Current Cycles Prototype Buildlog...

[Thud]

Whip,
This is all you need for shafting....its oil hardening drill rod blanks.
http://www.mcmaster.com/#catalog/117/3643/=cfg3of

9 bucks for a 3' length.

 

[Whiplash]

cool, THANKS! Good find... I'll do that for sure!

 

[Whiplash]

OK Thud, I ordered the shafts you suggested, along with the needed bearings for them, hopefully they work out well. Do you think I need to harden them? I was considering getting all the set screw divots drilled in them and then hardening them along with the gears using the oil quench method. What do you think? I figure the gears at least should be hardened no? Thanks for the help, its my first gearbox and I want it to get the job done!

 

[gwhy!]

OK Thud, I ordered the shafts you suggested, along with the needed bearings for them, hopefully they work out well. Do you think I need to harden them? I was considering getting all the set screw divots drilled in them and then hardening them along with the gears using the oil quench method. What do you think? I figure the gears at least should be hardened no? Thanks for the help, its my first gearbox and I want it to get the job done!

I case harden my gears and are holding up well, I just used 12mm silver steel bar for the axles and I have not had any problems ( as of yet ) I expect you know but when case hardening with oil don't use semi or fully synthetic oil only use the cheaper stuff . I got my gears from http://www.technobotsonline.com/gears/mod-1.5-steel-spur-gears.html not sure if they deliver outside the uk and they don't have a massive selection of gears but the ones they stock are a pretty good price.

 

[Thud]

Whip,
I NEVER "harden" shafts unless they are actual bearing surfaces.(like for a sprag to ride directly onto) no reason to destroy the ductility of decent steel that is spinning on its axis.

Just use good design so there are no long spans of unsuported force or any long sections where torsional flex would become a factor. (none of that is on play on your tiny gearbox)

 

[recumpence]

I have been using case hardened shafts from McMaster Carr on all my drive units. They are not as cheap as the drill rod, but still very innexpensive. I have heard horror stories of machining through the case hardening making the shafts break. But, I machine flats and drill dimple holes in these all the time and, after thousands of miles (and pulling huge power through them), I have never had a problem with one, ever.

The reason I bring this up is, it has been my experience that life is so much easier when using good precision shafts and these seem to work best for me. I have had problems with inconsistency in diameter and straightness (is that a word? :wink: ) of lower cost shafts.

Matt

 

[bandaro]

The reason I bring this up is, it has been my experience that life is so much easier when using good precision shafts and these seem to work best for me. I have had problems with inconsistency in diameter and straightness (is that a word? :wink: ) of lower cost shafts.

Like the "10mm" ones I was going to buy, then I put some verniers to them and they were 9.6mm... now imagine that error spinning at 8000rpm. As a motor shaft. The magnets can hit the stators at 9.85mm... Apart from that I have had no problem turning down shafts, but thinner ones should definitely be good steel.

 

[Thud]

For sure, you can easily garantee quality of a steel by "over buying" a specification for the application.
If you know the performance requirments of your designs & do a little shoping you can do much better.
For fun, look up the ANSI standards for drive shafts somtime :wink:


I'll highlight a few things you should consider for your app.

mcmaster part # =8893K45
qyt = Each
In stock for $8.53
More About Steel Alloys
*Drill Quantity = Individual Drills
*Drill Bit Style = Drill Blanks and Rods
*Drill Rod Type = Precision Ground
*Drill Bit Composition = Grade O-1 Oil-Hardening Tool Steel
*Surface Treatment = Precision-Ground
*Overall Length = 36"
*Length Tolerance = +1/4"
*Diameter = 1/2"
*Diameter Tolerance = ±.001"
*Specifications Met = American Society for Testing and Materials (ASTM)
*ASTM Specification = ASTM A681
*Temper/Condition = Annealed
*Hardness = Rockwell B89-B110
*Maximum Attainable Hardness = Rockwell C57-C62
*Yield Strength = 50,000 to 99,000 psi

I read above where you intend to weld to these shafts? That would negate the money spent for a case harden shaft..(since welding will destroy any consistancy of the atributes that warrented the increased cost initialy.)

 

[Whiplash]

These are rated at .001 diameter tolerance and are called "tight tolerance" shafts so I am pretty confident they will be fine... great deal as well, for under 10 dollars for three feet of 1/2" and less for the 3/8"!

 

[Whiplash]

Whip,
I NEVER "harden" shafts unless they are actual bearing surfaces.(like for a sprag to ride directly onto) no reason to destroy the ductility of decent steel that is spinning on its axis.

Just use good design so there are no long spans of unsuported force or any long sections where torsional flex would become a factor. (none of that is on play on your tiny gearbox)

Thanks for the help! Yeah, I have about 1.5" of span including where the gears are riding, so I will keep the shafts out of the fire then! LOL!

 

[Whiplash]

I just got the shafts and bearings. Look nice and the tolerances are great! I should have something to show after the weekend! I will try to hit it hard for the three day weekend and get this thing up and running, albeit with only three phases working since I still need to make a new Hall sensor setup because I lost one...

 

[gwhy!]

