Keyway broach bushing slop?

[DPittman]

How much is too much? I just received my Aliexpress keyway broach set and was surprised that the broach cutter fit so loosely in the bushing on the smaller bushings. The bigger ones are not as bad.

Won't this be potential for crooked keyway?

 

[Canadium]

Sure looks excessive to me! As if metric and imperial sizes have been mixed. Mine are all a snug fit.

 

[Canadium]

There must be standard broach and bushing dimensions and tolerances for metric and imperial sizes but surprisingly I can't find any such thing in my old Machinists Handbook. There are lettered styles I think the ones I have are all either B or C.

 

[Arbutus]

I have a several sets of Dumont broaches. The bushings and broach fit with 0.002" clearance. No slop at all.

I would send that set back to Aliexpress.

 

[DPittman]

I have a several sets of Dumont broaches. The bushings and broach fit with 0.002" clearance. No slop at all.

I would send that set back to Aliexpress.
View attachment 30559

I think you're right. Oh boy I don't look forward to this.

 

[Tom O]

What does it measure out as? Can you just not make another one they are pretty simple.

 

[DPittman]

What does it measure out as? Can you just not make another one they are pretty simple.

Haven't measure them yet, and yes I could make them but when I buy them I expect them to be right.

 

[Proxule]

LOL they thought those shims you use to enlarge and keyway where meant to go in the sides as well as the back.
Sigh

 

[Canadium]

If the bigger ones are fine they may have included the incorrect style of broach cutter for the smaller bushings or vice versa. It would be very instructive to know the measurements of the bushing slot and the broach base.

 

[Mcgyver]

I think you're right. Oh boy I don't look forward to this.

Sending it back? not a problem in my experience, not as nice and friendly as Amazon (commercial culture: here the customer is king, there the manufacture is king) but Ali waves a big stick and you get to return things with them paying the shipping.

Agreed it has to go back.

 

[DPittman]

Sending it back? not a problem in my experience, not as nice and friendly as Amazon (commercial culture: here the customer is king, there the manufacture is king) but Ali waves a big stick and you get to return things with them paying the shipping.

Agreed it has to go back.

Yes it looks like returning it won't be so bad but then I loose my UPS fees and have to pay that again if I order again.

 

[PeterT]

Kind of ghetto fix idea but maybe you could bond in feeler gauge stock on either side of broach, using the broach/assembly during the fit up? That way you would have pretty hard rubbing surface. I don't know how much shear force the joint surface would see during broaching if that's even viable. Loctite retainer might be an option. Silver soldering would be tricky. The question is - is the slot too wide or the broach too narrow vs. specs? If the broaches are OK, they should at least send a replacement guide part if you show a pic of the dimensions of both. I'm guessing that making a new guide involves some work, maybe hardened & ground?

 

[DPittman]

Kind of ghetto fix idea but maybe you could bond in feeler gauge stock on either side of broach, using the broach/assembly during the fit up? That way you would have pretty hard rubbing surface. I don't know how much shear force the joint surface would see during broaching if that's even viable. Loctite retainer might be an option. Silver soldering would be tricky. The question is - is the slot too wide or the broach too narrow vs. specs? If the broaches are OK, they should at least send a replacement guide part if you show a pic of the dimensions of both. I'm guessing that making a new guide involves some work, maybe hardened & ground?

From the YouTube videos I have seen making a new bushing would not be all that hard and doesn't not need to be hardened and ground. I've got Aliexpress ok to return the whole set but I'm hoping to get just the 3 lousy bushings replaced. I really don't want to have to repurchase a whole set and pay courier fees all over again.