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Father-of-Ash Mon 23 March 2015 13:06

WOW These parts are big!! Toledo, OH
Hello everyone,

Like almost everyone else here, I've been here behind the scenes for 3-4 years and finally found a reason to build One! :D

I'm an auto mechanic for the past 15 years as well as doing custom computer builds and repairs. I was frequent on the forums when I first found out about mechmate, but haven't been around for over a year now. Much reviving to do.
I plan to do a 6' x 12' table mainly for cutting aluminum plate, which is my main concern. I know there are a few people who cut aluminum but I'm not sure how much chatter they have in the finished product (mostly worried about circles/ovals). I know mechmate is designed for wood but i would prefer to complement it rather then buy a different machine(if that's possible). I have a few ideas on how I think I can minimize chatter please let me know how crazy / stupid they sound.
1. Add weight to the gantry, fill tubes with cement?
2.use thicker plate for the y-car(which means bending points will have to be adjusted?)
3. And widen the y-car for an added z-slide opposite of the original z-slide ( all other gantry plates will have to be widened as well)

I have more uneducated questions that I will ask in appropriate locations.
In the mean time, more reading.

All your inputs and criticism will be greatly appreciated.

Gerald! Thank you for this fantastic machine and everyone supporting it.

smreish Mon 23 March 2015 19:54

Welcome to the group.

1) Mass added to the machine will change dramatically the motor size needed to drive the axis'
2) The y-car is very rigid - not sure why this is a consideration.
3) y-car already fits 2 z slides. I have done it twice. But, if you want dust collection - you will have to route that outside the y-car to suite your needs.

....NOTE: I am not an engineer and can only tell you I have cut plenty of .120/.187/.250 alum plate on the MM with no issues with the correct lubrication, cutting bit and feed rate without any undue modifications to the machine.

Build particulars.
10" channel sides
standard MM railing and Vee wheels
7.2 OM geared motors
20T pinions for Alum / switched to 35T for wood and faster JOGS.

Father-of-Ash Tue 24 March 2015 08:32

Thank you Sean,

I knew i should of caught up on reading.:o
Hopefully by tonight I'll be able to read through your build once again.

I haven't purchased the plans yet, I would like to get a rough estimate on cost first.

can anyone tell me what the biggest disadvantages are in electronics, the Chinese 4 axis 2M542 with bob for $180 vs. the Gecko 203v and PMDX setups?

servant74 Tue 24 March 2015 19:36

From what I have seen, it can cost between $2000 and $8000 USD in the USA, depending on your 'scrounging' abilities and luck finding used steel and equipment.

The metal and laser cut parts are about half, and the electronics/steppers/electronics enclosures/etc are the other half.

Software can go from free/open source to High$ cad/cam packages hooked onto high$ proprietary software that may require a 'good computer' to make it run.

'Typical' costs if you are careful and shop around are about $5K USD. This doesn't include your time and possibly some tools you may not have.

Some folks find steel suppliers that can cut the metal and punch the right holes but modifying any of the plans to get them to do that is up to you. That is a trade off of time vs paying for the service supplied. ... Like I said, there are tradeoffs.

Still, the Mechmate is IMHO a better than many other CNC rigs for $20K or more. (Persionally, I compare to but that is just me.)

Father-of-Ash Wed 25 March 2015 00:37

Thanks Jack,

I decided to already purchase the plans so I can get a better idea of what I am doing.
I'll eventually put up my shopping list. I just got done printing out all the PDF files and organized them in a binder to look through at work(on my free time);)

Does metalhead Mike email the rest of the files? All I had for download were 5 PDF files and a frequency calculator.

btw...shopbots look like MM's little sister.

servant74 Wed 25 March 2015 10:46

The first MM was a old version of Shopbot with 'mods'. Ever since (If I remember right) it has been it's own design ... Thanks to GearldD!) A few changes have happened, but not a lot showing to me the solid design it is. It is not all things to all people, but the design is flexible enough for many uses and personalization.

Pretty much the plans are what they are. I got mine back when they were free for registering, but Mike change that when GeraldD 'retired' and sold the site. ... Not good or bad, but that is how it is and what Mike is asking is very little for what you get, including the support of this community!

This group does address lots of issues for all kinds of CNC, but we try to focus on MM and related issues. For non-MMers, there are other good forums online. (Since you purchased the plans, sorry, you are stuck here! :-) ). I have seen some MM issues brought up elsewhere, but this forum does a great job.

Disclaimer: I have not built one 'yet', but would like to eventually. I may build another smaller machine that is not as capable, but a MM is still my long term desire. As I get older, it might not be reasonable though, but it doesn't keep me from dreaming.

Father-of-Ash Thu 26 March 2015 09:53

Originally Posted by Father-of-Ash View Post

btw...shopbots look like MM's little sister.
What i meant by that is that shopbots look very whimpy when compared to MM, especially for that price tag.

