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lbhsbz
11-29-2010, 06:55 PM
I bought a fullsize mill to do valve jobs, but the tooling required is rather pricey, so I've decided to attempt to make what I need to at least get me through a few jobs until I can afford to buy the real stuff.

This is what I'm trying to make.

http://www.tnsmachines.com/CylHeadEquipment/ThreeAngleTooling.aspx#d

The picture on the right.

I'm only concerned with making part B and C. I will buy pilots and buy the toolholders.

Part C has a 1.000" ball on it with a drive pin and part B" uses a 1.000 socket in it.

The ball is easy enough...ball turner on my lathe. The socket is somewhat troubling. I can make a lathe tool to cut it, or I can try and do it with a ball nose end mill on the mill. Problem with number 2 is that the Tree can only accomodate a 3/4" tool shank...and I'm having trouble finding a 1" ball nose with a 3/4" shank on it. I figure I'll make the socket first and hand polish it with emery cloth, then machine the ball and use the socket to test fit and sneak up on the finish size of the ball...when it almost fits, polish it with emery cloth till it does.

Any better ideas?

winchman
11-29-2010, 07:20 PM
I doubt the socket really needs to be spherical. Two conical surfaces at 60-80 degrees to each other should work just fine.

whitis
11-29-2010, 07:23 PM
Depends on how much of a sphere you need to machine and other dimensions.

You could take, for example, a 3/4" cutter with a 3/8" shank, not to picky about what kind as long as it cuts on the bottom corners. Mount the part on a rotary table or indexer, vertical or horizontal axis, and tilt the mill head over at an angle (or tilt the rotary table) until the edge of the cutting tool is on part center axis. Then rotate the work while turning the cutter. This can produce an inside hemisphere, maybe a little more than a hemisphere. If you need more than a hemisphere in one piece, you will never get the ball in, anyway.

Toolguy
11-29-2010, 07:26 PM
Use a 1" ball end mill on the lathe either in the tailstock or in a boring bar holder on the toolpost. I got an ER40 collet chuck with a M3 taper shank and a set of ER40 collets for the lathe and an ER40 chuck with an R8 shank for the mill. This greatly expands my options on both. Maybe you could get an ER40 chuck with a 30 or 40 taper shank and turn it into a shank that will fit the Tree mill spindle. ER40 goes up to 1 inch/ 25mm. I think McMaster-Carr and MSC both have 1" ball end mills with 3/4 shanks.

Lew Hartswick
11-29-2010, 07:28 PM
How much of the female hemisphere is there? These can be turned
with a radius turner up nearly (I did say nearly) to a hemisphere. I've
done some for a local "artist" and a matching male enough smaller
radius to accomodate the thickness of the material he was pressing
into a dome shape. The trick is to have the cutter at a 45 angle
rather than straight on. I don't have any pix right now but if you are
interested I can take a few later this week.
...Lew...

topct
11-29-2010, 07:33 PM
What about using one of those impact wrench flex joints?

oldtiffie
11-29-2010, 07:37 PM
I doubt the socket really needs to be spherical. Two conical surfaces at 60-80 degrees to each other should work just fine.

Agreed.

All that is needed is two circles of contact on the ball in Part "B". Use "Teflon" or similar.

Use a standard 1" ball - anneal and polish it. Drill for the driving pin/s.
Silver-solder the ball to Part "C" and pin/s to the ball in "C".

lbhsbz
11-29-2010, 08:25 PM
So...I just had another brilliant idea.

First, I'm wondering if any of you have any idea why this operation uses a ball driver? I imagine it has to do with the fact that most of this type of work is performed on an air table and that the ball driver makes lining stuff up a bit easier. I've questioned some automotive machinists who said that with a rigid head, they saw more errors in seat/guide concentricity than with the ball driver.

So, Say I use a thrust rated ball joint swivel bearing (like a one sided heim joint...press the socket end into my piece that fits in the chuck, and press the ball end over the secondary driver. Machine a slot in one and drill a hole in the other for a pin and I've got a drive set that costs me $50.

