Installing The DRO

I walked into the shop this morning wondering what I should do for the next few hours. The to-do list is long but I was feeling a little lazy. I wanted to machine the nut mount for the leadscrew conversion to get that project out of the way. I also have the axles for Dennis which were long overdue. There is also the reorg of the shop to prepare for the arrival of the PD400. On one corner of the bench is the simple steam engine waving at me... Boy, I'm lost.

I finally settled down to install the DRO and work out the mounting to hang up the monitor on the window grill.

Lathe DRO
These are the parts that read the turns of the handwheel:


The DRO thrust collar was fastened to the back of the stepper motor using 2-part epoxy:


The thrust collar caused the setscrew on the handwheel to clamp too close to the edge of the shaft. Sherline's instruction is to drill and tap another #10-32 hole for the setscrew as close as possible to the plastic encoder gear.


I followed the instruction to do this by clamping a dowel pin to the handwheel using the existing setscrew. I do not have any 1/4" dowel pins around, and so had to make do with the 6mm dowel pin with some adjustments.

Job done for both handwheels:


You can see, from the existing setscrew hole, the end of the motor shaft:


The encoder housing was next. Quite an easy step:


I have a problem here; the encoder housing has the tendency to rotate when I turn the handwheel a bit faster. The instruction calls for a drop of super glue to mate the housing and the thrust collar should this happens. I'll do that as soon as I get myself some super glue.

The RPM sensor was mounted next, after I stick the decal on the pulley. Before applying the decal, I cleaned the pulley surface with adhesive removal to rid it of cutting fluid and oil. Didn't do a good job sticking the decal as it is slightly off centre.


I screwed up when fastening the sensor to the belt housing; it was a little too far in, causing the plastic arm of the sensor to pop up. The correction was easy - just relocate the sensor and fasten it with the self tapping screw on the belt housing.


With all the wiring work done, it was time to plug in the wires to the DRO.


The RPM sensor tested ok. I turned the speed control knob all the way up and it displayed top speed of slightly above 3000 rpm. This is in line with the number shown on the handheld tachometer I used sometime back. Sherline's advertised top speed is 2800 rpm.


The X axis tested ok but not the Z. I swap the encoder to see which is the culprit. It turned out to be the encoder I was using for the Z. I opened up the cover that house the wires of the encoder.


Strange things happened - it works with cover off!!! I screwed back the cover and it stopped working. This shows that 1 or few of the wires' exposed contacts came in contact with each other when the cover is pressing down on them. That's all I can do for this. No knowledge to work out a solution on my own or do further testing. I'll bring it back to Mike for a replacement.

This is a video showing the problem:

There are 2 parts that are useless if you are installing the encoders to the back of stepper motors. I'll keep them unless someone wants to take them off me.


Some thoughts on the DRO kit. The plastic parts looks and feel flimsy. I'm a bit disappointed with its quality. I expected some harder plastic material being used. The handwheels felt stiff after the encoder housings were installed. Turning them will take quite some effort from now on... Sigh...

Mounting the LCD monitor
I bought the wall mounting bracket for LCD monitor hoping to modd it for use on the aluminum window grill. I wanted to fabricate a pair of brackets to allow the wall mount bracket to be fastened on them. Due to the messiness of the bench at the moment, I decided to just hang the LCD monitor using part of the hardwares provided with the wall mount for the time being.

This is how it looks:


Some space is now saved as I can have the small keyboard I've just bought on the Soigeneris controller box.

Oh, one more thing: I've now rolled up the blinds to free up the grills for use. To shield my machines from direct sunlight, I sticked 2 pieces of black cardboard bought from the neighborhood stationery shop to the glass panels, leaving the top uncovered to allow some natural light.


That's all for now.


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BobCadCam v24 - I did it again!!!

I wrote to BobCadCam asking the total cost to upgrade all my licenses from v23 to v24.  I indicated in the mail that I do not wish to be contact via phone due to different time zone, not wanting to be disturbed while I was asleep.  Their sales rep sent me a mail and we started emailing each other a few hours ago with my queries on my existing licenses.  He called after, saying that it is easier if we just talk.  A few minutes later, I made the payment via PayPal.

This round, I decided to try my hand at hammering down the quoted price, after reading much about this topic on the forum.

The sales rep started at a total of USD1,520, including shipping and custom tax (GST included, as I was told.  I'll verify this when the package gets here).  I went on my plan and managed to bring down the price to USD600, inclusive of shipping (USD480 for the software and USD120 for shipping & tax).  To think that I paid a total of USD1,600 the last time for the same set of stuff for v23.

These are what I'm getting for v24 (2 seats of everything):

1) Mill Pro, Lathe, BobArt;
2) Training DVD;
3) Simulation level 2;
4) Editor level 2.

For the v23 I bought the last round, I bought over a period of time (upgrading and adding on) the above plus the v22 training DVD.  The v23 training DVD wasn't available when I first started on the software.

I've them promised to deliver the package to me before I go on leave from August 15 for 2 weeks.

Frankly, I don't really know if I need the upgrades.  Maybe its the newer graphic and the few toolpath and features that attracts me to them.

Like I always like to say, let's see how things go.

Sherline DRO kit received today!!!

Just a short note to express my excitement. Picked up the DRO kit for the lathe from Mike this later afternoon. Was a little rush as I was supposed to meet a client later.

Will be doing a write up after I get it installed.

In this shipment, I've the 2 QC tool holders, tailstock extension, the slide extension for thread cutting with DRO (don't know what is that actually. I'll figure it out later).

That's all for now. Waiting for my client to come back down with some documents.


