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rmcphearson
03-19-2012, 06:39 PM
I just brought this back to the shop. It's a Marushin MVA. About 4.5' tall, about 800lbs I guess. X axis travel about 12" give or take a couple. T slots are about .480" wide. Dails are in .002" incriments. Single phase wired for 220. I'm trying to figure out how to wire it for 110 but I don't see any diagrams on the motor.

Three speeds via pulleys but there is an extra set of pulleys that can be changed out. The spindle has about .010" of wiggle. I'm hoping I can adjust the preload. Brown & Sharpe #9 collet system with draw bar, but no way to lock the spindle. I'm looking for a 1/2" collet and 1/2" shank chuck to get started. I need something to drill more than mill but I havn't had any luck finding the right machine and could not pass this up. I will want to trade this for something more appropriate like a Jig borer or 3/4 mill at some point.

If you have any info on this machine or advice let's have it please.

Roland
http://s717.photobucket.com/albums/ww175/rmcphearson/Marushin/

uncle pete
03-19-2012, 07:21 PM
I don't know anything about your mill. In fact it's the first time I've heard ever about one like that. I wouldn't sell it. It's way too rare. Tony at www.lathes co uk. would certainly want pictures of that if it's not already listed. Maybe? Jeff Beck at, tools4cheap.com might have collets that would fit that mill. For it's weight and size that's got to be a real rigid mill.

Pete

Black_Moons
03-19-2012, 08:57 PM
Can't read the text on the motor at all due to how blury the pictures are.

Taking photos too close to the subject results in a less detailed photo then taking a smaller photo further away in focus.

If its speced to use over 10A (2hp) at 240v, you don't want to put it on 120V anyway or you will need to run a new circuit with 12awg wire, as opposed to running a new circuit with 14awg (or rewiring an existing circuit to 240v)

Yow Ling
03-19-2012, 10:44 PM
There was one for sale on the local auction site a couple of months ago

http://www.trademe.co.nz/business-farming-industry/industrial/manufacturing-metalwork/other/auction-446803885.htm

dont know anything about them really, seeing as Im an Induma man myself.

plunger
03-20-2012, 05:08 AM
Looks like a scarecrow:)

rmcphearson
03-21-2012, 11:08 AM
The good news is the spindle brg nut was loose ( not locked). Snugged it up. I took the motor to a motor shop but they can't figure how to jumper it without a schematic, unless they take it completely apart. They can't find a schematic either. GE motor 5KC45PG75EX. 5 amps at 220, 10 amps at 110. 3/4 hp.

The other good news is how easy it appears to take the spindle apart if I want to have the socket ground to a different taper. A very simple and rigid design.

Roland

gcude
03-21-2012, 11:48 AM
Around here, we don't see many mills with the X feed handwheel on the left side.

Alistair Hosie
03-21-2012, 02:19 PM
It's not the prettiest mill I have seen for sure.Have fun. Alistair

rmcphearson
07-13-2012, 07:12 AM
I've been using it recently and holy mackeral these people must have been tiny! I'm wondering how old this thing is because the average user must have been about 4'2". It's sitting on a 1' high crate and I have to hunch over to use it.

Anyway, I got an old palmgren 4" vise that swivels and pivots and that might be why all the chatter when I take heavy cuts in steel. I finally figured out that 2 axis must be locked. (This is all new to me). The whole mill vibrates when I get the chatter because it's just teatering on the crate. The chatter is certainly not coming from the spindle. Anyway, I'm starting to enjoy it and learning a lot.

Roland

Doozer
07-13-2012, 07:24 AM
http://i717.photobucket.com/albums/ww175/rmcphearson/Marushin/P3180001.jpghttp://s717.photobucket.com/albums/ww175/rmcphearson/Marushin/?action=view&current=P3180001.jpg

Does it have a quill?
Kool lookin though.

Looks like a Hobart dough mixer and a Clausing 8520 had sex.

