Brown Sharpe Micromaster 618 Series I

Proud new owner of a 64 series I. It grinds immaculate, even better than i thought was possible coming from a 6x12 manual grinder with no coolant.

I am having trouble with the cross feed feeling like it is binding up and certain parts of its travel. If i put in in auto feed for one quick movement, it will go away and i can continue feeding. Not sure if it is related but 'dress' traverse (slower of the 2 quick feeds) does not go all the way to the sides of the chuck. It will stop an inch from each side. And the fast feed makes a noise like something is dragging across the leadscrew lengthwise.

Not sure if any of this is normal or if it is just an old machine that sat for very long and now starting to get some use.

Anyway, i am super happy with it even though i have been only using it manually since i picked it up.

Great surface grinder!
That machine today would be a lot of money. $50,000+

I have a MicroMaster series 2 with similar issues. It was terrible when I got it. Went through everything and found an incorrect bracket on the cross traverse screw causing a bind. Fixing that helped a lot but didn't solve it completely.

I think it is due for a rebuild in the cross feed valve, the spools and bores are worn a little, allowing more leakage than should be happening. So the valve is bypassing oil instead of pushing it through into the cross feed piston. Yours may be having a similar issue. Until I get the valve rebuilt, I get around mine by turning the hydraulic pump speed up a little with a VFD, which in effect gives less time for leakage and a sharper push on the piston. I've been running it at 70Hz instead of 60.

The symptoms you're describing with the dragging sound across the screw sound like hydraulic system issues too. The cross feed nut is a split bronze piece that is forced apart with hydraulic pressure when you use auto-feed, rapid traverse or dress. It sounds like it may not be separating correctly. You might need to disassemble that and check clearances or gaskets etc.

Where or who could rebuild the valve(s)??

Janderso said:

Where or who could rebuild the valve(s)??

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You'll have to look around for a place probably. I was planning to get my valve bodies' bores honed round and straight, then have the spools hard chromed and grind and lap them to fit myself. They need to be pretty close, don't want more than two or three tenths clearance ideally.

Bourne & Koch (Brown & Sharpe is under their umbrella now) might do valve body rebuilds but I don't even want to know what the price would be... I saw some of their prices for simple gaskets and my eyes almost popped out of my head.

Before you worry about that being your problem though, I would recommend going through the way lube system and making sure the metering valves are working correctly. On my grinder several lines were plugged solid. See more here:

https://www.practicalmachinist.com/...s-feed-problem-though-379187/?highlight=Brown

eKretz
thanks for responding. I read all your posts and you have a ton of knowledge. I'm gonna take a photo of a castle nut in the rear of the upright that looks like is for adjusting. not sure what it adjusts.

I've semi rebuilt a few lathes and mills but the hydraulics on this grinder seem pretty intimidating.

RobbyWeeds said:

eKretz
thanks for responding. I read all your posts and you have a ton of knowledge. I'm gonna take a photo of a castle nut in the rear of the upright that looks like is for adjusting. not sure what it adjusts.

I've semi rebuilt a few lathes and mills but the hydraulics on this grinder seem pretty intimidating.

Click to expand...

You should be able to find the hydraulics schematic on vintagemachinery.org.
That's where I found everything I needed for my Micromaster.

Yeah there are manuals available in several places. The hydraulics aren't that complicated once you get into the system and look at the schematics to see how everything's working together. Everything complicated looks intimidating at first, but it gets simpler with understanding. It really helps if you can take the stuff apart and see how it works too. I'm happy to help if I can, I'll keep an eye out for your photo.

Hey eKretz

I appreciate the help and encouragement. I attached 2 photos. One of my machine from the front and another of inside the rear of the upright column. I adjusted the castle nut and it allowed the rapid and the dressing motions to get further to each side but the rapid still sounds like it is not opening the half nut all the way and dragging accross the lead screw. Im wondering if the next step would be to check and see if the high side pressure is enough as maybe that would keep the half nut from opening enough.

Any thoughts or suggestions would be appreciated. Let me know if photos arent visible.

RobbyWeeds said:

Hey eKretz

I appreciate the help and encouragement. I attached 2 photos. One of my machine from the front and another of inside the rear of the upright column. I adjusted the castle nut and it allowed the rapid and the dressing motions to get further to each side but the rapid still sounds like it is not opening the half nut all the way and dragging accross the lead screw. Im wondering if the next step would be to check and see if the high side pressure is enough as maybe that would keep the half nut from opening enough.

Any thoughts or suggestions would be appreciated. Let me know if photos arent visible.

Click to expand...

Hmm, that's a little different than the Series 2. That looks like a bearing locknut, but I'm not sure why there would be one in that spot, there should not be any rotary motion there as near as I can figure. Can you get a picture of what's underneath? That bearing locknut is on upside down as well, probably to make it easier to engage the lockwasher I'd guess. I'm at a loss to explain that one. It looks to be at about the same location as where the cross feed nut should be, but that would be underneath.

Oh, and yes I would absolutely check the system pressures. There should be two relief valves, one for high side pressure and one for low side. On the Series 2 those should be 110psi and 5-6psi, respectively. I would think they'd be similar on Series 1 machines.

as always thanks eKretz. I'll get out in the garage this week and see if I can check the pressures and see underneath the column.

I sincerely appreciate you taking the time to respond and help. work is very busy these days and time in shop is hard to come by.