Author Topic: 1909 Mercedes Aero Engine  (Read 7323 times)

Offline Old Bill

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Re: 1909 Mercedes Aero Engine
« Reply #135 on: February 06, 2019, 09:03:02 PM »
Many thanks for your thoughts Chaps. All very much appreciated. I have played games with the speed, tool angles, depth of cut and feed rates but to no avail. I kept going in the hope that I would strike the 'sweet spot' but alas and I am now 1.2mm oversize. I did a couple of spring cuts but each time, it just picked up the resonance. All extremely frustrating! Perhaps I should have made the shaft longer to change its frequency.



Mind you, this is the most amazingly rough bored finish I have ever seen!



The only plus side is that at least the hole is in the right place.



The hole is just shy of 9/16" so perhaps I will try an expanding reamer just to tidy it up a bit.

To get it low enough for the camshaft hole, I had to make sure that the casting hung over the edges of the cross slide. Drilling that hole will be the next challenge.



There is not much satisfaction in this one.

Steve    :-\



Online Jo

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Re: 1909 Mercedes Aero Engine
« Reply #136 on: February 06, 2019, 09:12:01 PM »
I know how you must feel Steve  :( and I still have mine to look forward to  :toilet_claw:

Jo
« Last Edit: February 06, 2019, 09:15:51 PM by Jo »
Usus est optimum magister

Offline stevehuckss396

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Re: 1909 Mercedes Aero Engine
« Reply #137 on: February 06, 2019, 11:30:17 PM »
I find that if I get some chatter I cut spindle speed in half. If it chatters again cut in half. Just today I had to use a boring bar to bore a 2 inch bore 6-1/2 deep blind hole. I was down to 150RPM but got a good finish. Took forever!
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline john mills

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Re: 1909 Mercedes Aero Engine
« Reply #138 on: February 07, 2019, 06:01:32 AM »
could you use a shorter bar .set tool cross hole closer to  the hole so it just goes through the one hole have the a different tool for each hole that way the tool is supported near the chuck for that first hole the last hole is closer to the last hole the centre bore it would be a shorter bar over all ,if you could mont a bush next to the centre hole
make a bracket mount of that tee slot.that would help could the centre  be done before the sump is put back. 
just some thoughts from a automotive machinist that has done a bit of line boring on line boring machines
they had arms which could be moved and placed next to the hole.but a bit hard for the centre  when the sump is on.
   John
at least use three separate tools one for each hole so the bar can be much shorter.
looking again could you while the sump is of mount a support bush on a bar across the tapped holes on the lower face
« Last Edit: February 07, 2019, 06:07:40 AM by john mills »

Offline Roger B

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Re: 1909 Mercedes Aero Engine
« Reply #139 on: February 07, 2019, 09:41:42 AM »
I know it's a bit late now :( but Jason B used a much shorter boring bar mounted between centers so he could turn it around to cut either end without disturbing the cutting tool setting (you wil need to reverse the lathe I think  :headscratch: )
Best regards

Roger

Offline Jasonb

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Re: 1909 Mercedes Aero Engine
« Reply #140 on: February 07, 2019, 11:02:26 AM »
Yep, that's what I suggested back in post #24

Offline john mills

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Re: 1909 Mercedes Aero Engine
« Reply #141 on: February 07, 2019, 11:53:09 AM »
using the long bar the fixed steady could have been used as close as possible to the cutting tool shift to the other end when cutting that but the centre would need more support the shorter bar would be better.
i would set it up again and try again with a shorter bar.