--Doozer

winchman
07-13-2012, 10:35 AM
It looks like there's a stop of sorts on the Y and Z travels with the round thingie engaging the notches on the left side of the dovetails. How does that work?

uncle pete
07-13-2012, 10:43 AM
Roland,
Since you say this is new to yourself, you might try adjusting the gibs on each of the slides for minimum play. That could be another possible reason for having chatter. You aren't climb cutting are you? If those gibs need adjusting, then it's a safe bet the feed screw nuts will also need some work if they are adjustable for minimum back lash. But if your milling in the conventional direction, the feed screw backlash won't have any effect. And yes you need to lock each axis except the one your using.

Pete

legendboy
07-13-2012, 10:50 AM
I would love to have that just because its so obscure. I think its pretty cool

Bob Fisher
07-13-2012, 02:03 PM
Why do I not see a "Z" adjustment handle? I can see Z gibs or dovetails but don't see the means. Looks like a sturdy machine to me! I'd keep it. Bob.

winchman
07-13-2012, 02:22 PM
The Z adjustment is done with the handle below and to the left of the Y handle. Much like a Bridgeport.

I'm still curious about the things that look like stops on the Y and Z dovetails.

That's about the same size as my Swedish Abarboga Maskiner, but it looks sturdier. I can't tell if the head tilts. That's a handy feature.

Dr Stan
07-13-2012, 04:37 PM
Looks like a Hobart dough mixer and a Clausing 8520 had sex.

--Doozer

Now that's funny. :D

BTW stout lookin' machine for its size. You may also want to try Anderson Tooling http://www.usedtooling.com/home.php for collets, etc. No affiliation other than being a customer.

rmcphearson
07-13-2012, 07:03 PM
It looks like there's a stop of sorts on the Y and Z travels with the round thingie engaging the notches on the left side of the dovetails. How does that work?

The round thingie below and near the right side of the table? I don't know but it goes round and round as I turn the Y handle. It's driven by a pinion gear that engages a rack under the table. It's got 4 tapped holes 90 degrees apart on it's od.

No quill and the head does not tilt.

rmcphearson
07-13-2012, 07:11 PM
You aren't climb cutting are you?

Pete
I don't know the exact definition of climb cutting but I think I understand cutting against the backlash. I snugged the gibs but I don't know if the feed screw nuts can be adjusted. there's about .020" of backlash.

I quickly burned up the bottom of my endmill. Got the rpms way down and when I use the side of the endmill which is still sharp to mill the edge of a piece of 3/8" angle iron I'm still getting some chatter as I feed it into the endmill. I think my rpms are way too slow now. This is frustrating because I am actually trying to make some things that I need and learn at the same time.

Thanks for the help.

Dang I'm getting tired of hunching over! I need to make a base but have too many other things going on.

uncle pete
07-13-2012, 08:52 PM
LOL, Well you may want to change your user name to Quasimoto or the Hunchback of Notre dame. It's good to keep your options open. You are going to need to build a fairly short but very heavy duty stand for it.

That rack and pinion feed makes me think it was an optional item that could be ordered for light production machines much like the Atlas Horizontal mills. I'd personally doubt it was the normal standard issue. But I've been wrong multiple times before.

Climb cutting is where the tool starts out at the full depth of cut per revolution and sweeps out to the minimum of cut. Conventional milling is just the opposite.

There's many diagrams all over the net that will explain it far better than I can describe it. You made it here and were able to join this site, so there's no real need for me to hold your hand for something you can obviously Google yourself. Simply plug in "conventional and climb cutting on a milling machine" and you should get a few decades of reading.

Looking directly down on your milling head, the spindle and cutting tool should be rotating clockwise. Let's say the part your milling needs to be started at the front or closest edge towards yourself. Due to the spindle rotation, you'd want to start your cut from the front left hand side and move the X axis from left to right. That's conventional milling. Climb cutting is just the reverse and it can be done. But it requires a machine in almost new or at least in very tight condition with the slide gibs and feed screw nuts to be very well adjusted for minimal play and backlash, yet not adjusted so tight it puts excess wear on the machine due to drag on the equipment from everything being adjusted too tight.

