Tag Archives: CNC conversion

Comparison of 12V DC LED light strips in shop light conversions (3528 vs 5050 vs 5630)

Shop light using 12V DC LEDs using 3528/5050/5630 Flexible Light Strips   In an earlier post I shared how I converted shop lights to low cost LED lighting using readily available 12V DC LED light strips with 3528, 5630, and 5050 SMD LEDs as pictured above.  These lighting strips are very low cost ($5-8/ 5M roll shipped)  and provide an easy way to add light to any place you need it, not just for a shop light conversion.  You can run them off an AC to 12V DC power supply or a 12V battery, which makes them extremely handy in the case of a power outage.   In this post I compare the differences between each LED strip and share which one makes for the best shop light conversion.

SMD LED light strip comparison

Theoretically the 5630 LED is one and half times brighter than the 5050 LED which is three times brighter than a 3528 LED.  However, this does little to tell you which one is really the best light.  Interesting is that the part number actually refers to the size of the individual device, with 3528’s being 3.5 x 2.8 mm and so on.  All have approximate 120 degree emitting angles, the angle at which the light radiates outward from the chip.  You have to be a bit careful with the whole lumens or candela rating on LEDs. These are measured  via standards and tell you nothing about the color/quality of the light produced.

12V DC LED Light strip Comparison

Above shows one of my shop lights converted with 3528 LEDs light strip.  I used three lengths of light strip on this lamp. It produces an amount of light that is considerably less then two 48″  T32 bulbs, but is still more then adequate for some shop spaces.   The power rate of 0.08W/led for 3528’s makes it the lowest power per LED device of the three.  It also has the lowest rated light output.  The light output by these strips is a good color.  By this I mean observed quality.  I am not talking about measured wavelengths.  It has a very very slight cool or  purple tinge to it, but it is almost unnoticeable. Not noticeable at all without a grey card Kodak photo scale reference handy. For lower power less used areas I think these strips are good. I would not use these in an area I was using all the time as they do not emit enough light.  I used these 3528 LED light strips inside my 3d printer enclosure and they work wonderfully for this application.  If there’s not enough light you can simply use more of the strips.

12V DC LED Light strip Comparison    Rated at 0.5W device on strip, the 5640 LED’s are theoretically the “brightest” of the three I’m comparing for shop light use in this post.  I find the light emitted from these to be very purple and harsh.  I strongly suspect, that the LEDs used in these strips are a low cost clone of the Samsung 5640 OEM chips and thus the poor light quality. This is my least favorite of the lighting strips. I would not recommend the 5640 light strips for any applicaton, the light generated irritates me.  Additionally, even with 3 rows (instead of 2 of the 5050 strips)  it has less apparent light generated then the 5050 lamp with 2 rows.  The real drawback is the color on this one,  Have I mentioned that I find it highly irritating?  I only converted one lamp to these and I will put it in a location I almost never use because of my dislike of the output lighting.  I may even change it over to 5050 strips eventually.

12V DC LED Light strip ComparisonThe clear winner of these three and my favorite is the 5050 LED strips.  With a power consumption of  0.24W per device, they have a  good balance between color output, and total light intensity.  Two strips seems more then adequate, vs three of the other strips.  I really like the quality of the  light produced by these strips.  It is a bright white without any weird or subtle tint.  It almost feels like natural lighting.  These strips are so good I ordered several more rolls of this light strip for the remainder of my shop light conversions as the bulb or ballasts continue to fail.

One last thing to note, the angle of light produced by led strips is 120 degrees. This is different then fluorescent tubes that generate light in 360 degrees.  I find these LED conversion shop lights work better in high bay applications then in lower ceiling spaces.  the 10 ft ceilings give the light plenty of room to spread out, at 8ft you get a lot less square footage covered by the direct light.  I suppose some sort of plastic diffusion panel would help with this somewhat.

As they say, your mileage may vary, but this post aims to share my experience. It may be that the strips I purchased on ebay are to blame for my opinions.  If you want to order the same strips I did, here is a link to the ebay listing for strip lights.  If the link no longer works, the sellers name is  cnredceo.  If you search you should find them easily enough.  His shipping is very fast, and the packaging is excellent.

** If something should change in 6 months or a year, I will return and edit this post to include any noticed issues or failings.

antibacklash ballscrew upgrade on RF45 ZAY7045 Milling machine – Part 1

Antibacklash ballscrew upgrade for RF45 ZAY7045 milling machine

I converted my lathemaster ZAY7045 milling machine (a RF45 clone) to 3 axis CNC about 3-4 years ago with whatever parts and materials I had on hand as a proof of concept experiment.  The CNC conversion was one of the best things I have ever done.  I instantly fell in love with CNC machining.  At the time, I made the decision to run with the original very poor ACME threaded leadscrews with their 0.100″ pitch, AKA 10 turns per inch.  My original conversion could hardly be called more than a down and dirty hack but it did work.  Several problems with my original approach became apparent.  First and foremost  among my cnc machine woes was the ridiculous backlash on the factory parts, especially on the x axis leadscrew.   I programmed and tuned anti-backlash algorithms in my control software that are quite amazing, but they only compensate for the backlash rather then remove it.  With the extensive use the CNC mill gets  the backlash had been growing worse steadily. When the backlash reached 0.047″ I decided it was time to replace the x axis ACME threaded leadscrew with a nice anti-backlash ballscrew setup.


