m134b Posted October 3, 2010 Share Posted October 3, 2010 Here is one link I found useful. http://www.nojolt.com/how-to-build-a-rotary-phase-converter.shtml Ken Link to comment Share on other sites More sharing options...
jgun Posted October 6, 2010 Share Posted October 6, 2010 I contacted Automation direct today in regards to using an AC freqyency drive to power my mill. The tech that I spoke to told me that the drives are usually used in order to control the speed of an AC motor. He told me that I would need to bypass the toggle switch that turns on my mill and wire the drive directly to the motor, using the switch on the drive to turn the mill on and off. I forgot to ask him about reversing the motor for tapping or other apps. He also told me that I would need a seperate AC drive for each machine I want to run. These all sound like things I don't need/want to have to do. The only thing he told me that sounds like an advantage over the Phase converter is that there is no reduction of motor horsepower with the drive as there is with the converter. If I opt for the AC drive I will need to purchase a second one for the lathe I plan to add later on. I would hope that there is some reason, other than the extra power output, that would justify the added compexity/expense of going for the AC drive. I post this in the hope that someone who has used the AC drives can either verify the accuracy or inaccuracy of the info I got, and maybe give me some advice as to just what advantages I would have with the Drive, aside from the increased power. Link to comment Share on other sites More sharing options...
Pat Miles Posted October 6, 2010 Share Posted October 6, 2010 I run a rotary phase converter for my Bridgeport so take this info for what it is worth. My understanding regarding VFD's is that you have infinite speed control, also. I am sure that a VFD will provide reversing capabilities. Yeah, buying a VFD for your future lathe will be a killer but I wonder about powering your lathe and milling machine off of the same VFD just not both at the same time. How about an extension cord affair where you plug whichever machine you are going to work with into a receptacle that is fed by the VFD? I would make a list of your concerns and contact the company again as well as other manufacturers of VFD's. You might also take a look at the Practical Machinist website. It has a forum dedicated to phase converters, rotary phase converters and VFD's. Also don't overlook the thought of building your own RPC. Much less expensive than buying one. Pat Link to comment Share on other sites More sharing options...
mike cyrwus Posted October 6, 2010 Share Posted October 6, 2010 A rotary phase converter, from what I understand, doesnt reduce the output of your motors; its the static converters that do. I have a 5hp phase-matic pushing a 1.5 hp mill and a 2hp lathe and I can easily start one while the other is running. I couldnt be happier. Link to comment Share on other sites More sharing options...
Pat Miles Posted October 6, 2010 Share Posted October 6, 2010 (edited) A rotary phase converter, from what I understand, doesnt reduce the output of your motors; its the static converters that do. I have a 5hp phase-matic pushing a 1.5 hp mill and a 2hp lathe and I can easily start one while the other is running. I couldnt be happier. A rotary phase converter will provide full horsepower rating to your machine while a static phase converter will allow half or a little better. If yours is an RPC it is providing a total of 3.5 hp for both of your machines with some to spare. Pat Edited October 6, 2010 by whatmeworry Link to comment Share on other sites More sharing options...
jgun Posted October 7, 2010 Share Posted October 7, 2010 Right now I'm using a static phase converter from Phase-a-matic. When I called them up to inquire, they told me that in a noncomercial application such as mine, I wouldn't have any real need for the RFC. With regards to the AFD being able to infinitly control motor speed, I have a varidrive head on my mill so I already have that capability. I haven't yet encountered a situation where I felt that I came close to lugging the motor but once I locate a sutable lathe, I may find the reduction in motor power to be more of an issue with that. I purchased the static based on the recommendation of the tech rep from Phase-A-Matic, but also because the RFC for my app was 3 times the price of the static. I'm going to look into the option of building my own RFC. The only questions I have regarding them are, I have been told that since they have a large electric motor, that they generate a lot of heat and noise. Since I have a one room shop the converter will have to be in there with me. Do you guys find the noise/heat generated fome them to be any problem? Link to comment Share on other sites More sharing options...
Pat Miles Posted October 7, 2010 Share Posted October 7, 2010 I have 10 pounds of neat $hit in a 5 pound single car garage. Haven't any heat issues whatsoever. My RPC was noisy until I put a foam foot comfort mat under it. The mat is a piece of the interlocking squares that is sold at Costco or some of the big box home stores. With the RPC running I can carry on a conversation a couple of feet from it. When I fire up the BP it easily drowns out the RPC. Pat Link to comment Share on other sites More sharing options...
z40acp Posted October 7, 2010 Share Posted October 7, 2010 RPCs were the way to go a few years ago and if built yourself without having to buy a lot of the componets, are still good. Just going by memory but I think you need a motor 1 1/2 times the size you are wanting to run. The static converters are just not good at all. An RPC will give you a good steady source of power. I think whatmeworry has answered the heat and noise issue. I never had one myself but I never heard anyone complain about heat from theirs. Keep in mind two motors running are going to be louder than one. If you had to buy a RPC or a VFD I think the VFD would be more economical. The idea of buying a VFD sized for the larger motor you will run and using some twist lock plugs sounds like a good one. How often would you want to run both at the same time? You could mount boxes on the wall by the machines and fuse each correctly. Just unplug the two sides of the VFD and move it over to the other machine and plug it in. Yes, you would use the VFD as your switch for starting and reversing. I think another small advantage would be the ability to run just a little slower or faster than your varidrive head can do. They have really come a long way in the VFDs and are so popular it has driven the prices down. Link to comment Share on other sites More sharing options...
