubs for cargo trikes are heavier duty than the less expensive ones. Here's a 12V cordless drill unit

drill_23-440x330.jpg


Theres a need for a compact 2-speed trans for E-motorcycles, because of the speed (freeways) and weight of the vehicle, and the short range they are restricted to by the limited battery space.

I have read about E-car conversions that use the original manual transmission, and the builder only used 2 of the 5 forward gears (plus its a convenient reverse). For a small car that is limited to 40-MPH, a single-speed reversible motor might be easier, but for freeway speeds a home-builder has a much easier job if you have gears.

In a cars auto trans (I've read) that the ring gear is allowed to turn, then oil pressure is applied to a small piston that chokes a band around the outer rim. So, many ways to get the desired result. We cant just select two gear ratios and order them (if thats possible from an industrial site, theyd be very expensive)

planetary-gear-unit.jpg


I'm more interested in finding a planetary thats already the right size for a medium-sized motorcycle (hopefully one thats easy to find cheap and used), and figuring out the easiest way to adapt it into a 2-speed...A geo Metro auto trans might have one about the right size...

"Money can't buy you happiness...but it can give you a more pleasant form of misery" -J. Paul Getty
 

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Re: Geo metro auto tranny parts

I was thinking the same thing!

That would be extremely strong and reliable.

Even though the Geo is "small" it is huge compared to a lightmotorcycle.
What's the power on a geo 3 banger? 50hp

Matex has some high torque rating planetaries. The planetary I bought was cheap but 110 inlb.
~5000 in-lb ~ 400 ftlb!! yikes.
http://matexgears.thomasnet.com/item/all-categories/torque-range-301-11-478-in--lbs-/3mef20?&seo=110

So, it's better to pick the smallest one possible within good margin.

There are references lurking around here to a Nexus3 with mars/etek on a
chopper bike. Gary G? Gary, how many kw are you putting through your Nexus3 setup?
 
"...I happened upon a used 18volt Makita hammer drill that a friend was tossing in the garbage as the batteries were worn...So I took it apart to find a very nice 3 speed planetary transmission with clutch. All hardened steel, Each stage uses from 3-5 planets so there is always a lot of gear tooth contact made. Shows no wear at all.

Locking the 1st internal ring gear results in low speed.Locking the 2nd internal ring gear gives a 2nd higher speed. Locking 2 and 3 together and letting them spin gives high speed. The clutch is also very nice..." (looks modular, if we only wanted 2 gears, seems like we could just use two of them, whichever 2 gave us the closest to the ratios we want)

Edit: some lower-torque cheaper drills have a plastic ring gear, link with pics:
http://www.canadiancontractor.ca/english/techtips/article.jsp?content=20080605_095011_20036

Edit: heres a spec list with details on the most popular drill gear-sets:
http://www.robotcombat.com/store_dewalt_gearboxes.html

makitatrans001.jpg


makitatrans002.jpg


"so you're a big fan? thats good...if it gets any hotter around here I'm gonna need a big fan" -Groucho Marx
 
The drill 3 speed looks like it may have potential . Does it fit into a tube housing ?
I found a surplus 16:1 planetary gear box on a motor that looks to be super beefy. It's rather heavy
though, the case it's in is made of 1/2 in thick AL. About 4" diameter. These industrial units even have roller needle bearings
on the planet gears ! The planet gears are about 9/16 diameter, and it is a 2 stage reduction. Maybe with some
machining I can reduce it's 9 lb weight.
I am waiting for a second unit to be shipped to me, it has a higher ratio still. Efficiency of these gears is claimed 90%.
You can tell when you peek inside that they are very high quality, they list for between $600 USD to $900 USD each.
Not practical for making a bunch of bikes, but fine for a one-of DIY bike. Used gear box can be had for < $100 .

RC motors need close to 60:1 ratio for crank drives.
 
MitchJi said:
Hi Paul,

Timma2500 said:
Hi guys.

Liveforphysics - i'm looking at using a Rino Mechanical PGC23 40:1 Planetary Gearbox with my 2700w outrunner. Using a HTD 5m 15mm belt and pulleys from motor to gearbox, gearing will be around 30T/60T to keep the input rpm below the 5000rpm max. It won't be cheap but with a nominal output torque rating of 60NM and max output torque of 90NM - 120NM, it should handle the power no worries. Body size is: L 80mm x H 65mm x W 65mm - quite compact for the rated output.

Paul :)

Looks nice!

Do you know about how much it costs?

