Resources for working on BP with noisy vari-speed head and non-functioning oiler?

Feel free to skip down to the fourth paragraph below if you want to cut to the chase, but if you want the background, read on: I have just acquired a Bridgeport Series I with the 2J2 head (2hp, vari-speed), vintage 1972. Condition was acceptable - reasonable wear but not much backlash; some rust from sitting unused; the DRO mostly worked (one cable had been pinched and kept one axis from working, but I've already fixed that), and the power X-axis feed mostly worked (a little unreliable at the slowest speeds - I'm hoping that's just a matter of cleaning or replacing the potentiometer).

BUT - because the seller does not yet have 3-phase power, I could not hear the head run before purchasing. (He is a welder, wanting to get into some machine work on the side, and bought a bulk lot of machines from Purolator; this was one of the two mills he bought.) On the plus side, the price was right - $1500, which included delivery and rigging (!!!), and he is a friend of a very good friend, so I felt comfortable moving ahead with it.

I finished putting together an RPC last night and fired up the mill. The head is noisy, rattly, especially at higher speeds - but I was not too surprised, since I understand that this is a common issue with these vari-speed heads. I've put together a 3-minute YouTube video that shows the mill and includes the noisy head if you want to take a look/listen: BP - YouTube

So here are two questions (actually three - 1a, 1b, and 2): 1) I am already searching through old forum threads and YouTube videos and other internet info on what is involved in digging into the head. But a) I'm overwhelmed by the sheer number of posts/videos/etc., so I'm wondering if anyone can point me to the most reliable and/or helpful resources, and b) particularly if you watched the video, it is most likely to be the plastic sheave on the output side, or on the motor side, or is it likely to include a bad bearing, or ??

2) Not mentioned above, but noted in the video, I'm not seeing evidence that the single-shot oiler is succeeding in putting out any oil. Obviously my first step will be to see if the pump itself is working, but I'm guessing the more likely culprit is clogged up lines, or even more likely clogged up metering valves. From the manual I found on line, it looks like the distribution block and metering valves are in the knee. Do I have to take the table off to get to that, or is there another way to access it. (I can't see any other way, but there's always hope ...)

On the plus side, even with the noisy head, and even before I've trammed the head, I tried a couple of test cuts, and I can tell that this is going to be a VAST improvement on my unmentionable previous mill. The spindle seems to be nice and smooth. I do need to make some adjustments on the head controls, but I believe everything works.

No doubt I will have further questions as I put this mill into working order ... thanks for any advice, help, resources, etc.!

The top end of the mill can be apart in about 15 minutes.
Noise usually starts with belt wear-and that translates into an out of balance problem that beats up the plastic sleeves.
Plan to replace the belt, sleeves and keys for the front disc and the motor disc.
Compressing the spring on the motor is not difficult provided you have a competent helper and the correct snap ring pliers.

The risk of running the mill without tearing it down: none to serious. No risk and not because the mill is bullet-proof. It may be in an early failure stage.
Serious risk if the wear to the plastic sleeves is so bad they wear to the point of metal to metal contact especially with the motor shaft. Shaft scoring means replacement parts.

Bearing noise may be undetectable. Check the top bearing cartridge where the drawbar is inserted. If after running the mill for ten minutes or more and the top surface of the cartridge is uncomfortably warm plan to replace this bearing. The two bearings in the cradle housing can be inspected at teardown.

It might be a nice video but generally I do not watch them. Too many bad ones out there and it feels like I was playing Doom and have vertigo-barf syndrome.
Was a maintenance machinist for years so a heads up is that these mills are easier to work on if you down load a manual first and skip the video chefs.
John

http://bridgeport.askmisterscience.com/bridgeportlit.htm#1

jhruska said:

The top end of the mill can be apart in about 15 minutes.
Noise usually starts with belt wear-and that translates into an out of balance problem that beats up the plastic sleeves.
Plan to replace the belt, sleeves and keys for the front disc and the motor disc.
Compressing the spring on the motor is not difficult provided you have a competent helper and the correct snap ring pliers.

