Yet Another New Burke #4!

Glenn Brooks

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hello all,

Just picked up a great little Burke #4 Mill at an estate sale today! Very cool little machine. It seems to have been in partial restoration in a past life as the lead screws and bearings have no discernible play in them, and the paint is in good shape.- very good shape actually for a build date of 9/1942. It also has what looks like a vertical attachment, and a new, uninstalled Delta 1 hp 110/220 motor, in addition to the original Master gearbox motor, three new, store bought arbors, and a brand new B&S #9 US MADE Tapered reamer. I did not recognize the vertical attachment or the arbors as such until I brought it home- (the machine is disabled and in pieces).

I do have two questions.

1) Master gear drive motor- the motor makes a scratchy metal on metal bearing noise on the Edge of the motor end of the motor/gear box assembly, when I turn the drive axle by hand. So it sounds like a bearing on the end of the armature shaft is gone.

So, my question: Do you think this motor is worth trying to repair - maybe with a new bearing?? Or should I just discard and figure out how to install the Delta 1hp motor that the prior owner purchased ( with the apparent intent of replacing the original Master )?? If so, is a 1 hp replacement motor to much horsepower for the drive chain???

2) collet availability: there are no collets with the machine. Would these be B&S #9?? Are they rare/unobtanium??

Thanks much for any info anyone could provide .

regards
Glenn image.jpg image.jpg image.jpg
 
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I don't have a Burke #4, but I do have a Burke Millrite, and am a member of the BurkeMills Yahoo group. The #4 definitely has a Brown and Sharpe #9 taper spindle unless it has been modified. Collets to fit are available on Ebay fairly cheap, more pricey than import R8 collets, but less than a lot of other collets. You probably do not need a whole set, at least to start out. 3/8, 1/2, 5/8. and maybe 3/4" should be enough. You can also get a B&S #9 to #2 or #3 Morse taper adapter to use that tooling as well. A ER collet set could also be adapted to the machine pretty easily, You do need to watch out for running out of headroom due to adapters and excessively large tooling stickout. I recommend that you join the Burke Yahoo group:
https://groups.yahoo.com/neo/groups/BurkeMills/info
Please stay a member here as well. This is a very useful and friendly site! Nels, the site founder, has a #4 Burke.
 
Thanks Bob, good to know! I think I did just join the Burke site on Yahoo- at least I signed up, sort of, but can't see the conversations. So maybe awaiting moderator approval.

I will look for maby a 1/2" and 3/8" collet on eBay, as you suggested. Come to think of it, the machine came with a 3/4" end mill holder - brand new I think. It's the kind that holds the end mill with two set screws on the collar.

Can't wait to try out horizontal milling! Should be lots of fun after my good ole Grizzly bench Mill/drill.

Cheers
Glenn
 
I am going to paraphrase the responses you got on the Yahoo group, without the rabble:

Some Burke #4s have a Master type RA 3/4 HP single phase 110 volt gear head motor. Mine is 220/440. This motor is a repulsion-induction type motor, which reverses its direction by shifting the brushes. The rear bearing on the motor appears to be a sleeve bearing, as it has an oil "cellar" (a kind of reservoir for lube oil set below the level of a bearing). First , check if there is any oil in gear case. There are some screwed plugs on the gear case. The Master gear head motor on a Burke number 4 mill is usually mounted on a bracket that Burke furnished with the milling machine. This bracket bolts to the mounting feet on the motor. The result is the motor and gear case are oriented so the mounting feet are at some angle rather than level or nearly so. Start by removing the plugs on the gear case and seeing if any oil is left in it.

The rotating element in an AC motor of this type is referred to as the "rotor" rather than "armature." The rotor has two bearings - one is at the tail end, and is mounted in the end-bell of the motor casing. The front bearing may well be set in the front wall of the gear case. The pinion of the reduction gearing may be machined on the rotor shaft. This is an old-style gearhead motor, where the motor and gear case have to be assembled together since there is no front end-bell on the motor. The rotor shaft with its pinion gear passes thru a clearance hole in the "bulkhead" on the gear case. This bulkhead separates the gear case from the motor casing. A slinger (disc) on the rotor shaft is fitted to prevent any of the oil in the gear case from migrating into the motor casing. No oil seal used. The rotor shaft/pinion has a front journal that is supported in a bearing in the front wall of the gear case.

