the Wadkin Temple VFD and motor demo at the GCRJF

[jack forsberg]

The 3rd annual Great Canada Rust Junkie Fest at the Wadkin Temple (AKA my shop) was better than ever. its a gathering of machine lovers form all over. I thought you may like to see one of the videos demos of a machine motors and VDFs

http://i927.photobucket.com/albums/ad111/tool613/rust%20fest%2017_zps3acczhhx.jpg (http://s927.photobucket.com/user/tool613/media/rust%20fest%2017_zps3acczhhx.jpg.html)

just got to stand on my feet after 8 weeks so i am hobbling a bit.



https://www.youtube.com/watch?v=AdctA3PjY9c

[Allan Speers]

Actually, Matt gave some pretty bad advice in this lecture:

He said that if you run that 1700 rpm motor at 30 HZ, it will turn at half that speed, "and run just fine."

That is not really true, because it's clearly not an inverter-rated motor. At 30 HZ, it will not have the same horsepower (even if it's a constant-torque VFD, which that one doesn't appear to be.) Worse, that motor will overheat. Additionally, Inexpensive VFD's like the one he's holding create constant square wave spikes. These spikes create additional heat, and can destroy a motor's bearing grease.

Non-inverter motors should not be run at less than 20%, according to Baldor, Leeson, and TECO.

Inverter-duty motors have better insulation and cooling fins, plus special grounded bearings so the spikes don't travel through the grease. They can be run safely at +/- 50%.

[Frederick Skelly]

Pretty neat Jack! Thanks for posting.

Have any idea how many people attended?

[jack forsberg]

Actually, Matt gave some pretty bad advice in this lecture:

He said that if you run that 1700 rpm motor at 30 HZ, it will turn at half that speed, "and run just fine."

That is not really true, because it's clearly not an inverter-rated motor. At 30 HZ, it will not have the same horsepower (even if it's a constant-torque VFD, which that one doesn't appear to be.) Worse, that motor will overheat. Additionally, Inexpensive VFD's like the one he's holding create constant square wave spikes. These spikes create additional heat, and can destroy a motor's bearing grease.

Non-inverter motors should not be run at less than 20%, according to Baldor, Leeson, and TECO.

Inverter-duty motors have better insulation and cooling fins, plus special grounded bearings so the spikes don't travel through the grease. They can be run safely at +/- 50%.

So your advise is to not use the free motor that came with the machine because you will burn it out? instead buy a new inverter duty motor that can handle the pulse wave(square sign) and save the grease in the bearings even though its only 240 volts and the problem is one of higher voltage motors that run continuously. all VDFs are pulse wave and motor don't care because there dumb. I have been running old motors from the 50s as low as 20hzs for session of 1 to 2 hours for 6 years now in a real shop and have yet to see a problem with any of the 6 machines running running on VFDs even the 600 volts ones feed with a RPC. . I find the old motors have way more iron in them them than the new inverter duty and take a long time to heat up .if your concerned you can put a fan over the motor to help cool or start with a motor with more polls. I general set machines up in the low end of the pulley drive and over run the motor(above 60 HZ ) for speed control anyway. A 1 HP motor on a drill press is plenty of HP for a woodworking press as you still have lots of power at the low end(1/2 hp is lots to drill wood). If you what more power start with a larger HP/lower speed motor as that is the general wisdom in the industry for machines that run in the lower HZs and need power(pumps). On machines with mechanical drives that are married up with the VDF drives the power at the working end of the machine is greatly expanded so the lower hz is over come for most operations . The drive I show is a cheap volt /hzs FM50 Drive protecting a $20 motor but one can get vector drives for a bit more money and these are better at low end torque if in fact that is what the machine needs.

the idea of the VFD presentation was one for those that are confused by 3phase motors and VFDs and gives them a way to try it out at the risk of a $20 motor that they were going to toss. . if they wish to dive down the rabbit hole and learn more that's good too.


