How to Machine Inside Splines?

Broaching, for one.

doing splines is above my level of expertise , but i need to do some internal DIN 5480 splines

does anyone know if tooling is available to do them " in one pass " or must they be done with broaching on an indexing table / dividing head.

wondered if you machined the ID hole and then used tooling similar to thread taps that are tapered , intermediate and bottom except with linear cutting edges that you can run in and out of the hole

I don't know how this is done in mass production, but one could imagine an array of broaches all rolled up as one. If it can be pressed all the way through the hollow piece, one pass would do. If not, it would require something similar to taper/plug/bottom taps.

There are following possible approaches depending on the quantity:

1- as already recommended for big quantities since tooling is very expensive

2- cutting on a gear machine with a special tool since the ratios tooth head to root and pressure angle are not the same as for usual gears. It is a good approach for medium quantities.

3- Cutting the profile on a CNC spark erosion machine either with a solid electrode or by wire cutting (more economical) good for small quantities and short splines

4- Cutting a trapezoidal profile defined such that it is tangent to the shaft involute spline flanks either by wire as above or tooth by tooth on a hobble machine (better vertical).

I was years ago obliged to use last approach for the internal "spline" of sprockets which had to transmit heavy torques (lateral chain transmission on caterpillars). The shaft was even conical (its spline as well) in order to give an axial positioning.

It worked very well since the curvature of the flanks was small (big equivalent radius) and the contact pressures with acceptable limits. It took only a couple of hours to define according to the shaft spline the tool geometry.

bingo . thanks 34point5

Broaching -One for sure

And Electroforming

And LaserCNC withIndexing -- http://www.cncinformation.com/

mm

EXACTAMUNDO!!!!

thank u for the answers... i looked up broaching, and i was wondering if a hydraulic press with multiple custom cutters cut to match a hole in the pulley... it would be forcing chunks at a measured rate, and it would cut splines but would take several passes to cut...

I didn't see information about the spline needed to determine the method of cutting it. i.e., length of bore - is it a through bore? what is the ID of the bore? What is the material? If it's a hardened alloy, broaching tools that would cut it may be hard to come by. Also if the bore is very long, or not a through bore, broaching would not be the answer.

If the spline is not tapered, a vertical shaper can be used to form the teeth - sort of like cutting multiple keyways in with a bushing for support.

As mentioned, a good CNC wire EDM can do them fast and accurate.

13 splines .6450 thick steel plate(bought at steel plant in midloathian texas) .9660 outside diameter of splines and .8430 inside diameter

For mass production Broaching is the answer, but you should have hydraulic broaching machine and you have to get broach specially made. If quantity is small then you can get it done on Slotting machine where each slot is machined which is time consuming but less expensive.

baker87

my apologies for hijacking your post . very impolite of me

trust you're getting the answers you need :)

I'm with Ken, as a job shop owner for thirty-five years, you do what you do best and sub out jobs that are out of your expertize.

Wire edm for through spline ... 30 mins to program ... 60 mins cut ... approx figures ... most splines I have had to cut for repair are not true to a standard, can be all over the place ... usally cut a 1.5 mm thick gauge to make sure it is right ... I do not think in 15 years of cutting splines I have ever struck one that was standard ... had to cut a 137 tooth spline, from memory I think it was that many teeth, it was a odd number, blind so I hand stroked it on a mill, took me a day, every body knocked it back but it wasn't so bad ... it was for a maserati diff.

Batt

34point5's post 6 shows what I was trying to describe in post 3. Thus, a picture is worth 51 words.

There are two ways, one is with a shaper but the inside dia needs to be big enough to accept the tooling,the second is to use broaches with an indexing head. there is a third way but it requires a powerful press and a broach that has the same shape as the spline and is pushed through in one go, not a DIY solution.

Bazzer

Super Hobs and Broaches manufactures a wide range of worm hobs at beat industrial price. You just need to visit the site for more information about different type of hobs. You can also get the more information about spline broaches from the site http://www.gearcuttingtool.com/products/Spline+Hobs/11 .