Elmer’s #5 Geared Engine . . . maybe

[kwoodhands]

Hello, not sure if I grasp exactly what you are suggesting, but I would advocate for buying holders for such tiny end mills. I was fortunate enough to have them supplied for every size imaginable where I was employed during my machine career so I have a drawer full of all sizes from ( 1/16" to 3/8" ID ) all with 3/8" shanks. They are not pricy to buy, have hardened and ground shanks and they run dead-on. Just something to consider before investing too much time in making one ( or more ) which will not run as perfectly as a purchased item. Luck !

I bought a set of R-8 holders that included 3/16,3/8,1/2,5/8,and 3/4" diameters. I often use small endmills with shanks that are either 3/16" or 1/4" for 1/64 / 7/64 endmills.
There are few sources for 1/4" diameter holders but after reading your reply I did find reasonably priced 1/4" and other sizes on E-bay.
$18.75 for the 1/4" , fair price . Thanks for your reply, I didn't know the holders came in so many sizes, I went buy the sets you usually see advertised.

mike

 

[a41capt]

Congratulations on one fine looking and running engine! I enjoyed watching your build and your various work around during construction.

Thanks for sharing it all with us!

John
Camp Verde, AZ

 

[Cymro77]

Fascinating read. Cool engine.

 

[Brian Rupnow]

Congratulations!! You have done yourself proud. Overcame adversity, worked until you have a good looking running engine.---Brian

 

[bmac2]

Thanks guys. I have been tempted to add some weight to the flywheel by drilling 6 ¼” holes in alignment with the ends of the spokes and filling them with either lead or steel pins. But I’m quite happy with the engine as it is and there’s always that next project calling.

Who knows maybe this will motivate someone to try that next engine or other project even if they don’t have all the "correct" parts or materials.

 

[JohnBDownunder]

Thank you for posting a most enjoyable read and model.
For what it's worth I have in the past increased the mass of an aluminium flywheel by drilling holes in the outer rim and filling them with lead. Lead being about 7 times denser than aluminium it works.
Call the filled holes decoration or paint the rim??
Great model.
John B

 

[propclock]

Great engine , great read, did you ever post the dro code?
I cut an internal ring gear using Gearotic I used delrin for low noise. 2X ? Elmer size,
I like engines bigger and 1/16th was my smallest
end mill needed for milling the teeth, You are motivating me to
finish it. At the time the cost of boston gears and Gearotic
License was the same. I use Gearotic quite a bit.
Thanks for a great project.

 

[bmac2]

Great engine , great read, did you ever post the dro code?

Propclock I must apologise for not getting this out to you sooner. I planning to put it into the download section but was having trouble getting it to upload and then just plane forgot. I’ve put the wiring diagram and the Arduino sketch for the DRO display and the Tachometer in the zip file.

For prototyping I used a UNO because it has the 3.3v supply needed for the scales. For the final build I used some 5v Mini Pro’s I had around so I had to add a separate 3.3v regulator and use a voltage divider on the data lead going out to the scales.



The LED displays are great and unlike the original iGaging I can read them from across the room. I got them from Banggood for around $4 Canadian https://www.banggood.com/MAX7219-Re...U-p-907849.html?rmmds=search&cur_warehouse=CN

The tachometer has both the I2C and parallel wiring diagrams.

 

[oliver jenner]

Hi b mac, great work. Been really interesting following your progress. Im also interested in what you have done with the DRO and was just wondering if you had the arduino sketch to make a metric readout? Thanks, Oliver

 

[bmac2]

Hi Oliver welcome to the forums.
I got the sketch from WMello on another forum and it just worked straight out of the box so I’ve never really looked at it. I think if you change Line 112 to read v=(DroMea*25.4); it should work.

 

[oliver jenner]

Thank you, been following builds on here for a while but have only just decided to register. There are a lot of talented people on here and great projects.

Ok will try changing that line of code and see what happens. Cant see why it wouldn't work. I dont suppose you would consider shearing the PCB design you had made for the arduino boards to go on?

Thanks, Oliver

 

[bmac2]

No worries Oliver

I have to say that my filing system sucks, what I could find was scattered all over my laptop and two network drives. But in my defence I probably didn’t think I’d need them again. The wiring list and wiring diagram will probably be the most useful. I used toner transfer to make the board but managed to find the positive and negative for the CPU board. The breakout board for the scales uses surface mount USB “A” connectors so if you cable them out is would be a lot easier. I’m not sure if the power/tach board is the one I ended up using. It has the power jack, 5v and 3.3v regulators and an input jack for the tach. The file CPU_Mounting_Board_etch_silk_top shows where the three jumpers go on the board. Hope you can make sense of this and if you make one how about posting a build.

 

[oliver jenner]

Thanks again for uploading the files. They are going to be a great help. I’m sure I will be able to make sense of them. Will definitely try and post a build when i have collected all the components together.

 

[lancer]

Hi Bmac2
I am interested in this project which I have been ages to find something similar to it.
I has to questions if you no not mind.
1. Can you please tell me the value for the resistors you used with W2 to ground in your wiring diagram.
2. I have a china vernier, will this project work with it. ie batter voltage is 1.5V and not 3.3V as you used.
Thanks for uploading the project.
Lancer

 

[Brian Rupnow]

Bmac--Somehow I missed this thread. Your engine looks and runs very well. Old Elmer designed a lot of really neat stuff, but I find that in general, they are just too damn small to be comfortable machining. I have redrawn a couple of his engines at 1.5:1 scale, and I find them much easier to manage.

 

[bmac2]

Hi Bmac2
I am interested in this project which I have been ages to find something similar to it.
I has to questions if you no not mind.
1. Can you please tell me the value for the resistors you used with W2 to ground in your wiring diagram.
2. I have a china vernier, will this project work with it. ie batter voltage is 1.5V and not 3.3V as you used.
Thanks for uploading the project.
Lancer

Hi Lancer

If you want to interface to a china Vernier have a look at this link.

Arduino reads digital caliper - martin's useless and useful creations

I was messing around with it a while ago and the code works. The code as written just outputs to the serial monitor in the Arduino IDE (your computer) but it would be simple to have it go to any type of display you want.

 

[lancer]

Hi Lancer

If you want to interface to a china Vernier have a look at this link.

Arduino reads digital caliper - martin's useless and useful creations

I was messing around with it a while ago and the code works. The code as written just outputs to the serial monitor in the Arduino IDE (your computer) but it would be simple to have it go to any type of display you want.

Hi Bmac2
Thanks for the reply, I will try to understand the way to build it.
One more thing can you tell me the value of the two resisters you use in you project, what I can see from the video they look to be 100 Omhs.
Lancer

 

[bmac2]

Sorry Lancer I missed that. I assume you’re talking about the 2 resistors on each of the USB connectors going out to the scales. That’s just a voltage divider to drop the 5v clock signal from the Arduino to the 3.3v that’s safe for the iGaging scales. R1 (going to +5) would be 100ohm and R2 (going to GND) would be 200ohm to give an output signal of 3.333v.

https://ohmslawcalculator.com/voltage-divider-calculator

For a 1.5v vernier caliper R1 would be around 250ohm and R2 100ohm. That would drop it close to 1.5v (1.429v). Being butt lazy I have an app on the old i-pod I use to listen to audio books/music in the shop.