Frederick its was a great time and about 75 junkies came

http://i927.photobucket.com/albums/ad111/tool613/rust%20fest%2018_zpsbgkysij7.jpg (http://s927.photobucket.com/user/tool613/media/rust%20fest%2018_zpsbgkysij7.jpg.html)


http://i927.photobucket.com/albums/ad111/tool613/rust%20fest%2019_zpswumrkbo1.jpg (http://s927.photobucket.com/user/tool613/media/rust%20fest%2019_zpswumrkbo1.jpg.html)


http://i927.photobucket.com/albums/ad111/tool613/rust%20fest%209_zpsgmfsqa8u.jpg (http://s927.photobucket.com/user/tool613/media/rust%20fest%209_zpsgmfsqa8u.jpg.html)


http://i927.photobucket.com/albums/ad111/tool613/rust%20fest%2011_zps771s9azu.jpg (http://s927.photobucket.com/user/tool613/media/rust%20fest%2011_zps771s9azu.jpg.html)

http://i927.photobucket.com/albums/ad111/tool613/rust%20fest%204_zpsvaoee3sq.jpg (http://s927.photobucket.com/user/tool613/media/rust%20fest%204_zpsvaoee3sq.jpg.html)


http://i927.photobucket.com/albums/ad111/tool613/rust%20fest%206_zps5ktp86m1.jpg (http://s927.photobucket.com/user/tool613/media/rust%20fest%206_zps5ktp86m1.jpg.html)

[David Kumm]

My experience is similar to Jacks. I run about 50 machines from 75 years old to new and find the old large frame cast iron motors almost impossible to screw up with non commercial woodworking usage and 230 volt input. RPCs had more issues because of the range of motor size I use- 1-25 hp. By far my biggest motor problems have come from relatively new ones. The advances in insulation have allowed manufacturers to stuff more wires into smaller frames and run motors hotter than in the past. Wires can take it but the bearings tend to fail sooner and when they do all kinds of bad things happen. While I would always buy the sensorless vector type for the small price increase, I would not be afraid to run old motors like drill presses, mills, etc at 20-30 hz. Not 24-7 but for the relatively short periods we stress our machines. If I were buying a cheap new motor that I wanted to run on a vfd it would be inverter duty for sure. It will be more efficent but will die before my old large frame motors though. Dave

[Allan Speers]

Why so defensive, Jack?

I have written what I was very specifcally told by Baldor, Leeson, and TECO, and all three tech knew I was a hobbyist woodworker. Feel free to call them and tell them they are wrong. - And then get NEMA to change their insulation ratings.

Additionally, you say "All VFD's are pulse wave and motors don't care because they are dumb."
Uh, how to respond? Better VFD's have filtering on their output, to minimize the voltage spikes that do the damage. And Inverter-rated motors are "smart" enough to also have specially grounded bearings, that channel any spikes that do exist to ground, instead of letting them travel through the grease. You can even buy these grounded sleeves and install them on non-inverte motors, but they're quite expensive.

Just because you've never had a problem, or that you have big old cast iron motors, is not a good reason to tell someone else it's OK to slow a non-inverter motor to 50% speed. That's like my grandma saying, "Cigarettes are perfectly safe, I smoked two packs a day all my life & I'm just fine."

-------------

It's not my intention to argue, just to correct some rather serious misinformation.

Other than that, it looked like a really cool get together. I wish I was local !

[M Toupin]

It's not my intention to argue, just to correct some rather serious misinformation.


I've been banned from OWWM ! I don't even have a clue why. Seriously.

How ironic... You spend you're time correcting, arguing with or disregarding very knowledgeable sources (in this thread and a plethora of others) and then tell everyone you're correcting misinformation with a sentence that starts with "I've been told by...".

Guess you don't read your PMs either

And just for the record, I'd consider Jack "very knowledgeable" with extensive first hand real world knowledge and experience.

Mike

[Jim German]

Thats a great video, very informative. Very timely for me as well as I'm looking for a VFD for my shiny new (well 40 year old) Bridgeport that should be showing up this weekend. Does anyone have a recommended VFD source? I've been looking at http://factorymation.info http://driveswarehouse.com and http://www.wolfautomation.com/ . Not sure which one to choose though. Teco seems to make both a "compact Micro" one and a "Vector drive with PLC control" one. What's the difference between them?

[jack forsberg]

How ironic... You spend you're time correcting, arguing with or disregarding very knowledgeable sources (in this thread and a plethora of others) and then tell everyone you're correcting misinformation with a sentence that starts with "I've been told by...".

Guess you don't read your PMs either

And just for the record, I'd consider Jack "very knowledgeable" with extensive first hand real world knowledge and experience.

Mike

Thank Mike for the more than generous comment but I'm just a woodworker who's Been running old motors on the VFD's because the motors that came with the machines were free . The worst case scenario is I need a new motor and I've been working on blowing one up for six years still no luck with that , of course I would buy a used three-phase Motor if I did.