Can anyone tell me about the .dxf files? The purchased plans only have the PDF files. I have 2 local shops I'd like to get quotes from for the cutting and bending.


servant74 Thu 26 March 2015 13:03

Shopbot is a forefather of MM. MM is the stronger child of the ShopBot. The current SB is the weaker sibling of the current MM. The genetics changed in the SB as the design changed over time.

As far as I know there are no DXF files in the 'package'. The MM design came about before quite so much CAD was prevalent, so no DXF files that I know of. There might be a few that builders made for their own purpose, but not of the entire machine.

Suggestion: Copy/reprint the relevant pages for the potential vendors. ALWAYS keep a copy of the files and a printed copy available for reference. When building, you should have another copy in your shop to get dirty and build from.

Father-of-Ash Thu 26 March 2015 15:51

Thanks for the suggestion Jack.

As for the dxf files, I was referring to the files for the parts that need to be laser/plasma/ water jet.

rcboats1 Thu 26 March 2015 22:25

Save yourself the trouble and get them from Mike.

Look under products.

smreish Fri 27 March 2015 20:00

I just visited the page at mikes under products and saw the Rev 1.o of the grinding skate in my shop after the first mock-up before Gerald put the skate into the drawing package. WOW - that brings back memories. If you look really close, I didn't have a brake in the shop to bend the 3/16 steel plate, thus had to weld up the angle bracket on the skate.

....and all those fasteners - Goldberg would be proud!

Gerald D Sat 28 March 2015 05:34

I wouldn't say this is my best ever design, but the hours put into it to make it "buildable" in all corners of the world seem to have paid off. :)

It is a bunch of common materials, spiced a little by the use of CNC laser cut parts. SB machines have to be lighter because they have to ship them out as kits at an economical price, and they have to be more expensive because they have labour to pay. When you are given guide prices for MM builds, that excludes shipping and labour.

The other ingredient in the MM recipe is this Forum that serves as the instruction manual. It assumes the potential builder has done his homework and has a basic understanding of what he is getting into.

Father-of-Ash Sat 28 March 2015 13:26

I knew this was going to happen...

The more I read, the harder it is for me to settle on an idea from any perspective of the build.;)

I am going to try and draw out the table in cad:eek:

Amazing how much I have forgotten in 1.5 years, I wish I wrote notes.

Gerald I understand and want to thank you for you time and commitment in making these plans and this community.:)
......I'm still in the homework process, but hopefully by the end of next weekend I will have settled on most of I would like to do as far as table design and build process goes.


MetalHead Sun 29 March 2015 20:23

Welcome aboard . As far as the build, get your size (6x12 I think you said) then build the machine direct drive to get it going . Use a basic control box design and spend your money up front on a good spindle setup. You can upgrade off of that platform very easily . Don't over analyze , the design is very flexible thanks to G's design and the forums input.

Fox Mon 30 March 2015 17:00

I wouldn't say this is my best ever design, but the hours put into it to make it "buildable" in all corners of the world seem to have paid off.
It would be interesting to hear what you would have done different in hindsight (always easier looking back) ? Or is that just the perfectionist in you speaking :D?

Gerald D Tue 31 March 2015 00:17

I prefer not to look back at it . . . I have enough on my plate to look forward to :)

Father-of-Ash Wed 01 April 2015 02:20

Thanks for the input Mike.

Plans have moved forward much faster then expected, I plan to make most of the electronics purchase by next week and get started with the recommended kitchen table.
Naturally I have a few questions....ok a lot of questions but its already 2am here so I'll quick for now.

I definitely would like to use the belt reduction and not sure if 7:1 is overkill? I do like a little bit of overkill only when i think it might help in the future. But if 4:1 does a great finish job on aluminum plate then i would go with the ratio with the faster jogs.

I saw a lot of people raising the question of tooth contact in the belt reduction units but I couldn't find anyone having issue with it. is there a preference in whose design to go with?

The stepper I picked out is the PK299-F4.5A for the X & Y, and the PK296-F4.5A for the Z. How does Motion king compare in quality and duration? 34H2A5850 & 34H2A2827 respectively. still need to calculate a power supply for the system.

Found this 4kw Chinese spindle and VFD, there are slight differences in all These Chinese spindles and I'm not sure how many different manufacturers there are. Can anyone point me to a reputable ebay seller or other recommended sources? also not sure what a good price is for such spindles.

Would anyone recommend the double Z-slide for added stability? I would be using the extended Z-slide according to plans. I would like to try cutting aluminum 3D parts...

I apologize for annoying questions, I am one who is reaping the benefits of this forum. Hopefully my project will bring something new to contribute to it......although doubtful.