The risk of running the mill without tearing it down: none to serious. No risk and not because the mill is bullet-proof. It may be in an early failure stage.
Serious risk if the wear to the plastic sleeves is so bad they wear to the point of metal to metal contact especially with the motor shaft. Shaft scoring means replacement parts.

Bearing noise may be undetectable. Check the top bearing cartridge where the drawbar is inserted. If after running the mill for ten minutes or more and the top surface of the cartridge is uncomfortably warm plan to replace this bearing. The two bearings in the cradle housing can be inspected at teardown.

It might be a nice video but generally I do not watch them. Too many bad ones out there and it feels like I was playing Doom and have vertigo-barf syndrome.
Was a maintenance machinist for years so a heads up is that these mills are easier to work on if you down load a manual first and skip the video chefs.
John

http://bridgeport.askmisterscience.com/bridgeportlit.htm#1

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Many thanks, John. That 15 minutes for you will probably take me 5 hrs , but still encouraging to hear that it could be this quick. Question about weight issues: do you remove the motor first? Do you remove the head entirely, or just parts of it? As you can see, I'm still a little unsure exactly where to begin.

And as for the movie - it's not exactly Oscar-worthy, so I don't think you missed too much!

Sent from my SM-T230NU using Tapatalk

My go to for Bridgeport parts is High Quality Tools:
High Quality Tools Inc. - Milling machine replacement parts, machine tools, end - MILLING MACHINES - SERIES I

H&W is good also:
H&W Machine Repair & Rebuilding - Parts and Service for the Metalworking Industry

You can rebuild the head in place if you don't mind standing on the table. The motor has to come off to do much of anything; do you have the parts and service manual? They outline a procedure for freeing the vari-drive from the belt that quite frankly, I've forgotten.

I believe on my mill I can reach the Bijur distribution block with the table in place, but there will be no easy way to flush the lines. Pull the table and the job becomes much easier. Buy new meter units, even though they are expen$$ive. Cleaning the old ones rarely works.

Dennis

H&W is the place I use. they have made their own videos covering a lot of the work needed on the Bridgeports... H&W Machine Repair and Rebuilding
- YouTube

On my mill, the manifold is attached to the saddle. It's fed by a rubber hose. The oil reservoir is on the knee. There are no metering valves inside anything. Disconnecting the metering manifold from the machine Mackey it easier to disconnect the lines. I used a proper flare nut wrench, but I'm sure others don't.

These oilers are super expensive. Before you tear it apart and rebuild it, see if it works by disconnecting the lines in a few strategic places and pumping it the lever to see if there's flow. The metering valves only allow a tiny bit of oil thru. It might be working fine.

Thanks to @modelman and @swatkins for the love, totally appreciate it.

I am not a head rebuilder, but if you wanted to call and talk to Barry (our owner and head rebuilder), he wouldnt mind walking you through anything on the head. We offer free phone support and he can definitely help diagnose/walk you through any part of the machine you need.

800-285-5271

Jon
H&W Machine Repair

Many thanks, Jon - I had already bookmarked H&W, and I will be looking at the videos as soon as I get a chance. I'm definitely feeling more confident about digging into this, and no doubt will be headed your way before long for new bushings and belt. (Hopefully I won't need any new bearings as well, but we shall see ...)

AdamC said:

These oilers are super expensive. Before you tear it apart and rebuild it, see if it works by disconnecting the lines in a few strategic places and pumping it the lever to see if there's flow. The metering valves only allow a tiny bit of oil thru. It might be working fine.

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And therein lies the problem. This system is designed to have the lube points "daisy chained" along a single supply line. The meter units limit the amount of oil that comes out at any one point, so others further down the line get their share. Typically the meter units are right at the lube points.

Bridgeport sets their system up as a parallel system, with all the meter units on a single manifold, and "tail pieces" to then take the metered oil to the lube point. Some of these tail pieces are 18" long. It will take about 972 strokes of the pump for the drop of oil from the first stroke to come out the other end of the tube. There is no flow to keep the line clear. If the oiler was allowed to run dry and the line plugged with a mixture of dust and coagulated oil, it will never clear; the oil will just go elsewhere.

