[banctecbobn]

Caprirs,

Your making me think way to hard. lol

I agree with your post except the egg shaped hole. The hole being egg shape is exactly what I thought at first but in thinking about it I'm not really sure. You could be right or not. Thinking about this long and hard enough I'm about ready to fire up the old Shoptask to see what the results would be, but then again on my Shoptask I might get any result or anything between. (joking......not really)

I'm very interested in this whole thread cause I am wanting to purchase a manual IH, upgrade it to CNC, and then bore motorcycle cylinders. I plan on moving the CNC electronics from my Shoptask to the IH mill. I emailed IH once about buying a manual mill and just the CNC mechanical hardware (screws, mounts and such) but didn't receive an answer/response. Not enough funds to purchase their complete turnkey CNC.

Bob

[Cruiser]

I never said I would, could, or did ! and was only answering some questions ! made a couple of points ! NOW, you guys can do say whatever you want but keep in mind that 1D10T rules apply

[banctecbobn]

What is the 1D10T rules? I'm not a machinist......just a hobbist.

[garagefela]

What is the 1D10T rules? I'm not a machinist......just a hobbist.

ID10T = idiot

[IHCNC]

Hi Guys;
Seeing how much interest the 460 picture generated, I called Stan and asked for his procedure. Here is his email to me.
Hi Gene,
Thanks for the call about the Ford 460 Big Block pics. I had not seen them posted before. It was interesting to see what some of the bloggers had to say about this not being possible.
It is true that the IH mill quill travel is not sufficient to get to the bottom of the hole by itself. I was able to get the necessary travel by starting the mill with the cutting tool just above the cylinder and with quill retracted. I gradually extended the quill to its full travel and then, with the mill still running, lowered the head until the cutting tool reached the bottom of the hole. At that point, I turned off the mill and then raised the head and quill to bring the tool back up to the top for the next pass. I made several small passes this way, taking light cuts, until I got to the final diameter that I wanted. I probably could have taken more off with each pass, but since I had not tried this before, I wanted to play it safe so as not to risk ruining the block.

I did find in my early experimenting that the block needed to be mounted to the table very rigidly and so I fabricated some special fixtures to accomplish that. Those included the supports and hold down bolts you can see in the pictures, as well as a heavy angle plate behind the block that is bolted to both the block and the table. The original ‘home made’ boring bar that I tried wanted to chatter, so I also had to make some modifications to that design. The bar you see in the pictures is the one that was actually used to bore the holes. There is no swarf shown in the pictures because I cleaned it up before taking them. That’s just the way I like to work.

I was happy with the surface finish that I got and I did not have any problems with the holes being out of round. I left about 5 thousandth’s on the diameter for honing, but if I were doing it again I would reduce that to about 3 thousandth’s. That would have considerably reduced the manual labor I had to do during honing and the original finish after completing the boring process was more than sufficient to have allowed that.

I am not an engine rebuilder, so I am not suggesting that the professionals should do it this way. It was more of a challenge for me just to prove to myself that it could be done without the specialized and expensive equipment that they use.
You are welcome to add it as a post if you think others would be interested in knowing how it was done. I might also mention that the top of the block was about 16” above the table using the mounting method that I came up with. As a result, I could not get the head high enough to have the quill completely extended with the cutting tool above the hole. That is the reason I used the two-step process of extending the quill and then lowering the head.

By the way, I was in New Hampshire earlier this spring, only about 100 miles away from your location in New Britain. I had hoped to have time to stop by to see your operation, but my schedule did not work out that way. I am still very happy with my IH mill and expect it will serve me well for a long time to come.



Regards,



Stan




--------------------------------------------------------------------------------

[Cruiser]

Hi Stan,
Glad to hear that all came out well for you. I'm sure that some of these 1d10t engineers & machinists will tell you how ya did it all wrong ! All I gotta say is I totally agree with you to get it closer to the finish size. I have found that when sanding or honing a machined surface that the first .0006 goes away in a heart beat, then you have to work at it to go further. With that I'd say get to .0005 to .001 when possible. Having a course stone would help to get closer too, but still lots of work. I don't really like the idea of having a stall point in a bore but on first cut then OK. I was thinking that a tape measure might have got it there then bore. You didn't say if you only did that on first bore or all or I missed it. Many light cuts is definitely the best bet that way if any peculiarities while cutting it can be adjusted for and dividing up the total material to be removed into equal passes gives a known quantity or quality to work with.
You didn't say but are you just rebuilding or is it going to be a racer or stump puller ?
nuf chatter ! Anyway, Thanks for posting Stan !

[BobWarfield]

Makes sense to me, Stan and Cruiser.

A point that got glossed over is the exact requirements of the bore WRT the entire length of the bore.

The stroke of a Ford 460 is 3.85" stock and more if building a "stroker" motor. The pistons are inserted from above and do not travel the entire bore. While it is no doubt undersirable to be too cavalier about the entire 8" depth of the bore, machining the top quill travel and then following up with Z-travel means that top quill travel of 4.75" is pretty consistent. The far reaches of the bottom of the bore can stand a few thou of error because the piston never travels there.