Is it quiet? If you are running a belt anyway, and if its not as quiet as you like, you might want to do something like 20t/80t to further reduce the input RPM.

Hi MitchJi, i havn't been on here for a little while...

Yeah the box looks great but i have decided to go with a BaneBot P80 16:1 planetary gearbox instead. A lot cheaper - $105USD vs $325USD for the Rino gearbox! Hopefully the quality will be ok for our needs and they are rated up to 85ft-lbs / 115NM torque which should be enough for most of us. Plus they have full spare parts backup if anything breaks or wears out. :D

Not sure how its going to go for decibels, i'm going to wrap some sound deadener around the middle round part of the box in an effort to reduce noise plus it will be enclosed so hopefully it'll be reasonably quiet if done that way.

Can't wait for my favourite courier to arrive with it to start playing lol!

Paul :D
 
12p3phPMDC said:
Gary G? Gary, how many kw are you putting through your Nexus3 setup?

There is a guy in SD named Dave, who has a bike shop in Pacific Beach called Rusty Spokes. He's the one who builds custom choppers using Eteks and Mars motors, running off 36V/50Ah SLAs. All of them use standard Nexus 3 hubs. Not sure how much power he is putting through these, but I'm guessing 5-10kW, in any case.

When I wsa running my Cyclone 1000W setup, it hit peaks of about 2650W, but that is at the battery. I'm currently working on this bike (a 20" Dahon Mariner...) right now. Initially, I'm using the same Cyclone 1000W motor and the 55A controller, but with different gearing. Instead of going through the crank, the motor now drives a jackshaft with a #25 chain drive as a 1st reduction. There is a 24T sprocket on the motor shaft and an 80T sprocket attached to a White Industries ENO freewheel, on the jackshaft. The output of the jackshaft is an 18T track cog which drives a 36T sprocket on the Nexus-3 hub. The crank now has a single 44T chainring, on the standard Cyclone freewheel setup. It drives a 22T sprocket which is also on the Nexus-3 hub. The big reason for doing a dual chain to the rear setup is so I can "reclaim" use of the pedals. It still requires a freewheel on the crank, but now it doesn't have to be an expensive ENO, as it is not carrying the main load anymore.

Doing dual cogs/sprockets on the Nexus hub required a lot of trial and error, and head-scratching, but I finally have a workable solution. What I did was used a Dimension "Big Cheese" 110 BCD adapter plate and then drilled 4 holes to add a 22T 64BCD "granny gear" chainring. Sandwiched in between these is a 16T Nexus cog. I also had to use about a 2" hole saw to open up the hole in the adapter plate, in order fo it to fit over the front portion of the Nexus hub, right behind where the cog slides onto. With this arangement, the 22T sproket is on the outside, and the sprocket the jackshaft drives is on the inside. I'm using a standard Sugino 36T 110 BCD singlespeed chainring, but there are lots of choices here. I have a 53T, but I've seen even larger ones around.

After I get a baseline of the performance with the Cyclone setup, the first thing I will do is replace the controller with one of methods modified 18-FET Infineon controllers, and up the current to about 80A. I'm initially using a 16s5p a123 pack, but I may also try upping the voltage by adding another 8s5p pack. With an 80A limit. the power should go up close to 4kW, and with a 24s/80A configuration, closer to 5.5-6kW. With an 80V setup, I'll change the 18T cog on the jackshaft to a 12T.

After I've killed the Cyclone (gotta stop hanging around with the testosterone kids... :mrgreen: ), I will pull out the Cyclone, and install my 3210-10T (kV of 135, vs about 70 for the Cyclone...). With the 16s5p pack alone, I'll change to a 14T motor sprocket,, driving the 80T and go up to a 40T sprocket on the back, driven by the 18T cog. Going up to 24s will again require dropping down to a 12T cog on the jackshaft.

Finally, when the sensored 3220-7Ts are ready (hopefully in the next couple weeks...), I will put this in place of the 3210, and open up the current on the controller to 100A+, and really see if I can start breaking things. :shock: :mrgreen: If the Nexus-3 can survive that, I think it can handle most anything. Methods is going to set his 3220 up with a Alfine 8-speed hub, which has a disc brake, and also is supposedly very strong, compared to the other hubs, like the Nexus-3/8. His setup will also put even more power through, as he will use a 24s LiPo setup so about 10 more volts and who knows how many amps. :wink:

Once I get the jackshaft mounted, and the basic setup complete, I will take some pics and start a new thread.

-- Gary
 
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