No pic for this post. Just to dicument what I tested like night, before turning in.

I stripped the handheld contactless tachometer to see if any solder joint came loose. The tachometer decided to start working again after I put the board back to its case.

To start my test, a small piece of black stick was pasted onto the larger spindle pulley. With the trimpot turned to max, the readout showed a number above 10,000 rpm. As the display was jumping around quite a bit, I don't know how much above 10,000 rpm it really was running at. If you remember from my previous post on installing the pulley, I didn't adjust the preload of the spindle.

Maybe it's time for me to make a lithopane of my family with the higher speed spindle pulley installed.

After fooling around for a couple of weeks, I've finally completed the 3 rollers... Learnt quite a bit along the way on cutting such small wheels.  Bulk of the time were spent on the notebook working on the CAD drawings and setting up the roller blank.  My breakthrough came when the Thai hobbyist (Instagram handle max_pannara) replied with his method of holding down the rollers.  But, unlike him, I'm unable to remove the completed rollers by plying them off with a flat head screw driver.  I did manage to work around the problem by drill through holes in the recess holding each rollers and tap them out from the back.  This is not very efficient as I'll have to indicate the plate in again after each batch.  Since I'm will not be making many, I'll live with the trouble.

I'm looking to take videos of the machine in operation.  Saw from the iPhone App "Geek" that a GoPro look-alike is going for about SGD 50 to SGD60 excluding shipping.  Very tempted to get one to try but I've to control my spending.

Ok, that's all for the day.  Hope to update you folks soon on my activities in my home shop.

Be blessed!

Everyone has been telling me that to mill with tiny endmills, I need very high spindle speed.  The max speed of the default Sherline spindle is 2800 rpm, which mean that I've to go extremely slow (around 50mm/min) and very shallow (like 0.2mm in aluminium) if I'm to use a 1mm endmill.  The last roller I need was done at 100mm/min with DOC at 0.20mm per pass.  I was told that I'm risking the endmill.

I remembered buying the 10K pulley upgrade from Mike of SG Tooling several years ago and started digging through the boxes.  Found it still wrapped up in plastic in the box.  After reading through the installation guide many times, I proceeded to put it on the machine.

Its now 2.30am in the morning.  I think I better stop here and get some sleep.  I want to bring the girls out tomorrow to walk along the river near my place.

Let me leave you with this video of the spindle running up to its max speed, whatever it is, since I didn't adjust the spindle preload and have no way to test.  Click here to view on YouTube:  Sherline 10k RPM Pulley in operation

Have a blessed week folks!

After the failure in removing the roller from the fixture, I wrote to the Thai gentleman again seeking his advice.  While waiting for his reply, I decided to drill through each recess with a smaller diameter size drill.  This way, I can tap the rollers out after they've been machined.  It will be tedious doing it this way as I'll have to re-indicate the fixture for every batch.

It was nerve racking watching the mill went round doing its job.  I was so afraid of breaking another endmill.  I was told that with endmill so tiny and my max. spindle speed at 2800 rpm, I should go no more than 56mm/min feedrate and at DOC of 0.2mm per pass.  It will be painfully slow...  For this roller, I went at 100mm/min instead.  It turns out well except having to spend quite some time deburring the tiny spokes.  With my "old flower eyes" (long sightedness, started when I crossed 40...), it was painfully difficult.

Next up, upgrading the Sherline to 10,000 rpm pulley.

Busy day today at home. We hosted steamboat lunch and dinner at home for my wife's family and mine. I sneaked into the workshop in the afternoon to figure out how to use the centering indicator I bought many years back. This round, I managed to figure it out.

I sought for suggestions and help over at MetalworkingFun forum. Those guys there are just superb! Suggestions poured in and with so much patience! Very friendly bunch of people. The thought of using double sided tape came to my mind when a gentlemen the spoke about using some kind of tar to hold the rollers while machining. Bought a big roll of "super sticky double sided tape" from Horme after dropping my colleague off yesterday. This round, the roller didn't move! One problem down. The next to figure out is how to zero my part more accurately. Check out the pics of the finished rollers and you'll know why.

I'm quite happy with the result from the 2nd attempt. Closer inspection of the part revealed that I may not have found the exact zero of the axes though I'm very close. I'll do the next 5 and submit for testing before moving to the next spoke design.

My dad has also commissioned me to make a batch of stainless steel bushings for his dispenser. I'd the CAD done last night and should be able to machine a test piece next week to check fit.

Be blessed!