Most of you don't have that much travel imagining doing an accurate bore 4" deep, do you? In this case, based on my experience with the IH, I doubt you'd have a few thou error between quill versus Z travel anyway if your machine is well set up and dialed in.

And, as has been mentioned multiple times, it is absolutely normal practice to hone in the final few thou.

All in all, it would not be economical to use an IH for this purpose in an engine building shop, but it is eminently practical to do so for one off work and not even all that hard to figure out how to set it up.

Of course it'd be even easier with a CNC'd mill as then it is all Z travel which is pretty accurate.

From an economic standpoint for production, your biggest issues are that the pro-machines can handle much faster feeds and depths of cut, and they're optimized better for fast setup. Remember you want to dial in the center of the bore more on crankshaft features than on the existing bore for best results. Also remember that taper is your enemy and you're extending quill and tooling quite a lot. Take very shallow depths of cut indeed for such a project.

Cheers,

BW

[Cruiser]

Bob, The bore is not going to be the same depth as the stroke ! It will in fact be somewhat deeper to manage the skirt of the piston at the bottom of the stroke ! So ! You missed that one and I'm sure that it will be recorded on your permanent record ! Sure it is a point in moot but valid !
Next, is that in reality the bottom of the bore is ignored when boring, It is the center of the crank journal that is dialed in then the top of the bore and if blue printing is being done it is then geometrically proved before boring.
Then there is the economy point you mentioned ! It is not economical or faster to go for the gusto and machine to size for the plain and simple fact that an oops will not only cost a block but the wait to get a new one will really slow things down. You will have to consider that there are so many variables that change while doing any machining job that you can not in reality take everything or anything for granted.
I have machined many different jobs in many different machines and one thing is common ! Never trust ! especially if it is high tolerance !
You make it seem too damned simple.

[EvanVH]

Second, the picture by the OP shows a single tip tool which will produce unbalanced cutting forces.

Where in your experience have you found that a single point cutting tool produces an unbalanced cutting force.

A single point tool is the only tool to use. I have bored 3 inch holes in tool steel with a +/- .0005 tolerance.

If the machine were perfectly rigid, this would not be an issue but the machine in the pictures does not fill us skeptics with confidence against those kind of cutting loads.

Perfect is a myth or for somebody who has no clue .

Well unless your skeptics can come up with a finite element analysis of why this machine is not rigid enough. Nobody cares.



Evan

[Caprirs]

Where in your experience have you found that a single point cutting tool produces an unbalanced cutting force.

A single point tool is the only tool to use. I have bored 3 inch holes in tool steel with a +/- .0005 tolerance.

I am glad the OP has followed up with more info. I am also glad he has had success thus far. I will be much less skeptical when I see video of that engine on a dyno or in a car.

Machines have different rigidity in different directions. Most conventional VMCs are more rigid when the cutting forces are applied towards the column as opposed to cutting in the x axis which adds the twisting of the head. Also, most machines have play between the table and saddle as well as play between the saddle and the base. Unless machine maintenence has been a top priority, these are often different in x and y.

As the single point tool rotates, the machine will move and deflect as the backlash in the ballscrews and gibs is constantly taken up. Conventional engine boring machines are massive with massive quills and are designed to handle this. A benchtop hobby machine is not.

My first question when such tolerances are stated is how was the bore measured? When discussing cylinder bores, diameter is typcially not sufficient to describe the geometry. Cylindricity and roundness are equally critical in this particular application. An egg has a diameter. It makes a poor piston though. How round does a Ford big block cylinder need to be? Any one have the specification?

Also, the hone is going to follow the bore. If the bore is not straight and round, the final cylinder will not be either.

My experience is based on when I worked for a machine tool builder and used a Renishaw ballbar tester to check the accuracy of the VMCs we manufactured. It is also based on work I did doing machine tool calibration for a customer using a laser interferometer and ballbar testers on their Niigata and Makino HMCs. I spent a lot of time adjusting gibs, tramming machines, and adjusting backlash.

I think way too many machinists have too much faith in the accuracy of their machines and measuring devices.

[philbur]

One should not mistake a smooth, shiny surface for a precision surface.

Phil

[oltimer]

philbur
it must make you feel real special that a prestigious gold poster that loves to boast about his vast knowledge and mastery on the worlds greatest machines is skeptical about what a hobbyist might do and report on a hobbyist blog seems to side with your overwhelming mastery of the same machinery. maybe both of you should start your own forum and call it we know more than you all. neither of you are any help to anyone who reads this blog and in fact you probably keep honest to goodness hobbyist from ever posting anything so as not to receive your bombardment of bs. thats all it is, egotistical bs from people that love to read their own bs.
oltimer

[EvanVH]

I think way too many machinists have too much faith in the accuracy of their machines and measuring devices.

Caprirs

You do have some interesting experience. Did you ever work as a machinist? I agree that there are a lot of machinist out there that have really no way of knowing how accurate there machines are.

