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Clean & Refurb of Small Sunnen Hone

Conrad Hoffman

Diamond
Joined
May 10, 2009
Location
Canandaigua, NY, USA
Years ago I did a lot of very close tolerance honing and had been hoping to find a machine for myself for a good few years. Strictly an advanced hobbyist here, so it had to be the right machine at the right price. It finally happened and after 5 rolls of paper towels, 1/2 gallon of V&PM Napatha, a spray can of carb cleaner, a good razor scraper and about 18 hours of elbow grease, the MBB-1660 looks near to new.

My guess is, as long as the belts go around, people do near zero maintenance on these. This is just a brief note to describe what I did. The trick is to remove the motor from the top of the head, along with the side panel. At that point you can stuff a rag or paper towels in the bottom and spray all the internal parts with carb cleaner- bearings, bushings, lever points and sliding springs, until everything is cleaned up and moving freely.

The manual specifies 20W oil for most everything but IMO one can do better and maybe extend the maintenance interval. I used two things- Superlube Synthetic Low Viscosity Oil (no PTFE) and their Synthetic High Viscosity Oil (with PTFE). All sliding and rotating bushings get the low viscosity. The sliding springs, screw threads of the tension adjustments and anything else with looser tolerances or higher forces gets the heavier oil. Similar cleaning and oiling was applied to the rear (accessible) parts as well. Carb cleaner is effective at brightening up the big aluminum pulleys. Seems to work well now, though it wouldn't surprise me if a bearing or two would benefit from replacement or relubing. Also oiled the motor and replaced the plastic hoses.

The oil reservoir is designed for 15 gallons of honing oil, about $300 worth of stinky MB-30. As an experiment, I'm going to try reducing this to a gallon or two- I'm not doing high volume production work, nor removing a lot of material. I'm thinking a heavy plastic dishpan under the pump, and redirecting the pan drain back to same. The drain is 3/4" NPT, with an elbow and down pipe. One can unscrew the down pipe, then remove the elbow. My plan is to replace it with a hose barb and hose for the redirect. This loses the benefits of the sediment tray, but I'm hoping that won't bother much at my usage level. I'll post more when I see how this works.
 
Conversion done. Female hose barbs aren't common so a standard male 3/4" NPT with a 5/8" hose barb plus a female to female coupling does the job. The hardest part is getting a couple wraps of Teflon tape around the tray drain. I kept the tubing size 5/8" because you don't want oil backing up in the tray. A 12 quart polypropylene dish pan from Walmart (Sterilite) for $1.79 is the new reservoir and a plastic tube goes from the drain to that. The end of the plastic tube should be notched/cut so no matter how it sits, the flow won't be restricted. Since everything sits in the existing reservoir, any leaks or drips will be contained. We'll see how it works over the next weeks.
 
I have enough oil to fill it, but don't want to. Because my usage is low and it lives in my unheated shop, nothing good is going to happen to 15 gallons of stinky oil in an open tank. More likely I'll find some dead rodent floating in it. By limiting the amount to something sensible I can change it out when necessary. Photo when I can get one.
 
Pics of the beast, plus the somewhat sad 612 grinder I'm fixing up next to it. It has a latex housepaint job, but I'm more interested in getting it up and running, than refinishing it. BTW, the hone doesn't have a dent in the side, that's just a reflection from a window or flash or something.

MBB1660_cleaned.jpg..MBB_rear.jpg..Boyar.jpg
 
Oh lord yes, We've got one of those in the shop for honing dowel holes and button holes on small details. Works like a champ. Did it come with a full set of mandrels and hones?
 
Is that a Sanford Grinder?
Mine doesn't have house paint but it's similarly sad.
I might get to it someday, it's only been here about 15 years.

One word on the hone WOW!

I see all those pulley grooves and I think
"VFD". But you've got a showroom original there.


 
The grinder was important because I needed to have it in position before the hone could be shoehoned in. Alas, I only have arbors and stones for the two sizes that interest me (0.281" and 0.5"), but would certainly like to get at least the standard fractions up to an inch. Why those two sizes? My first love is audio equipment and those are bearing sizes for many turntables that I'd like to upgrade or refurbish. Audiophiles get all anal about bearing quality.
 
No association, but I don't think I've missed the Steam Pageant in a couple decades. It's just a few miles away from me- I always hear the whistles and if the wind is right, I can smell the coal fires.
 
Tricks of the trade-

Headlight restorer/polish from the auto store also works great on plastic indicator crystals.

The Sunnen dial indicator tends to get really gunked up because oil from the operator's hand drips down from the adjustment knob above. This ones dial was completely trashed. A new one was drawn up in CAD, printed on a photo printer and glued to the original aluminum plate. Yes, I still need to clean up some gunk around the spindle.

MBB_dial.jpg
 
The oil reservoir is designed for 15 gallons of honing oil, about $300 worth of stinky MB-30. As an experiment, I'm going to try reducing this to a gallon or two- I'm not doing high volume production work, nor removing a lot of material. I'm thinking a heavy plastic dishpan under the pump, and redirecting the pan drain back to same. The drain is 3/4" NPT, with an elbow and down pipe. One can unscrew the down pipe, then remove the elbow. My plan is to replace it with a hose barb and hose for the redirect. This loses the benefits of the sediment tray, but I'm hoping that won't bother much at my usage level. I'll post more when I see how this works.

I have 5 gallons of oil in mine, and about $100 of 6061 blocks I had lying around to bring the level up to where the pump would work. I'm in CA so couldn't get MB30, but have a different oil instead MAN-863 which doesn't seem to bad as far as odor goes.

I couldn't be without my 1660, I've been collecting a lot of mandrels off ebay recently, and it's been a great investment.

BTW, nice 1660 you have there!
 
Oh lord yes, We've got one of those in the shop for honing dowel holes and button holes on small details. Works like a champ. Did it come with a full set of mandrels and hones?
A full set of mandrels and stones is more than a bunch of machines.. Just an example... To buy all the set-up to do holes from .060 to .062, and a dozen stones cost me 300 dollars. If I am lucky, one stone hones 2 holes... Larger Mandrels/stones DO last longer.
 
Many years ago, maybe late '70s early '80s, we bought a new 1660 where I worked. It was incredibly cheap because Sunnen knew they had you on all the tooling, of which we had a lot. It was the old razor and blade business model.
 








 
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