The VFD will never get damaged by Old motors so what's the real risk Here. I've read all of the documentation from the Motor companies and of course their literature is to protect there devices and of course they are going to recommend the most friendly way To run their product as long as you crack open your wallet. There going to tell you how old motors are no good because this is what sells new motors. If I or others had listened to the VFD manufactures years ago who could not agree that VFD's could take single phase input and would be damaged and warrantees void We would not be where we are today. what's been developed would not be here Had it not been for amateurs and hobbyists as well as engineers going against the recommendations and experimentation of single phase input for phase conversion to which the VFD was never designed to do.


If you're the kind of guy that needs your hand held with guidance and reassurance with warrantees and guarantees who looks to vendors for their recommendations and products this type of thing would not be for you.
if you're the type of guy that likes to build things and you don't believe everything someone selling you product tells you when you actually might find this quite Inlightning to try ,it certainly won't cost you very much moneywise and remember I'm not selling you anything . That's right my advice comes with no guarantees you only get what you paid for and seeIng this advice is free take it for what it's worth and what you paid for it.

[jack forsberg]

Thats a great video, very informative. Very timely for me as well as I'm looking for a VFD for my shiny new (well 40 year old) Bridgeport that should be showing up this weekend. Does anyone have a recommended VFD source? I've been looking at http://factorymation.info http://driveswarehouse.com and http://www.wolfautomation.com/ . Not sure which one to choose though. Teco seems to make both a "compact Micro" one and a "Vector drive with PLC control" one. What's the difference between them?

Jim the first thing to start with is the motor tag information do you have a pic of the motor tag and we can start from there. Your budget and what it is you actually want the VFD to do well actually determine what type to get and or any other apparatus to make it work

[Jim German]

Jim the first thing to start with is the motor tag information do you have a pic of the motor tag and we can start from there. Your budget and what it is you actually want the VFD to do well actually determine what type to get and or any other apparatus to make it work

Unfortunately I don't have a picture of the motor tag, I did take a look at it and saw it was 1.5hp @230V. It's a variable speed Bridgeport so I don't need the VFD to do speed control. I'm also perfectly comfortable wiring in a pot or external control switch, so it doesn't need a remote control pad.

As for the budget Its just a hobby for me, so I don't need something that's going to be 99.9999% reliable or anything crazy, but I don't like buying crap either.

[David Kumm]

Jim, I'd give any a call and tell them your application. I think you will be in the 150-225 range depending on how top end you go. Both factorymation and driveswarehouse are well known. I don't know how the Bridgeport variable speed works so you need to explain that to the vfd guys to make sure everything is compatible. My mill just swaps pulleys so I didn't have to figure that out. Generally you don't want anything between the vfd and the motor except wire. Dave

[jack forsberg]

Unfortunately I don't have a picture of the motor tag, I did take a look at it and saw it was 1.5hp @230V. It's a variable speed Bridgeport so I don't need the VFD to do speed control. I'm also perfectly comfortable wiring in a pot or external control switch, so it doesn't need a remote control pad.

As for the budget Its just a hobby for me, so I don't need something that's going to be 99.9999% reliable or anything crazy, but I don't like buying crap either.

reeves drive i take it on the mill? i take it you are going to use the controls switches that are on machine to control the VFD?


http://www.practicalmachinist.com/vb/attachments/f11/5552d1218052911-request-pictures-vfd-installations-lathes-240-v0lt-3wire-fm50.jpg

here is your basic Volts / HZs the FM50 for $167

http://www.factorymation.com/Products/FM50_230V/FM50-202-C.html

here is a cheap Vertor drive the EV/JNEV

http://www.wolfautomation.com/products/28926/compact-micro-ac-drivebr14-to-3hp-single-or-3-phase-brteco-evjnev-series


external pot 10 omh


http://www.ebay.com/itm/3590S-2-104L-10K-Ohm-10-Turn-Rotary-Wire-Wound-Precision-Potentiometer-Pot-/361292052718



whats good about the key pad type is all the vfd parameters are stored in the pad and you can buy extras for about $15 each. What this does it let you use the VDF for more than one machine. just program each pad for each machine and add a plug to the VFD motor side and a Cat5 jack for controls and its as easy as popping in key pad and plugging in the machine.


