rotary broach, unless you have a small amount of parts and then maybe wire or conventional edm.
there are other ways, but what machiens do you have to work with? there are other ways for short runs, but how big are the splines.....i've millied similar shapes.
You probably have it by now, but if you still need it and it is .750, Just let me know. I got this as part of a drive shaft(dana 6N, but 15/32") from surplus center for $25. I cut off the welds and take everything apart then I use the parts to make the shafts I need. I don't need .75" 14 spline, but I don't throw stuff out. I broached out a couple to make 7/8" square receivers. Sometimes they have great deals on components that can be broken down into parts that are worth 10 times as much.
Theo, sorry I don't mean to be a pain in the rump, but I just thought of something else. If this is for a propeller hub, will the bearings in the gearbox withstand a thrust load? Sprocket output shaft bearings are designed for radial loads, so...
Rotary broaching may be an option, but may also require more than one broach to reach the tooth height required.
Have you considered waterjetting the blank including the teeth and spline, then finishing on the lathe?
No propeller, prop shaft can also be the drive shaft on a car:
Originally Posted by Arnold's Design
(Engineering / Mechanical Engineering) the shaft that transmits power from the gearbox to the differential gear in a motor vehicle or from the engine to the propeller in a ship or aircraft
Yeah, I am aware of this. I've designed, fabricated, and machined them at various points, not for cars, but for industrial machines. I wasn't sure if it applied in this case, though I'm thinking that you're correct. His 3d model of the adapter looks a lot like propeller hubs I've seen, so I just kind of assumed. The ultralight community who does mods like this is actually a pretty small group of people, so it is actually fairly rare. My bad.
Originally Posted by Chippingaway
Yours if you want it.
Turn a pocket in a piece of round stock, with counterbore as needed to clear the nut that holds the sprocket to the shaft. The sprocket fits into the pocket with a close enough fit so there's no radial play. Shouldn't need too wide of an outer shoulder around the pocket with the adapter made of steel.
Turn a thick washer to fit over the shaft, between the ending and sprocket. Drill and tap a hole at every other tooth. Drill matching holes in the outer part of the adapter.
Slide on washer, install sprocket, bolt outer part of adapter to washer. With a tight clamp fit it won't be going anywhere, especially with grade 8 socket head bolts, counterbored into the adapter.
The outer end of the adapter can be turned and drilled to mount a flange mount U-joint.
This can be made by us by turning, milling, drilling and keyway slotting machine with or without hardening.
Better to have the same part to make it as copy.
You can be in contact with us at email@example.com
I had a customer bring me a file for a similar countershaft, I found a company on the net that had close enough on the shelf. The company did countershafts for drag bikes, I believe out of 86xx material of some kind, hardened. Tough stuff, and price was about 2 hours shop time. I'll see if I can recall that company, so long as it doesn't violate this blogs rules....
That being said, maybe waterjet the center geometry, leave .002"- .003", CNC mill the final out with a couple of dustoff paths.
Originally Posted by pistonskirt
Haven't read thru the entire thread, but the Spline off of your MV engine probably matches one from one of the Jap bikes they make adapters for. I would email them and ask what bikes they have splines for, and find a local bike breaker, take your sprocket there and see if it fits one of them.
Originally Posted by Theo
I enjoy making stuff for myself, but no sense in reinventing the wheel.
internal spline RE;
Buffalo Gear, Inc. for gear manufacturing of precision gears including spur gears, metric spur gears, helical gears, worm gears, pinion gears, ring gears, planetary gears using cnc milling, keyway milling cnc, threadmilling send them your(splined) part with a return usps return shipping label draw the other part out give them a tolerance they'll do it . fast turnaround ... i don't estimate for them but if you want this obstacle out of the way they can do it.
Clamp/jig it on a laser table -the programing cost might be $$ ?- how many do you need
kevin - kkfab
You get this thing figured out yet?
I do stuff like this all the time. Reverse engineer one off's, burn the perfect spline, etc etc.
It would be better to burn it on an EDM I think that way you don't have to tool it for shaping, even if it is a standard spline. With the EDM you clamp it to the table do a hole pickup to find center and go. It's just a time thing, but I do it *all the time*.