Climb cutting will pull the work into the cutting tool by the amount of backlash your feed screw and nut has unless the table and workpiece weight and the drag on the slides exceeds the cutting tool forces. Conventional milling will keep the feed against the flank of that feedscrew so the cutting is constant. Climb cutting can work in your favour, but you need to gain enough experience with conventional milling before you start playing around with something that may or may not work on your mill just due to overall wear on the slides and feed screw adjustments.

Your vice as you mentioned may also have some or all of the effect for what your experiencing right now with the chatter. As I mentioned before, your slides and feedscrew nuts need to be well adjusted before a fairly inexperienced person can definately pinpoint that it is in fact the vice that's the totall cause of the problem. Offhand? I'd think it is. But I wouldn't ever bet on that fact. With machining, each and every one of the problems need to be dealt with before you can specificly say exactly what solved the issues. Machining can be an absolute bitch that will make you tear your hair out at times. Other times? It (LOL) has the odd few seconds where everything goes as planned.

Pete

rmcphearson
07-13-2012, 09:21 PM
Thanks uncle pete. I did a little reading and confirmed that what I was doing today was conventional milling with the side of the endmill and still got some chatter. I'll try clamping something directly to to table next and see how it goes.

winchman
07-14-2012, 01:33 AM
Well, that makes me even more curious. I hope you post more info about that feature as you start working with the mill.

Has anyone seen anything like that on other brands of milling machines?

DFMiller
07-14-2012, 11:46 AM
Rack and pinions and stops are used for "production Mills"
My little Barker PM came with them and no leadscrews. I am in the process of adding the leadscrews. It was an option on the Barkers but the spares from the factory are very spendy.
A production machine is intended to be set up for one operation at a time.
Set the stops then push and pull the levers.

Nice looking little machine.
Dave

winchman
07-15-2012, 06:41 PM
In looking at the picture again, I just realized that the notched pieces are gibs that move along the dovetails. Roland said earlier that the rod with the disc on it is driven by a spur gear off the leadscrew.

It's now obvious that it's not a travel stop at all, but I can't see any advantage to having the gib set up that way.

Has anyone seen this before, and can you explain how it works?

Arthur.Marks
07-15-2012, 07:22 PM
The gib for the knee looks normal to me. How else is it done? Either the gib is affixed to the knee or it would be affixed to the base column. The latter would need a very long gib only held tight to the dovetail for the length of the knee engagement. That would be less than a third? of its length---prone to all sorts of muck getting between the gib and the dovetail, then. Also much harder to grind flat a thin gib so long. The screw holds position of the gib by having a slot in it that an adjustment screw collar fits into.

winchman
07-16-2012, 12:02 AM
All the gibs I've seen have a taper on the outer side that fits against a taper in the part that moves. The length of the gib is about the same as that of the moving part, measured along the dovetail. They're secured with an adjustment screw that controls the engagement of the tapers to make the sliding joint tighter or less tight.

It appears these gibs are positioned by the curious round pieces on rods that rotate as the leadscrews are turned. What isn't clear is how that adjusts the position of the gib to control the tightness of the dovetail joint.

Arthur.Marks
07-16-2012, 12:29 AM
Naw, I think you misunderstood. The thing that rotates round 'n' round as the leadscrew is turned is the big blue circle on the right of the knee under the table. The Y-Axis gib is on the left side dovetail when facing the machine. The big blue circle thingie is on the right. The column gib is also on the left. Both gibs look completely normal and as you describe to me. The screw has a collar that engages a slot cut into the gib. This is how it adjusts position (tightness/looseness). It looks like there are two slots so as the gib wears, you can change to the farther out slot to gain more adjustment. That part is a little unusual, I'll admit. Still works the same. The gib for the table must be adjusted from the left, but it is not seen in the pictures. The one underside of the table is from the right of the knee, and you can see the flat end of the gib in the dovetail. The rack and pinion is what drives the blue circle thingie.

winchman
07-16-2012, 07:04 AM
Thank you so much. I just overlooked that Roland's response in post #17 was talking about something on the other side of the table. It was downhill from there.

Those gibs probably have very slight tapers, and the slots let you take advantage of it without having a long adjusting screw sticking out.

Makes a lot more sense now.