these type drive should be put in an incloser and all i do is strip out old motor control disconnects for the box and use them like i have here for a band saw

http://i927.photobucket.com/albums/ad111/tool613/004-29.jpg


http://i927.photobucket.com/albums/ad111/tool613/005-30.jpg

i cut a window and put Plexiglas to see the drive when closed.

here is the drill press with just a foam seal around the face of the drive so it can be controlled with out opening the encloser.

http://i927.photobucket.com/albums/ad111/tool613/wadkin/DeltaVFD003_zpsc4486ee5.jpg

[Jim German]

I don't know how the Bridgeport variable speed works so you need to explain that to the vfd guys to make sure everything is compatible. My mill just swaps pulleys so I didn't have to figure that out. Generally you don't want anything between the vfd and the motor except wire. Dave

It's purely a mechanical system, known as a Reeves drive as Jack mentioned. Basically the pulleys can be varied in size to adjust the speed.




here is your basic Volts / HZs the FM50 for $167

http://www.factorymation.com/Products/FM50_230V/FM50-202-C.html

here is a cheap Vertor drive the EV/JNEV

http://www.wolfautomation.com/products/28926/compact-micro-ac-drivebr14-to-3hp-single-or-3-phase-brteco-evjnev-series



Whats the difference between the two?

[jack forsberg]

It's purely a mechanical system, known as a Reeves drive as Jack mentioned. Basically the pulleys can be varied in size to adjust the speed.



Whats the difference between the two?

for phase conversion and motor control nothing. The sensorless victor drives like the JNEV give much better torque with speed control at the low end and adjust the voltage to the motor for better power at the bottom. The FM50 maintains the volts /hzs Ratios and so can be ajusted to motors that are 208/220 volts from your 240 input with out a transformer. you just set your base frequency. you can do this with the Vector drive you just have to change to to volts/ Hz but then the JNEV is not operating as a vector drive anymore

here is a chart of torque loss with a FM50 and it does drop off after 20 hzs


http://rich.homeunix.com:443/VFD/pics/v-hz-torque.jpg


here is the JNEV

http://rich.homeunix.com:443/VFD/pics/sv-torque.jpg

[Todd Willhoit]

It is all about the application.



...if you run that 1700 rpm motor at 30 HZ, it will turn at half that speed,... At 30 HZ, it will not have the same horsepower...
True. For constant torque, the horsepower is linearly proportional to the shaft speed. For a variable torque application, the horsepower varies nonlinearly (<50%HP @ 50% speed), but varies nonetheless. Constant power occurs above synchronous speed when the inverter output voltage is at its maximum and field weakening is employed. Under load at 50% speed, the output current of a VT inverter will be less than that of a CT inverter. (Simplified explanation.) As such, the power consumption is less, and more importantly, far less than a motor operating across the line. For this reason, an owner can operate a typical pump or fan more efficiently at reduced speed with a VT inverter v. throttling flow with a valve or damper - "and run just fine."



Worse, that motor will overheat.

Non-inverter motors should not be run at less than 20%, according to Baldor, Leeson, and TECO.

Many factors determine whether a motor will overheat. Load, speed, duty cycle, cooling, ambient conditions, etcetera. A TEFC inverter-duty motor operating at 100% load and 20% speed with ONLY a shaft-mounted fan will overheat in short order unless it is overdesigned by 1000% or installed in the Arctic. However, that same motor with an external, separately-controlled cooling fan will operate just fine. There are motors that have no cooling fan whatsoever. They operate perfectly when appropriately applied.



Additionally, Inexpensive VFD's like the one he's holding create constant square wave spikes. These spikes create additional heat, and can destroy a motor's bearing grease.
Better VFD's have filtering on their output, to minimize the voltage spikes that do the damage.

Voltage-source inverters control motors with pulse-width modulated output waveforms. These are square waves of varying widths. The result of the voltage pulses is a current waveform with lots of harmonics. (not purely sinusoidal) Most inverters have a setting that allows adjustment of the carrier frequency, or number of pulses per second of the output waveform. Increasing the carrier frequency causes the transistors to switch more often, generating more heat in the inverter. It also results in a smoother current waveform which produces less heat in the motor. Decreasing the carrier frequency has the opposite effect. There is no free lunch.

The bearing damage you reference is due to shaft currents that create a voltage differential across the bearing. When the voltage is sufficient to track through the bearing components, pitting and other damage can occur. This is generally of greater concern with large motors, large currents, and high carrier frequencies. Actual heating from shaft currents is infinitesimally small compared to heat generated from bearing friction, which is, in turn, infinitesimally small compared to stator and rotor heating.