I just got the shafts and bearings. Look nice and the tolerances are great! I should have something to show after the weekend! I will try to hit it hard for the three day weekend and get this thing up and running, albeit with only three phases working since I still need to make a new Hall sensor setup because I lost one...

Hi Whip,
Did you get to test the halls with a meter?.

 

[Whiplash]

Not yet, I will before I make a new one but they got roughed up a bit when the motor came loose once...

 

[Whiplash]

Hey all! I am getting real close to a working prototype on the new gearbox!! I had to order a few bearings that I needed since I changed the layout a tiny bit but they should be here Tuesday... I will be running the motor through a #25 chain until I can afford to get a nice belt setup working but this will get me up and running until then. I also found a brand new 11/34 cluster that I FORGOT I HAD! So this combined with the new ratio of 27:1 from the new box should really make climbing monster hills a breeze and still maintain the near 40MPH I am looking for for top speed! I am hoping to be fitting this all to the bike this coming weekend so I will keep you posted. I have the box somewhat together but I still need the third stage of gears since I only ordered 4 bearings when I needed 6! Otherwise I would have it mocked up already! Oh well, but I am looking forward to the final assembly as the gears "SEEM" really quiet spinning by hand so I am hoping it will be!! With oil and a sealed box, it should be fine.... Hopefully the final build!! Updates coming soon!

 

[Whiplash]

Hey all, I just wanted to post a pic of my best friend that passed today.. He will be missed DEARLY and it is a shame he got cut short in a fun life. The only Boxer that could actually recycle (give him any box and he would tear it up to little tiny pieces ) His Liver failed and he got very jaundiced and we had no choice... ONLY 7 YEARS YOUNG.. R.I.P. My good friend.... We will always love you...

 

[AussieJester]

aww man soz to hear you lost ya best buddy i have had dogs most of my life
you get so attached to them, they are always happy to see you no matter what time of night you
get in, when they finally go its a great loss, best advice wait a few weeks then get a new pup

KiM

 

[Whiplash]

That is what everybody keeps telling me. It makes sense, just hard to think about right now... At least we have the new baby to keep us in good spirits...

Thanks for the kind words..

 

[amberwolf]

I sympathize...

But AJ is right---though I have never been able to stand being without one for even a week, so far, before checking around to see who needs rescuing. There's always somepuppy out there waitin' for ya to pick 'em out of their cage before the needle comes.

 

[Whiplash]

Agreed! That iswhere I will get one when the time comes! That is the only place to get em!

 

[Whiplash]

OK, so I needed to do something to keep occupied, so I went out and bored the last gear out for the 1/2" output shaft and popped the bearings in the sides and did a quick mock up. It looks like its going to work! I need a few spacers the hold the gears in place under load and still need to drill the gears for the set screws but its looking like I will be in business! Spinning by hand feels nice and smooth so far and they make no noise at all at the RPM I am spinning them. I will be welding the gears together in clusters so I will not be relying on the set screws to hod the torque, just to hold them in place on the shafts. I may move the gears around a bit but this should be VERY close to final setup!

 

[AussieJester]

OK, so I needed to do something to keep occupied, so I went out and bored the last gear out for the 1/2" output shaft and popped the bearings in the sides and did a quick mock up. It looks like its going to work! I need a few spacers the hold the gears in place under load and still need to drill the gears for the set screws but its looking like I will be in business! Spinning by hand feels nice and smooth so far and they make no noise at all at the RPM I am spinning them. I will be welding the gears together in clusters so I will not be relying on the set screws to hod the torque, just to hold them in place on the shafts. I may move the gears around a bit but this should be VERY close to final setup!

Now you have my attention hehe thats definitely starting to look like a more 'salable'
box than the chopped up scooter thing you had before. If these work and are quiet
they could be just the shot for RC motored setups ...

KiM

 

[Whiplash]

Thanks AJ! That means a lot coming from a fab guy like you! I am taking my time on it so I don't miss any little details along the way that could improve the design. I am fairly confident this little guy will be JUST what we "through the gears" guys are looking for, and its really compact too, moreso than even the other one!

 

[AussieJester]

I am fairly confident this little guy will be JUST what we "through the gears" guys are looking for, and its really compact too, moreso than even the other one!

This is the ticket IMHO...Timma2500 (Paul) gets ridiculous efficiency with his setup
running 1200watt cyclone through his gears, blows me away after each ride
when we compare stats. This setup will definitely appeal to those looking for lightweight
e-bikes that will both climb like a mountain goat and keep up with cars
on the road, speaking of light weight haha... Have you eve seen a frock motor in
the flesh? ES member Danny Mayes bought one of those new Crystilite HT35? things
up my place last week i honestly could not believe the weight of this thing, i now see
more clearly why frock bikes handle like snot, break/bend and twist rims, also left
me amazed people put these on suspension bikes and ride them offroad..

KiM

 

[bandaro]

we need a "like" button... If that thing is quiet with speed then I would be very interested in looking into gears, they are so compact compared to chains and belts...

 

[Whiplash]

That is what attracted me to them in the first place, its sooo small, I can't believe it! I just have to weld the gears together then heat treat them and I should be ready to go...