No.3 Moore Jig Grinder

Anyone extensively experienced with these machines? we have one in our grind division of my shop (mint condition) and nobody knows howto use it, ive got all the levers and such figured, just wondering actual grinding / setup techniques. As well, the automatic down plunge feed seems jumpy on the way down but not up. Any help would be grateful. thanks

I worked in the jig grinding room at Dayton Reliable Tool from 1982-'85 (we had over 60 #3's in varying configurations then). I still have a couple of friends running jig grinders there.

The easiest way to figure out the problems you're having would be for you to send it down to me and I'll let you know. Seriously, jig grinding is an art. Newbies had to start by grinding holes for a year before they were trained to do contouring (manually)and then jig milling. In the early '80s all we had were stone wheels and then the borazons and diamonds started coming into play. I can tell you that no matter what speed head you're running, wear ear protection!

I've have no way of diagnosing the jumpy feed, but these machines use a LOT of velocite 6 oil, and you better have a good air dryer. I've attached a photo from DRT's website showing an example of the type of contour and milling work that used to be done there on jig grinders, now done on Makino's for cost efficiency (and there's very few left that know how to manually jig grind/mill). It is a simple machine to operate when you understand the basic operation and the part geometry required.
photo

I don't know of any books on jig grinding, I know a lot of shops here in Dayton really benefitted from all of the training ex-DRT employees took with them when DRT laid off 300 people between '96 and '98. But I digress. -Mike

well, what i wanna know is, am i just treating the setup like a boring job on a mill ? indicator to find my hole fine tuning the depth of cut and im just using stones for now so what air pressure is good because i dont see any rpm guages. by the way i'll only be using the machine for mainly boring simple holes which we dont trust a reamer to do. its a plain grey colour i see lots on ebay which are the same. but with the feed: it goes down real jumpy and faster then it comes up. the machine is hooked up to our shop airline, dont think theres a vapor seperator.as far as i can tell its in mint condition. I'll try and snap some pics of it.

Jones'R,

Your setups are only as limited as your imagination and resources. I always preferred setting up on a rotary table (easier alignment and it brought small parts up closer to me), but a good set of parallels and t-slot clamps work well too. Your RPM's are determined b your air pressure settings. There were 3 different RPM heads, a 40,000, 60,000 and 100,000. 40K head was black and kind of cylindrical, 100K head was silver and cylindrical, the 60K head was standard and started out about 2 1/2" in dia. at the bottom and ended up about 6 1/2" at the top with large radiused sides.

Your air pressure working range for each head is 40 psi at the low end, 60 psi at the high end (for most grinding applications). 60 psi for stone wheels for sure. Prior to dressing the sides, use some carborandum to dish the bottom of the wheel so there will be a sharp edge on the sides. Dress your wheel with a diamond, preferrably held in a magnetic v-block (to keep it ridgid). After the wheel is dressed cylindrically, relieve all but the last .1" at the end so you're only grinding with that small amount of wheel surface contact. Set the spindle for length of stroke with the 2 small knobs above the handwheel on the right. Use your T-handle allen wrench to adjust the air head so the wheel is just barely touching the side of the hole then switch to the graduated feed on the top of the machine to control size. Flip the lever on the panel to start the head running, press the button to start the oscilation of the head and the other button to start your stroke. Starting out, limit yourself to about .002" feed and let your wheel spark out before taking your first measurement. I used Starrett small hole gages and a good micrometer to get close, then switched to Deltronic pins for final fit. There is a whole lot more to consider as far as positional accuracy and alignment but I'll assume that you already have that covered. I'd be getting a dryer in the air line for this machine, those heads used to be several thousand dollars to have the bearings replaced. I haven't jig ground since 2000, but if you have any specific questions, fire away. -Mike