Better VFD's have filtering on their output, to minimize the voltage spikes that do the damage.

Better = $$$$. Few off-the-shelf inverters have output or input filtering because it is not necessary and doesn't fit the price point. Output filtering is generally a low priority, save for the case of extremely long cable lengths as in down-hole applications. Endpoint junctions in long cable runs create reflections that can result in voltage spikes doubling (or more) the original output voltage level. This is not an issue with a 50' run of cable in a shop.

[Matt Mattingley]

Actually, Matt gave some pretty bad advice in this lecture:

He said that if you run that 1700 rpm motor at 30 HZ, it will turn at half that speed, "and run just fine."

That is not really true, because it's clearly not an inverter-rated motor. At 30 HZ, it will not have the same horsepower (even if it's a constant-torque VFD, which that one doesn't appear to be.) Worse, that motor will overheat. Additionally, Inexpensive VFD's like the one he's holding create constant square wave spikes. These spikes create additional heat, and can destroy a motor's bearing grease.

Non-inverter motors should not be run at less than 20%, according to Baldor, Leeson, and TECO.

Inverter-duty motors have better insulation and cooling fins, plus special grounded bearings so the spikes don't travel through the grease. They can be run safely at +/- 50%.
Alan sorry you didn't like my presentation, The motor I was demonstrating was a 60 hz 5hp. 234/468v 3ph. And 60 years old, table saw motor. At one point in time in it's live it was being run off of 550 V. When I took it into the motor shop to have it inspected, the guy who took it apart said the windings were actually heavier than required, and could hold some extreme variances. He was a little appalled that the motor shop that was contracted for him to put a sticker on it that it was OK to run at 550v. That all being said, I'm not gonna toss that motor out to run it on single phase 220. I'll just slap on a VFD.

I'm not sure would you've done this differently??

[Allan Speers]

I'm not sure would you've done this differently??

What I would have done is I would have been very clear that such an operation is not recommended with every motor any every VFD. Even if you have a 60 year old, massively overbuilt motor, someone else may have a modern, Chinese motor with class B insulation. Irrespective of Todd's excellent info, above (it sounds like he knows what he's talking about) it seems like a very bad idea to imply that it's OK to do something that the motor and VFD manufacturers specifically warn against. Plus, that's good information to add to a presentation about VFD's.
For instance, Todd writes, above: " A TEFC inverter-duty motor operating at 100% load and 20% speed with ONLY a shaft-mounted fan will overheat in short order unless it is overdesigned by 1000% or installed in the Arctic. However, that same motor with an external, separately-controlled cooling fan will operate just fine....." - But you did not mention adding a fan, not that your particular motor is overbuilt and so can take the extra heat. Do you seriously not see how this is a problem?

One might also ask: If I can do all that with a low end 3ph motor and a cheap VFD, why do some machines (top-end lathes, for instance) use those massively expensive brushless DC motors? Well, you know why.

And one might ask Todd: If spikes are primarily a problem only with higher HP motors, then why do Baldor & Leeson use those very expensive bearing-ground devices on even their 2 HP inverter-duty motors? It raises the cost of those motors by at least $100, which is obviously significant. I think this is a reasonable question.

--------------

Maybe you guys could put a text disclaimer under that video at that specific point in the (otherwise excellent) presentation. - And perhaps have Todd Willhoit write a short article on the whole thing, then add a link to that article in the video text. - But I would err on the conservative side, when making any recommendations to total strangers.

[jack forsberg]

Alan sorry you didn't like my presentation, The motor I was demonstrating was a 50 hz 5hp. 234/438v 3ph. And 60 years old, table saw motor. At one point in time in it's live it was being run off of 550 V. When I took it into the motor shop to have it inspected, the guy who took it apart said the windings were actually heavier than required, and could hold some extreme variances. He was a little appalled that the motor shop that was contracted for him to put a sticker on it that it was OK to run at 550v. That all being said, I'm not gonna toss that motor out to run it on single phase 220. I'll just slap on a VFD.

I'm not sure would you've done this differently??

I think you should show that British thermal Houston motor Made for Wadkin Matt Matt. I guess you could've done what that Irish guy did and pull the Core Out and convert it to single phase Old school. I wonder what Baldor have to say about that one. YA let's see that shining beauty that there is no replacement for

[Matt Mattingley]

This is the 5 hp BTH motor that was used in the demonstration of the VFD.

