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mcphill
01-06-2012, 01:15 PM
I am trying to troubleshoot speed dropping issues at low speed and low torque operation at low speed on my 1610L. I am trying to find out why my spindle does not operate properly at low speeds (under 1000 rpm).

You are committed to your customers, and you want to be as open source as possible, so I thought I would give you a chance to help out your customer base. You did not respond to this request with the needed information buried in another thread, so I wanted to make a new one to ensure that you would see the request from a customer in need of help. I know of at least 2 other users who have similar problems, and have not resolved the problems after extensive troubleshooting over the phone and replacement of parts with Mikini. If we, together, can find a solution, it would allow other users with the same issue to learn from the experience.

In order to assist in my troubleshooting activities, could Mikini please provide the following specs on the spindle motor (states as 3 hp linear motor on the machine):

Resistance, in Ohms
Inductance, in milli-Henry
Ke - Peak, in Volts per 1000 RPM
Rated Current - Peak, in Amps
Number of Poles

Thanks in advance.

If Mikini can't, or for what ever reason won't, provide this information, I will get it through testing and/or experimentation. If I need to discover the information on my own I will certainly post it for the rest of the end users to have full access to - as is the purpose of forums such as this. Posting information is not a crime, and it does not open you to any liability. It is physical information/specifications about a piece of hardware that is provided on the Mikini 1610L - a motor that for some reason does not have a motor plate. Having a motor plate that states this type of information is a common industry standard.

Thank-you in advance for your cooperation in providing these attributes to the motor.

Al_The_Man
01-06-2012, 01:25 PM
Hopefully you will get an answer a bit more informative than the US buyer of a RR Silver Ghost, when asking for the motor HP, Rolls answer was 'Sufficient'!.

BTW I would be interested in knowing the physical size of the motor and/or a Pic if you have it?
Al.

mcphill
01-06-2012, 04:44 PM
Ok, so you did respond to the buried thread, thanks. Your response is here: http://www.cnczone.com/forums/1046017-post1.html

My response to your response is as follows.

Requested information:

Resistance, in Ohms
Inductance, in milli-Henry
Ke - Peak, in Volts per 1000 RPM
Rated Current - Peak, in Amps
Number of Poles

What I understand as a response:

Resistance: Not given
Inductance: Not given
Ke - Peak:

You stated "Peak rated continuous RPM is 6000... Peak voltage is 320 VDC". If calculated as 320 V/6k rpm this would yield Ke = 53.33

However, if we calculate it as Ke=Kt=T/i, and use your numbers of 7 ft-lb (1344 in-oz)/30 amps you get 44.8 - likely includes some of your de-rating.

I would say a value around 50 V/1k rpm for Ke will suffice as a starting point.

Rated Current: 30 amps
Number of Poles: 4

FWIW, I do have electrical schematics that FAR exceed what was provided for the Mikini for both my Ford truck and my Audi TT. For the TT I have over 50 pages of schematics, down to the exact color and specific function of each and every wire in every wiring pigtail/loom. This from a book that was purchased, not "gleaned" from the internet. I'd be happy to purchase such information from Mikini, but as we know, you want to provide as much as you can as Open Source, so I am happy for both of us!

Now for those resistance and inductance values - care to share? Again, it is a relatively simple matter to measure what I need, but if you can provide this information I would greatly appreciate it!

Thanks in advance for your cooperation/participation in this thread!

mcphill
01-06-2012, 04:51 PM
Al,

Thanks for your interest!

Here are a few photos:

http://images44.fotki.com/v220/photos/1/435091/10321339/CIMG1554-vi.jpg

http://images51.fotki.com/v278/photos/1/435091/10321339/CIMG1555-vi.jpg

http://images56.fotki.com/v371/photos/1/435091/10321339/CIMG1556-vi.jpg

More at this link: BLDC on Fotki (http://public.fotki.com/mcphill/mcpi-inc/mikini-1610l/bldc-photos/)

MIKINI MECH
01-06-2012, 05:39 PM
McPhill,

Sure thing. We've published all of the details on how to troubleshoot your drive system. If you're interested in doing so, we welcome your reply and results. We also welcome your comments as requested on new products and documentation.

We've also published fairly comprehensive performance specifications and relative comparisons of drives further to your request for information - link below, post # 25

http://www.cnczone.com/forums/mikinimech/144157-happy_new_year_mikini_mechatronics.html#post1046077

Correct, our motors are custom wound, and then de-rated, as stated, here, and on our website.

We believe the inductance and winding information is design and manufacturing information not required for your stated purpose of troubleshooting, and is not currently public information that we provide. We can work to make it so, if needed. We simply ask this : document a troubleshooting procedure that requires these values, with our motors and drives, that will provide a comprehensive answer.

We will review it, and if valid, make it part of our official documentation. If it helps for use with our systems within the "definition of intended use", we're fully committed to providing it.

If your intention is reverse engineering, or modification, simply measure the values you need as you have stated you will previously. If you need them, measurement of them will take less time than asking (or even typing them out perhaps) .... Not trying to be defensive or evasive, just restrictions we have to work within. And we're happy to work with you on them, as we've offered.

Might want to double check assertions in regards to information not presenting liability - this is not an truly anonymous forum. We have zero intentions of it ever being an issue from our end, but you might have no idea what your, or someone else's insurance company or lawyers might do. Actually far less likely to be an issue on a machine, than on something that might occur on a vehicle for example. The only reason we even comment is you've publicly asked us to correct statements we believe to be inaccurate. We want our users to be as safe as possible, and understand liabilities that are being incurred, intentionally, or unknowingly.

Again no offense, at all intended here. None. We're trying to be helpful, contributing, and supportive to our customers, and the industry in general.

Hopefully it's entertaining reading as well - hence our attempt at color, for that, and only that, reason.

:idea: Might have to look at an Audi next time around. Is that a manual from Audi, or third party ?

Ford offered a free dyno test yet :)

Any ideas on new products (for Mikini, or the industry in general to offer) ?

Got any good ideas on how to deal with the inter-tied insurance & risk issues we deal with as a US based industrial equipment manufacturer ?

We encourage all to be in touch, via any form of communication,

Mikini Mechatronics, LLC



Ok, so you did respond to the buried thread, thanks. Your response is here: http://www.cnczone.com/forums/1046017-post1.html

My response to your response is as follows.

Requested information:

Resistance, in Ohms
Inductance, in milli-Henry
Ke - Peak, in Volts per 1000 RPM
Rated Current - Peak, in Amps
Number of Poles

What I understand as a response:

Resistance: Not given
Inductance: Not given
Ke - Peak:

You stated "Peak rated continuous RPM is 6000... Peak voltage is 320 VDC". If calculated as 320 V/6k rpm this would yield Ke = 53.33

However, if we calculate it as Ke=Kt=T/i, and use your numbers of 7 ft-lb (1344 in-oz)/30 amps you get 44.8 - likely includes some of your de-rating.

I would say a value around 50 V/1k rpm for Ke will suffice as a starting point.

Rated Current: 30 amps
Number of Poles: 4

FWIW, I do have electrical schematics that FAR exceed what was provided for the Mikini for both my Ford truck and my Audi TT. For the TT I have over 50 pages of schematics, down to the exact color and specific function of each and every wire in every wiring pigtail/loom. This from a book that was purchased, not "gleaned" from the internet. I'd be happy to purchase such information from Mikini, but as we know, you want to provide as much as you can as Open Source, so I am happy for both of us!

Now for those resistance and inductance values - care to share? Again, it is a relatively simple matter to measure what I need, but if you can provide this information I would greatly appreciate it!

Thanks in advance for your cooperation/participation in this thread!