The jumping that you see in the auto feed is from air on one side of the piston in the cylinder. Be fore you can bleed it you must fill the tank or youll just let more air in. Like brakes on a car.There is a big box on the right side of the machine,the shop air goes into it.Should be a regulator knob, a little glass window and a pressure gauge. Keep the oil about in the center of this window. To fill it shut off the air and remove the knurled knob at the top of the window pump oil in with a oilcan till the level is right.The regulator knob adjusts how neutral the handwheel is while you are grinding.(The handwheel is the steering wheel looking one,the spiderwheel is the four levered one that raises the whole quill housing).Lower the head with the handwheel a couple inches and turn the regulator knob in,the pressure on the gauge by the little window should go up and the head will begin to rise on its own. Adjust this knob until the handwheel stays where you leave it. The handwheel should feel the same in either direction. To bleed air out look at the top of the quill housing where all the hoses go from the base to the quill housing. With the handwheel raise the head up and down and youll see a shaft about 5/8 or 3/4 in diameter that goes up and down with the handwheel,its up at the top by the hoses.On the end of it is a knurled knob like the one by the little window.This is where you bleed out the air. Set the feed at full stroke (3 5/8 travel)and a reasonable speed and loosen the knob about a half turn,you should get air then oil.tighten the knob and run it some more.Do this over till the feed smooths out.If this doesnt fix it there may be another problem,valves sticking etc.As far as I know there were only four grinding heads made for the #3 (not including the slot grinder).The smallest and fastest holds a 1/4 shank and runs 60,000 at 100psi. The 1h.p. head is the most common. It holds 3/8 shanks and runs 40,000 at 100psi and 25,000 at 60psi. After that there is one that is 12,000 at 100psi it has actual collets that you can change and some quills that fit in there place. Youd think this one would be the handiest but its really loud and just has no power. You can hear the wheel slow down when you dress the wheel. Other than the normal safety stuff there is only three things to caution you about.#1 is wheel overhang vs wheel speed. Start a new wheel out at about 40psi dress it, norbide it, and get it running true. A little faster,dress some moresneak up on it. Ive seen guys stick a new mounted wheel in and fire up at full speed ,the shank bends at 90 degrees,destroys the motor and sounds like a helicopter.#2 When using the feed set the stop on the left side of the head to the end of the stroke.The trip lever by the hand wheel overides the micro switches you set the stroke length with so if the solid stop is 1 inch below it will go right past it.#3 There is a big counterweight in the column that helps you raise the quill housing with the spider wheel.Its connected with a peice of roller chain you can see up by the air bleed plug. Should this chain break the spider wheel freewheels and the quill housing and this big counterweight drop at the speed of light,this will ruin your day,inspect the chain,they wear out.Good luck.

ok, i'm definately getting a hint here, how about positioning, locating, etc. I dont have a DRO right now, but lets say i did. I'm shooting in the dark here, but would i rig up an edge finder ? how would i get to an exact location, i think this is one of my last questions so far..p.s. what is a good oil to use

these machines use a LOT of velocite 6 oil

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What do you want to use the oil on? The nameplates on the grinder tell you specifically what oil to use in each resevour. Velocite6 and Vactra2 are Mobile Oil products. You will not be using any oil or cutting fluid for the grinding operation itself. Grind it dry.

There is a whole lot more to consider as far as positional accuracy and alignment but I'll assume that you already have that covered.

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My mistake. Get yourself a good .0005" horizontal dial indicator and an indicol that fits your spindle to hold it. Use the indicator to align the part and find the edges to set zero. -Mike

Ive been told by several different Moore feild service guys that it takes at least 12 months to make the screws that are in your #3. The owner has the one I run serviced at least every three years. This machine is at least 25 years old and runs an average of 25 hours a week. About a year ago Moore did a table positioning check on it to check the accuracy of the X and Y screws. I watched the procedure and the worst area was right in the middle of the Y travel, there was a 60 millionths error. DRO? You dont need no stinkin DRO. Grind a hole to a known size,then crank the table off 6 or 8 inches each way, ink up the hole with a felt pen and dial back to the same numbers. You can take the ink out and not change the hole size a bit.

The shaft on the top of the grinder which has the bleeder screw has air and oil slowly leaking through, i am guessing this isnt normal, as i have tried numberous times to bleed the system but still can not get a smooth up and down feed..

