liveforphysics
100 TW
Whoa! That's awesome! Like a 1-time-use broach made of aluminum to cut into steel, and yet it worked! Outstanding!
Fitting freewheels to splined freehub drivers
- Thread starter Miles
- Start date
gwhy!
100 kW
The freewheel hub is case hardend steel I did try and keep the "cutting edges" as sharp as pos when i was cutting them. I think it should be good for a few freewheels.
j3tch1u
10 kW
brilliant!
conceivably, if one were to grind the cutting edges to precise angles..with a little tapmatic cutting fluid this broach would probably be good for a dozen passes.
now i'm wondering who makes the hardest steel freehub drivers.
conceivably, if one were to grind the cutting edges to precise angles..with a little tapmatic cutting fluid this broach would probably be good for a dozen passes.
now i'm wondering who makes the hardest steel freehub drivers.
@Gwhy:
that's a heck of an idea!
gwhy!
100 kW
j3tch1u said:
All though it worked first time ( but it wasn't perfect by a long way, but usable ) I did try and cut another freewheel and it was rubbish using the same 'broach' the cutting edges were shot so my question is what would you say is the best angles to make the cutting edges. I have another 2 steel scrapped freewheel hubs that I wouldn't mind giving it another shot at to see if the cutting can be improved. The first try was suck it and see but I also think with a bit more care in making the cutting edges on a one pass broach it could be a winner.
spinningmagnets
100 TW
The CroMoly steel freehubs are $24 new from Niagra (plus tax and shipping), some are cheaper but they are likely aluminum. Perhaps theres a way to anneal them (heat them up, and let them air-cool slowly to soften the metal), then, shape the teeth with a dremel/file...,
Then, harden the metal again? Reading about primitive tech, you heat the metal to a certain temp, then quickly cool it by dunking the part in a solution of warm oil and fine charcoal powder. I believe that results in a hard skin (case hardening?).
http://www.niagaracycle.com/advanced_search_result.php?keywords=freehub&sort=2a&page=1
Then, harden the metal again? Reading about primitive tech, you heat the metal to a certain temp, then quickly cool it by dunking the part in a solution of warm oil and fine charcoal powder. I believe that results in a hard skin (case hardening?).
http://www.niagaracycle.com/advanced_search_result.php?keywords=freehub&sort=2a&page=1
TylerDurden
100 GW
Your first looks damn good.gwhy! said:
I searched the Google for "keyway broach" images.. the only differences easily seen in the pro-versions are more space behind each tooth for chips and the teeth are each stepped a royal-hair shorter as they near the front of the broach.
jmygann said:
not sure if anyone has anything running yet jmygann, Miles has some and mine are at Lukes, so hopefully ill have them around the time my motor shows up, testig will follow soon after with a straightforward setup, although this depends on etard coming through with a monster sprocket for me, i guess i could run my current extron just for testing so a few weeks maybe a month away for me.
D
j3tch1u
10 kW
gwhy! said:
i'm no expert in broaching but from what i gather, you probably want to treat each spline as if it were it's own keyway broach. instead of a radiused profile i'd just do straight angles. how long is the driver and what is the depth of cut? find out approx how many teeth you could fit on it and calculate the pitch. divide the spline depth by #teeth to get rise per tooth. since you probably won't fit that many teeth on the driver maybe go with an aggressive hook angle of 20% and back-off angle of 2%. easiest way i can see is to throw it on a lathe, taper the driver almost down to the valley (but not quite) and start shaping your angles. i am sure it would prove to be a vast improvement on tool life since you are now distributing the cuts across many teeth. anyone with broaching skillz care to chime in?
from wikipedia:
* P = pitch
* RPT = rise per tooth
* nr = number of roughing teeth
* ns = number of semi-finishing teeth
* nf = number of finishing teeth
* tr = RPT for the roughing teeth
* ts = RPT for the semi-finishing teeth
* tf = RPT for the finishing teeth
* Ls = Shank length
* LRP = Rear pilot length
* D1 = Diameter of the tooth tip
* D2 = Diameter of the tooth root
* D = Depth of a tooth (0.4P)
* L = Land (behind the cutting edge) (0.25P)
* R = Radius of the gullet (0.25P)
* α = Hook angle or rake angle
* γ = Back-off angle or clearance angle
* Lw = Length of the workpiece (not shown)
liveforphysics
100 TW
I just broke my lathe tool post holder doing your freewheels decano. Lol.
