Auto quill feed problem on my Bridgeport

[Bernd]

Well when I went and bought the mill I asked. "Does the power quill feed work?" "Yes, it does." He shows me. Good.

After I finally got the machine in a running state I tried the auto quill feed. Worked fine until the drill touched the work. Then it stopped. I played around with it but couldn't get it to feed down. Ok, a problem to look into later. In the mean while I did a little research and found a good place on the interweb that has replacement parts for a Bridgy. I also found a schematic of the parts and part numbers. To bad you can't make out the pic to well since it is to small. So a little  .

Well today I decided to investigate why it doesn't work. In about 3 hours time I had a majority of it a part and diagnosed what the problem was. Lets say it was  and leave it at that for now. I've got a few pics to show and explain what I think happened. Yes, "Happened" 


This is the place that the engagement lever usually resides. Notice that bronze bushing in back? Also the gear at the top of the hole. This drives two sets of gears like on an outboard motor.


This is were the clutch resides with it's brass worm gear. The worm gear you see is the gear that drives the worm gear.


These are all the parts that fell out.  Just kidding. I had to remove them they didn't fall.


This is the shaft that the worm gear attaches to. Notice the pin and hole through the shaft? That my friends is a drive pin that apparently goes through the worm gear and fastens it to the shaft to keep it from spinning. If I stick the pin in the hole there is nothing sticking out on either side of the shaft. Conclusion, the pin is sheared. That's why the feed would only go down till the drill touched the work and no further. It was friction driving the quill. Now, why did the pin shear?


This is my conclusion as to why it sheared the pin. This is the drive clutch. Notice the spring? It's wound up tight. No spring movement at all. Somebody had screwed the thing together so tight that the clutch could not work when the down feed ran into something solid and couldn't go no further. Consequently the pin was the weakest point and let go.


Here's a view after I got the machine back together after the move into the basement. It's to help orient yourself on the parts of the previous 5 pics.

So, now I know what needs to be fixed, but, I need to get that worm gear out to pin it back on the shaft. Problem is that bronze bushing that you saw in the first pic is keeping from getting at the gear. From what I can deduce there are two ways of getting it out. One would involve taking the whole head of the machine. That's a big "NOT A OPTION" or remove the bushing. Problem is the bushing is stuck in there quite tight. I have in mind making a puller and getting it out that way.

That's about it for now. I'll post more as I get to fixing this problem.

Bernd

[John Stevenson]

Those gearboxes are licensed from Timex   

Done  many of these, just tap the first part of the bush and then pull it out with a length of studding, If you only put about 3 or 4 threads in you can still reuse the bush.

The book states that the power feed can only be used up to a 3/8" drill. That's pathetic on a machine this size.

John s.

[CrewCab]

Bloomin eck John ................ is there now't you don't know     .........   nice one, let's hope Bernd can now get his Mill sorted fairly easily then 

CC

[Brass_Machine]

A PITA I must say. Mr Stevenson has some good advice. At least at this point it looks like you just need to replace the spring and pin. Maybe the bushing if you wad it up. Thankfully (and hopefully) it isn't a hard to find expensive (more) gear or shaft or some such part.

I imagine with your ingenuity and skill it will be up and running by Sunday  

Eric

[John Stevenson]

Bloomin eck John ................ is there now't you don't know     .........   nice one, let's hope Bernd can now get his Mill sorted fairly easily then 

CC

When our local college packed the engineering side up we bought a lot of the machines, including 6 Bridgies, 5 manuals and one CNC.
Kept the CNC but sold the others on, everyone had the power feed stripped.
My manual has had the feed robbed to get some of the others working, To be honest i haven't bothered repairing it as i don't use it.

John s.

[Bernd]

Ah John, one of us must have read the others mind. I'm going to make a puller to pull the bushing out. I'm going to try and save the bushing and get it out without tapping in though. You forgot to tell me that there are two, yes two, set (grub) screws that hold the bushing in.

The spring should be fine once I loosen up the threaded screw that adjusts it for tension.

Your comment about it only being able to handle a 3/8" drill would make sense due to the smallness of that drive pin. I don't think the drive was designed to use as a drilling mechanism. It is supposed to be used with a boring head so you have a constant feed rate.

Who ever had this machine from the time it left Kodak in Rochester to the time I got probably had no idea you couldn't use the feed to drill large holes.

I imagine with your ingenuity and skill it will be up and running by Sunday 

Eric

Thanks for the vote of confidence. The first two I have, but to be up and running by Sunday, I don't think so. The SWMBO has told me I need to get that pantry in the kitchen done or else I'll get a and a and a  if I don't. So it might be a few Sundays before I get up and running again.

Regards,
Bernd

[Bernd]

Well Eric must know me to well be now.  I made a puller today and removed the bushing.

I know I said I needed to work on the kitchen pantry. Well I did, but did you know wood glue takes a while to dry. 


Here's a pic of the puller I made. It's made from a piece of brass coated steel. I turned down the end to the inside diameter of the worm gear. Then I made a grove in it to a diameter of 5/32". Drilled and tapped the end for a 1/4-20 scrrew. Then I made a "U" shaped washer to fit the grove. The rod is 3/8" dia.


Here it is assembled in the housing. Not much to see.


Here is the bushing, U washer, pull rod and screw. Worked great.


And here's a pic of the whole assembly. Notice the hole in the worm wheel were the pin goes.

Now all I need to do is make a pin and reassemble.

Eric, you may be right. I might have it back together before Sunday.

Bernd

[Darren]

Bernd you make it look so easy, bet you're pleased 

[CrewCab]

Eric, you may be right. I might have it back together before Sunday.

I doubt the word "might" even enters the equation     ............   

Nice going Bernd.

