Thursday 5 August 2021

3D printed hand wheels for driving 1605 ball screws

My DIY micro lathe project continues and one step I made recently was that I designed and made two hand wheels, which initially will be used for driving the X and Z shafts. These are 1605 ball screws, which in the end will be stepper driven, but that will be the last step of this crazy project, and until then I will need these hand wheels for my tests.

The idea was to make them large enough so that they can comfortably be rotated even at fairly high speed. I also wanted the handle to freely rotate, just like on professional hand wheels. This would make it easier to handle and turn at better precision. I did not add any scales, if I realize that I need it, I can always add that later. Instead of milling one, I decided to print one out of PLA. I know that real aluminium hand wheels would have been much better, but this is enough for my needs now, and I also find 3D printing fun, so I went for a printed solution, instead of a milled one. The designed is made in FreeCAD.

 The hand wheel consists of three 3D printed parts assembled together with M6 screws. I could have printed in two parts, but thought that this way it offers greater flexibility, and if I don't like the coupler I can always use a different one, made out of aluminium, or sone other material. Perhaps printing in two parts would have resulted in a nicer design, so maybe if I make new ones, I will change and try the two parts solution.

The wheel is 80 mm diameter, which I found just right in size. The wholes in the wheel are 5 mm holes for threading with M6 threads. On the other side of the wheel there is a circular pocket for an M6 nut which will hold the shaft coupler. 

 

The shaft coupler has a 10 mm diameter pocket on one side, and a 5mm hole on the other side. The 1605 ball screw shaft is 10 mm in diameter, so it fits well to that. The coupler is fixed to the shaft with two M3 x 5 mm grub screws through the two M3 nuts. The 5 mm centre hole is threaded for the M6 x 30 mm screw which is used for fixing it to the wheel. The nut will hold it firm enough, but if necessary, I can always glue the two pieces together as well.

The handle is 42 mm long and 16 mm wide at the widest part. Inside there is an 8.2 mm hole to fit a 31 mm long tube in it. This tube acts as a spacer to provide the right distance from the wheel and it allows free rotation of the handle. The screw is a 50 mm hex cap screw.


 

The screw can be tightened quite firmly, and because the tube is 1 mm longer than needed, the handle is a bit lose. This solution provides a very good free rotation of the handle

The screw is well hidden in the 10 mm pocket, giving it an extra good look.

Printing took about 7.5 hours in total for the three parts, but my printer uses only a 0.4 mm extruder. I printed with 0.25 mm layer height. The material is PLA, which I find is rigid enough for this sort and is also very good for tapping.

Just click on this link if you like this and wish to print the stl files:

https://drive.google.com/file/d/1pXTQiNqAh5BduZgYsOqA2MmtVy5DofAO/view?usp=sharing 

The files are provided free of charge, download and use the stl files if you wish.

If you find this useful and find that it saves you a lot of time and effort then I am very happy. I have however spend many hours and days on developing, testing and documenting every step of what I do, including this seemingly simple hand wheel. As a token of appreciation, your donation is of course welcome, but there are no obligations and the sky won't fall on you if you decide not to donate. If you however wish to contribute to my activities, then just click on the button below and that will allow you to make a donation if you do wish to do that.

 
 

Wednesday 30 June 2021

My UCCNC Probe Screen version 4 is now available

This UCCNC probe screen is free for you to use. 
If you find this probe screen useful and find it saves you a lot of time and effort in setting up your CNC then I am very happy. I have however spend many hours and days on developing, testing and documenting every step of it. As a token of appreciation, your donation is of course welcome, but there are no obligations and the sky won't fall on you if you decide not to donate. Click on the button below if you do wish to donate, or just continue if you don't.

 
 

The Probe screen is back to normal

 
Finally I managed to finish version 4 and is now available for download.

Klick on this link to download the zipped files.

When you click on the probe tab after a successful installation you should see this screen. The way the main Probe Screen looks like is unchanged, compared to the previous version. After installation you must configure your own probe screen parameters. This is important to do before first run. Please read the provided manual.