Pics soon to follow, you will love this 1/8" deep cut it made in 1 pass once to tool post tipped into the freewheel. Lol.
Fortunately, its all going to turn out fine, I'm making a trip downtown for a little tougher tool holder. Lol
Pics soon to follow, you will love this 1/8" deep cut it made in 1 pass once to tool post tipped into the freewheel. Lol.
Fortunately, its all going to turn out fine, I'm making a trip downtown for a little tougher tool holder. Lol
Thud
1 MW
The first issue in play, is the free hub is the "minor" size of the assembly.
A proper broach will be sized to cut the parts to fit over the hub with designated clearance.
not a big deal as you can open them with a file Like Miles did in the first example.
2nd would be the steel the sudo broach is made from. You could attempt to harden it further using "Kasonite" surface treatment.
Many ways to skin the proverbial CAT.
I am shocked Gwhy didn't lock the freehub into that dicta freewheel. (them things are case hardend proper) Also if you could modify the free hub to pass directly through, the tool life will be extended dramaticly the backward rub will kill a standard broach in a couple of passes.
A proper broach will be sized to cut the parts to fit over the hub with designated clearance.
not a big deal as you can open them with a file Like Miles did in the first example.
2nd would be the steel the sudo broach is made from. You could attempt to harden it further using "Kasonite" surface treatment.
Many ways to skin the proverbial CAT.
I am shocked Gwhy didn't lock the freehub into that dicta freewheel. (them things are case hardend proper) Also if you could modify the free hub to pass directly through, the tool life will be extended dramaticly the backward rub will kill a standard broach in a couple of passes.
liveforphysics
100 TW
It was cutting so nicely until that damn tool post holder base cracked! lol It's not a big deal though, I will be up and running again in a few hours.
That's your freewheel sitting in there D
Fortunately that big chunk it took when it broke and the carbide bit-in will all disappear once I take the edge down the rest of the way, so no harm done. Oddly though, I through the dial indicator back on the piece to check run-out after the event, and I had it dialed in to 0.001", and after it jammed and stalled the lathe, the run-out was at ~0.025"... It looks like it just got cocked in the chuck though, and I think it will all be fine.Enjoy the pics of the 1930's lathe
No starting capacitor either, so you've gotta hit the switch and spin to get it going, and it runs in whichever direction you start it spinning, which is kinda nice for some jobs. -Luke
liveforphysics
100 TW
This picture should make you smile D.
Just finished up another batch today, including yours.
Now it's just a matter of getting me to the damn post office... lol... I'm like the worlds least responsible guy for mailing things... I've probably got 10 little wacky things piled up on the shelf by my front door that all need to be mailed out to various places...
Just finished up another batch today, including yours.
Now it's just a matter of getting me to the damn post office... lol... I'm like the worlds least responsible guy for mailing things... I've probably got 10 little wacky things piled up on the shelf by my front door that all need to be mailed out to various places...
well thats the way to start a morning before a long slog at work, thank you soo much Luke they look great!!!
now get to the post office double time!!! :lol:
really looking forward to getting my grubby hands on these and will be stripping the bike ready for their arrival early next week.
Again many thanks Luke 8)
D
Once these are finished, if anyone needs to for any reason use them on the *left* side, here you go:
http://www.recumbents.com/mars/pages/proj/tetz/VFS/projtetzVFS02lefthanddrive.html
Turns a regular freehub (he calls them freewheels but he means freehubs) into a left-side version.
http://www.recumbents.com/mars/pages/proj/tetz/VFS/projtetzVFS02lefthanddrive.html
Turns a regular freehub (he calls them freewheels but he means freehubs) into a left-side version.
gwhy!
100 kW
I dont think the dicta freewheels that i have been playing with will not be any good for cutting slots into ( Ok for light peddle power and works ok) there isnt enough meat on them. The WI FW has the shoulder which will make it a much better mechanical fit. I have decided that I may try and get a die and cut threads onto the freewheel hub.. Question is do anyone know where I can get a 1.37x24tpi die without paying the earth for it, I think Miles posted up a link way back in this thread which I have had a look at , just wondering if anyone has other links ( uk based would be much better ).
there isnt enough meat on them. The WI FW has the shoulder which will make it a much better mechanical fit. I have decided that I may try and get a die and cut threads onto the freewheel hub.. Question is do anyone know where I can get a 1.37x24tpi die without paying the earth for it, I think Miles posted up a link way back in this thread which I have had a look at , just wondering if anyone has other links ( uk based would be much better ).