CSEMARTIN Posted October 7, 2010 Author Share Posted October 7, 2010 This is why I put on a single phase 220V 1.5 HP Baldor motor. I didn't want to deal with Variable Frequency Drives or Phase Converters, or the heat or noise, or trying to figure out which one would work best for my application. It all just seems like a big headache to me. Link to comment Share on other sites More sharing options...
jgun Posted October 7, 2010 Share Posted October 7, 2010 What does a single phase motor for a bridgeport go for? Link to comment Share on other sites More sharing options...
mike cyrwus Posted October 8, 2010 Share Posted October 8, 2010 My rotary converter is pretty quiet. maybe a little louder than the mill when its running, but its a non issue for me. Link to comment Share on other sites More sharing options...
Pat Miles Posted October 8, 2010 Share Posted October 8, 2010 What does a single phase motor for a bridgeport go for? If it's a name brand motor it should go for a long time. Sorry, I just couldn't hep it. Pat Link to comment Share on other sites More sharing options...
CSEMARTIN Posted October 8, 2010 Author Share Posted October 8, 2010 What does a single phase motor for a bridgeport go for? $453.33 http://www.machinerypartsdepot.com/site/1478157/product/SP2SP Link to comment Share on other sites More sharing options...
Pat Miles Posted October 8, 2010 Share Posted October 8, 2010 As a comparison, the 5 HP American Rotary Phase Converter like I have sells for $481.50. I'm not trying to say one direction is better than the other, just wanted to show cost of another option. If you purchase a lathe with a 3 phase motor in the future you can power it off of the same RPC. Pat Link to comment Share on other sites More sharing options...
jgun Posted October 9, 2010 Share Posted October 9, 2010 That was one of my concerns, The idea of having to switch the motor on each machine to single phase could get pricey, especially if I were to buy a lathe and then upgrade to something better later on. Right now the mill is running fine on the SPC, the third one so far. If/when this one goes I will have to decide between the RPC or VFD. I have a friend that has a small shop with 3 CNCs, a couple of manual lathes and a Bridgeport. He uses a RPC with no problems, of course the RPC is located in another room away from the machines. I realize that my application is different than his, so I might be able to use the VFD becacuse I don't expect to have more than a lathe and mill, but I'm not sure if having to control switching from forward to reverse on the drive vs reaching up to the switch right on the mill, is something I want. Also,although it wouldn't be a big deal to plug/unplug the mill/lathe when I wanted to use one or the other, unless there is some other advantage to the VFD I would opt for the RPC just for the convenience and the ability to add machines without added complication. Link to comment Share on other sites More sharing options...
CSEMARTIN Posted October 18, 2010 Author Share Posted October 18, 2010 Finally.....making chips. Link to comment Share on other sites More sharing options...
m134b Posted October 18, 2010 Share Posted October 18, 2010 So.... are you the type to just walk on them til' they cause enough drag on pant legs to drop a cape buffalo, or do you sweep? Either way, post up some pics! Link to comment Share on other sites More sharing options...
Pat Miles Posted October 18, 2010 Share Posted October 18, 2010 My rotary converter is pretty quiet. maybe a little louder than the mill when its running, but its a non issue for me. Mike, Is your RPC sitting on a rubber mat or on a concrete floor. A rubber/foam mat will make it much more quiet. Pat Link to comment Share on other sites More sharing options...
CSEMARTIN Posted October 19, 2010 Author Share Posted October 19, 2010 So.... are you the type to just walk on them til' they cause enough drag on pant legs to drop a cape buffalo, or do you sweep? Either way, post up some pics! Broom and a Shop Vac. I made a mounting bracket for the y-axis. The precision stuff was done on a friends mill. All I had to do was mill .300" off the bottom so it would clear the crossfeed bracket. Today, I finished installing the digital read out, and the x-axis encoder isn't reading. It just oscillates between 0.0000 and 0.0002". Luckily, it's still under warranty so I'll send that off tomorrow. I can't believe this crap! Again, +1 on Mike at candomachinery.com. He's been superb to deal with. If you're in the market for anything he sells, don't think twice about going with him. Link to comment Share on other sites More sharing options...
mike cyrwus Posted October 21, 2010 Share Posted October 21, 2010 My rotary converter is pretty quiet. maybe a little louder than the mill when its running, but its a non issue for me. Mike, Is your RPC sitting on a rubber mat or on a concrete floor. A rubber/foam mat will make it much more quiet. Pat its bolted to the wafer board it came out of the crate with, and its on top of a rubber door mat. one of these days Ill make a rubber isolated mount, or something like that. Glad to hear you got chips flying! Link to comment Share on other sites More sharing options...
CSEMARTIN Posted November 20, 2010 Author Share Posted November 20, 2010 The x-axis is back from Heidenhain and working properly. Now, it's time to install it and get to work. Link to comment Share on other sites More sharing options...
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