(Click on the image for larger view)

 

 

Additional features

 

 The additional features offered looks a bit different from the previous version because of some changes implemented in UCCNC. If you don't need or like the additional features then you can skip this part. In that case the original UCCNC RUN tab screen will be displayed and you must click on the PROBE tab to be able to run my probe macros.

(Click on the image for larger view)

 

 

Necessary update due to changes in UCCNC

This update was necessary due to a change made in UCCNC software some time ago. I did not notice this, since I was using an older version of UCCNC, but it's been pointed out to me that the Probe screen is not working in the latest UCCNC version (1.2111). I tested it, and unfortunately this was the case.

The error turns up at the last step of the installation of Probe Screen, and after shut down and restart of UCCNC, the screen got messed up and looked like this on the right here.

This was of course not usable as it was, and after some investigations I found the answers to how to fix it. Basically, the fix was very simple, I had to renumber some screen elements, but due to lack of time, I could not provide an update as fast as I wanted. The work is now done, all the necessary files are updated and available for download using the link above.

There are no changes in functionality, and since all the macros work just like before, these are untouched. Only the screen element file is changed, as well as the user guide.

As usual, I made several test installations, following my manual to the letter, so I know it works. But as usual, I only have the UC300ETH_5LPT, so I can only test it with that one. I have however no doubt that it works with the other controllers also, assuming you follow EVERY step of the manual during installation. Unfortunately, installation is not "plug and play", you must read the manual and take care of not making any mistakes. There is no other check than your own eyes and brains, so mistakes will not be easy to correct if you make some. Please don't forget to take backup of your own installation before start, just in case you make a mistake. You can have several UCCNC installations on the same computer, just use different names. However, for UCCNC installations and how to do that, please consult the UCCNC manuals.

Download and use if free of charge.

https://drive.google.com/file/d/1jkz8lAx-H69ugspRS_sUoSQ56FR_xFwb/view?usp=sharing 

Good luck and enjoy.

 

Monday 17 May 2021

Using my 4th axis (also called A or Rotational axis) as a "poor man's lathe"

 

I bought a rotational axis ( 4th axis or A axis call it whatever you like) for my CNC with a 4 jaws chuck. I intend to use this as both a 4th axis on my CNC, or as an independent "poor man's lathe". I know, it will be a very primitive lathe with a lot of limitations, but I intend to try it out anyway to toy with and to learn. Maybe later on I'll buy a real lathe as well, but for now this will do. I am sure I can use it for some sort of work, but I will see that later.

To get the lathe function I had to design a control box. This is based on an Arduino Uno module with a 2x16 lines LCD. It is a very simple design, using only three buttons, one for clockwise rotation start, one for counter clockwise rotation start and of course, one for stop. Stepper acceleration and deceleration is also implemented, with a possibility to select acceleration in 7 steps. The chuck rotation can be adjusted between zero and 380 RPM, which is the maximum. This corresponds to 2280 RPM on the stepper, due to the 1/6 reduction pulley the stepper drives the chuck with. So it is a respectable rotation speed for being a stepper. The rotation speed is set using a rotary encoder and that speed is saved in the EEPROM, so after a power off, the last used rotation speed is restored. The rotary encoder push button is connected to the Arduino reset and acts as an emergency stop, in case there is a need for stopping as fast as possible. Of course, this means no deceleration, just an abrupt instant stop.

For powering and control I also built a separate PSU, which provides 48V 7A DC through four individual 12V power supplies connected in series. Three of these are 9A supplies, the fourth is though only 7A, which is why the maximum is limited to 7A, but considering that the stepper is only 3A, I figure that the PSU will be good enough for the purpose.

The PSU box also contains a DM542 stepper driver, which is configured to the maximum current and 2x micro stepping, which results in 400 steps per rev.

