Is this Sunnen 660 a good hone?

[Garwood]

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I'm thinking about picking up a better hone than the Sunnen LBN I have. The LBN is a bit clunky to use and while it has a ton of small mandrels, few of them fit my needs well. It's also very low power. I've used a 1.5" mandrel a lot and it does not have the power to really run it.

This 660 popped up and the seller seems to be selling it for someone else, or maybe a family member that passed away. They're not knowledgeable about it at all. It appears to have a large assortment of modern style mandrels and truing sleeves. Looks like it was used for rods and small cylinders judging by the shit stacked around it so mandrels probably cover a huge range. Looks like it also has some kind of Sunnen bore gauge and I don't know what the indicator below size adjustment knob does, but it has that (my LBN is from the 30's, it has a motor. That was it's high tech feature). The 660 also looks like the motor has been changed out and the motor looks larger than original. Maybe larger to run the larger mandrels?

My use is occasional automotive stuff, basically just my own engines. I also have a product in the works I need to hold a .663 bore to about a tenth or two. If I can't hit it in the lathe I want to have a solid plan B or a way to fix the occasional oops parts. Better than the LBN does it anyway. I think just in general I like having honing capabilities because it's a game changer when you have to work to tenths.

Thoughts on this 660? Is $1500 a fair price? It seems reasonable to me, but I've seen Sunnen prices vary wildly.

 

[Mud]

It even has the parking meter gage. I don;t know model numbers and such, but I'd think it's a go get it price.

 

[MwTech Inc]

Yea great price! You're probably getting short on money so I'll give you $500 for the old worn out Blanchard to help you out.

 

[Barbter]

That looks in very good nick - very clean?
Lots of tooling - well worth the money ida thought?

 

[Garwood]

Ok. So I asked him for a better pic of the model # and its an LBA-660. That makes it 1950's and not much different from the LBN I have. The bore gauge has a .37 to 1.5" range. Not ideal for me.

 

[Mud]

The bore gauge has a .37 to 1.5" range. Not ideal for me.

I've never had one, but the ones I saw in use had interchangeable points to change size, sort of the way the bore gages do. That does appear to be an old one, I see one on Ebay for $1500 and one for $500

 

[Spruewell]

I have one that looks to be identical. I got it out of a local automotive shop with a pile of mandrels and 3 bore gauges. The gauges are really nice and super quick to use when you are inspecting a lot of parts. $1500 is a good price. One tray of those mandrels cost more than that

 

[Oldwrench]

Honing depends on technique and scrupulously, obsessively, relentlessly truing the mandrel. Be prepared to make truing sleeves. The closer to the desired finished diameter your sleeve is, the more accurate your results. Remember the hone follows the existing hole in the work, it doesn't depend on its own spindle to control roundness or straightness. You can hold bores to +/- .0001 with an old 1930s plain-bearing model if you keep after the mandrel.

 

[Mud]

Honing depends on technique and scrupulously, obsessively, relentlessly truing the mandrel. Be prepared to make truing sleeves.

Would you expound on both points? Do you make the mandrel slightly undersize, so it's on size after it's used to true the stones? When is it junk? What's the proper procedure for truing the mandrel stones?

 

[Garwood]

For the +/- a tenth stuff I've been doing it seems like truing is fine as long as the sleeve is somewhat close- like within 25 thou or so. The only thing I've found is to make sure you flip the sleeve around often and use it both ways.

If I use honing fluid running on the sleeve it doesn't work. I just give it a little spurt of fluid then work it for awhile to get a grit slurry then flip a couple times and go until the sleeve has even pressure from one end of the stone to the other.

If the stones are shorter than the sleeve and you can stroke the whole length of the sleeve you don't need to flip.

 

[Oldwrench]

Would you expound on both points? Do you make the mandrel slightly undersize, so it's on size after it's used to true the stones? When is it junk? What's the proper procedure for truing the mandrel stones?