CC

[Darren]

Wood glue takes "days" to dry doesn't it......I "know" floor tiles adhesive does. Can't walk on it for at least a week can you chaps 

[Bernd]

Well I hit a snag. In the very first picture I posted you see the brass bushing that I took out. Now note that right above that bushing you'll see teeth from the drive pinion. This drives the two gears on the shaft I took out.

It's in the way. I can't get it back together again. That gear needs to go up out of the way so I can get the shaft in that I took out. No way can I get it up. I'm thinking I might need to take the top part of the machine off.

John Stevenson I need your expertise on this one. Can you remember how they get that drive back together? Is the shaft with the wrom gear all assembled first? I can't see any way of getting a pin in through the worm gear and shaft when it's in place.

Bernd

[CrewCab]

Wood glue takes "days" to dry doesn't it......I "know" floor tiles adhesive does. Can't walk on it for at least a week can you chaps 

Errrrrrrrrrrrr .............................. No ...................... generally PVA takes a couple of hours to achieve a  reasonable strength, 24 hours is pretty much full strength or near enough .......... if you use the rapid setting ................ etc .....  it's quicker 

AS for floor tile adhesive are we talking vinyl or ceramic ............. though whichever ........... the adhesives will set within an hour or two, OK: let me rephrase that, adhesives that will set fairly quickly are readily available; believe me I've used most of them, including those that don't do what it says on the tin  which can be very frustrating 

CC

[Darren]

Er, live alone by any chance Steve?

Either that or you love a heavy workload   

Wood glue takes "days" to dry doesn't it......I "know" floor tiles adhesive does. Can't walk on it for at least a week can you chaps 

Errrrrrrrrrrrr .............................. No ...................... generally PVA takes a couple of hours to achieve a  reasonable strength, 24 hours is pretty much full strength or near enough .......... if you use the rapid setting ................ etc .....  it's quicker 

AS for floor tile adhesive are we talking vinyl or ceramic ............. though whichever ........... the adhesives will set within an hour or two, OK: let me rephrase that, adhesives that will set fairly quickly are readily available; believe me I've used most of them, including those that don't do what it says on the tin  which can be very frustrating 

CC

[Bernd]

Well it's 4:00PM Friday and the mill is back together and the quill feed is working like it's supposed to.

Guess I bet the Sunday dead line for getting it running again and I got a bit done on the kitchen pantry. 

Pics tomorrow of how I did it. I think I can now safely say I can fix a quill feed on a Bridgeport in less than a day, if I have the parts.

Bernd

[Brass_Machine]

Well it's 4:00PM Friday and the mill is back together and the quill feed is working like it's supposed to.

...

I owe you a coffee or other beverage. Make sure you hit me up at Cabin Fever! 

Eric

[Darren]

Great stuff Bernd,

 know where to come now should I ever have the need !!! 

[Bernd]

The machine is back together and working like it should. Darren helped without knowing it. He posted a link to a website for machine manuals. I took a look and found a whole set for the Bridgeport. They covered the 2J Variable speed head that this machine has. In an exploded view I saw that it's possible to separate the motor and variable drive from the spindle and quill feed by undoing just 3 bolts. But how to get the that up high enough to get at what I need to move inside. Well, why not let the machine do the heavy lifting.


I turned the whole head 180 degrees and brought up the knee till the whole works rested "gently" on the table with wooden blocks underneath. I unbolted the three bolts that hold the two parts together and I ……………


Lowered the table till the spline to the spindle came apart. Then I turned it back…..


90 degrees and I could get at taking out the drive shaft of the gears. Underneath that bracket is the bushing I needed to move up to get that gear that I showed in a previous pic up high enough to put the drive shaft with worm gear back in.


Here's the bracket and knob for engaging/disengaging the quill drill. Once I was able to move a few of the bushing around I got the drive shaft in and reassembled almost everything.


Here I'm assembling the two parts back together by "slowly" cranking up the knee. I brought up till there was enough threads on the bolts and then gently tighten the bolts and drew up the motor drive till everything was tight.


And here we are all buttoned up and ready to turn the motor back to it's upright position.

It's all back together and running. All I need to do is readjust the quill clutch. I left it quite loose in case I had a jam up or something. The best part was I had no left over parts. I usually have at least one or two parts left over from such an adventure. Also now that I have a better manual I can do a few more checks on the machine.

Now it's back to tramming in the head to make sure it's square to the table and it's time to get back to making tooling and steam engines and………………………

Regards,
Bernd

[Brass_Machine]

I would have never thought about doing it that way. Very ingenious 

Eric

[Bernd]

Well what can I say Eric. Perhaps is from the years of working in a very large machine shop and watching when maintance repaired machines. Plus I had no way of going but down to get it apart.

I used to work for a gear machine manufacturer in Rochester, NY. see if you can come up with who that is.

Bernd

[John Stevenson]

Bernd,

I can't for the life of me think how I got the shear pin in but it wasn't that way.
I know that as I have never stripped the head on a 2J before, I also have the manuals with exploded views but it doesn't make it clear there is another way.

Nonplussed in Nottingham..........

[Darren]

Glad to have been able to help Bernd,

I thought shall I ? Nah, those old timers will already have seen it 

But I did anyway......

[Bernd]

John,

It's the only way I found to be able to assemble that shaft with the gears on it, then slide it in and drop the drive gear back down on it.

Perhaps it'll come to me later as to the easier way.  I've been know to do things the hard way before finding the easy way. 

Bernd

[Bernd]

Glad you did Darren. It makes it easier than haveing to look for it.   

Bernd

[CrewCab]

Nice Job Bernd  ......... Lateral thinking .............. or to be more precise inverse thinking 

CC

[Bernd]

Thanks CC. I call it lazy thinking. How can I do this without creating to much work.

Bernd