Topics Help Profile Register   Last 1 | 3 | 7 Days Search Tree View

Forum Miscellaneous / General / Whatever / Catchall . . . . Mounting 4th axis rotating indexers or lathes under the gantry

< Previous Next >

Thread Last Poster Posts Pages Last Post Archive through February 21, 2007 Normand Blais 25  1  02-21-07  09:19 pm   Closed: New threads not accepted on this page

Author Message   Gerald_D Registered Username: Gerald_d Post Number: 975 Registered: 11-2005 Posted on Wednesday, February 21, 2007 - 09:28 pm:        Yikes, I didn't think of that factor. Valid point.   fabrica Registered Username: Daya Post Number: 289 Registered: 10-2006 Posted on Thursday, February 22, 2007 - 03:55 pm:        So finally what do you guys suggest.   Gerald_D Registered Username: Gerald_d Post Number: 977 Registered: 11-2005 Posted on Thursday, February 22, 2007 - 03:58 pm:        Still say that you should get exactly the same motor/gearbox as for the rest of the Mechmate, but then to add further gearing/belting/.... to that motor.   fabrica Registered Username: Daya Post Number: 291 Registered: 10-2006 Posted on Thursday, February 22, 2007 - 04:03 pm:        Can we think of a tooth belt driven pulley.   fabrica Registered Username: Daya Post Number: 292 Registered: 10-2006 Posted on Friday, February 23, 2007 - 05:05 am:        Can some guy recommend to me a good source from which I could buy a good set of head stock and tail stock. I also need to know weather I could do them in my workshop itself.   Arthur Ransom Registered Username: Akransom Post Number: 24 Registered: 09-2006 Posted on Friday, February 23, 2007 - 06:24 am:        On my site at http://turningaround.org/4_axis_mill.htm near the bottom is my head stock and tail stock are shown. All off the shelf iteams except for the #2 Morse tapper in the end of the tail stock quill.   Arthur Ransom Registered Username: Akransom Post Number: 25 Registered: 09-2006 Posted on Friday, February 23, 2007 - 06:37 am:        Today I worked on doing motor tuning on the indexer axis and it is running great at 300 RPM. Got too involved and didn’t try faster speeds. At this time I don’t see any need for speeds over 100 RPM except when rounding rough stock. At this speed it takes 11 minutes to make 1 pass of 96”. Also I have order a set of laser cut parts and will replace my crappy gantry with the MechMate one.   fabrica Registered Username: Daya Post Number: 293 Registered: 10-2006 Posted on Friday, February 23, 2007 - 06:45 am:        Art, What were the prices that you paid for these items and what was the source of that you bought them from.   Arthur Ransom Registered Username: Akransom Post Number: 26 Registered: 09-2006 Posted on Friday, February 23, 2007 - 03:56 pm:        1.25" allthread Macmaster Carr $40 ? Nuts $20 ? 4 jaw chuck Harbor Freight $16 Live center $95 Oneway lathe pillow blocks $10? Machining #2 moris taper $20 I used the Oneway line center because I have a backup one, the Harbor Freight chucks screw on,and the bearings are replacable.   fabrica Registered Username: Daya Post Number: 294 Registered: 10-2006 Posted on Sunday, February 25, 2007 - 07:50 am:        Gerald, If I am to go by your suggested configuration where the gearing ratio changes depending on the diameter of the stock. I need to work with stocks having diameters ranging from 1" to 12". The RPM's I would like to work with would range from 1-200. Assume that I will have a 3.2 gearing ratio on the motor. How many sets of pulleys and belts will I need.   fabrica Registered Username: Daya Post Number: 295 Registered: 10-2006 Posted on Sunday, February 25, 2007 - 07:54 am:        Sorry, reference to the earlier post my motor gearing ratio is 3.6:1.   fabrica Registered Username: Daya Post Number: 296 Registered: 10-2006 Posted on Sunday, February 25, 2007 - 08:40 am:        Gerald, I did some quick calculations on a worksheet I got done to do RPM calcualtions for the indexer. If I use a 3.6 geared motor and set the pulsing speed to 45,000 RPM and also if i set the pulley ratio to 1:1.8 (1" pulley on motor shaft and 1.8" pulley on head stock shaft). I would get a indxer RPM of 200 (This i feel should be the minimum for rounding up work on rough stocks). AS per your theory which says that the pulley diameter should be equal to to the diameter that you are working on then the max diameter of the stock that I can work with would be 1.8" in diamater. If I need to work on 12" stock (with 12" pulley mounted on Headstock shaft)I can only operate at a max RPM of 30 RPM. The other option available to me is to do the rounding of the square stocks on a basic turner with no stepper involvement and then transfer the workpiece on to the machine we propose to build.   