1. On the sleeve bore tolerance it depends somewhat on the material being honed. A harder workpiece will tolerate more deviation. Garwood's estimate of .025 is completely safe for steel and hard anodized aluminum. For bare aluminum I'd replace the sleeve before then, but that's just me.

2. In a production environment you could fill a 5-gal bucket with sleeves in 60 days, but that may just indicate obsessive-compulsive disorder. In a job shop a sleeve would last a year. There is some debate about the effectiveness of a smooth bore versus a coarse-feed bore for retention of the abrasive grains but I don't have an opinion.

3. As G'wood described, the oil is used in hining to flush the loose abrasive and the chips from the cut so as not to wear out the mandrel (or shoes, in the case of replaceable shoes). One-piece mandrels are hard; shoes are made in various materials. The standard Sunalloy is pretty good without being overly embeddable. For truing you lap the mandrel or shoes to conform to the sleeve, using the same abrasive slurry you normally flush out. Just get it wet and shut off the stream, then start honing. While reciprocating the sleeve try not to expose more than 1/4 of the shoes and stone but do make sure of complete coverage. Then wash out the mandrel with WD-40.

Evidence of a properly trued mandrel is a uniform, uninterrupted end-to-end crosshatch in your workpiece.

 

[Oldwrench]

Oh, yes, as G'wood sez—absolutely flip the workpiece or sleeve end for end, it will help cancel out any taper.

 

[Garwood]

I just figured out what's wrong with my Sunnen LBN! The spindle floats in and out! This causes the size to jump randomly.

Before I take the whole thing apart, anyone know how to adjust spindle endplay and what it should be?

 

[Oldwrench]

That's a plain-bearing machine, it has oil cups. I modified ours with two 1/4" copper tubes soldered into a large cup, elevated well above the journals so they stay flooded. Sorry I don't remember how to establish end play but I just tried ours and it won't move. Probably there's a thrust washer somewhere. Maybe it's part of the pulley hub.

While there's no mechanical difference between automotive and industrial machines, Sunnen divided their sales force between the two specialties and painted automotive machines red. Even today your customer number starts with either "I" or "A." I am sure Sunnen can provide a parts breakdown for your hone.

 

[Garwood]

It had about 25 thou freeplay.

I loosened the setscrew in the drive pulley hub. I put a bessey clamp from the spindle face to the pulley hub, lightly snugged it up and tightened the set screw.

With zero endplay something new happened- The mandrel loosened up when I let off the pedal! I had no idea it was supposed to do that!

What was actually going on was that I had the spring tension pressure too light not understanding what that did and when I was letting off the pedal, instead of the mandrel collapsing, the spindle would shift. When I'd start honing the mandrel collapsing movement would gradually work out and I'd fight it every time I put my foot off and back on the pedal.

Thing was, it wasn't obvious at all what was happening because it really didn't happen unless I was using a truing sleeve. The long engagement of the truing sleeve would put a load on the motor and the mandrel size would "jump" and lock up in the mandrel. It actually made it seem like the mandrels were worn heavily tapered. You can't really measure the mandrels so I thought most of mine were badly worn tapered. Nope. Just my own ignorance.

I thought my hone was junk when really I just didn't have a clue what I was doing!

 

[Mud]

^^^^^My observation about my own struggle with shit like that is - "Everything is so much harder when you don't know WTF you are doing".

 

[Oldwrench]

Don't feel bad. How a hone works is NOT obvious. The wedge and spring return was a very clever invention, as was the asymmetrical arrangement of the shoes vs. the stone(s) to prevent chatter. You would think that skinny little wedge would wear out, or cut a groove in its guide slot, or any number of other failure points, but because the process improves a bore to the tune of only a few thousandths it doesn't really have to maintain an accuracy over any distance at all—unlike the crossfeed screw of a lathe, for example, where wear is revealed by the tool falling behind the dial. The tiny cutting range of a hone will repeat to the point of having to make sure you don't try the go gage with the part a bit too warm or it will shrink a tenth and grab it.