What method be to line ream (hone) 2 installed bushings that need 0.0007 to 0.0013"
Four parts just arrived in shop and need to be line 'reamed' (incorrect process) to true up two bushings taht are separated by 3" from inner side to inner side, and 5" out side to outside.
The existing diameter /s are Ø1.4955 to Ø1.4962" (and at 1 place I measured 1.4970" but it is slightly out of round by 0.0008")
The desired diameter range is Ø1.49626 - 1.49682" The surface finish must be 32 or better (a 16 would be best)
The perpendicularity from the main part to the line reamed bushings is exact. Meaning no tolerance to speak of.
Also, these are the blade grips on an EC145.
In the picture, look at the 4 large diameter holes on the cardinals, close to the outside diameter of the blade clamps.
I am 50/50 on this project. It may be worth the hassle, maybe not.
I mean we DO make and work on flight critical components (always under a customer's PMA or an existing STC) but this is tight, and I don't have tons of confidence of doing it in my shop.
First off:
1) Flight critical.
2) People can die if something goes wrong.
3) There is a LOT of money on the table.
I believe a reamer would only rub / burnish, and I would only have 1 shot at getting it correct. Not my favorite option.
Boring in a CAT40 wouldn't be my favorite option either. Removing that small amount doesn't seem like it would work either.
Roller burnishing?? The upfront tooling would be pricey, but may work well....
Barrel lapping may work...
Most of my local vendors are into gun drilling & honing.
Would a quality lapping company be able to perform within the above stated parameters?
(In this case I am thinking https://holespecialists.net/honing-services/ )
Is there another method I should look to?
Thanks,
Doug.
Four parts just arrived in shop and need to be line 'reamed' (incorrect process) to true up two bushings taht are separated by 3" from inner side to inner side, and 5" out side to outside.
The existing diameter /s are Ø1.4955 to Ø1.4962" (and at 1 place I measured 1.4970" but it is slightly out of round by 0.0008")
The desired diameter range is Ø1.49626 - 1.49682" The surface finish must be 32 or better (a 16 would be best)
The perpendicularity from the main part to the line reamed bushings is exact. Meaning no tolerance to speak of.
Also, these are the blade grips on an EC145.
In the picture, look at the 4 large diameter holes on the cardinals, close to the outside diameter of the blade clamps.
I am 50/50 on this project. It may be worth the hassle, maybe not.
I mean we DO make and work on flight critical components (always under a customer's PMA or an existing STC) but this is tight, and I don't have tons of confidence of doing it in my shop.
First off:
1) Flight critical.
2) People can die if something goes wrong.
3) There is a LOT of money on the table.
I believe a reamer would only rub / burnish, and I would only have 1 shot at getting it correct. Not my favorite option.
Boring in a CAT40 wouldn't be my favorite option either. Removing that small amount doesn't seem like it would work either.
Roller burnishing?? The upfront tooling would be pricey, but may work well....
Barrel lapping may work...
Most of my local vendors are into gun drilling & honing.
Would a quality lapping company be able to perform within the above stated parameters?
(In this case I am thinking https://holespecialists.net/honing-services/ )
Is there another method I should look to?
Thanks,
Doug.