Bamboo Tips - Tips Area - Mills |
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I'm attempting to make a Dickerson-style mill. Does anyone know what the headstock where he attached the 60-degree cutters is called and if it is available anywhere? Is there anywhere I can buy a ball bearing 1" mandrel that is ready to go and to which I can just attach the 60-degree cutters? I assume the shaft has to be keyed, otherwise the cutters will slip? I see McMaster-Carr has a 3/4" ball bearing mandrel. Will it work? I have been looking at 1" keyed shafting through (MSC) and pillow blocks. But I would have to thread the shafting to place the nuts on either side of the cutters. Is this the way to go? I don't want to buy anything that I can't use. (Tom Nigro) Let me start with a disclaimer: I have never built a final taper mill myself. I now own one that is still being assembled as I write this. BUT, I have talked to everyone about mills that I can, and I write it all down! My advice is to stick with the 1" shaft so that you have access to more common cutters. Whatever you do, do not mount the cutters on a shaft directly attached to the motor. Use pulleys. I saw the Bellinger big mill this weekend, and I was told that it is problematic to have the shaft directly attached to the motor. The motor vibrates and causes run out on the cutter end. A belt attached to a pulley seems smarter, and you can use it to increase the cutter speed to the proper rate when matched with a steady feed rate. The 5700 rpm range seems to be about the recommended speed. Most motors I see are 1750 rpm so far. Of course, you have to match the RPMs with the right speed of feeding the cane through. I could send you some pics of the old Orosz mill I just bought. It may help you out. A decent design. When matched with some other things that have been posted, you should have a good start. My best advice is to ask Chris Lucker or Ed Hartzell. Or call any other professional maker who runs one day in and day out that likes to talk. Some great guys out there. Some are getting older. Don't miss out on their expertise. (Bob Maulucci) I made my mill and used a shaper spindle on which to mount the cutters. They were once sold by a mail order hardware company, but have not been in their catalog for some time. Dickerson made his own spindle using a casting and ball bearings. You should be careful about this as the spindle should be rated to deliver at least 4,000 to 5,000 rpm. If you make your own mill you will need some machinery like a lathe to do the machining necessary . People have been talking about converting a surface grinder to a mill and that should work. The investment would be about 300 to 400 dollars used. A small planer might also be possible for a smaller price but would require more work to make it into a rod machine. (Ed Hartzell) I have seen some nice surface grinders for $400-600. The only problem is that they run 1700 to 2500 pounds from what I can tell. That is great if you can get on home. I was quoted $800 shipping on a $400 surface grinder. Look local. That great weight would be a big asset, but the hard part is the moving it. (Bob Maulucci)
Can anybody point me in the direction of were I could purchase mill cutters that I could use in making a non-tapered beveler. The bore of the cutters would need to be 5/8 of an inch with a key slot in it (if I am not wishing for to much) to fit the shaft of the motor. I looked in the archives because I think I remember someone posted this kind of info before. For an example of what mill cutters I am looking for one could look at the bevelers on the Golden Witch web page. I just about got everything put together to make a beveler (total cost so far $0) and that is except the mill cutter which I believe will be my only expense. Also one more technical question. Would running the mill cutters on the the motor shaft at 1725 RPM be enough or should I step up the the speed of the cutters with a shaft, belt, and pulley system? The reason why I ask is if you look at the photographs of different bevelers the cutters are mounted on the shaft of a common TEFC, 56C face, 1/4+ HP motor that runs approx. 1725 RPM. (Robert Holder) I can only tell you answers based on what the experts have told me regarding finishing mills and cutter speeds. I would look at MSC or Travers to see if they have the cutters. Travers is where I got quad cutters for the Bellinger mill I once owned. It had a one inch 60 and 45 degree cutters (see Travers Catalog p. 230). I only see 1 and 1.25" hole diameters available. As far as speeds go, the suggested speeds should be somewhere around 5700 RPMs. I would also recommend a 1 to 1.5 HP motor. You really need to get a hold of Chris Lucker or Ed Hartzell if you want to know what's best. They are the real experts. My mill is still a long way off, taking back seat to the beveler I am working on. Let us know how it turns out. (Bob Maulucci) What diameter of cutters are you spinning at 5700 RPM?? RPM doesn't mean that much to me with out cutter size, as the three factors of cutting speed are surface feet per minute, rpm, and cutter diameter all have a lot to do with one another. Change one and the other two change. the old formula is rpm = sfm * 12/3.14 * cutter diameter simplified is rpm = sfm * 3.82/cutter diameter. Disclaimer, the above formula is for imperial units not metric. After figuring out the sfm and rpm then the chip load per tooth and chip load per revolution can be figured. From these numbers then the inches per minute of feed can be determined. I always thought it funny that you have surface feet per minute and then the feed is figured in inches per minute on milling machines and inches per revolution on a lathe...(Brad Love) The rpm's are not the sole issue -- you need to think about the relationship between rpms and the diameter of the cutters. For example, in the mid 80's at least, Charlie Jenkins used 2 inch three wing Sears shaper cutters that he custom ground and ran at 9,000 rpm. Dickerson used 2.75 inch cutters and three inch cutters running at 5749.9 rpm. If you do the math, you will see that the surface speed of the three inch cutters at 5750 is not far from the surface speed of the two inch cutters at 9000 rpm. One quarter horse is too light. Try 3/4 to 1.5 horse. Three quarter horse is the lightest I have ever used. A BIG motor will allow you to shove 2x4's through the cutters. All that being said, I would make two recommendations. Get the regular old 2.75 HSS cutters with too many teeth for wood cutters. They work fine for roughing, and even work for finals. They are the easiest to find at most any tool supply houses. They are the least expensive. They have a one inch hole, but that's okay. Get a shaper head with a one inch shaft from Mooradian (East Los Angeles) or a pair of pillow blocks and a one inch shaft. Use pulleys to step your speed up. Ten and three inch pulleys would give you the speed you need for a comfortable hogging feed rate of about one inch per second. I don't want to poo poo anyone's designs, but you know a motor shaft and bearing is not really designed to take the stresses of hogging bamboo. Also, there is runout and play in motors. Stick with one inch shafts. You will be pleased with the big squares of bamboo you can shove through the cutters in a single pass. You will pity the guys taking light cuts with routers. Use a bed of MDF (medium density fiberboard). You will need to make a relief for the tips of the cutters into the MDF. The relief will give you a guide for where the fence and spring loaded guides go. Since this will be a roughing mill, you will not need to make manual adjustments in cutting depth, however, in the few of these type roughers I made I allowed the bed to be shimmed so that the bed could be raised. But, you will probably find that rough sixties about 0.220 will suit you fine. (Chris Lucker) Since I have posted this to the rodmakers list I have gotten in contact with Chris Lucker and many others about this project and I have learned a lot about bevelers since then. The project to build a non-tapered beveler took more than I had thought previously. But I am happy to say that I have nearly completed building this machine. All I have left to do is redo the hold down mechanisms to a different style because my first attempt didn't do the trick when I tested out the machine. (Robert Holder)
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