TorontoBuilder
Ultra Member
I thought I was a company that was parting out a darbert... lemme look and get back to you
Milling Machine - $950 - Mississauga
- Thread starter boilerhouse
- Start date
Congrats on the move, that worked out way better than any DIY scenario!
Lots of options to think through on the motor/pulley thing, just have to do the homework.
Good Luck and enjoy!
D
I wonder if you could replace the guts of the head and make your own EVS setup. I have one and its awesome. I can shoot you a few pics tomorrow if you'd like. Its very simple. Two timing gears and a belt is all there is. No backgear, no variable sheaves, no brake (has a locking pin). Being that you need to source a motor anyways and are missing parts, it might be simple enough to do. HH Roberts sells evs heads and might have diagrams. Pretty sure my head came from them.
Last edited:
I like this as an idea.
It was only in really REALLY recent times that VFD's escaped the "you can't afford that!" range of prices.
Another option is to look in to a Servo Motor as a power source. Same sort of deal as using a VFD, just a different means to get control of the speed it runs at, from what I sorta understand...
But if you went with a two pulley set-up, made one a little under driven for low speed use, and one a little over driven (bigger pulley on motor than on spindle) for high speed use, I think you would have a heck of a machine, capable of almost anything you might want, be it running a wee cutter fast, or a large cutter relatively slowly. Belt changes only when REALLY needed!
If I'm not mistaken @jcdammeyer runs a servo motor on his mill.I like this as an idea.
It was only in really REALLY recent times that VFD's escaped the "you can't afford that!" range of prices.
Another option is to look in to a Servo Motor as a power source. Same sort of deal as using a VFD, just a different means to get control of the speed it runs at, from what I sorta understand...
But if you went with a two pulley set-up, made one a little under driven for low speed use, and one a little over driven (bigger pulley on motor than on spindle) for high speed use, I think you would have a heck of a machine, capable of almost anything you might want, be it running a wee cutter fast, or a large cutter relatively slowly. Belt changes only when REALLY needed!
Yep! And he is a WAY better guy to ask than I, as he is, in reality, the guy I look to, as a source on the like!
Thank you. Yes. When I priced out 3 Phase 2HP and higher end VFD plus shipping than the Bergerda AC Servo c/w encoder. And I was ordering another AC servo set for the XY so shipping wasn't as bad amortized over all the motors.
The down side is the motor shaft did not match the existing pulley so I had to cast and turn my own. And then I didn't want to destroy the driven pulley in order to make room for the encoder on the spindle so I had to cast and machine yet another one. We won't mention taper in the wrong direction and therefore pulleys on the wrong side...
Or that I think I have a tad bit of wobble on the driving pulley and that it's not balanced...
In the long run, I'm glad I went AC Servo. Easy enough to add a 0-10V module or just a pot for 0-10V or manual speed control except I'm running LinuxCNC. So yes I'd do it again.
But. If you can find a 3 phase motor that matches your existing pulleys it may still be a better solution.
Well mimicry is the highest for of flattery, they say. I think my long term plan is to convert to CNC so a servo motor might be a good way to go. I have a cnc that cuts aluminum just fine which might help with the parts. John, if I could see some pictures and maybe get the model of servo I would appreciate it. Thanks everyone for the suggestions.
Here's the original. See how tall that motor is. And I have a low ceiling. It's why a Bridgeport Clone never found its way into this shop. It's a 2HP single phase 1725 RPM with an intermediate 3 step pulley. Range of speeds was 270 to 2950.
I made new plates and mounted the new motor in roughly the position of the pivoting intermediate pulley.
This was with the first motor pulley I made and the 4 step with inner cone taper driven pulley had no room for an encoder. But definitely not as tall. The motor pulley just barely made it down low enough.
And just to prove I screw up really badly the above photo shows the new two step pulleys. However, I'll have to redo either the motor pulley or the cone driven pulley so that the small one drives the bigger one.
In either case I haven't moved the belt in ages.
And as @David_R8 observed with a 1/2" end mill held in a TTS end mill holder the motor didn't bog down when the TTS Holder and cutter was pulled out of the 3/4" R8 collet in the spindle.
The motor I chose was the 110SM-MS0630. It's rated at 1.8kW (~2.3HP) and 3000 RPM.
Oh and @David_R8 saw it turn at 1 RPM.
Oh and we finished milling with a 9/16" 4 flute held in an R8 Collet. We did back off the RPM but the motor was never stressed.
I can't say enough good things about the support I've received from the Bergerda Factory.
I'm gonna look at the innards of the head and see if there is a good way to adapt. The variable speed head may need a bit of thinkating as to how to adapt it to a motor that doesn't have a long shaft.
The Bergerda Servo Driver was selected by Donald Chen (my contact there) and is the SDD20NK9D.