Gerald_D Registered Username: Gerald_d Post Number: 1013 Registered: 11-2005 Posted on Sunday, February 25, 2007 - 08:55 am:        Fabrica, you are starting to realise to difference between an "indexer" and a "turner"(lathe)... - indexer turns the work at low speed while a fast spinning cutter (router) takes deep cuts. - lathe turns the work at high speed, while a static cutter takes shallow cuts. They are completely different machines. You seem to want an indexer that has the speed of a lathe? With a router driven cutter, the speed of the workpiece can be much slower. Rough turning in a lathe is good. Sandpapering in a lathe is also very good. Sandpapering on an an indexer is hard work. I would pick 2 gear ratios max. Probably 3:1 and 9:1. The idea is that you can have: - direct drive - 3x slower than direct drive - and 3x slower again (9x) Don't pick the middle ratio in the "middle". If your top ratio is 10:1 the middle appears to be 5:1 but that is actually 5X from the bottom and 2x from the top.   Gerald_D Registered Username: Gerald_d Post Number: 1014 Registered: 11-2005 Posted on Sunday, February 25, 2007 - 09:00 am:        It is easy to do this theoretically, but you need to find practical pulleys or gears....   fabrica Registered Username: Daya Post Number: 297 Registered: 10-2006 Posted on Sunday, February 25, 2007 - 01:47 pm:        What you mean is that a diference between a indexer and lathe is that the same job that is done on a lathe at high RPM's could be done on Indexers at a low RPM. But for sand papering and rough cutting lathe is a better option. OK assuming that If I take the indexer path, I already have a stepper with a 3.6 gearing. If I drive it direct the max RPM would be 375, With 3:1 gearing 125 RPM and with 9:1 gearing 42 RPM. Your suggestion is to do trials with chains and sprockets.   Gerald_D Registered Username: Gerald_d Post Number: 1016 Registered: 11-2005 Posted on Sunday, February 25, 2007 - 03:06 pm:        Here is an example of true indexer work. As you will appreciate, the RPM is not a factor when cutting these shapes. And you cannot do them on a normal lathe. To sand them, they must stand still. This stuff can be done on indexers or lathes. People want to sandpaper them while they spin. Here speed is an important factor.   fabrica Registered Username: Daya Post Number: 298 Registered: 10-2006 Posted on Sunday, February 25, 2007 - 04:34 pm:        What I am interested in at the moment would be the second type of machine. Architectural wood coluns does not interest me at least for the moment. It will mainly be candle stands, stairways, walking sticks etc not exceeding a lenth of 48".   Arthur Ransom Registered Username: Akransom Post Number: 27 Registered: 09-2006 Posted on Sunday, February 25, 2007 - 05:09 pm:        Gerald now I begin to understand. What I have built is an indexer. What is the difference between a 4-axis mill and an indexer? Using 2" stock at 100 RPM it equates to 600 IPM. This would be too fast if I was Cutting with the point of the cutter but it has been my experience that I get a cleaner cut if cutting with the side of the cutter with the cutting edge coming down into the wood (climbing cut?). It is my interpretation that if I use the point of the cutter then for a 2” piece the max rotation will probably be 50 RPM and a 24” piece will be 6 RPM. Side cutting will probably be limited to 12” and less. What IPM range would you consider the max for side cutting? The only time higher RPM's are desirable are when roughing a multi sided piece to round. This is the code I am using, G0 Y96 A1000, for roughing and G0 Y966 A2000 for finish cut and I am side cutting. Is there a better way? On pieces where you can’t reach horizontal centerline to cut the cutting would be done as close to centerline as the tool will reach. This way the tool is still cutting with the side. The RPM speeds I have used in other posting are in doubt. If I set F200 then Mach posts feed rate at 200 but posts units/minute of 167. What is my actual RPM? Sanding solution. Sanding manually is a PIA. A better solution is a flap sander. Here is a version used on the Legacy that could be modified to MechMate. I see it as mounting on the side of Y car with manual Z and XY plane adjustment. http://turningaround.org/Pugn2.htm   fabrica Registered Username: Daya Post Number: 299 Registered: 10-2006 Posted on Sunday, February 25, 2007 - 05:16 pm:        Art, What does PIA stand for. I hope and pray that you meant "Pakistan International Airlines". Most of the Pakistani test Cricketers still work for this institution (Just having some fun on your account).   