A 20mm diameter ballscrew and associated ballnut were the largest that would fit under the saddle.  As is often the way with tools, bigger is better when it comes to a ballscrew and it’s load handling ability.   In this case it had to move a few hundred pounds of table, motor, vice, stock, cutting fluid, etc.  I initially wanted to stuff a 25mm diameter ballscrew under the table, but after disassembly, careful measurement showed that it would not be physically possible to use 25mm diameter ballscrews.  The new 20mm ballscrew will have a metric thread pitch of 5mm, roughly traveling twice the distance per revolution as it did with the original acme leadscrew.  This is not a problem as the CNC software I use to drive my CNC mill can easily compensate for the change in the leadscrew thread pitch.  The calculations to determine the new movement per step are basic and straightforward.


I don’t intend to wax poetic on the variety, quality, and types of ballscrews available. Plenty of companies offer excellent reviews of Ballscrew engineering calculations and selection criteria.  I chose to use a 20mm ballscrew with a 5mm pitch (Part #: SFU2005-C7 ) of 975  mm in length, available from kellinginc cnc. See the dimensions and specs below.

detailed specs for the SFU2005 ballscrew2005-c7-975mm ballscrew end machining drawings

Dealing with Kelling Inc. is problematic at best. I have made four separate purchases from them, and twice I have had problems.  One time they sent me the wrong part and then tried to make me use what they sent instead of what I ordered in spite of it not working for my application.  Finally though,  Kelling Inc. resolved that particular issue by sending me the part I ordered but it was a hassle to get them to do so.  With the ballscrew, my issue was that unlike other vendors they do not including the 15mm x 1.0mm nut that threads onto the ballscrew to clamp it against a 5202 double angular contact bearing.  Having used higher end ballscrews for industrial repairs and machine designs in the past experience shows that other vendors include this nut (a sub 1$ part) with their ballscrews.  Kelling inc’s answer when I called to discuss this issue was that the nut is not included, nor available for sale individually, but I could buy their fixed end bearing mount BK15-C7 (Fixed End) for  $82.95 and then get the 15mm x 1.0 mm pitch bearing retaining nut I needed. I was not about to spend $83 for a $0.87 part.   With no solution offered by Kelling Inc. I set about finding the rare and elusive 15mm bearing retaining nut.  Scouring the net and my supplier database from the day job I found an industrial supply company that would sell me a few of the 15-1.0mm bearing retaining nuts manufactured by whittet higgins, part number KM-02. I ordered my 15mmx1.0 nut from the local KAMAN Industrial Technologies office down in Manchester as they would sell to me with no minimum order fee.


The ballnut came pre-installed on the SFU2005 ballscrew.  It was installed flipped 180 degrees from what was needed to work with my design for my CNC milling machine.  Removing a ballnut can be a lesson in frustration and hunting for hundreds of small ball bearings on the floor if you are not careful.  The short lesson on how to correctly remove a ballnut is as follows.  Machine a removal guide that fits over your machined ends and is the same outer diameter as the minor diameter of your ballscrews threading.  For my SFU2005-C7  ballscrew this minor diameter is 18mm.  I turned down a piece of sch 40 PVC pipe on my 100 year old lathe (yup it’s on the to be replaced tool list. As an  aside, it will go to an industrial museum as a donation when I do eventually replace it with the shiny new 14×40 Lathe I have already picked out for myself).  In the right hand pic above you can see that even though I used a ballnut removal tool, I still removed it over a tray.  This is just in case something goes wrong and all of the small steel balls fall out.  Better to be safe then sorry here, so use a tray.

   Upgrading to ballscrews on a RF45 ZAY7045 mill drill

I designed the new ballnut mount  to fit the original 8mm mounting bolt holes on the saddle.  My ballnut mount design is such that there is no need to machine the ballnut. I did not want to risk contamination of the ballnuts internal raceway and bearing mechanism.   my design lowers the ballnut below the raised nut mounting boss on the saddle assembly. There is very little clearance in this set up, but it works well and does fit.   Here are technical drawings of my design: RF45 ZAY7045 mounting block for SFU2005-C7 ballscrew – sae units & in metric units   RF45 ZAY7045 mounting block for SFU2005-C7 ballscrew – metric units

As you can see in the upper left photo, I had to clip the corners of the ball nut mount.  This is not reflected in the above drawings, but you should machine the corners off the ballnut mount before disassembling your machine if you copy my design.  I did it by hand with a carbide burr and hand files.  Also note that I have not yet installed a zerk fitting into the ballnut. I hope I can find a tight M6-1.0 90 degree Zerk fitting that will fit and clear the table.  For now I plan to use grease on the ball nut.  In the future I will add a self oiling system to the CNC machine and will convert the ballnut over to oil lubrication at that time.  Oil lubrication is superior in that it tends to wash away contaminates from the ballnut rather then collect them as grease does.

That is all for part 1 of the ballscrew upgrade on my CNC milling machine. This post continues in part 2.