The price I paid is now old and he might have even given me a deal to help penetrate the North American market. I ordered a 60SM series 400W as a spare and maybe to upgrade my Lathe along with the 110SM series 1.8kW for the spindle. That one cost me $360US. FedEx Shipping was $170. The smaller servo was $280.
For me it all started with the two DC Brushed Motors that were different and X kept losing position and Y was always warmer. They were too old for warranty replacement since they weren't exactly the same.
Shipping costs along with the price (which was higher 4 years ago for some reason)
NEMA34 1125oz/in Dual Shaft Servo Motor KL34-180-90, SKEWED ROTOR DESIGN |
High-Torque Stepper Motor, Stepper Motor, Driver, Stepper Motor kit, DC Servo Motor, DC Servo Motor kit, Stepper Motor Power Supply, CNC Router, Spindle, and other Components.
www.automationtechnologiesinc.com
And I was looking for a knee motor replacement at the time because the Gecko Stepper driver failed and max up speed of the knee was 25 ipm. Too slow for my liking. So all in all at the time I ordered two AC servos to replace the brushed motors and one 750W motor for the knee.
The support was so good and I was really happy so I ordered the spare 400W motor and the 1.8kW.
All in all I don't regret it although my nice compact cabinet idea went out the window. Haven't gotten back to redesigning it to hold the drives so they are on the wall behind the mill.
Oh and one of the reasons Donald Chen said their motors are more expensive is because they use Japanese Encoders. So I took the cover off one of the motors to verify that. Sure enough Japanese brand, made in China. He said they didn't like the cheaper Chinese branded encoders. Not reliable enough. So anyway, he told the truth about the encoders. When I priced one it was $80 or so compared to $20 for a generic one from AliExpress.
I guess we have to remember that a German Lathe is more expensive compared to a Chinese reworked one from Grizzly Tools. Some of it may well be German labour costs but some of it has to be quality.
Note that on this mill the motor shaft isn't really longer than any other motor shaft. What they did is make the pulley really long.
Here you can see that I also made a long extension on the motor pulley.
I have been told that the Chinese are quite capable, of making and providing excellent quality machine tools, the problem, is that they will also cost as much as excellent quality machine tools from anywhere else.
Good castings cost. Good bearings cost. Skilled labor costs. Can't really get away from that anywhere...
I agree. The difference is rarely will you see the Germans sell junk. When I attended the CANopen Conference in Germany a number of years ago the Hotel where I stayed had a dinner room isolated from the kitchen area by a sliding glass door.
Nowhere in the rest of the world (Haven't been to Japan yet) have I heard such a quiet door. When I got home doors like the ones at grocery stores etc. were downright painful.
But I agree with you. I've seen some good quality stuff come out of China but it's not as cheap as the other stuff.
On my mill, it has a 3hp 7200 rpm rated motor, VFD driven. The drive is a Parker Spindleblok, with a braking unit. It works fantastic, but does lose bottom end power below 100rpm for larger drilling, like i mentioned in another post. I could regear it and limit top spindle speed to 4k, from the current 6k rpm and probably be happy. A true servo would definitely be the way to go if you needed both.
I don't 100% agree with that. Chinese manufacturers pay less for skilled labour, less for energy, less for materials and much less for unskilled labour than we do. They also pay much lower taxes. Theoretically, they ought to be able to produce MUCH BETTER machines than we can for the same cost or even much less.
Well they do but most aren't willing to even pay they high end prices so it's the cheap stuff that sells and what people want.
When I worked in The Netherlands back in the early 90's we made machines that trimmed and formed the leads on ICs. One of the customers was Motorola and when I moved back here I even did some consulting for Motorola Japan.
But. The point is that our company was required to strictly adhere with the drawings of the equipment. If they said the cabinet was 220mm wide +/-0.1mm then the Japanese customers would reject it if it was 220.2mm wide. Even the Germans weren't that strict. And I've already described a sliding door there.
In North America price tends to trump (ha ha) quality. IIRC, I paid House of Tools $3295 for my mill. It came with a vise and a set of R8 collets. @David_R8 agrees the Vise is really big. I bought a smaller 4" one I use for most everything. But if they built a mill to the German/Japanese standards identical to mine it would have been way more expensive and out side my budget.
So the reality I suspect is if the Chinese built something to compete with German quality it would still be cheaper but they likely wouldn't sell very many. So maybe large volume, low quality, provides a better return on investment.
TorontoBuilder
Ultra Member
the chinese burn massive amounts of low quality coal to generate electricity and used in steel. I'm prevented from talking about their labour practices, and other business practices including raw materials extraction... I'm with the hairy guy. The chinese should be able to make lower cost premium products.
However, they have a policy to flood foreign markets with low cost consumer goods.