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"Follower" Rest

Got home today around 10pm. Kind of tired from work but since my dearest wasn't back from a prayers meeting for a boy with tumor, the shop looked welcoming. It'll be a short session, I promised myself, as I've a long day a head tomorrow, with last appointment starting at 9pm at a home in Yishun. I'll be focus to get the quick-fix follower rest working.

From the previous session, I observed that the 1/4" brass finger being in the way of the spinning tailstock center. A tapered end with a cut off should work. I fastened it down to the vise of the manual mill to cut the notch so that it can press against the turning stock on the top and against the cutting force. No measurements were taken; just eyeballing the depth and step over to what I felt is right.

I re-clamp the finger at an angle in the vise to mill the taper.

The finished work mounted in the A2Z QC holder:



I did some test cut with the QCTP at various angles. Best result was with the finger very slightly behind the cutting tool.




Managed to get 0.01mm difference in diameter across the cut length of about 55mm. Sweet!!!

A video to go along:

Sorry for the shaky video. It was taken with one hand holding the iPhone and the other turning the handwheel. Maybe I should get a real camera. But the Proxxon lathe comes first. Let's see how things turns out.

Edit: I would like to give credit to Alan Haisley of the Yahoo! Sherline Group for the idea on creating the notch on the brass finger.  Missed the mention due to disruptions when preparing the post.

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Tempering, aligning, and testing

Had a couple of hours in the shop while my dearest was out for her visitation in NUH as a church volunteer. Few things I would like to try out after reading and playing with the ideas in my mind.

First, is to make a center with straight shank - to be used with the ER16 collet. This was also my first time trying my hand at tempering steel.

I cut off a short section of 10mm steel rod and turn it down a little to descale it. The compound slide was set to an angle of 30-degree to allow an included angle of 60-degree.


After cleaning up with sandpaper, I heated the business end of the center with the Proxxon torch. This torch was bought quite a while back from Mike. So far it has only been used to burn some irritating black ants in the kitchen. I didn't manage to get it cherry red as described in some forum postings. Still went ahead to dunk it in a cup of water when I saw the change in colour.


Somehow, I like the darkish colour...


Tested it by using it to align the A2Z adjustable tailstock with a dead center mounted, a painful process but I managed.


The reason for this adjustable one is the drooping of the original tailstock when extended. I'll work on the repair I saw on the web when I have time.

With some time more to burn, I decided to test out the "follower rest"; using the A2Z QCTP and a brass finger mounted. The brass finger was taken from the fixed steady.


It didn't work as i thought it would. I experienced lots of chatter leaving ugly finishes on the stainless steel pin. The diameter was still bigger at the tailstock end though alignment on both end were done.


I'm hoping that this will not be the result I get from using the Sherline's follower rest, which I should be receiving on the 26th this month. The DRO kit and some other items I ordered should be in the same shipment of there is no screw up.

A bigger lathe is still haunting me. It's now seems that the Proxxon PD400 is the right one to go for. The Wabeco D4000E is my dream machine but the price is too daunting; it is quite a few thousands more than the PD400 but with slightly shorter bed 350mm vs 400mm.

With that being decided, The problem left is, how will I be able to smuggle it into my shop without being seen? Not an easy task as the PD400 is quite big to simple hide away from sight. Besides, the bright yellow (splash guard and chips collection tray) and green would stand out from the Sherline lathe and 2 mills, which are black. Sigh...


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New tools

I stopped the previous post frustrated. So thought of putting something more joyful today, being a Sunday - my new purchases. This always perks me up.


These were picked up from Mike the last 2 days. You can see the grooving tool at the far left with the 2 inserts next to it. The little inserts, smaller than the size of my finger nails, are USD23 each (excluding shipping and tax). I did a few tests of the thinner one (~0.79mm) on stainless steel. It "peels" off the metal like when you are peeling off an apple with a sharp knife. It cuts better than the HSS insert I bought earlier but it is also more than double the price of the HSS insert (USD10).

The round block is the raiser for Sherline QCTP. This will help, together with the tailstock raiser (the one below the round block) and headstock raiser (not shown), to increase the size of the stock I can turn on the lathe.



The above came in mid last week from Axminster UK. Took them a month to reach me as the parcel was returned due to unsuccessful delivery. But the service standard of the company's staff was so good that I don't feel a bit mad. There are 3 chatter free countersinks and a stop jig for the straightedge clamp in this shipment.

I'm always happy when I buy things for my hobby; just like a woman on their shopping spree.

Frustrating session!!!

Right after sending off the guests, I went straight to the shop to continue my work on the axles. With the best piece just done, I thought that I would be able to hold the 0.02mm tolerance I set for myself for the job, across the length of 54.1mm. Boy, I was wrong! very wrong! The next piece was out by 0.18mm. The piece after 0.19mm. What the hell went wrong?!

I clean up the lathe, put in a 10mm steel rod with about 75mm sticking out of the ER16 collet. Several light passes were taken with measurements taken at the 2 ends and the middle. After tapping the spindle with a dead blow hammer here and there, I managed to clock an error of 0.02mm across the 75mm. That is good enough for me.

I put in a new piece of 6mm stainless with only 20mm sticking out. Took 0.1mm passes several time while checking the diameters at both ends - I've 0.04mm of error at such short length!!! What's happening?!

Is it the collets I bought from CTC Tools in HK or is it the ER16 spindle I bought from Sherline?!

I'm too frustrated and tired to do further test. I've failed the session today. When can I get such simple job done?!

I've lost my confident at using the lathe. I need help. Who can tell me what I can do to right the alignment problem?

Anyone???

Lunch on me if you can. Please drop me a note. I'm desperate!!!