20 Most Recent Ammco Combination Disc/Drum Brake Lathe Questions & Answers

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A standard arbor which you should have been provided with should look like this... The standard arbor size is 1 inch. A used arbor is okay--but if it has rust on it, you should remove the rust with a wire-wheel mounted on a bench grinder (and be sure to use eye protection because fast spinning wire-wheels routinely throw off wires). Any arbor (especially new arbors) have to be lapped into the spindle using a fine lapping compound which can be easily found at auto parts stores. Apply a small amount of lapping compound onto the mating surface of the arbor and insert it into the spindle with the machine turning. Hold the arbor tight and let the lapping compound grind away for about 40 seconds. Remove the arbor and reapply another small amount of lapping compound--repeat the grinding process one more time. Remove the arbor and using a rag clean the lapping compound from the arbor. Clean the lapping compound from the outer spindle seat. The outer seat is easily accessed--the inner seat of the spindle is harder to access. This is cleaned by doubling a rag over the threaded end of the arbor. Holding the rag, insert the threaded end into the spindle and clean the inner seat. Turn off the machine and insert the arbor into the spindle. Insert the spindle "draw bar" (which you should also have) through the hole in the drum gear box (Infimatic gearbox) on the right hand side of the machine. Holding the drive pulley, tighten the draw bar. Next you have to check the arbor run-out using a magnetically mounted dial indicator as shown.... Mount the dial indicator on the machine's twin cutter (tightened down) and crank in the disc-feed carriage until the dial indicator can make contact with the arbor. Start the machine. The arbor run-out should be no more than 1 1/2 thousandths. If the run-out exceeds greater than 8 thousandths it cannot be straightened. Arbor with slight run-out problems can be straightened. (Note: If the dial indicator vibrates too much to get a reading--you will have to manually turn the machine using a wrench as described below). First try loosening the draw bar, and rotating the arbor 180 degrees and then re-tightening the draw-bar. Many time this will solve the problem or at the very least lessen the run-out or bring it within spec. If the arbor is still exceeds spec, then you have to straighten it. To straighten an arbor, manually turn the machine with the "Ammco wrench" (which you should also have) using the nut on the draw bar. Turn the machine until you find the high spot (straight up), then remove the dial indicator to prevent damage. Using a copper dead blow hammer, give the arbor a modest whack, and then recheck the run-out. Repeat the process until you manage to get the arbor within spec. Please note that straightening an arbor using this method will sometimes break the arbor off. You are rolling the dice when straightening an arbor--but this is the nature of the animal. Even brand new arbors sometimes need straightening. If you need more questions answered contact us at... http://www.brakelathe.net/

Most likely you have a stripped out "disc feed screw." This is a common problem I see several times a month in the field. The stripped out portion of the screw is near the end of the feed range obviously. If you need parts or more questions answered.... Buy Sell Used Brake Lathes Brake Lathe Parts

It sounds like the motor is bogging down due to bad bearings or something is making the shaft too hard to spin. Make sure all the spindles are free. If its happening under load, make sure the lathe gets up to speed before trying to make any cuts.

Yes, an Ammco 3000 brake lathe can be converted over to a 4000 model--most any year 3000.... preferably the later years after 1970. The problem with some of the early 60's models is that the cross-feed bore is not perfectly perpendicular to the spindle. If you convert one of these models, you will cut the rotor at an angle and then jam the machine. Later models can easily be converted. You will need... 1) A complete disc feed gearbox. 2) A driven pulley (the big one) set-up for a with a pin drive. 3) A complete spindle lock assembly for the Infimatic gearbox. 4) Possibly need a longer guide bar for the cross-freed. If you have a round guide bar, this is possibly long enough. If you have a "Double-D" guide bar (flat on each side), you most likely will need a longer bar. 5) A complete twin-cutter, with tool guides, tool holders, knobs, etc. We have all the parts you need for a conversion--or we can convert it expertly for you... Buy Sell Used Brake Lathes Brake Lathe Parts

If you live near a machine shop any lathe operator can steer you in the right direction, or you could call them. I'm not certain if Ammco is still in business. I had the same machine in my shop in 1976, not the same model # of course, but a model with the stand.

