Sunday, June 19, 2011

Minor Fixes

Given my inability to do serious work due to medication, I did 2 minor fixes which were long overdue.

Reworking the Tramming Tool
Wanted to do this for a while. I had the indicators mounted in the front of the holders, which was not inline with the spindle centre. The indicators' tip weren't sweeping along the same path in the previous setup.


Drilling done on the manual mill. The left hole a little off due to miscounting of handwheel turn. The 2nd one is right on the spot.


Done...


The tool in use.



Fixing the A2Z Adjustable Tailstock
This purchase has been sitting on my bench for quite a few months. Can't use it because of the threads in the 2 holes on the tailstock. The tailstock is the original from Sherline meant to be used on the mill with rotary table, but modded to use with the adjustable base by A2Z on the lathe. With the threaded holes, the tailstock cannot be fastened onto the adjustable base. So the threads have to go...


It was easier to align the drill to the holes on the manual mill than the drill press. 5mm drill was used to stripped off all the threads, which is the closest without enlarging the holes too much (tried 4.5mm, 4.8mm, and finally 5mm).


The tailstock mounted.

Next was to align it to the headstock - a painful exercise.


View from the top.


From the operator's side.


All done!!!

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Wednesday, June 15, 2011

Reassembling and Tramming

After being "unconscious" in the afternoon, knocked out yet again by medication, I was up feeling much better. I was actually being disturbed by the vibration of my phone; lots of missed calls and SMSes. Anyway, I'm awake. I returned all the calls and responded to all SMSes. Found myself back in the shop staring at the main mill that was in pieces. Decided to fix it up and tram it along the way.

This was how I left it previously:


I clamped a DTI in the vise and swept along X-axis.


Then mount up the column bed and swept it again.


The first time got me quite close and this time only minor adjustments needed.

The motor and spindle were them mounted. I fastened a 5" square in the vise and fix up the DTI in the spindle to align the Z to the table. First, the spindle up moved up and down with the tip of the indicator running along the square in the X direction to adjust the side tilt. This process is quite a pain as there is no micro adjustment available.


The forward/backward tilt was next. This was easier. Sherline provided a #10-32 SHCS at the back of the column for micro adjustment.


The tramming tool was used next for fine adjustments. With the A2ZCNC angle adjuster mounted in the on their spacer, adjustments along X is now much simpler.


This is not so along Y, which require the use of shims to square it up. Maybe I should workout something along the line of the angle adjuster.

Ok. Time to stop work. Will continue in the next session.


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Handwheel Repair

Wanted to go back office to clear up my pile today while on medical leave. Fever came back in the morning forcing more bed rest and the medication caused me to feel rather light headed.

Got up again feeling restless, I walked into the shop to look at the newly assembled mill. I broke one of the handwheels a while ago and have been thinking of getting it fixed. I remembered the warning on all forums not to operate any machines while under medication. I reasoned that I can still do light milling safely.

After fiddling around to remove the stiffness in X-axis, I proceeded to drill out a slightly bigger hole to fit an M5 button head SHCS.


The hole was progressively enlarged till the M5 screw cam slide in easily.

A flat is milled at the back of the handwheel to allow the screw to be tightened flat.


Next, some threads were removed in the middle section of the screw so that the plastic sleeve can rotate freely. This took a bit of time as the screw kept wanting to move out of the 3 jaw chuck.



Two nuts were used in the assembly; one against the face of the handwheel to stop the screw from loosening, the other loctited at the tip of the screw. The plastic sleeve was also shortened a little to fit.


The handwheel mounted. Works rather well! Glad to be able to save some money for other more useful stuff.

From the experience of using the manual mill, I found it to be easier to feel how fast I need to feed the stock to tool. With more practice, I should be able to determine what feedrate to set for CNC operation.

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Monday, June 13, 2011

Manual Mill Assembled

After church and lunch, we were back home for a while. I took the time to finish up the assembly of the 5410 mill. This project was put on hold as I was waiting for the gibs and gib locks to ship in. Mike was so kind to accommodate my picking up of the orders after dinner on Saturday.

With the previous experience of replacing the Sherline gib, the process of drilling the holes for the gib locking wires was pretty quick. But I took my time to make sure the hole on each gib is at the right location and at the right angle. No precision needed here; just mark and drill through.

Here is a pic of the Z and Y axis done.


The X axis completed. Spindle mounted for show.


The spindle motor was taken out of the box for the photo taking session.


While putting the belt onto the slots in the pulley, I saw an unsightly defect.