I would disconnect the hose from the pump and confirm it really does pump oil. Clean the bowl, and the suction filter on the bottom of the pump.You can then check if the meter units are working by disconnecting the tail piece lines from the meter units... tag the lines to put them back in the same order, as all the meter units are not the same; they have different flow rates.They are marked with a number, from 00 to 5 IIRC. You want the lines from different points back on the same flow rate meter unit. Any meter unit that doesn't pass oil, replace it with one of the same number. You can try flushing it with solvent, but I've never had much luck.

Now you need to confirm the tail tubes are clear, and this is much easier to do if the table is off, saddle too, for that matter. Bridgeport didn't bother to use threaded connectors to terminate the tail pieces, but instead used the "drive bushings" Bijur sold for use in limited space applications. You can sometimes pull the tube out of these, but then there is no guarantee the tube will stay in after reassembly. Bijur sold a tool for installing these; you could make one by grinding a groove the length of a center punch, but it's better if the tubes don't pull out in the first place.

http://www.bijurdelimon.com/fileadm...s/Datasheets/2900_B_ACC_Bijur-Tools_DS-R1.pdf

Dennis

awake said:

Many thanks, Jon - I had already bookmarked H&W, and I will be looking at the videos as soon as I get a chance. I'm definitely feeling more confident about digging into this, and no doubt will be headed your way before long for new bushings and belt. (Hopefully I won't need any new bearings as well, but we shall see ...)

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They sell a Kit that has everything you need for the upper head Bridgeport Rebuild Kits At 290.00 its worth it to just replace all the items at once and be done with it.. I only wish I had bought the bearings for the motor and did those at the same time. They are cheap and easy to do while you have it tore down. The motor bearings support one of the variable pulleys and there is a lot of side load on them.

Modelman said:

And therein lies the problem. This system is designed to have the lube points "daisy chained" along a single supply line. The meter units limit the amount of oil that comes out at any one point, so others further down the line get their share. Typically the meter units are right at the lube points.

Bridgeport sets their system up as a parallel system, with all the meter units on a single manifold, and "tail pieces" to then take the metered oil to the lube point. Some of these tail pieces are 18" long. It will take about 972 strokes of the pump for the drop of oil from the first stroke to come out the other end of the tube. There is no flow to keep the line clear. If the oiler was allowed to run dry and the line plugged with a mixture of dust and coagulated oil, it will never clear; the oil will just go elsewhere.

I would disconnect the hose from the pump and confirm it really does pump oil. Clean the bowl, and the suction filter on the bottom of the pump.You can then check if the meter units are working by disconnecting the tail piece lines from the meter units... tag the lines to put them back in the same order, as all the meter units are not the same; they have different flow rates.They are marked with a number, from 00 to 5 IIRC. You want the lines from different points back on the same flow rate meter unit. Any meter unit that doesn't pass oil, replace it with one of the same number. You can try flushing it with solvent, but I've never had much luck.

Now you need to confirm the tail tubes are clear, and this is much easier to do if the table is off, saddle too, for that matter. Bridgeport didn't bother to use threaded connectors to terminate the tail pieces, but instead used the "drive bushings" Bijur sold for use in limited space applications. You can sometimes pull the tube out of these, but then there is no guarantee the tube will stay in after reassembly. Bijur sold a tool for installing these; you could make one by grinding a groove the length of a center punch, but it's better if the tubes don't pull out in the first place.

http://www.bijurdelimon.com/fileadm...s/Datasheets/2900_B_ACC_Bijur-Tools_DS-R1.pdf

Dennis

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Thanks, Dennis - this is extremely helfpul. If the line is plugged (as opposed to the meter), is it possible to clear it out, or does it just have to be replaced?

swatkins said:

They sell a Kit that has everything you need for the upper head Bridgeport Rebuild Kits At 290.00 its worth it to just replace all the items at once and be done with it.. I only wish I had bought the bearings for the motor and did those at the same time. They are cheap and easy to do while you have it tore down. The motor bearings support one of the variable pulleys and there is a lot of side load on them.