I'd use the thrust rated setup so that I could use multiple secondary drivers, each with a different cutter on them...kind of like a quick change tool setup.

Thoughts?

lbhsbz
11-29-2010, 08:31 PM
What about using one of those impact wrench flex joints?

I'd like a little greater level of concentricity than those will afford I think.

jdunmyer
11-29-2010, 08:40 PM
I have an old Black & Decker valve grinder outfit. It came with a seat grinder driver (looks about like a 3/8" drill motor) that has a hexagonal stub arbor that's rounded into a ball shape. IE: a ball that has 6 'corners', if you will. The stone holders have a hexagonal socket. Unfortunately, the driver's hex has the corners worn off, so it doesn't work. Fortunately, the setup also included a flexible driver that can be chucked in a regular drill motor. The driver is sort of like this: http://www.stanleyproto.com/default.asp?CATEGORY=DRIVE+TOOLS&TYPE=PRODUCT&PARTNUMBER=J4764&strSiteName=PROTO&strDefaultCatalog=PROTO&SDesc=1%2F4%26quot%3B+Drive+Flexible+Extension+Soc ket+Driver

It's just a heavy-duty flexible spring/cable with a short shank on one end and a hex piece on the other. I'd bet you could find something similar, or adapt one of those flexible screwdrivers.

This thing is interesting to grind seats with: you put it on the pilot, drive it with a bit of pressure, and when the seat is fully ground, the thing chatters like a b****h. The finish looks pretty much OK and I've never had a problem with a valve job I've done, but it sure sounds terrible when doing it.

darryl
11-29-2010, 08:56 PM
I'm thinking the ball goes into the end of a cylinder, and needs to seat against a hemispherical seat. Why not bore the cylinder part, then fill the bottom of the cavity with a filled epoxy. If you put some mold release on the ball, it can be used to form the epoxy blob to a perfect hemisphere. My thinking is to use a metal filled epoxy and add some graphite powder to it for some self-lubricating action.

By the way, if for any reason you wanted to make the ball permanently captive in the socket, you might mold some wax behind the ball, then turn it to leave a cone shape. After the first half of the socket is made, the ball is inserted, held straight, and the cavity left is filled with the epoxy mixture. When it's fully set, you melt the wax out and you're left with a certain amount of room to angle the ball shaft in any direction.

Adding to this whole idea, you could turn a pair of half-sockets from your metal of choice, then cut one of them in half. The whole one gets epoxied into the bottom of the bore, while the two halves are then assembled behind the ball, then this assembly is epoxied into place. Mold release still required, but the end result is basically a metal on metal ball and socket. Nothing stops you from drilling a few radial holes around the 'back' part and epoxying some music wire pins into place, for some extra insurance against the parts coming loose and falling out.

topct
11-29-2010, 08:57 PM
What keeps the tool concentric is the pilot not the drive joint. In fact I will guess their joint, as nice as it looks, has a bit of slop in it.

randyc
11-29-2010, 09:23 PM
Use a 1" ball end mill on the lathe either in the tailstock or in a boring bar holder on the toolpost. I got an ER40 collet chuck with a M3 taper shank and a set of ER40 collets for the lathe and an ER40 chuck with an R8 shank for the mill...

I did exactly the same thing: Morse taper, Cat-40 and R-8 collet chucks + the full set of collets. The ER-40 system is now the "standard" on both of the mills and the lathe (spindle AND tailstock) ! It's an excellent system and one of my "good" decisions, LOL.

http://i97.photobucket.com/albums/l219/randy9944/P1010955.jpg

Cheers,
Randy C

winchman
11-30-2010, 02:54 AM
Do you have a picture or link that shows that tool (from post #1) being used? I'm having a hard time visualizing how it's positioned on the cylinder head.