Thank you,

KenC Wed 01 April 2015 03:46

7:1? no problem, just build it the way you like it.
Other places which you can over kill are, triple your steel weight, 25hp spindle, 50hp vane type vacuum pump, i7 16GB Ram, 32"monitor..... :D

smreish Thu 02 April 2015 02:05

Double z for added stability? The y-car is designed to have the spindle closer to the drive motor on the y car for this reason. Save the space for a dedicated tool - like air drill for pointing or dust/cooling

Fox Thu 02 April 2015 05:08

I prefer not to look back at it . . . I have enough on my plate to look forward to
all good, I can understand you do not want to come out of retirement by posting things and people starting to ask questions about it. Although I did made some customisations to the MM (mostly Z related), I am still very impressed with the good job you did.

Father-of-Ash Mon 06 April 2015 18:31

Hello again,

Sean I wont mention the stability of the Z-slide again I promise!:)

I do want to ask about the power supply i have picked. AN-10435 - 1000VA 35V

PK299-f4.5 x3 Bipolar parallel
2.5 inductance
1.9 VDC

PK296-F4.5 x1
1.5 inductance
1.4 VDC

Will the PK296 at the Z be ok if i use a current load resistor at the gecko as Gerald suggested a while back or is there a different maybe better way now? How do I deal or eliminate the over voltage issue since I'm using a 50vdc supply? I think max is 39VDC for that motor.

At first I did the calculations backwards and almost missed it.(the DC output is 1.414 times greater then the AC input correct? or did i just double confuse myself?)
Do I have room for two more motors down the road using this supply?

Sean, I have a silly question about the Neutrik XLR connectors you recommend. Do any of the male plugs fit the female? they seem to be class specific and i cant find the male plug for NC4FD-LX-B. The EMC class only comes in 3-pin which is recommended when viewing the 4-pin female.

Again I apologize for so many questions, just need to get it worked out in my head and hopefully only have a one time purchase of everything I need.


KenC Tue 07 April 2015 04:24

50V won't burn the motor... if it doesn't burn your driver 1st.

Father-of-Ash Wed 08 April 2015 12:46

Ken, so is that supply a good pick? are you saying the driver would burn up before it hurts the motor?

I figured out that connector issue...:o...silly me.

KenC Wed 08 April 2015 22:25

I would not pick this when I have all the choices in the world. but if that is what I have in the junk pile, I would try it out. won't harm a thing IMHO. If it doesn't work out, then I'll use a "more suitable" one.

Father-of-Ash Sat 11 April 2015 14:13

How much lower should i go to suit the pk296?
I used the gecko calculations and read alot from what Mike "Richards" and Gerald said, but still not sure how to pick a suitable supply with a different motor in the mix. Is 40 VDC too low for the pk299's? so maybe 45 VDC is ok?:confused:


KenC Sat 11 April 2015 23:49

the calculated figure is a guide, not something you must follow to the dot...
IMHO, get the calculated figure & use the nearest voltage you have. btw, nobody really want to use lower voltage, acceleration will go lower with it.

MetalHead Sun 12 April 2015 06:54


Your over thinking your setup. Go read Rusty Nuts thread.

You should use the same motors across the machine for simplicity.

PK299-4.5A (wired 4 wire) (or similar)
PMDX-134 (or 2 PMDX-133 if you want 5th axis growth but most don't do it even if they add for the growth)
Gecko G203V Digital Step Drive (4 at least, 5 if wanting growth)
Basic Control Box (Box, Back Plate, DIN rail, Contactor, switches, etc)
Heat Sink
External safety control boxes (Start, Stop E-Stop)
Wire 4 (164 feet) and 8 core (82 feet). Add footage if not mounting box on machine (But most mount box on machine.)

Now as far as simple wiring. LESS CONNECTORS IS BETTER.

You can use the DIN rail connectors as your termination points and compression grommets as your through box seals. Wire runs straight from the motor (Hard Wired) to the DIN rail connectors.

PMDX-126 uses 110V AC Power, so no secondary 5v/12v DC is needed. Simple hook up.

I also have a video I can send you ($20.00) that explains the contactor wiring.

I can supply all of these parts as one order.

Father-of-Ash Tue 14 April 2015 17:37

Thanks Mike, I will PM you for some pricing.

rcboats1 Wed 15 April 2015 12:08

You can't go wrong with Mike's kits. I have his video on wiring the contactor and if you are not strong on the electrical side this will help you.

pblackburn Thu 16 April 2015 15:49

The calculations are how to figure out the voltage. I have a PK299-F4.5A wired parallel and use 56VDC. There is a little bit of compensation that is required for torque to be maintained. That is why a higher voltage. I did have a calculator uploaded in the power supply section of the forum. How you plan on wiring the motors will make a change on the supply needed.

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