Taper bore keyway broaching

[Suzuki4evr]

Hi guys.
I have a customer that I quite often have to make a bush that is welded onto a flange. The bore is taper and there must be a 4mm keyway in there.

My question is this. Is there a better way to make a keyway on a taper bore than the way I do it? I have to broach at the same angle of the bore,so what I do is use my compound with a HSS toolbit to push out the material to get to depth. But I do not like putting so much pressure on the leadscrew of the compound,I don't think it is good for it. Here is a pic of how I do it. Hope it is clear enough.


Another question is,if I use my dividing head and put it in the vertical position at the angle of the bore of the bush, or just tilt the mill head at angle and clamp the part down.The angle is about 6 degrees, can you use the quil of the milling/drilling machine with a 4mm toolbit to broach the keyway?

If there is a better way out there to do this tipe of work irrespective of the angle of the taper, wich will work better than I am doing now that will save my compound from the torture I am putting it through, PLEASE advise on how to do it. Thanks for reading.

 

[Ed ke6bnl]

far from being a machinist but if will to purchase a keyway broach make a 4 mm slotted tapered plug to broach the opening

 

[Suzuki4evr]

far from being a machinist but if will to purchase a keyway broach make a 4 mm slotted tapered plug to broach the opening

I can be such an idiot sometimes. WHY WHY WHY didn't I think of that. Only problem, around here broaches are EXPENSIVE. But thanks for shining the light. You just might be a machinist after all. And so we learn every day.

 

[benmychree]

The preferred method would be to make a tapered broach plug as mentioned above; I have made many of them for similar jobs. Doing it with the compound in the lathe is a non starter. I had a Induma milling machine where a tooth was broken off the quill by trying to do the same thing by a previous owner, I had to buy a new quill, shipped from Italy to repair it If I had to do this as a repeat job, I would buy a broach and make a plug for it, if it was a one off, I'd use my slotter (vertical shaper) or the slotting attachment for my milling machine.

 

[Suzuki4evr]

Looking at prices for a broach now.

 

[BGHansen]

Don't know about shipping to your country, but on eBay a search for "4mm keyway broach" will give you lots of options. Ones from China are under $30 US. If you cut a lot of keys, you may consider a DuMont or Hassey Savage broach for around $100.

Bruce

 

[Suzuki4evr]

I am looking at those 30$ range broaches. I am comunicating with them now,but will most probably only hear from them tomorrow, they are sleeping now. I do thise size keyways about 2 or 3 times a year,so I am satisfied with that price range. Thanks Bruce

 

[Richard White (richardsrelics)]

I make a 4mm key way on a 5 degree taper for tools for my tool business. I had a 5 degree wedge made the set the part at that angle and whallah...Slap it in a arbor press and away we go, I am using aluminum hubs so it is really easy... I can give you a link to my site to see the end result but I do not want to break any rules as it is my side business...

 

[Suzuki4evr]

I make a 4mm key way on a 5 degree taper for tools for my tool business. I had a 5 degree wedge made the set the part at that angle and whallah...Slap it in a arbor press and away we go, I am using aluminum hubs so it is really easy... I can give you a link to my site to see the end result but I do not want to break any rules as it is my side business...

Thank you. Are you talking about H-M rules or your employers rules?

 

[kd4gij]

I key tapered inboard propellers all the time. with tapered plugs