The tool holder clamped to the small pin on the bottom just doesn't look substantial enough to give accurate results, but seeing exactly how it's used would probably clear that up.

topct
11-30-2010, 08:45 AM
Do you have a picture or link that shows that tool (from post #1) being used? I'm having a hard time visualizing how it's positioned on the cylinder head.

The tool holder clamped to the small pin on the bottom just doesn't look substantial enough to give accurate results, but seeing exactly how it's used would probably clear that up.

That's the tool setting fixture. It's used to set the angles/position of the cutters.

The thing I'm having a problem with is that everything is going to have to fit very tight but also let the pilot spin in the guide. With only one cutter there will be side forces to deal with. There is mention of a pilot lock screw so I am assuming that's what they are doing. I always thought the pilot should not spin so that any material removed is not dragged down into the guide by having the pilot itself move up and down in it.

Am I having one of my uh-oh moments?

jdunmyer
11-30-2010, 09:53 AM
The pilots on my B&D grinder setup don't spin in the guide, they're locked into place by a "reverse collet" arrangement, similar to how an expanding arbor for the lathe works. The stone holder spins on the pilot.

topct
11-30-2010, 10:30 AM
The pilots on my B&D grinder setup don't spin in the guide, they're locked into place by a "reverse collet" arrangement, similar to how an expanding arbor for the lathe works. The stone holder spins on the pilot.

That's right. It's that spring on the above mentioned tool and the mention of a pilot lock screw that leads me to believe that they are moving the pilot. If not I stand corrected. Also if not, then the pilot is going to have to fit into the tool with a very close fit to handle the force of a single cutter.

lbhsbz
11-30-2010, 04:03 PM
This particular system uses a "dead" pilot....they're available in both HSS and solid carbide in either tapered (0.001 over 2") or straight in 0.0002 incriments. The pilot should be a snug/tight fit in the guide, and the tool driver spins on the pilot. I was going to ream the driver to 0.0005" larger than the pilot top diameter, which is .385" for all valve guide sizes (souix type pilots).

The little pointy thing on the bottom in the picture is simply a cutter setting fixture..

The spring and bushing keeps pressure on the ball to hold it in the socket.

I've got a couple junk heads to play with so I might play with a solid driver and see how that works.

cuslog
11-30-2010, 04:30 PM
http://www.speedtalk.com/forum/viewtopic.php?f=1&t=21647&hilit=Valve+job+bridgeport
or go to Speedtalk.com/forum/engine tech and search "valve job bridgeport". Numerous threads, some with photos, lots of good info. Some guys are claiming very good accuracy with this type of setup.

lbhsbz
11-30-2010, 06:28 PM
http://www.speedtalk.com/forum/viewtopic.php?f=1&t=21647&hilit=Valve+job+bridgeport
or go to Speedtalk.com/forum/engine tech and search "valve job bridgeport". Numerous threads, some with photos, lots of good info. Some guys are claiming very good accuracy with this type of setup.

I've spent the last 2 months reading on that website...I guess I'm just trying to find a better (cheaper) way to skin the cat, as usual.

.RC.
11-30-2010, 07:17 PM
No one has mentioned the obvious yet....

D-bit cutter... Pictures to come soon...

.RC.
11-30-2010, 07:28 PM
Here is I think a 15/16 radius cutter... I used it to cut a ball seat.. Made out of some hardenable steel..

http://img.photobucket.com/albums/v606/OzRinger/d-bitcutter004.jpg

http://img.photobucket.com/albums/v606/OzRinger/d-bitcutter003.jpg

http://img.photobucket.com/albums/v606/OzRinger/d-bitcutter002.jpg

CCWKen
11-30-2010, 07:36 PM
I wouldn't even bother with a ball socket. Just use a tube. I think all that link is for is to act as a U-Joint. It looks like the pin goes through the ball and the socket drives the pin. The socket looks like it's slotted at the pin to allow for some misalignment. I have a cylinder hone with a similar setup. The socket is just tubular.

topct
12-01-2010, 09:00 AM
I wouldn't even bother with a ball socket. Just use a tube. I think all that link is for is to act as a U-Joint. It looks like the pin goes through the ball and the socket drives the pin. The socket looks like it's slotted at the pin to allow for some misalignment. I have a cylinder hone with a similar setup. The socket is just tubular.