Weighing in at 116 pounds , My two Baldor 5hp are 75,79lbs.
317858

Here is it ripped apart.
317859

Here's it reassembled with its 18 inch blade.
317860

[Jim German]

Wow, those are some giant bearing. How old is that motor?

[Phil Thien]

I enjoyed the presentation quite a bit, thank you for posting it.

[Erik Manchester]

Matt,

That is a beast of a motor, must take a long time to heat that much iron and copper up to any degree. Sorry I missed the live presentation, I'll be there next year for sure.

[Larry Edgerton]

Thanks Jack!

Question: I picked up a Walker Turner Industrial drill press, three phase 1hp with a reversing drum and a power feed for tapping, and have picked up a FM50 VFD to run it.

The reversing drum is in a nice location. Not that I will use it a lot but I do have some left hand bits around that I will want to use occasionally, and may some day take the time to figure out the tapping setup. Would you wire the VFD up using the reversing drum, or would you just eliminate and use the VFD for reverse? I assume the reversing drum just switches two leads back and forth.

I am not genetically disposed to like wiring I am afraid and have been putting this off for a while as I can run it on the converter, but it sure would be nice to run it on 110.

Thanks Jack, Larry

[David Kumm]

Wow, those are some giant bearing. How old is that motor?

6210 and 1306. Some old table saws used even larger bearings. I've seen 6309 and 6311. If you look closely at Matt's picture, it appears that the 6210 is a brass cage precision bearing. Very hard to source and expensive. The old machines were so well built that precision bearings were often used as large bearings support a much greater load but they can not run at as high an rpm as smaller bearings unless you go to a loose clearance. Rather than compromise, manufacturers often went to a precision brass or phenolic cage bearing that could provide load and speed. Increased the cost of the bearing about 10X but that was the way it was. Dave

[jack forsberg]

Wow, those are some giant bearing. How old is that motor?


Jim The British Thomson-Houston Co Ltd (BTH) started in 1892: General Electric Co (http://www.gracesguide.co.uk/General_Electric_Co) (USA) was created by the merger of Thomson-Houston and Edison General Electric.

http://www.gracesguide.co.uk/BTH

BTH made motors for Wadkin as early as 1922 and this motor design is that old and was made well into the 60s but to be fair to Wadkin BTH only made the stator and rotor and Wadkin built the shaft bearings and housing to fit there new line of electric drive machines. Wadkin was one of the first in the UK to bring Electric drive motor Woodworking machines to the industry and as such many of these were of the direct drive mount as an option over belt drive than dominating the industry.

the flatten motor design by BTH for Wadkin was to reduce the core diameter to improve the deep of cut the motor spindle could make. Wadkin had patents on this. the first motor drives for the Saw(the Wadkin PK) that Matt and I have were very experimental.

the saw in line belt

http://i927.photobucket.com/albums/ad111/tool613/sc000676c0_zps26cc204c.jpg

first electric drive 1922
https://forum.canadianwoodworking.com/attachment.php?attachmentid=68223&d=1383915612
both these early modles were of the fixed arbor type saw and what the BTH motor did was give the PK a tilting arbor with Electric motor drive. the same motor was built for the Wadkin AC cross cut saw and introduced in this 1922 catalog.

J.H.Goddard the Head of Wadkin at the time in May 1926 approached B.T.H and ordered a complete range of stator and rotor units suitable for driving woodworking machinery. by April 1928 Wadkin were able to issue their Booklet no 173, it stated that this was the first British Publication and probably the first European publication devoted exclusively to electric driven woodworking machinery, twenty-one machines are shown all were electric drive.

http://i927.photobucket.com/albums/ad111/tool613/wadkin/282318745_zps7b53a081.jpg

Wadkin had at it factory at Green Lane works a test department to test all the machines including electric drive. and machines from wadkin until the early 90s had a test number on the machine tag.

http://www.ktproductions.co.uk/woodworking/wadkinminsterworkshop/DSC_0427.JPG


http://www.ktproductions.co.uk/woodworking/wadkinminsterworkshop/DSC_0400.JPG
test department early 20s Green Lane Works(Wadkin & Co)

http://i927.photobucket.com/albums/ad111/tool613/wadkin/1920_zps240e3473.jpg



the Wadkin PK BTH motor in the fully developed Pattern Maker saw.

http://i982.photobucket.com/albums/ae301/matty355/sc0001efbd.jpg


here is my saw from the 50s and i can tell you Matt's will be no less stunning.

http://www.finewoodworking.com/uploadedimages/Fine_Woodworking_Network/Image_Resources/Magazine/230/011230077_01_1950s-wadkin-pk-tablesaw_lg.jpg

[jack forsberg]

Thanks Jack!