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SWatkins, I saw the rebuild kit, and hear what you are saying. I have to balance that against the fact that this is a hobby for me, and I already had to sweet-talk my wife into the purchase price for the mill, so I will need to proceed cautiously on further spending!

awake said:

SWatkins, I saw the rebuild kit, and hear what you are saying. I have to balance that against the fact that this is a hobby for me, and I already had to sweet-talk my wife into the purchase price for the mill, so I will need to proceed cautiously on further spending!

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I understand. And if that is the case... I happen to have some new belts and other variable speed items that are new and might be usefull to you.

About 2 years ago I bought one of the kits and rebuilt the head of my boss 5. After getting it all back together I discovered the motor shaft was in bad shape right at the end of it's travel and the options of repairing it were costly or time consuming enough that I switched directions and ended up putting a single pulley system on it and controlled the speed with a VFD.

I will have to look see exactly what I have left over but I had installed the bushings into the pulleys and then took almost all of that off.

If you are interested in it I will look tonight.

swatkins said:

I understand. And if that is the case... I happen to have some new belts and other variable speed items that are new and might be usefull to you.

About 2 years ago I bought one of the kits and rebuilt the head of my boss 5. After getting it all back together I discovered the motor shaft was in bad shape right at the end of it's travel and the options of repairing it were costly or time consuming enough that I switched directions and ended up putting a single pulley system on it and controlled the speed with a VFD.

I will have to look see exactly what I have left over but I had installed the bushings into the pulleys and then took almost all of that off.

If you are interested in it I will look tonight.

Click to expand...

Thanks! PM sent.

awake said:

Thanks, Dennis - this is extremely helfpul. If the line is plugged (as opposed to the meter), is it possible to clear it out, or does it just have to be replaced?

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The lines can be flushed with solvent, blown with air (get one of those rubber cone tips for your blow gun) or even punched through with a length of wire. The blockage should always be at the end at the ways, because what blocks them is crap ingested when the ways are run dry for a long time.The problem is it's hard to flush or blow them when the far end isn't open. The lines just end at a hole in the way surface on the saddle, with an oil distribution groove in the way. The oil is expected to creep out into the clearance between the way surfaces. In other words, no place for the crap to go.

Just looked at the Bijur systems on my machines; manual pump on the manual machine, timed electric pump on the CNC, but the plumbing is the same on both, except the CNC has a few lines that run up into the head. Right above the pump is a cross, with a pair of meter units that feed lines to the knee ways. Nicely, those are ported into the knee casting with threaded fittings; you can pull those lines and flush through the ports if needed, no need to pull the knee.

The last line off the cross is the hose that feeds the manifold on the underside of the saddle. There are eight lines coming off the manifold and running to the interior of the saddle. As I recall (it's been a few years since I've had a table off) two come up through each side of the table way surface, and are easily accessible when the table is off. Two dive down to the saddle ways, one each side. It's normally easy to see if these are oiling, as this is a total loss system, and oil should be running down the sides of the knee from these ways. If it isn't, best to pull the saddle off to find out what's plugged. The seventh line goes to the top of the lead screw nut casting, directly oiling the X nut, with the oil then draining down into the Y nut. IIRC, the last line just drips oil on the knee elevating screw, and gravity takes it down to the nut.

It is important that these systems have no leaks at the tubing fittings. Once past the meter unit, there isn't a lot of oil volume, and the oil you pumped today won't get to where it's needed until next week, or next month. Conversely, the oil to lubricate the ways today is the oil you pumped last week, or last month, unless it leaked out of one of the compression fittings, then it isn't there. Unfortunately, it's hard to note leaks on a Bridgeport, since the used oil from the ways runs down over the manifold, so it always looks oily.

I'm probably making this sound like a bigger deal than it is. These are robust systems that go for years with no maintenance, provided they are kept filled and used. It's when they start to dry out that troubles begin... and most my experience comes not from the Bridgeports, but from a injection molding press that had a sick Bijur system with about five dozen meter units.

Dennis

Here is what I have..

