crankshaft press

[Rick]

The rods should extend from the lever on both sides so you can flip it around to push the other direction.

better lever.jpg

Rick

[DBDBrian]

This is a boring bar I made, to re-bore a damaged bush housing in my timing cover, through the main bearings. It is turned by hand, and the cut is controlled with the adjuster in the centre of the handle. The bush could also be bored if required. I have not used it at present, as I have been involved with other projects. I have bored Triumph twin covers using a similar bar to good effect, and there is no question as to the bush being in line with the main bearings.
Brian

P1040598.JPG

Bar with sleeves to run in bearings, with cross bar against
sleeve to control cut.

P1040605.JPG

Cutter adjusting control scrwe

P1040613.JPG

Bar arrangement

P1040607.JPG

Cutter locked with centre grub screw

P1040621.JPG

Tool for advancing cutter position,
which can be checked with a mic

[Rick]

That's nice Brian- will probably make one just like it. I've never tried to single point a bore by hand- can you get a good surface?
Rick

[DBDBrian]

Thanks Rick, Yes you can get a good finish, obviously you need a good sharp tool, plenty of lube, and not too greedy with the feed.
I have driven bars with a slow electric drill, using a cap head screw in the end of the bar, and a cut off allen key in the drill as a driver.
This method is ok if the bore has an open end to control the feed, but with the blind bore as in the Ducati cover, and the feed control in the end of the bar, it would be awkward to power drive it.
I would think a similar arrangement could be used in the mill, and you would have feed control, but you would have to bear in mind you would be working blind.
I think your pre alignment jig would be a great benefit, I have seen two dowels run through reamed holes at 90 degrees to the pin in the wheels, but that's not always practical.
We seem to have two very interesting threads running together on crankshafts, all good to broaden the mind.
Brian

[CaptonZap]

A friend of mine rebuilds Formula V engines, and has a boring bar that he uses to clean up the main and cam bores. It uses single point cutters, positioned along the length of the bar.
The bar has some sort of drive device that is clamped by an arm to the case, and advances the bar at a given ratio to input revolutions on the bar, which he drives with a drill motor.
When I first saw him use it, he retracted the bar, and re drove it, for a total of three times through the bore. I asked him why three times, and he said that it gave a smoother finish, since the cutter would, in all probability, not retrace the original cut, and three times seemed to be the magic number.
I don't know if you could use that method on your bar or not. Just a thought.

CZ

[flanker]

Such interesting, good info. Enjoying the threads! Keep it coming rob

[Rick]

The press is done- will attach some pictures.
I had a piece of 35mm ground rod to use to check alignment- the crankshaft journals were a slightly smaller OD- probably less than 0.0005", so I shouldn't need to worry about binding. The pictures are with a 750 twin crankshaft, but it will work with a single crankshaft by sliding some reducer bushings on the journals.
Everything lines up great, and I expect I can get better alignment with the press than I can get banging with a big hammer- more experienced mechanics will be fine without a press.
Rick

press open 1.JPG

press open 2.JPG

press closed .JPG

press w crankshaft.JPG

[double diamond]

Looks very handy indeed.

Matt