Bullneck frame machining

[Steve Little]

Thanks Tom. Keep up the good work.

Hi Rob.
Your young fella introduced himself to me at the Bulli AMCA meet last weekend.
Solid young bloke and he held the conversation well. Good job dad.

Next fixture clocked in to the datum and synced to the readout of the machine.

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Guesses on the forging that is gunna get the treatment?

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[wideglide38]

Nice work Steve! I definitely enjoy your threads and your quality of work. Axle Plates?
William

[larry]

Look in the mirror.

[wideglide38]

Haha Rear Post/Rear motor mount. Good one Sneaky Steve

[hairynob24]

G,day Steve ,i heard he was with Mingo for awhile at the swap .Thanks for the kind words ,i was staying with some people in France a week ago and this fella has done 4 x cut down 2 cam Harleys ,in one photo i took Eric had a frame jig hoping Nick can make it ,cheers RobVID_21911126...0514_673.mp4 not sure if the video worked

[Steve Little]

Thanks William and Larry.

Customer had a go at removing the stiffener.

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I spent a couple more minutes with a cold chisel and a 2 lb hammer and removed the pieces obstructing the hole.
I needed to do this so I could get the boring bar through.

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My inside mic reads that I still have a thou and a half to cut out.

You know your close when the skin of the metal is so thin it peels up behind the tip and exposes the original bore.
I will finish this bore off and move to the next fixture. You may have seen in one of the previous pictures that the customer has welded up a missing piece of the trans support. I will have to machine it and drill the hole.

[Steve Little]

Next fixture clocked to the machine.

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Tightened the forging into the fixture.
While looking up at my digital readout, I wound the table across to the measurement to drill the hole.
When I looked down to see where the center drill was pointing I thought Whoaa!! What have I done wrong!

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Did a quick re-check of the measurement and it turns out the customer's attempt and re-creating the missing piece with a welder, was a little over exuberant.
Drilled the center drill to the appropriate depth and followed it with a 3/8” drill.
Used a 7/8 end mill to recreate the spot face for a washer to sit against.
Then licked the hole with a chamfer tool to take the sharp edge off the hole. The customer can remove the unwanted extra length.

Interesting side note.
That circular mark between the 2 strengthening ribs, is the original witness mark of HD's hold down clamp of their machining fixture.
The machinist has most likely passed on, but we see your signature old mate


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[Steve Little]

Hmm This is the fixture for the next operation but the rear engine mount isn't going to fit with the brake cross over tube, still in place.
I remember designing this fixture years ago, and those 2 pinch bolt posts were held in place with cap head bolts from underneath.
The young guy who used to drive the cnc machine must have added some welds for greater rigidity.

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Compared to a traditional mill, a cnc machine is blistering fast. But the increased speeds and feeds, create big loads on the fixtures.
If a fixture breaks and a spindle crash ensues, the repair bill can easily get into $10,000 or $20,000 in seconds.
Strength and rigidity are the standard catch cry for any experienced machinist who makes fixtures.

A well placed slice through the front weld and four or five measured whollops with the 2 lb hammer and it folded over and left the scene at speed.

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After fitting the forging and tightening it down for action, I fitted a 7/8” end mill and did a couple of cuts to clean up the welded deck. It took 0.020” to remove a twist from the accident and also level out the uneven welding of the deck.

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More gooda??

The exuberant deck fixing looks stranger from this side.


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[painterdale]

Man, this stuff is GREAT!

Dale

[hairynob24]

labour of love ,some hours have gone into it so far

[Steve Little]

Hi Dale and Rob. Glad the info has appeal.
A couple of friends like to get in my ear and reproach me for keeping 30 years of Harley frame restoration locked up in this leaky mind.
One buddy in particular likes to knuckle my brow about getting the information into print before it evaporates completely, but I don't think I have a hide thick enough for that.

These rear engine mount decks are surprisingly weak and are easily bent. When I used to restore frames it was my first port of call for things to check.

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This deck was no different. I brought the end mill down to touch the left hand side and locked it. Then wound the table across to see how the right side registered. That is a 030” feeler gauge between the tool and the deck.

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We cant have that sort of shenanigans. It took ;033" thou to clean it up.
The brake cross over tube was also slightly bent during the accident. The customer will rectify that.

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Rear engine mount ready for service again. Next forging will be the front engine mount.

[DANPATCH]

Good to see you on board .
I always enjoy all post . Keep it up.Very helpfull.

[Rooster]

Very interesting to follow along. Thanks, Steve!

[Steve Little]

Thanks Dan and Rooster.

Front engine mount took a beating as well. The side stand and clutch bracket are bolted to the left side and they must have come in contact with something. There's a pretty noticeable bend on the left side of the engine mount. Threads on both sides are no good and would strip if tensioned up. I will have to get advice from customer if he want me to address that issue. Anyway. On with the pictures.

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Instead of using the 100 ton press (red one in background) I thought I would see how the little 10 ton (orange) press would do the job.
This would give a backyarder an idea of how easy it is to straighten a bent forging.

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I'm proud of the little 10 tonner. It straightened it relatively easy. No bunch of grapes hanging out the back.
I did a bit of a pressing with the support blocks set wide apart.

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After a bit of press work and further assessment, I brought the support blocks in closer. The following shot shows the part still under pressure. After releasing the pressure, it didn't need any further persuasion.

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Set up one of the machining jigs for this picture and set it on the mill table. This allowed me to see how square I got the face in relation to the engine mount holes. I'm happy with that.

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[Steve Little]

See if the forum limit for a days posting is up.

While the engine mount was in this fixture, I decided to cut the top engine mount pads to take out distortion.
This is one of the cnc fixtures and made for multiple engine mounts. One by its self in the center kind of looks forlorn.

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0:020” needed to come off the pads to achieve a flat surface.

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All done. Onto the next forging. The rear axle needs its mates.