Taper bore broaching......what am I doing wrong?

Suzuki4evr said:
The breakage occurs on the first pass without any spacers. I made the plug so that on the first pass the broach will only start removing material about a quarter to half way up.
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Sorry, I miss-understood.
I can't tell from the photos, but wondering how you are assuring that the angle alignment of the base you made is in perfect alignment with the plug.
Just wondering if the broach isn't being driven perfectly vertical (in alignment with the ram).
Just trying to picture this in my little mind.

Ted
 
talvare said:
Sorry, I miss-understood.
I can't tell from the photos, but wondering how you are assuring that the angle alignment of the base you made is in perfect alignment with the plug.
Just wondering if the broach isn't being driven perfectly vertical (in alignment with the ram).
Just trying to picture this in my little mind.

Ted
Click to expand...
I almost thought you had the answer,but yes it is being driven vertically, but that is what the base is supposed to help with. Basically the broach,plug and bush is the vertically allighned on the machined angle and the flange is offset. The base piece as a section that fits into the flange,but is not in the way of the broach path. The only way I can make sure that the broach is upright is by eye. When I do broach,I dont just put pedal to metal,I constantly broach and release and check alignment.
 
talvare said:
I can't tell from the photos, but wondering how you are assuring that the angle alignment of the base you made is in perfect alignment with the plug.
Click to expand...
Put it this way,I will hold the base with my one hand and turn the flange until the broach is alighned and straight with the ram. Hope that helps.
 
Sometimes when broaches tend to hog in, I turn the part 180 degrees around on the press, or even sideways to lessen or eliminate the tendency.
 
Suzuki4evr said:
The base piece as a section that fits into the flange,but is not in the way of the broach path.
Click to expand...
Are you certain the broach clears the base piece when it is extended through it? It may clear it right at the bushing but since the broach will be at an angle going through the bore of the base piece it may be hitting the opposite wall when it is extended past the bushing.
 
RobertB said:
Are you certain the broach clears the base piece when it is extended through it? It may clear it right at the bushing but since the broach will be at an angle going through the bore of the base piece it may be hitting the opposite wall when it is extended past the bushing.
Click to expand...
I am 99% sure,but will on an old bush tomorrow, just to make 100% sure.
 
RobertB said:
Are you certain the broach clears the base piece when it is extended through it? It may clear it right at the bushing but since the broach will be at an angle going through the bore of the base piece it may be hitting the opposite wall when it is extended past the bushing.
Click to expand...
Hallo Robert. I have a suspicion that my 99% was not so acurate. I think you solved my problem. I took an old bush that did not have a keyway in and at first it looked like the broach is all clear of the base,but as you said when it came closer to the bottom it started touching the wall and would be pushing the broach forward causing it to dig in at the bottom and break the teeth. And by the looks of it it breaks around where the broach starts touching the wall.I must be honest,I did not think to check if that could actually be it because of two reasons. Firstly it really looked like it had plenty of space and B, I thought by myself why didn't the broach rather snap if the clearance was the problem. But it was opperators error and that's that. At least I now know what the problem is and I can fix it. Thanks Robert and everyone else who tried helping me.

I will be ordering a new broach and try again. I am attaching the link of the YouTube clip fro Keith Fenner I watched just for interest sake and I must say I did everything he said......just without the ring,watch and the Go-tee :D .

Thanks guys
 
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