Moore puts out a good little book on jig grinding techniques. They have illustrations of making a die for the old "Gillette" razor blades, with all the little contours. For precision and versatility, they can't be beat. You can hold .000050 all day. I ran one in the mid-70's for an electronic company.
<Off Topic>They told us that if we didn't take a pay cut they would have to send manufacturing to Asia. So we accepted the pay cuts to keep our jobs. Then they sent everything but the sales dept to Asia.

The manual has a lot of really useful info on troubleshooting the auto feed. It is one of the few manuals I have seen that is written by guys who work on the machines for guys that are working on them. Shouldnt be hard to find. Moore put out a few different books on metrology,machine habits,etc. You want the manual for a #3 jig grinder of your type. Get the wrong book and you will read 3 chapters on how a screw works.

"...Get the wrong book and you will read 3 chapters on how a screw works...."
LOL BTDT!

WA Toolman:

In my apprenticeship, the journeyman that ran the jig grinder made me read that book and the other one before he began to train me on the jig grinder.

I loved that machine. We have an NC now. Not as much fun, but easier to run.

The spindle feed mechanism is a air over oil system. Air provides the feed power, oil provides a controlled leak down for speed control.Make sure you have bled the air from the system completely,it may take a few tries.The air drier is very important.If that does not work you may have to change out your packings. What i have found on high time machines is that the bores on the air cylinder and the two oil cylinders become highly polished which produces a high amount of drag.The same holds true for the piston rods.I hone out all three cylinders on a Sunnen hone, just enough to get a 45 degree cross hatch.It only takes a few tenths,do not get carried away.You just want to remove the glaze.I put the piston rods in a lathe and using 400 emery paper polish the od's trying to get a 45 dgree crosshatch on them also.If you change out the packings use only wood or plastic tools to remove the packings from their bores.Be carefull, no nicks on anything.Replacement parts are unbelievably EXPENSIVE.Make sure the spindle counter balance is properly adjusted. DO NOT keep making your set up on the exact center of the table. Try to make your set ups on different quadrants of the table to prevent localized wear of both screws.Oil the machine first thing every morning, oil the quill again at noon (Moore calls it the slide).Oil is cheap.

Tram

split tenth said:

The spindle feed mechanism is a air over oil system. Air provides the feed power, oil provides a controlled leak down for speed control.Make sure you have bled the air from the system completely,it may take a few tries.The air drier is very important.If that does not work you may have to change out your packings. What i have found on high time machines is that the bores on the air cylinder and the two oil cylinders become highly polished which produces a high amount of drag.The same holds true for the piston rods.I hone out all three cylinders on a Sunnen hone, just enough to get a 45 degree cross hatch.It only takes a few tenths,do not get carried away.You just want to remove the glaze.I put the piston rods in a lathe and using 400 emery paper polish the od's trying to get a 45 dgree crosshatch on them also.If you change out the packings use only wood or plastic tools to remove the packings from their bores.Be carefull, no nicks on anything.Replacement parts are unbelievably EXPENSIVE.Make sure the spindle counter balance is properly adjusted. DO NOT keep making your set up on the exact center of the table. Try to make your set ups on different quadrants of the table to prevent localized wear of both screws.Oil the machine first thing every morning, oil the quill again at noon (Moore calls it the slide).Oil is cheap.

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Ok I've read that I can get a 1-1/2 deg tapper with my moore #3 I would like to set up the grinder fore zero deg. I see the mark and the 2 set screws I need to move around.so do I set my indicater in the spindle were my grinder wheel would be or on the out side of the spindle on the grind side?Man I wish I had that book

"Holes Contours and Surfaces" Written by the Moore Special Tool Company. Covers Jig Grinding. Call them they should have copies. You'll have to research who they are now, but I believe they still have the books.

Regards,

Stan-

Do you still need the book. I have several copies.

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The company I work for is having a Retirement (going-out-of-business) Sale after 38 years and liquidating their entire machine shop. Lots of SOLID equipment with plenty of life still left in them including this SWEET Moore Jig Grinder (Lot # 111); they don't make them like this anymore! Know anyone with a need or room to give them a second lease on life? Someone please save it from going to the scrap-yard!

MOORE JIG GRINDER MODEL NO. 3 SERIAL G1197 You must use our Rigger - Rigging Fee $300.00