I am not a person that gives out info on this forum unless I believe the info is accurate. I have been an inspector since 1988. I have programed LK, Brown and Sharpe, and Ziess. So....

The holes I ways talking about where a government job. All of the work was inspected buy a CMM. Which was calibrated every six months. A government source inspector came out and watched me inspect every part I made.

I was required to hold circularity of .0005 and +/- .0005 size. This was done on a Lagun knee mill. The shop had six manual knee mills, 2 large Kurakis, 3 Haas and a number of lathes.

We did not have any machine that would hold that tolerance with out a single point tool.

We also had a beautiful #3 Moore Measuring Machine that had laser interferometer DROs. The dials had .000020 deviation 1/2 a micron. It was very accurate but slow to inspect with.

Believe it or not that's my experience and opinion.

Tip for you. The IH mill weights 1000 lbs. If you call it a bench-top machine it really degrades your opinion. Which no body wants.


Question of the subject. How many VMCs that you worked on use linear guilds instead of ways.



Evan

[EvanVH]

philbur
it must make you feel real special that a prestigious gold poster that loves to boast about his vast knowledge and mastery on the worlds greatest machines is skeptical about what a hobbyist might do and report on a hobbyist blog seems to side with your overwhelming mastery of the same machinery. maybe both of you should start your own forum and call it we know more than you all. neither of you are any help to anyone who reads this blog and in fact you probably keep honest to goodness hobbyist from ever posting anything so as not to receive your bombardment of bs. thats all it is, egotistical bs from people that love to read their own bs.
oltimer

oltimer

do I hear those crickets again and again and again ?


Evan

[Cruiser]

OK I feel kinda
crickety ! .....................................chirp........ .................................................. .................................chirp............ ..............................................chir p..chirp.......................................... ........chirp..........!

[rangergt]

It wouldn't matter how perfectly round the cylinder was bored, it still wouldn't be round enough for the block heads that just keep spamming up good threads with their opinions that nobody cares for.

[mc-motorsports]

Experience is the teacher of all things.

[philbur]

A key component of any forum is the free expression of opinions. It’s not uncommon for opinions to differ. Reasonable adults then proceed to give considered arguments for their opinions and then somebody with a different opinion may challenge those arguments. By this process the discussion moves forward and the participants may learn something. Calling somebody who doesn’t share your opinion a Cricket or telling them to “GO AWAY” does nothing to improve the understanding of any of the participants and serves no constructive purpose.

To return to the technical discussion: Measurement is an integral part of any precision machining process. Little has been said on this subject. Failure to adequately measure the result represents a fatal flaw. A decent bore gauge would go a long way toward increased confidence. A cheaper alternative might be the judicious use of a DTI mounted in the spindle and used as a comparator. Neither would prove the absence of all possible errors but it would go someway. If you don't make an effort to verify the result you deserve all you get.

Phil

philbur
it must make you feel real special that a prestigious gold poster that loves to boast about his vast knowledge and mastery on the worlds greatest machines is skeptical about what a hobbyist might do and report on a hobbyist blog seems to side with your overwhelming mastery of the same machinery. maybe both of you should start your own forum and call it we know more than you all. neither of you are any help to anyone who reads this blog and in fact you probably keep honest to goodness hobbyist from ever posting anything so as not to receive your bombardment of bs. thats all it is, egotistical bs from people that love to read their own bs.
oltimer

[oltimer]

philbur
can't you read? nobody cares about your opinion. it is pure boastful bs. as i have said in the past go away and do us all a favor so we can discuss something important to us not you. start your own forum called its all about me the heck with the rest of you with lessor intelligence.
oltimer

[mc-motorsports]

Measurement is an integral part of any precision machining process. Little has been said on this subject. Failure to adequately measure the result represents a fatal flaw. A decent bore gauge would go a long way toward increased confidence. A cheaper alternative might be the judicious use of a DTI mounted in the spindle and used as a comparator. Neither would prove the absence of all possible errors but it would go someway. If you don't make an effort to verify the result you deserve all you get.

The first 2 sentences say it all, thank you.

Your efforts to teach and or pass along experience and or knowledge may be unrecognized in what seems to be a hobbyist forum, as previously stated.

You always admire what you really don't understand.

Engine machinst who spend the money on the proper equiptment or machinist in general who know the extent and capability of thier equiptment probably fall under the "1d10t engineers and machinist" that was previously mentioned.
My only response is anyone who owns a keyboard can post a reply here, anyone looking to learn unfortunaly needs to learn better before reading some of the BS, especially in this thread, and there is a reason that I pay an engine machinist to do my block work. Problem is most people here don't get it and the my only cause for concern is someone who wants to learn.

A proper procedure for every operation, "good enough" doesn't cut it in my world, sorry I ever posted, I didn't realize this was a "hobbyist forum", so I will remove my subscription to this thread and pay further attention in the future, then again, this may not be the best place to ask questions for anyone SERIOUS about learning.

MC