I don't know how this happen. The plastic housing should have protected the motor pulley from any knocks during shipping. I've been getting items from Sherline with scratches starting from the 8-direction column. Even the QCTP I bought recently has a scratch mark on it's top face. The pulley of the spindle came discolored (oxidation?). Those that are cosmetic don't bother me. But the cut on the motor pulley looks quite bad. Let's hope it doesn't affect anything.

After putting on the belt and tensioned it, I mounted the spindle assembly on the mill for some simple test. There was some high pitch resonance when I turn the speed control knob to it's max.   You got to tune up the volume to hear it. Recorded using my iPhone.

video

I'll be tramming the mill in my next session. Time to clean up the work bench to make way for the mill.

I also took some time to upgrade Mach3 to the latest lock down version and install the latest plugin for SmoothStepper. Had some problem with the lathe settings on Mach3. Couldn't get out of the blinking Reset button. Since the mill profile works fine, I duplicated the XML and change the screenset to lathe. Simple tests were done to determine backlash and the compensation applied. Works beautifully! Thanks Greg! Good job with the plugin. If you have some time, hope you can work on the manual.

Ok. Time to sleep. Meeting a client at 8.30am.

Parting pic - my lathe, after cleaning up the mess:


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Saturday, June 11, 2011

Grinding Grooving Tool

The grooving insert and holder I order from Mike will not reach me for another week or 2. Itching to do some work, I spent some time grinding my own using 1/4" HSS tool.

I want the width to be about 1mm or slightly less. The cutting depth will not be long to reduce the chance of flexing during cut.


The shape wasn't what I want but that's the best I can get from my grinder. You can see the business end sloped towards the shank, which will likely cause the groove to open up.


An idea come to my mind while trying to solve this: use the grinding stone with the Dremel rotary tool.


This gave a tight corner, allowing the 2 sides to be parallel (or almost).

The cutting width achieved: 0.95mm. Proper clearance were provided. It cuts really well without chatter.


The grooves completed. Next was to turn this segment down to 4mm.


This is my best piece thus far.

If you have not notice, the QCTP used is Sherline's. Adjustments is easier as the tool didn't move up when tightening. The tool post came with a hold down to prevent rotation during cut. A good investment.

I'm out for family dinner at time of writing this post. Hope to complete a few pieces of the axles, assemble the mill, tram it, and cut the flat. A tall order given the little time when I get home. Wouldn't be starting up late tonight as I'll be going church the next day; first service after 2 months...


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Monday, June 6, 2011

New Purchases

Just got back from Mike's with these:



The Sherline's QCTP with it's 3 tool holders and the optional 3/8" tool holder (far left). On the foreground is the slitting saw. I screwed up mine while using it to make the tramming tool.

What's not shown are the 2 replacement inserts. The 2 little carbide inserts, smaller than my finger nails, cost quite a bit - about $14 a piece.

It took me a while to decide buying the QCTP system from Sherline. Main consideration? Cost. It cost me more than twice the amount I paid for the A2Z version and with 1 holder less.

Sherline's system looks and feels more solid; having made of steel, unlike the A2Z's, which is aluminum.

I've also ordered the grooving tool and it's insert. These will only reach me in 2 to 3 weeks' time.

Meanwhile, I'm planning in my mind how I should approach the machining of the grooves on the axle, minimizing or if possible, eliminating flex (in tool and in the job). Spoke to Grandmaster Mike while at his shop. He suggested using a rotary tool to cut the grooves while the job spin in the lathe. Need to make a holder to mount the dremel on the lathe cross slide or to buy from mike the Proxxon IBE with the holder. Anyway, the IBE will only be in stock on Saturday. Will think about that.

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Sunday, June 5, 2011

Axle - an idea

The idea came when I was preparing to go work this morning. To minimize flex in tool, the grooving insert should do the trick. For the deflection in the job when applying the part off blade,I can start the job with the grooving done first when the stock is still at 6mm dia. Instead of cutting them at radius of 0.2mm, I'll just cut 2pm more. Once the grooves are done, the stock will be turned down to the required 4mm. The problem I can see using this workflow is the lost of the reference point (think it's called datum. But I'm not sure). This can be easily solved by using one end of the stock to start counting from.

What I'm going to do also is to use Mach3 with the stepper motors to help in positioning of the first groove, power them off and turn from there. Should work. I'll give it a shot.


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Failed attempt in making the axles

A disappointing session tonight. I was full of excitement when I got home from work and dinner at about 9pm. Planned the process in mind during the day of getting the grooves at the right places with minimal deflection from the tool and the pin.

I started aligning the headstock to the 100mm pin after cleaning up the ends as close to the chuck as possible. They came dead accurate at 6mm throughout from the metal shop.