fabrica Registered Username: Daya Post Number: 300 Registered: 10-2006 Posted on Sunday, February 25, 2007 - 06:04 pm:        Art, As I understand The main difference between a indexer and a wood turner is this. In a wood turning lathe the force to cut the wood is provided by the RPM and the weight of the stock. You need a powerful motor to provide this circular to motion to the stock. This is why you talk about this 1 Hp motor. In a indexer the cutting force is mainly provided by the router and not by the RPM of the stock. Due to this the machine has the luxury of turning at a lower RPM.   Gerald_D Registered Username: Gerald_d Post Number: 1018 Registered: 11-2005 Posted on Sunday, February 25, 2007 - 07:13 pm:        An indexer is a device which can control the exact rotational position of a workpiece. They can stop and hold with minimal backlash. Fabrica, you say you want to do the "second" type of work (candle stands, stairways, walking sticks etc.). For that you do not need a stepper motor (or MAch3 or gecko) to turn the wood because you do not need a precise stopping position to cut detail. Therefore you don't need an indexer. The right production machine for candle stands, stairways, walking sticks etc. is a copy lathe, and the MechMate will be perfect to cut the templates (or masters) to use on the copy lathe.   Gerald_D Registered Username: Gerald_d Post Number: 1019 Registered: 11-2005 Posted on Sunday, February 25, 2007 - 07:21 pm:        Copy lathe:   Paco Registered Username: Paco Post Number: 4 Registered: 02-2007 Posted on Monday, February 26, 2007 - 02:22 am:        It might still be interesting to use the CNC as the copy device... Check those out: link 1 link 2 link 3   fabrica Registered Username: Daya Post Number: 301 Registered: 10-2006 Posted on Monday, February 26, 2007 - 04:16 am:        Gerald, How am I to do the flutes on the stock. Paco Thanks for your info. I think the machine that you suggest is what I have in mind. How can I get more info on it. I need to mount this on to the mechmate.   Paco Registered Username: Paco Post Number: 5 Registered: 02-2007 Posted on Monday, February 26, 2007 - 06:03 am:        Fabrica, you though about it, I did and so some other did too, but the links I shared are from a talent fellow Botter that share his trial recently. I suggest you do a search on this forum and maybe post your questions directly to Brian. In fact, he might just be reading this thread HERE too...?! The concept is quite simple; it's pretty much what Gerald post above but the cutter is driven with the CNC X (or Y) and Z axis. You may want to chuck in a 60 deg. V tool bit for final sharp inside corner detailing...   fabrica Registered Username: Daya Post Number: 302 Registered: 10-2006 Posted on Monday, February 26, 2007 - 07:04 am:        Thanks Paco for your valuble info. I will get in touch with Brian.   Gerald_D Registered Username: Gerald_d Post Number: 1025 Registered: 11-2005 Posted on Monday, February 26, 2007 - 07:29 am:        The main reason I mention a copy lathe, is for production. In a country where labour is relatively cheap, a copy lathe will very easily beat a CNC indexer for speed, price and ease of sandpapering. Of course, a copy lathe can be equipped with CNC motors, but then I will put the "gantry" under, or behind, the workpiece so that the operator has maximum access for sandpapering.   fabrica Registered Username: Daya Post Number: 303 Registered: 10-2006 Posted on Monday, February 26, 2007 - 11:55 am:        No Gerald What I plan to do is to have this thing mounted on the Mechmate parallel to Y axis.   Gerald_D Registered Username: Gerald_d Post Number: 1035 Registered: 11-2005 Posted on Monday, February 26, 2007 - 12:08 pm:        You already said you would do that for making small quantities of samples, and I am not arguing with you. I am simply pointing out some options for mass production.   Thomas M. Rybczyk Registered Username: Rypper Post Number: 8 Registered: 07-2006 Posted on Monday, February 26, 2007 - 02:45 pm:        Fabrica, Here are a couple more pictures of another Shopboters lathe\indexer. I also will be doing this to my machine at some point. Good Luck, Tom   fabrica Registered Username: Daya Post Number: 304 Registered: 10-2006 Posted on Tuesday, February 27, 2007 - 03:50 am:        Thanks Tom for your info.   reza forushani Registered Username: Reza Post Number: 100 Registered: 01-2007 Posted on Tuesday, February 27, 2007 - 10:41 am:        Fabrica Where are you with your laser deal?   fabrica Registered Username: Daya Post Number: 305 Registered: 10-2006 Posted on Wednesday, February 28, 2007 - 02:45 am:        I have received the optics the gun is on the way.