Question: I picked up a Walker Turner Industrial drill press, three phase 1hp with a reversing drum and a power feed for tapping, and have picked up a FM50 VFD to run it.

The reversing drum is in a nice location. Not that I will use it a lot but I do have some left hand bits around that I will want to use occasionally, and may some day take the time to figure out the tapping setup. Would you wire the VFD up using the reversing drum, or would you just eliminate and use the VFD for reverse? I assume the reversing drum just switches two leads back and forth.

I am not genetically disposed to like wiring I am afraid and have been putting this off for a while as I can run it on the converter, but it sure would be nice to run it on 110.

Thanks Jack, Larry


Larry the drum switch you have is most likely 3 poll single throw . To use it with the VFD you would take it out from switching the motor power( you can switch motor power on a VFD if its large enough to run more than one motor at a time and sized correctly but should be avoided) use the drum switch for switching the VFD from the control side (low voltage). in that case you would only use one of the 3 contacts in the drum switch to control rotation command to the VFD. The old drum switches are very robust and i would do it that way to keep the machine period.

[Matt Mattingley]

6210 and 1306. Some old table saws used even larger bearings. I've seen 6309 and 6311. If you look closely at Matt's picture, it appears that the 6210 is a brass cage precision bearing. Very hard to source and expensive. The old machines were so well built that precision bearings were often used as large bearings support a much greater load but they can not run at as high an rpm as smaller bearings unless you go to a loose clearance. Rather than compromise, manufacturers often went to a precision brass or phenolic cage bearing that could provide load and speed. Increased the cost of the bearing about 10X but that was the way it was. Dave
Dave great eye,lol.317893 317894

[David Kumm]

Dave great eye,lol.317893 317894

I'm not that observant. Saw the bearings in another post and because I'm anal about bearing quality, I've never forgotten and never seen any to buy. Polymide has replaced brass in most self aligning bearings. I doubt you could buy those two for $1000. Probably got the saw thrown in for free. Dave

[jack forsberg]

[QUOTE=David Kumm;2446809]I'm not that observant. Saw the bearings in another post and because I'm anal about bearing quality, I've never forgotten and never seen any to buy. Polymide has replaced brass in most self aligning bearings. I doubt you could buy those two for $1000. Probably got the saw thrown in for free. Dave[/QUOTE

There were two PK motor types by BTH for the PK. A TEFC motor with a 6210 deep grove bearings on the blade side 1306 in the rear,that was the model ZEF . Matt's Motor is the model ZF a ventilated enclosed motor that increased the depth of cut by a half an inch because the windings are up against the aluminum motor casing and used a SKF RL 16 double Rowed self aligning machine bronze cage Percision bearing with a SKF RM 6 self aligning Machine brass cage rear bearing. Matt's got the best Motor option that Wadkin offered on the PK.

[David Kumm]

I forgot about the ZEF. I think those bearings are even harder to find in brass cage now. Isn't that the most rare motor too? Dave

[jack forsberg]

I forgot about the ZEF. I think those bearings are even harder to find in brass cage now. Isn't that the most rare motor too? Dave

i think its a later model and not sure how rare I have this motor Dave and my bearing are still good after 75 years. Consolidated bearing out of NJ can make them for you for about $250 each.

[David Kumm]

i think its a later model and not sure how rare I have this motor Dave and my bearing are still good after 75 years. Consolidated bearing out of NJ can make them for you for about $250 each.

Sounds fair. SA bearings will be more expensive than a standard deep groove but less than high precision deep groove. Cage material will dictate cost but high precision generally isn't needed because the outer rotates on two axis anyway. ( You and I are likely the only two who care ) Dave

[jack forsberg]

Sounds fair. SA bearings will be more expensive than a standard deep groove but less than high precision deep groove. Cage material will dictate cost but high precision generally isn't needed because the outer rotates on two axis anyway. ( You and I are likely the only two who care ) Dave
:p:p:p:p:p:p:p:p:p:p:p:p