The Home Machinist!

Hello All,

New to the forum. I am in need of some help if possible. I have a Smithy Granite 1324 that is currently having issues with the motor or controller. It no longer works and blows the fuse in the controller box when turned on. Now I have spoke with Smithy about this and they recommend replacing the motor and controller for $700.

Now the reason for the post, Has anyone installed a none smithy motor and controller? Preferably a brushed type? If so any recommendations? I'm not really a fan of the Chinese brushless set up smithy is offering as it has always given me small problems.

Thanks

-Jay

$700 to get back to the exact same point of having an obvious failure prone system that will at some point also fail again? If it were me I'd check the motor HP rating, mounting type, it's output shaft diameter and length and then just convert over to a 220V 3 phase VFD system. Much more durable if you choose decent components and it will give you many more control options than the stock set up ever had. That may not be quite a direct conversion though. It's highly likely your current motor uses what's known as an Asian specific frame and shaft size. There not an exact interchange with off the shelf imperial or metric motors so at least one new pulley and maybe a bit of work to the motor mount might be required. Over the years I've read dozens of forum posts complaining of poor reliability with systems just like yours and further problems later on after these components were replaced.

amen to pete's suggestion

Thanks For the Replies,

Pete, the motor is a DC brushless 2hp system and It's face mounted via 4 hex bolts and each corner. I would like to replace this current system with a better and more simple setup although I'm not sure where to start. Can you tell me where I could find a good motor and controller box?

Thanks

https://cdn.shopify.com/s/files/1/1845/ ... 1577043647

If you are sure the motor is cooked..

Find a 3 phase AC 220 v motor that will fit - or a brushless DC if necessary.

The rest is cookbook

However if the motor is good..then all you need is a new controller of better quality.

Blowing fuse on power on may well only be a control problem .

Blowing the breaker may not be the motor or controller at all.

On my ShopTask Tri-Power (may even be the same 2 HP motor), the bearings on the quill got tight and the extra resistance was enough to blow the wall breaker every time I would turn on the mill. I had the bearings replaced and it fixed the problem.

Have you tried running it without the belt for the quill installed?

Bill Shields wrote: ↑Mon May 17, 2021 8:40 pm If you are sure the motor is cooked..

Find a 3 phase AC 220 v motor that will fit - or a brushless DC if necessary.

The rest is cookbook

However if the motor is good..then all you need is a new controller of better quality.

Blowing fuse on power on may well only be a control problem .

Thanks for the Reply Bill, much appreciated.

toddalin wrote: ↑Tue May 18, 2021 12:52 pm Blowing the breaker may not be the motor or controller at all.

On my ShopTask Tri-Power (may even be the same 2 HP motor), the bearings on the quill got tight and the extra resistance was enough to blow the wall breaker every time I would turn on the mill. I had the bearings replaced and it fixed the problem.

Have you tried running it without the belt for the quill installed?

Hi Toddalin,

Yes I have, everything is very smooth running except when I had the failure. Prior to the failure I was having a odd running situation. If the machine was left standing after a period of time (say a day or so) without use the machine would power on but turning the potentiometer would result in delayed spindle movement. It would stutter or suddenly would come on abruptly and mimic the dials speed pattern that I created when I was trying too get it to spin up, afterwards the motor would function normally until I let it sit again.

I could never figure out why it did this but it only got worse. Eventually It came on one day at what seemed like max rpm while trying to get it to spin up and I hit the stop button. Ever since then power on resulted in a blown fuse. Also the motor was noticeably harder to turn which normally spun pretty easily.

Depending on your location, but if your in North America and if it were me I'd give these guys a call. https://www.automationdirect.com/adc/home/home I've not personally dealt with them yet, but they seem to always get good reviews on the forums. Yes there's definitely cheaper ways to go by ordering motors and VFD's off Ebay, Alibaba, Bangood etc. But going cheap by your machine manufacturer is already the primary cause of your issue. How common it still is today I don't know, but I've read a few past forum posts where some of the cheapest VFD's didn't come with all the internal components to even work. And while programming a VFD is easy enough, you do need a good well written user manual. So I'd try and buy something with a familiar and respected name. Hitachi, Mitsubishi, Baldor etc. Counterfeit's aren't unknown either, so buying from an established dealer who's going to back up what they sell is to me the much safer idea.

It's sounds like you have a normal face mount motor, but you'll still need a few measurements. Size and thread pitch of the mounting bolts, spacing of the mounting holes, motor shaft diameter, it's shaft extension length, keyway size if it's got one. And if there's space issues, the motor length and diameter in the area it has to physically fit into. But if you do have the room where the motor mounts? Then to me it's not a bad idea to step up maybe 1/2 - 1 HP more just for the added torque at lower rpms. All this is a bit of work and as mentioned I'd fully expect to have to do some simple fabrication to at least the motor mounting plate or even replacing it. With face mounted motors there normally just a flat plate with a few holes to mount the motor and a pivot hole for belt tension so that's easy enough. What shaft / keyway size your OEM motor has might also create issues matching your existing pulley to the new motor. At most that might require a new pulley. Fwiw and from my own experience with my step pulley 3 ph mill. I'm still planning on replacing my already variable speed single ph lathe motor with a 220V 3 ph and VFD just because of it's much smoother and quieter drive plus all the options it allows for motor control.

Jay79 wrote: ↑Tue May 18, 2021 2:05 pm the motor was noticeably harder to turn which normally spun pretty easily.

I was reading controller until that line.
How hard is it to turn?
A brushless motor with the belt removed should spin almost effortlessly. If not, the bearing (s) are likely your problem.
And a cheap fix too.

Ok, Thanks Pete, appreciate the link.

Within a few months of getting my machine, the controller let out it's magic smoke. I repaired it (replaced the SCRs on the board) but it happened again real soon. Then I discovered there was a problem with the motor itself -- a brushed DC 1.5hp, 180v motor. Some of the windings were shorted, and the over-current was taking out the controller. The manufacturer replaced it under warranty and I replaced the controller with a KBWT-210 PWM type controller rated over 2hp and 260vdc. Never looked back, better low speed torque, quieter running -- no, scratch that, *much* quieter running -- and a few features like soft starting and overload protection.