Thud
1 MW
here you go Gwhy. I am pretty certain Mud has one of these large dies.
http://www.msdiscount.com/columnar.aspx?category_site=STARTOOL&cat_id=1188&prod_id=30911&referer=http%3A//www.google.com/search%3Fhl%3Den%26rls%3Dcom.microsoft%3Aen-us%3AIE-SearchBox%26rlz%3D1I7DMUS_en%26ei%3DVAtPS-2HBZSqNuam_ZYJ%26sa%3DX%26oi%3Dspell%26resnum%3D0%26ct%3Dresult%26cd%3D1%26ved%3D0CBAQBSgA%26q%3D1+3/8%2522+x+24+thread+die%26spell%3D1&sessioncookieset
http://www.msdiscount.com/columnar.aspx?category_site=STARTOOL&cat_id=1188&prod_id=30911&referer=http%3A//www.google.com/search%3Fhl%3Den%26rls%3Dcom.microsoft%3Aen-us%3AIE-SearchBox%26rlz%3D1I7DMUS_en%26ei%3DVAtPS-2HBZSqNuam_ZYJ%26sa%3DX%26oi%3Dspell%26resnum%3D0%26ct%3Dresult%26cd%3D1%26ved%3D0CBAQBSgA%26q%3D1+3/8%2522+x+24+thread+die%26spell%3D1&sessioncookieset
gwhy!
100 kW
Thud said:
Thanks Thud,
Its ordered....
j3tch1u
10 kW
gwhy! said:I dont think the dicta freewheels that i have been playing with will not be any good for cutting slots into ( Ok for light peddle power and works ok)
your local machinist can cut the external threads on the lathe and they will come out tighter. i bought one of those dies and never use it.
liveforphysics
100 TW
gwhy! said:I dont think the dicta freewheels that i have been playing with will not be any good for cutting slots into ( Ok for light peddle power and works ok)
If you're not going to use an ENO (or something else that has a meaty shoulder), you've only got the shallow threaded interference area between the two pieces to use for holding torque.
Shallow threading the splines of the hub would be a substantially weaker option than using the same available interference material to be loaded against a spline. Using threads doesn't increase the amount of interference area available, it just uses it in a mannor substantially less conductive towards holding torque.
gwhy!
100 kW
liveforphysics said:gwhy! said:I dont think the dicta freewheels that i have been playing with will not be any good for cutting slots into ( Ok for light peddle power and works ok)
If you're not going to use an ENO (or something else that has a meaty shoulder), you've only got the shallow threaded interference area between the two pieces to use for holding torque.
Shallow threading the splines of the hub would be a substantially weaker option than using the same available interference material to be loaded against a spline. Using threads doesn't increase the amount of interference area available, it just uses it in a mannor substantially less conductive towards holding torque.
I will be only using one threaded freewheel for the peddels ( but dont plan on using the peddels much ) the other sprocket will be direct onto the free hub I not worried about the cogging effect of the motor when peddleing (as I wont be
) so really having a thread on the free hub is only a means of locking my 95t sprocket to the hub and having isolation from the crank arms. Also Im not interested in having a geared hub either. eventually i would lock the free hub so I can use regen and plug braking.
liveforphysics
100 TW
gwhy! said:liveforphysics said:gwhy! said:I dont think the dicta freewheels that i have been playing with will not be any good for cutting slots into ( Ok for light peddle power and works ok)
If you're not going to use an ENO (or something else that has a meaty shoulder), you've only got the shallow threaded interference area between the two pieces to use for holding torque.
Shallow threading the splines of the hub would be a substantially weaker option than using the same available interference material to be loaded against a spline. Using threads doesn't increase the amount of interference area available, it just uses it in a mannor substantially less conductive towards holding torque.
I will be only using one threaded freewheel for the peddels ( but dont plan on using the peddels much ) the other sprocket will be direct onto the free hub I not worried about the cogging effect of the motor when peddleing (as I wont be
Ok cool.
You can be the guinea pig for us to see if it will hold up under human pedal torque by threading the tips of the splines. If they are both steel, I think it has a good chance of lasting under pedal power if the front sprocket is big, and the back is small.Similar threads
