Hi, so my grandpa was a machinist all his life but stopped in the 70s when he had an awful car wreck. Im an architectural metal worker and used to work as a Rougher outer on a bridgeport with a tree head so configured slightly different than most vertical mills. Anyway my grandpa is living but no longer capable of showing me how to use THIS machine which i am soon to have at my shop. Main issue is the brake lever spins freely, on looking inside there appears to be no shoe or means by which it can actually stop the spindle from spinning. I can find NO manuals for this machine.
Wouldn’t that be a “nice to have” feature, but not otherwise impair the function of the mill?
If so, maybe it broke a long time ago and he just left it running in it’s current condition. I personally don’t mind waiting on the thing to spin down while I’m working, and if I know old timers, sometimes they come up with silly and unsafe solutions like a “feed this piece of aluminum into the spindle to stop it” instead of fixing the brake.
Aren’t brakes needed for tool changes?
Yes they are…hence my wish to fix it…that being said…a screwdriver somewhat works…so long as your not using it to slow the spindle down …its just a pain.
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The brakes in the Bridgeport are more of a band that tightens on most models. It just helps it spin down faster and is not required to use the mill (assuming no broken parts floating around in side).
The draw bar pulls the collect up into the spindle and doesn’t rotate the spindle. There is a pin inside the spindle that prevents the collet from rotating and may be what you are thinking about… Ours broke a a couple months ago and needs to be replaced - we need a special wrench to loosen the part of the spindle assembly. However, collets are still been pulled up with without rotating.
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I know our pneumatic draw bar doesn’t need the brake, but I thought the brake was needed when it was a manual drawbar, not to keep the collet from rotating inside the spindle, but to keep the spindle from turning with the torque from the wrench on the drawbar. Remember, the collet and drawbar spin with the spindle in normal operation, otherwise the tooling isn’t doing anything either.
Sort of like you can remove a car wheel in the air with an impact wrench, but to do it with a breaker bar, it still needs to be on the ground, or otherwise secured from turning.
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The drawba, a long steel rod that is threaded at the end and thread into the collet, and are coaxial so when the drawbar is tightened it is pulling up with the collet’s taper engaging the engaging the inner matching taper surface of the spindle. The friction keeps the collet from rotating and instead pulls it up or pushes it out. Since the drawbar at the top is held centered on the spindle when it is encounters torque resistance, the same spindle that is being used to support the drawbar as the collet is, so the spindle doesn’t spin. The pin inside the spindle only is to stop a few degrees of rotation so the collet is quickly engaged.
Probably not the best description … but basically because it is pulling up and not rotating the collet the brake isn’t used.
Partly I think we are talking about two separate issues. Torque to turn the spindle, drivetrain and motor is quite different from torque to spin the collet in the spindle.
I have very vivid recollection of causing the spindle to turn by use of a wrench on the drawbar. However, thinking about it, all cases I remember this happening were times that due to being tall and stout, I had been asked to try and get out collets that were clearly over tightened, and I had to use the brake to hold the spindle from turning, as the drawbar clearly required more torque to loosen than the motor and drivetrain required to turn by hand. But thinking further, the times I used the mill myself, proper torque to the drawbar did not exceed the breakaway torque required to turn the spindle, drivetrain, and motor by hand, or at least not at the speeds I had it set at.
I replaced the brake lining on a Bridgeport Mill I had at home several years ago. The cost was about $15 for the part but took several hours to install myself since I had to remove the motor and belt housing. Any competent mechanic can do it. MY suggestion is the get the brake working again.
So in my brief search Ramill is essentially a model number thats made by Ramco. This may make it easier for you to search & find books.
I did a short search in Insustrial Manuals with Squat for books in my short search.
http://industrialmanuals.com/ramco-m-1021.php
This is how I came across the name
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The picture sure makes it look easy to replace the brake shoe. Item 1 says to remove the top section. The top section includes the motor, belt assembly, and top casting. Your photo shows the variable speed drive which is a real bear to disassemble. On a 40 year old machine I had some difficulty gets some of the bolts loose. It’s always that last bolt that takes 30 extra minutes to break loose. The shaft bearings should probably be replaced if you have to remove them during the process.
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I call it the one bolt one screw complex…the entire process is easy until you hit the bolt or screw that breaks strips crossthreads etc…thanks…i knew nothing about ramco only the name of the machine and theres no spec plate.
Yeah ive figured out its basically i standard j head in mist every way except…looking inside the brake level leads to …nothing…ill study these pictures and drawings. And if there is a solution and readily available bridgeport parts it should be interfaceable… if not the screw driver…does work…
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If you go out to the Machine Shop Wiki Page you will find a section about the Bridgeport Mill. Check out the User Manual and it will give you some basic information about how to change out the motor. Heck, once the motor and belt assembly is pulled, then the brake mechanism is in full view to replace. I am not familiar with your specific brand of Mill but they are all basically copy-cats of the Bridgeport Mill. Several years ago I had a complete parts breakdown manual for the Bridgeport so I’m sure a copy is available out on the web somewhere. If you find a copy then do everybody a favor and have it added to this Wiki page for others to use. Good luck.
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this is right, especially on the bridgeports with belt gearing in high gear trying to loosen the drawbar nut without braking the spindle will just cause everything to spin.
see e.g. pg 2-9 here http://fab.cba.mit.edu/content/tools/bridgeport_mill/Bridgeport.pdf
I really just need to take the top off before i can say more but that is a bit of an ordeal as its one large casting that the motors sits on…i may be able to endoscope through the side vent to find out more but yes the tooling is changeable at this point with the screwdriver method but its certainly on the list of things to fix…finally figured out all levers and autofeed businuess…do all mills have reverse autofeed option? Mine does and im rather curious as to what kind of operation one would use such a feature for.