There is also a relay inside the box. This relay decides if the 4th axis is to be driven as A axis by my CNC using UCCNC software, or independently run as a "lathe", controlled from my control box and rotated non-stop until i press the stop button. The relay can be switched from the control box and the default setting (with the relay off) is that the rotational axis is controlled by UCCNC.

Yesterday I made a short video about testing the control box functions and showing the rotations. I have not used it yet as a lathe, still waiting for some necessary tools before I can do any real tests, but I thought this can be interesting to show as well. Maybe it will give other people some ideas as well.

I intend to share the Arduino code here as well. It is well commented, so based on the code, the simple box can easily be built by anyone understanding the basics of Arduino. I will need to add some file header information before I post it here, but it will be posted soon.

I hope you will enjoy watching this video. I will make a new one once I start using it as well.

Friday 1 January 2021

Update regarding the External auto focus assist light for mirrorless cameras

 

Quite often I receive questions about this item, asking about the availability. The message I answer with is that this item is still sold and made, and I will continue making it and selling it as long as there is interest for it.

 

 

 

Currently I have two specifically designed sensor heads, one is made for the Nikon Z7/Z7 series the other is for the Nikon 1 and the Sony a6000 series cameras. Actually, the device works with any camera, as long as you can somehow install the sensor head above the AF assist light of the camera. Unless you have a Nikon Z6/Z7 body, the Sony a6000 type of sensor head is the most appropriate one to attach to the camera body because of it's shape. Never the less, if you have a specific wish for a type, just tell me your camera model and I will design a sensor head for that camera if possible. Of course, I will not charge anything extra for this work, but I can also not test it, and it may also take a few extra days. In some cases it is not possible to design it without having access to a camera body, so in those cases I have to decline this work, in that case you can decide to order with the universal sensor head separately delivered to you, in case you want to check it, or install it another way. The actual light sensor can also be attached to the camera using a simple black electric insulation tape, but it is not as nice. Never the less, it is the last resort, and it allows you the use of this external AF assist extender to be used on any camera.

Some people gave me feedback about installation of the black box on the flash and they said that they used Velcro instead of the supplied adhesive putty, which I include every time. I chose the putty because it is reusable, removable and leaves no stains, no residue which may be impossible to remove from the flash without strong chemicals, which may even damage the flash, so personally I advise against Velcro solution. The supplied adhesive putty is non-toxic, even though it should be kept away from children and pets. Also, only very little of it is needed, which means that you should not use all I include in the sending. Of course, this is up to you, but personally I found it sticks too hard if too much is used. Of course, a good question is "what's the definition of too much"? Well, I leave it up to you, but only a thin layer is needed to hold everything firmly in place. What is very important is that the small window of the sensor head is not covering the AF assist led of the camera, so that when the LED light up, all that light is passing to the sensor.

For all other details, please read this blog post: https://adapting-camera.blogspot.com/2019/03/the-external-auto-focus-assist-light-is.html

You can also watch the demonstration video I made about this device: 


Not much is changed from the original design. The box I am using now is slightly smaller, and I am using black round cord, which in my opinion looks better than the grey or white I used before. Also, another change is that I am using even stronger green LED now, but the main purpose is not to increase the intensity, but to reduce the power use to make the battery last longer. Increasing the intensity would  mean that the range increases, which would be good, but it would also be too strong for the eyes if the model is less than two-three meters (7-10 feet) from the camera, and in my opinion, that is too far in many cases. Never the less, the range is already good enough for most situations.

The installation of this device is very simple. It comes delivered with everything needed, except the battery, which you have to buy separately. Here is a short video showing some installation alternatives.

 

I have also received some questions about why I am not making it to project a pattern, instead of just a simple round torch like light. The reason is that to ba able to do that, the light must be even stronger, preferably laser and also needs a specially designed prism. This makes it very complicated, since I can't make the prism, it would also be tar too expensive to make, and probably not sell-able. I tried, but gave up the idea pretty early, already before the first device was made.

Anyway, thank you very much for all the feedback, and I am glad that you all like this item and thank you very much for the support.