If you need help with this still let me know, I could probably help At the very least I would do the inspection (with my analytical inspection machine) and give you the results for free. I'm sure I could also talk my boss in to burning it for you on our EDM for free too if it's only one part.
Let me know.
Internal spline, how to do it?
You might not favour the following suggestion, but it is practical and with care would provide you with a satisfactory drive.
Firstly check the male drive for any uneven wear. Just by sight you will be able to tell the difference in surface finish between the running part against the unused part and whether or not it is even. Give it a good clean and make sure that there aren’t any burs.
To establish a basic geometry of the male drive you need to have a useable PCD by measuring chords – this requires a helper. Select a drill size such that the shank just lays in the spline with a bit proud – get another one, exactly the same diameter shank and lay that into the spline that is nearly opposite; say No.1 and No.7 and take a measurement across the drill shanks and note it. Work all the way round the splines until you have a table of all 14 chords. Then do it all again. And compare the two tables.
Expect small differences between specific chords but there should not be any due to measurement. When the two tables have comparable chords get the average chord length and subtract the dia of the drill this is the PCD of the tangent where the drill shank meets with the spline tooth.
Measure the root and overall diameters by doing similar tables reducing measurement errors to a minimum by doing many and the result will give you a good picture of just how precise the male spline is. Compare with measurements from the sprocket you have to determine what clearances you need.
To make a trial female spline cut a piece of gauge plate about 3/16” thick big enough to hold in a four jaw chuck with reverse jaws so that there is plenty of space behind it.
Face it with a fine cut dead on centre right up to the centre. Change the tool for one with a sharp point as used for threading - but without any radius at the tip – take it past the centre point and bring the cross slide back to the centre. Zero the dial and bring the tool back to the radius of the PCD. Put on a cut sufficient to mark out the PCD turning the chuck by hand. Do the same for the o.d. as per your sprocket.
Next job is to use the pointed tool to mark across the PCD with the 14 tooth centres.
Since you can cut the sprocket this shouldn’t be a problem – or take a base from a 70 T gear.
Before taking the plate out of the chuck put a Slocomb centre spot into its’ middle and witness mark the plate against the two jaws that you use to release it.
Centre dot the PCD marks and drill – pilots first and then finish with one of the drills you used to measure the chords.
Put the plate back into lathe chuck and bore out the i.d. for the spline.
The rest is tedious hand filing work using the sprocket you have as a backing guide.
Once you can get a tight fit onto the male spline chose and mark a mating pair of teeth and always keep these together. Blue the male spline very lightly and work on the driven face of the new teeth start with getting two to blue that are virtually opposite – any more that that would be a bonus.
When you have a prototype doing it for the final job is easy.
In industry there has to be manufacturing tolerances and your spline drive will be no exception - for really accurate working hand fitting is often necessary. Good luck Colin
Last edited by custardcats; 11-30-2012 at 04:47 PM.
Reason: error in arithmatic
This doesn't have to be so difficult.
Hello from NJ, I have had jobs of this nature in the past, out of alum and steel. We have a water jet and have done the entire sprocket using the water jet. From your pic some secondary machining is required, Much cheeper than a broach, and its just a sprocket, not rocket parts. (form ,fit , function).
Dear Theo... Some sixty years ago I have the same problem.
Your sprocket has 15 teeth. With a pitch of 1/2in it means some 60,6mm primitive diameter, and according the scale of the photo, the splined shaft must be 18 to 20mm dia at least. The tooth depth is then some 2 mm. In the photo are they 14 splines.
The thickness of the hub is at least 5mm. Then, young man, the best way is the file.
You should see first of all, where are the centering surfaces of the splines. They can be in the outside diameter, in the inside diameter or in the sides (not common). Then, assume the centering is in the inside diameter, draw the pattern of a teeth, trace the splines, set the sprocket in the vise, take a good file and in one hour or less you will have your splines.
More important than this is in my opinion, if such a poor thickness in a sliding joint will be sufficient to transmit the required torque, and furthermore, how is the sprocket guided so that it runs perpendicular to the shaft. ¿Hat it perhaps some sort of bushing to guide it?