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Wanted 9 tooth broach and cutter

ducky1

Plastic
Joined
Mar 28, 2020
Looking for a broach to cut 9 tooth internal involute spline to accommodate a 25MM shaft. Spline specs are 10/20 DP - 30*
Also need a cutter that I can use in a mill with r-8 collet to cut this same spline on a 25MM shaft.
Internal spline will be in Delrin plastic and external will be in steel.
 
You don't specify whether you're looking for Flat Root, Fillet Root, or Major Diameter fit type Splines, but I think you're not likely to find a 10/20 DP 30°PA 9T broach, regardless. Combined with your desire to use a milling cutter to install the external teeth ( and the fact that people don't usually install Involute Splines with space cutters ) leads me to think there may be some confusion in your search. ( Much more common to use them for SAE Splines. )

This might be one of those times that letting us know what you want to accomplish might be helpful in getting you there.
 
You don't specify whether you're looking for Flat Root, Fillet Root, or Major Diameter fit type Splines, but I think you're not likely to find a 10/20 DP 30°PA 9T broach, regardless. Combined with your desire to use a milling cutter to install the external teeth ( and the fact that people don't usually install Involute Splines with space cutters ) leads me to think there may be some confusion in your search. ( Much more common to use them for SAE Splines. )

This might be one of those times that letting us know what you want to accomplish might be helpful in getting you there.

Thanks for your reply.
I have order a Machinist Handbook to help me with this. Reading thru other threads I found that I need to find this out as well Flat Root, Fillet Root, or Major Diameter fit type Splines. I am including a picture of the male spline tooth hope someone can ID.Webcam-1585493428.jpg Webcam-1585493428.jpg
The application is a 1976 MF 1655 tractor with a mower deck. These are the quill shafts that hold the blades. These plastic pulleys are a wear item and no long available. I what to make replacement pulleys and possibly an occasional quill shaft if needed. If a broach is too costly I thought of cutting a splined shaft into segments sharpen them and stack them with a spacer the same OD. as the ID of the spline for a guide to keep it centered. I would have make some reliefs in the spacer to accommodate the chips. My other thought was to cut a the splined shaft at a taper cut and sharpen teeth and cut a chip relief.I don't see any need to harden as we are cutting plastic. I am retired have access to a lathe and a mill and not worried about recouping a lot of my time.
Here is another Pic that my help.Webcam-1585495920.jpg
 
Okay, don't shoot me, zahn, but this is for a lawnmower ...

Take 3/4" piece of steel bar, braze a piece of high speed across the bottom with one edge across the centerline, hand grind the shape to match your male sample part then stick the thingy in a collet on the Bport and cut your shafts with a dividing head.

Find an old-fashioned boring bar with the square slot in it, straight across not the ones at an angle, grind a segment of high speed to match the internal, then rotary table and hand slotter it in the Bridgeport with the quill handle. Light cuts. Very light cuts. Luckily 9 goes into 360 evenly, it's a bitch if you have to keep track of minutes and seconds :)

As long as you are only making a couple, this'll do it and won't cost anything. If you use 7075 aluminum for the female and have it hard anodized, it should hold up pretty good while still being easy to machine. Or steel, I guess. 8620 will cost a minimum charge to carburize ($50 ?) but it'll last a lot longer. Still easy to machine. Prehard 4140 and all that, eh. Not my preference but whatever you like, might save a few bucks on heat treat and if your time is not hugely valuable, why not ? Won't hold up as well as carburized though. I guess you could kasenite it yourself, might be kind of fun.

Plastic is real easy to machine but you already know how well that holds up :)

those are flat root, btw.
 
Thanks for more ideas. Now we have another clue to the puzzle (Flat Root).
Let me update the specs here.
25MM shaft. Spline specs are 9 tooth 10/20 DP - 30* Flat Root.
The reason I am hung up on a broach is there will be some demand for these pulleys and I my wind up making quit a few. Your ideas are greatly appreciated.
 
25MM shaft. Spline specs are 9 tooth 10/20 DP - 30* Flat Root.
Is there anymore I will need to know to get a quote on a cutter?
 
Here is what you need to do. Forget the 9 spline dodad. Get something ready available and sell the pulley and shaft as a set. You could make it square, hex, 2 sided whatever you get to match. Inside and out. It is a grasscutter for goodness sake. You could do it all on a milling machine with just endmills. What am I missing here. You can offer someting inexpensive as a set made out of anything you want.
 
25MM shaft. Spline specs are 9 tooth 10/20 DP - 30* Flat Root.
Is there anymore I will need to know to get a quote on a cutter?
The od is very unlikely to be 25 mm. It's going to be inch and you should measure that correctly. There's a place called Broachmasters in Auburn CA that will make you a broach if you can't find a surplus one. Call Ash Gear first just in case. The other poster had a good point, if you are making both parts, you can just get something close. I'd still broach it for production because broaching is the fastest easiest method on the planet. In fact, call around to some places that do broaching and see what they have and just have them pull the parts for you. You mighta coulda oughta shoulda modify your design to fit what's available. Cutters for the male part are easy.
 
Call Ash Gear, they should have a a space cutter in stock for about $100.. Shape the ID in your bport with a hand ground cutter and an old boring bar per EG's suggestion. Broachmaters is still there but having a broach made is not going to be inexpensive.
Finding a broaching house with the correct broach is not impossible- just get on the phone and start calling-
Pioneer Broach in Atwater, CA Pioneer Broach in LA, HiAngle Drive Line in Chico, CA . Broachmansters also does broaching as well as making broaches.
 
Tommy 1010. I think you are right. Thank for getting me on the right track.
Thanks to all for some very goo idea.
I'll let you guys know what I come up with.
PS it measures 25MM and has a 6205 metric bearing
 
PS it measures 25MM and has a 6205 metric bearing
Ah, so they choppd the od down a little to fit thorugh a bearing. If you just duplicate it for yourself doesn't matter, but if you try to make a print you should properly measure the tooth thickness over wires. First guess is they just turned forty off the od but you should confirm that.

People don't cut DP teeth to metric sizes .... sane people don't, anyhow.
 
Now that we know what it is and what it does, I have to agree with EG and suggest adaptation to anything commonly available. If you just must duplicate it, you'll be far and away better off to simply make a form tool and single point it/broach it in your shop, as I do not believe they even make a space milling cutter past 12T-13T. ( none for 9T )
And, Ash's broaches jump from 6T to 11T, with nothing in between. So, you're definitely looking at custom and that's never inexpensive. Jess from High Angle is a member here. You might see if he happens to have that configuration. Wouldn't hurt to ask. Good luck.
 








 
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