Check for oil in the gear case if you are hearing squealing, and if none is found, fill initially with diesel fuel or kerosene and run for maybe 3 0 seconds, then drain. This should flush out any sludge and get the kerosene worked up into places that have not seen oil for some years. After draining the kerosene, fill with oil. For light duty, and getting slung up to lube possible sleeve type bearings, use an ISO 68 oil, and maybe add a little Lucas Oil Extender. This is an additive sold in automotive stores. It has tackifiers, and causes the oil film to "stick" to gear teeth a bit better.

It is possible that the noise you are hearing is the centrifugal switch inside the motor. This is a switch that energizes the start windings (in single phase motors) so the motor will start turning when it is turned on. This switch will open the start winding circuit when the motor reaches about 3/4 of its rated RPM.

It is composed of a rotating piece (mounted on the rotor shaft) with counter-weights that mechanically overcome spring tension when the motor reaches a specific RPM. This usually involves a rotating ring (which is part of the centrifugal starting device) that is in physical contact with a stationary set of contact points. Hence, they are rubbing against one another until the motor reaches an RPM that causes the centrifugal weights to pull the contact ring away from the switch and break the start winding circuit. If you can, plug the motor in and see if the squealing stops when the motor spins up to speed. If you are in doubt, take it to a motor shop and ask them about the noise.

The ISO 68 oil is still thin enough to lube sleeve type bearings and won't hurt older bronze bearings. Get some oil in the gear case and tail bearing of the motor, if it is a Master type RA 3/4 HP single phase 110 volt gear head motor.

Do not be too quick to discard that Master gearhead motor. Clean it, lubricate the gear case and tail bearing, and see if it quiets down. If not, it can be rebuilt.
 
Thanks Nels. I just read the replies on the yahoo group also. Great info and sound advise. Thanks for posting the info here also. You are right, the yahoo groups format is very hard to follow and participate in.

Glenn
 
I too have a no 4 and she is all original except for new bushings. I do like this little mill, very fun to use. I have the original motor with the gear case as well and it works just fine. A lot of people change out the motors on these for whatever reason. Mine works well so I leave it alone. If I ever had problems with it though I wouldn't have a problem changing it out, maybe a 3 phase with a vfd, just because it is so versatile. Or a dc treadmill motor with a controller. But for now if it aint broke I aint gonna fix it. The vertacle attachment is getting a little hard to come by and is very desireable. It takes a 3c collet, mine works well. Get yours put back together and tuned up, she will serve you well, great little machine for the hobbiest, it thinks it's a bigger machine than it is.
 
There is a rehab here by RMack that is stickied. Also, Mick Finch did his, and I'm pretty sure I have it.

I didn't restore mine, but it is fully assembled. So if you need to see assemblies, I can take pics.

Problem with the Yahoo group - they spend 5 mins answering your questions, and hours showing off how much they know .
 
I have stickied the rehabs and some other posts . Hope they are of help.
 
Thanks Nels, I read through the stickies. Very useful.

I've got the Burke mostly cleaned and painted and ready to reassemble. Still,sheetrocking my shop so no room at the moment to install it. It's spot is stacked with tools and junk from the area I cleared to put up the insulation and rock. Takes twice as long for mud to dry due to cold temps...

Also, on the plus side, I plugged in the motor and turned it on. Runs perfectly in forward and reverse. No oil in the case however.

So question: how much oil should one put in the case? (this is the original 110v gear head motor from master)

I seem to vaguely recall someone, somewhere, cautioning about not overfilling the case... But can't remember if this caution relegated to a Burke, or Van Norman.

Thanks
Glenn
 
Just now reassembling the Burke #4... Waited way to long to put the pieces back together...

Can anyone say what these three round pieces do? Actually I've only installed one, as shown in the attached photo. I have two more identical pieces that fit below the one in the photo, on the remaining two cap screws.

They appear to be a cap nut or locking nut to put tension on the cap screws that hold the vertical table to the main column. If so, is there any special adjustment procedure, torque pounds/method to tighten - adjust the vertical table???
It's all very mysterious to me as these parts don't show up on the Us Army Burke parts list or operators Manuel.


Per the photo the one I have reinstalled is about 1 1/2" long x 1" diameter , drilled lengthwise to accept the cap screw as it exits the table casting. There is a small ( > 1/8") set screw in opposite end with unknown purpose, and a 1/4" hole drilled cross wise thru and thru, which I assume is used to hold a 1-4" rod to assist in tightening/turning the end cap.

Thanks
Glenn

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