Three new belts and the bushing side of each pulley that have the new bushings already installed

Pm on the way..

awake said:

Many thanks, Jon - I had already bookmarked H&W, and I will be looking at the videos as soon as I get a chance. I'm definitely feeling more confident about digging into this, and no doubt will be headed your way before long for new bushings and belt. (Hopefully I won't need any new bearings as well, but we shall see ...)

Click to expand...

i put the full rebuild kit into a BP a few years ago, imho most BP's that are noisy it's the bushings on the vari-drive disks. the belt I took of was in perfect condition, all the bearings were in great shape, just the bushings were shot. it went from sounding like a diesel that had thrown a rod, to a very quiet machine

On the lube side I would replace all the metering valves, pull off the table and replace all the plastic lines that go under the saddle and all the hoses.

If you do replace the metering valves, get Bijur units, don't use the cheaper asian knock-offs. I've seen big flow variances between valves allegedly having the same value

Modelman said:

The lines can be flushed with solvent, blown with air (get one of those rubber cone tips for your blow gun) or even punched through with a length of wire. The blockage should always be at the end at the ways, because what blocks them is crap ingested when the ways are run dry for a long time.The problem is it's hard to flush or blow them when the far end isn't open. The lines just end at a hole in the way surface on the saddle, with an oil distribution groove in the way. The oil is expected to creep out into the clearance between the way surfaces. In other words, no place for the crap to go.

Just looked at the Bijur systems on my machines; manual pump on the manual machine, timed electric pump on the CNC, but the plumbing is the same on both, except the CNC has a few lines that run up into the head. Right above the pump is a cross, with a pair of meter units that feed lines to the knee ways. Nicely, those are ported into the knee casting with threaded fittings; you can pull those lines and flush through the ports if needed, no need to pull the knee.

The last line off the cross is the hose that feeds the manifold on the underside of the saddle. There are eight lines coming off the manifold and running to the interior of the saddle. As I recall (it's been a few years since I've had a table off) two come up through each side of the table way surface, and are easily accessible when the table is off. Two dive down to the saddle ways, one each side. It's normally easy to see if these are oiling, as this is a total loss system, and oil should be running down the sides of the knee from these ways. If it isn't, best to pull the saddle off to find out what's plugged. The seventh line goes to the top of the lead screw nut casting, directly oiling the X nut, with the oil then draining down into the Y nut. IIRC, the last line just drips oil on the knee elevating screw, and gravity takes it down to the nut.

It is important that these systems have no leaks at the tubing fittings. Once past the meter unit, there isn't a lot of oil volume, and the oil you pumped today won't get to where it's needed until next week, or next month. Conversely, the oil to lubricate the ways today is the oil you pumped last week, or last month, unless it leaked out of one of the compression fittings, then it isn't there. Unfortunately, it's hard to note leaks on a Bridgeport, since the used oil from the ways runs down over the manifold, so it always looks oily.

I'm probably making this sound like a bigger deal than it is. These are robust systems that go for years with no maintenance, provided they are kept filled and used. It's when they start to dry out that troubles begin... and most my experience comes not from the Bridgeports, but from a injection molding press that had a sick Bijur system with about five dozen meter units.

Dennis

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Again, Dennis, super helpful, and many thanks!

In terms of removing the table ... do I need to remove the variable-speed power drive for the table, or can I run the table all the way to the right and slide it off?

Actually, I guess I need to ask about how to get it off - my uninformed assumption would be that I remove the handle and bearing block from the left side (assuming I do what I've said above) and that lets the table continue to move until it is off.

Also, I'm thinking about positioning the knee such that the table is right at the height of a rolling table that I have; this way I could support the table on the cart as it comes off. Good idea? Awful idea?

swatkins said:

Here is what I have..

Three new belts and the bushing side of each pulley that have the new bushings already installed

Pm on the way..

View attachment 198913View attachment 198914View attachment 198916View attachment 198917

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Looks good, and I will respond via PM, but just a quick question that may be of general usefulness: I know there is the drive belt and the timing belt ... but not sure what the third, thinner belt is for. I guess I need to go back and look again at the manual - I've been paying attention to the drive sections, so haven't looked for where another belt might go.