After fiddling with the arm of the DTI stand, I managed to get the DTI in position.



With the extra length on each end (the final length of the pin is slightly less than 60mm), I'm able to start the cut away from the tailstock.



The pin look a bit like a main gun of a tank with the extra bit after turning the 50mm section down to 4mm.



I was to quick to faced off the excess, not thinking that I would still need it to hold the pin while cutting the grooves to avoid deflection - mistake #1.

While I was adjusting the cut off blade on it's holder, the bottom part holding the blade chipped off. Too much force with tightening down the cap screws - mistake #2.



You can see from the pic (the whitish strip at the top of the photo above) that the blade cannot be fastened to the holder anymore...

I'm force to end the session without completing anything. Have to order another tool holder from Mike and at the same time, order the threading and grooving tool holder and inserts from him. These are rather costly. The little insert cost SGD32.20 each and the holder SGD73.50. Both before GST...



PN 2269 measures 0.031" (or 0.7874mm) where PN 2270 is 0.062" (double the size at the cutting edge). PN 2268 is the 60-degree threading insert. Good that the holder can take 3 different inserts. Otherwise, more $$$ out of pocket.



This is the holder I mentioned.

Dennis, if you are reading this. Looks like I'm not able to complete the job and lack the required skill to do it. I'll continue working on the axles but please find someone with more experience to get the required done. When I've mine done, I'll give them all to you - no charge. Not even the cost of the stainless steel. I owe this to you for wasting your time waiting. Sincere apology.

Ok, enough of the failure. Good news to me. Boss is granting me the next weekend off; both days!!! I plan to bring the children out for some movies, do some shopping, and... I'll try to think of some activities... maybe go blading with them. It was their uncle Douglas that has been bringing them blading while daddy spending time with strangers in showflats over Sundays and public holidays.

Time to wash up and sleep. Tomorrow another day at the showflat. Drop by to say hello at Terrasse if you can. A packet of coffee would be good ;-)


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Friday, June 3, 2011

Nose Gear Stub Axles - Part 2

Though I reached home rather late tonight (10.30pm), I was determined to at least test out the idea given by Mike.

With the same setup from the previous session, I started cutting from the middle of the 5mm pin marking the start of the 4mm section till I've about 0.2mm to the final dimension of 4mm (for about 30mm). The tool post was then turned a little such that I can turn the shoulder square against the 5mm section.



The end nearer to the tailstock cannot be reached by the 3/8" tool, it'll be faced off later after the grooves are done.



The grooves were done next using the parting tool. The blade had to extended out more than my comfort level to have the QCTP clear the live centre body. I observed 2 problems with this setup: 1) flex in the part off blade, and 2) flex in the middle of the 4mm section. I should have try to use the steady rest close to the grooves to minimize flex in the job.



The job after cutting the grooves.



Next was to part off the unused part that was held in the collet.



This was easier than I thought. Expected some problems from my previous experience in parting off aluminum.



It's now passed midnight. Time to clean up. Long day tomorrow.


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Thursday, June 2, 2011

Purchases from RDG Tools

I was buried in my work an hour ago when I received a parcel from Sing Post. It came all bundled up in layers of plastic bags and paper envelope. I ripped the wrapping apart to uncover a set of Transfer Punches.






I'm wondering if the smaller diameter pieces can withstand the knocks from the hammer... I guess it should.

I remembered the one I made from a piece of leftover steel rod. Think I chose the wrong angle for that one. The 60-degree point didn't allow enough of it's shank to be guided by the holes to make an accurate enough mark.

There were other stuff I ordered (2 pcs of 25mm plastic ball with M6 threads for the grinder rest I'm trying to make, a #0 MT revolving centre etc) which are not in the parcel. Guess they split the items up to reduce shipping cost.


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Stainless Steel Rods

I was meeting a business partner for lunch at our favorite hawker centre in Jalan Beseh yesterday. Popped over to the metal shop nearby before heading back office to buy 10 pieces of 6mm diameter stainless steel rods of 100mm long.


They are for the pins that I'm making for Dennis. I do have a long piece of 7.96mm dia stainless at home but to cut them cost me more than buying them cut to length. The 3 cuts I made using the Proxxon mitre saw cost me a brand new cutting disc... Wow... I never thought I would see such fast wear with my infrequent use of most of my stuff.

The only thing left to do now is to find time to do the work. My boss loves us so much that some of us are scheduled to be on duty on both Saturday & Sunday this coming weekend :(

I'll see if I've some time after my last appointment tonight. Very unlikely as it only starts at 7.30pm and expect to end around 9.

I'll pray hard for more time and no sacrifice in revenue.

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