First off--your model Ammco is their "El-Cheapo" model. Yeah, they work, when they work that is. I doubt that your problem lies within the spindle bearings. But it could-- I suggest that you tug on the spindle to see if you get any back and forth end-play, or up and down play.... if so, you are screwed. This machine is not worth the effort, money and time fix this problem. As for the arbor... This model uses the same arbor that the better 3000, 4000, 4100, 7000 and 7100 models. Every time you replace an arbor (new or used) you have to... A. Lap the arbor into the spindle using lapping compound (just like lapping valves in a cylinder head) The lapping compound is then cleaned out of the spindle and off the arbor, then... B. You then have to check the "runout" with a dial indicator. These are obtained cheaply at Harbor Freight FYI. With the dial indicator mounted (magnetically) on the twin-cutter check the arbor run-out. The runout (two inches from the spindle) should be no more than 1 1/2 thousandths. One thousandth or under is optimal. Any reading over 8 thousandths cannot be straightened. C. If the run out exceeds 1 1/2 thousandths, you have to then straighten the arbor. To straighten the arbor you will again need the dial-indicator and a heavy copper hammer.... With a wrench on the end of the draw bar (far right on the end of the drum gearbox), rotate the machine (counter clockwise) until you find the high spot on the arbor (carefully watching the dial-indicator). Remove the dial indicator and give the arbor a whack with the hammer (not too hard if this is your first time) when the high spot is directly straight up. Install the dial-indicator and check the run-out again. Sometimes you will get it on the first whack--sometimes you will have to go through an ordeal until you get the arbor in spec. And remember--sometimes you can bust the arbor completely off on the first whack. They are hardened and allegedly tempered, but some are more hard than others. If it breaks off--tough luck. You need to get another arbor. I have personally straightened arbors more than 30 thousandths out (once)... and I don't want to repeat that ordeal. Sometimes arbors cannot be straightened (bent in strange ways) and cannot be straightened. When loosening a rotor, do not allow the work to dump onto the arbor. This is the main reason they go out of whack. Buy Sell Used Brake Lathes Brake Lathe Parts

There's a lot of reasons why a brake lathe chatters during a cutting operation. They range from lack of maintenance, adjustments, cutting speeds, wrong cutting tools and so on and so forth. Be a little more specific. What kind of machine are you using? What are you cutting? (rotors? drums?) Are you using the proper silencers? Come back with some answers please. Buy Sell Used Brake Lathes Brake Lathe Parts

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You might try buying a manual for it. There is one on E-bay right now. might be $14.00 well spent.

Hope this helps.

Bob

Not enough rigidity, wrong speed, wrong feed rate, wrong depth of cut, wrong or dull tooling...

Drum brakes don't have calipers - they have wheel cylinders and a backing plate. Do you want to replace it all with original parts, or do you want to convert drum brakes to disk brakes? A conversion will be very expensive, and might not give you the results you expect. A brake system needs to be thought out carefully to work out all the details before you begin. Like... your proportioning valve will need to be changed, and the master cylinder will probably need to be changed. Then you have to find suitable calipers that can be mounted on your axle. If you're looking to just replace what's there on a drum brake axle, then... remove the brake shoes exactly as if you were doing an ordinary brake job. The wheel cylinder will be held in place by two bolts from the other side of the backing plate, but you'd better disconnect the brake line FIRST. If it's very rusty in there, expect a lot of trouble getting things apart. You may end up replacing brake lines, too.

Order a slightly shorter belt or put another idler pulley in somewhere (assuming the machine is in a condition to make one).

The problem isn't clearly explained. but the main shaft bearings go bad after awhile and it's one day thier good the next job their bad.

The cross feed drive shaft is connected to the cross feed spindle via a coupling that resembles a universal joint that is threaded onto the end of the cross feed spindle. Either one of the roll pin holes in the drive shaft coupling has worn and the roll pin fell out or it has broken, or the coupling could have came un-screwed from the cross feed spindle. Remove the 4 bolts that hold the cross feed gearbox on and slowly pull it away from the machine and you should see the coupling I'm describing. My guess is that the roll pin broke or fell out due to wear. You can buy a new drive shaft and coupling or drill and install the next larger roll pin. Either way you should download a parts list for your machine. Just search for it, they can be downloaded free.