They have to use a tight fitting ball socket to make up for the fact that the tool will have a problem with the side forces encountered with the use of a single cutter. They are using carbide for the pilot to make it stiff enough,,, hopefully.

They also have to dial in the the pilot in all axis for each and every guide. Even with the use of the ball and socket to drive it.

If the cutter head had two or more cutters on it, it would be much easier to use and the alignment issue would be much easier to deal with.

CCWKen
12-01-2010, 11:30 PM
That would make sense. I'd say scrap the whole idea of that single cutter tool and use Neway cutters then. They're not that expensive and just a few will do many types of engines. They have small starter sets or you can select individual cutters and build the set you need to get started. If the OP can buy a full size mill and associated tools just to do valves, a few cutter heads and guides are pocket change. Cripes, you don't even need the mill!

http://www.newaymfg.com/frame.htm

whitis
12-02-2010, 12:59 AM
I was originally thinking you needed more than a hemisphere cut in one piece, which of course would prevent assembly, so I didn't mention the obvious. If you already have a ball turner, it becomes an inside hemisphere cutter if you extend the bit past the axis of rotation.

lbhsbz
12-02-2010, 04:10 AM
That would make sense. I'd say scrap the whole idea of that single cutter tool and use Neway cutters then. They're not that expensive and just a few will do many types of engines. They have small starter sets or you can select individual cutters and build the set you need to get started. If the OP can buy a full size mill and associated tools just to do valves, a few cutter heads and guides are pocket change. Cripes, you don't even need the mill!

http://www.newaymfg.com/frame.htm

I don't have an bottomless wallet....I'm simply tired of paying good money to people that screw things up for me. I sold my grizzly benchtop mill for $900, sold a 454 out of another boat I'm Parting out for $950, and spent $1700 on the new mill and the vfd setup. I do at least one engine a year, so the right tooling will pay for itself.

Here's what sucks about the neway stuff. You need a different cutter head, at a couple hundred bucks each, for every range of valve size. I would need to buy 4 cutter heads to do a 3 angle job on my BBC heads. That's about $800 right there, then another $3-400 for the drive setup, and a couple carbide pilots at $150 each. Then if i need to do some smaller heads, i need to buy more cutter heads. Another thing I don't like is that it's designed to be driven by hand....when I spoke with them they seemed to frown on using a mill. Also, there is little flexibility in profiles and angles.

With the single cutter setup, the initial cost will be about the same, and and will be much more versatile with respect to different valve sizes and different seat profiles. Since I'll already have the head fixtured on the mill table for the guides/seats, it only makes sense to use the mill for cutting the seats. Additionally, I have it in my head that aligning using a coax indicator on the mill would result in better seat to guide concentricity than spining the tool by hand with a wrench hanging 10" off the side of the axis. on the mill, I will also be able to use a Z-axis DRO to control the depth of cut, such that all my seats are cut to exactly the same depth. The only thing that needs to change from the largest to smallest valve sizes with the single cutter setup is the toolholder and pilot.

brucepts
12-02-2010, 09:09 AM
I'll second or third the discussions over on Speedtalk, those guys do this for a living and they almost all use single cutters on a mill. They are holding .0005" runout but that does not come "cheap". Notice in the discussion the last cut is almost always done by hand driving the spindle.

One guy makes a very nice milling fixture, need to do a search for that, I know a bunch of guys are using that fixture in their shop.

My thought would be to simply use a drilled hole for your driver socket the accuracy is held by the pilot in the valve guide hence the reason they are using carbide pilots.

Search for Larry Meaux (Maxracesoftware) over on ST he had an outlet for the drivers and holders and had a bunch of pics which would be good reference.

This is one of my Winter projects myself . . .