Simple Tramming Tool - Design Stage

I'm supposed to be busy today, but I'm not.  Most of the preparation work for the reunion dinner earlier tonight was done by my mother-in-law and the helper.  I spent a few hours in the shop trying to tram the mill after the incident the night before.

It was tough this time.  Couldn't seem to get the tilt right for both front/back and left/right.  Just don't understand why it was so difficult this time round.  After struggling for quite a while, I've the front and back giving me almost the same reading (< 0.01mm off).  Left and right tilt is still off.

I thought of the tramming tool made by John (bogstandard) and would like to make one myself.  I would like to keep it very simple, given my current level of skill (or lack of).  I've 2 digital dial indicators bought last year from CTC Tools right after reading John's thread on MadModder.net.  Some measurements of the DDI were taken.  I initially thought of using simple geometries to represent them to work out the dimensions of the holder which I'll be making but 3D Content Central came to the rescue.  They've a 3D model of a Mitutoyo DDI that is pretty close in dimensions as mine!

After tweaking the downloaded model and added the mounting plate, I completed the simple model of the fixture:






With the DDIs:

I've to keep the DDIs close together as the width of my table is only 70mm.  The distant between the centre point of the tips is 65mm.

Hope to start work soon....

A2ZCNC Leadscrews Upgrade - Fabricating the Z-Axis Stepper Motor Mount - Part 1

By looking at the title, you will know that I didn't finish the job.  It looks a simple part to make but still, I didn't make it.  There was an accident as I screwed up.  I'll show the pics towards the end.  The loud sound really scare the hell out of me... Mmmm... come to think about it, it is not a bad thing that the hell is out of me.... lame...

Ok, back to business.  After facing the aluminum piece and squaring it off in my previous session, I painted the top face red with a marker and layout the 4 holes to be drilled.  2 will be tapped M4 and the other 2 will be made into a slot with counterbore for the original sherline screws to be mounted at the end of the z column.

I originally planned to use a set of the holes to hold the stock down for profiling.  But given the size of the job and the holes pretty near the cut line with the capscrew head in the way, I decided to fasten the stock onto a pair of 123 block.



Using a 6mm steel dowel pin to find edges.



Drilling the holes...



Testing the tapped holes with a M4 SHCS. A little wobbly.  The tap was made in India. I changed to the Japanese tap I bought, much much better result.



Setting up for profiling of the little arc on the center front. Diameter of 10mm

 


The T-nut broke even before I started tightening.  Defective stuff.  Replaced and moved on.



A sudden loud noise and I saw the whole spindle swung to my left turning the column...  It was just touching the surface of the work piece...



More obvious from this pic.  Am I trying to make use of the 8-directional feature of this mill? Nay...



Think I'll fly cut the top face for a thinner than specs piece...



Looking straight at the mill.  The spindle is now facing around 30 degree to the left.

I hope I didn't wake anyone up with the loud noise.  I hit the e-stop pretty quickly.  Else the 1/2" endmill would have hit the clamp.  I must have done something wrong with either my setup or the approach.  I'll think about that for while before commencing work.  Looks like I'll be spending some time tomorrow to inspect the mill for damages and re-tram the machine.

On a lighter note, Mike (SG Tooling) sent me a pic of a leaf he milled onto a piece of pine.  He was demo'ing Vectric Cut3D and took the sample to this mill.  Nice stuff.

Whatever is the name of that leaf, it sure looks nice.  Good job, Mike!

Ok.  1.12am now.  Should be working till maybe 3am but have no mood after the incident.  I'll retire to bed and start again tomorrow.

Proxxon Bandsaw - Smoke Out!!!

It was Christmas night.  All silent and peaceful except the sound of the Proxxon MBS 240/E Bandsaw doing its work, cutting across a piece of aluminium 25mm thick.  It was a cut that I've been accustomed to making on the little machine since its acquisition when I smell something burning.  It started rather faint which I thought was the dye which was used to layout the cut lines reacting to the heat.  Smoke started when the smell got stronger.  The bandsaw came to a halt...

The bandsaw was dead...

I thought initially that it was time for me to start shopping for a new one.  Went around my favorite shopping district - Kelantan Lane to see what's available.  2 was found which would serve my needs for now.  Both Taiwanese and one cheaper by 1/2.  Both are much bigger than the little Proxxon and weigh a few times more.

The SGD400+ horizontal bandsaw is rather basic; fully manual except, of course, the movement of the blade.  Not very satisfied with what I saw, I went on my search.

At Hup Hong in Jalan Besar Plaza, I saw what I need which can still fit into my little study converted shop; the Waytrain UE-100S.  It features a automatic cut off at end of the job and auto-feed which is controllable.  Spotting a slightly bigger frame, it can be converted to a vertical bandsaw but with a tiny table.  The only thing that stop me from grabbing it on the spot is its price tag of SGD782 before tax; a little on the high side especially after going over budget for the month on the precision leadscrew conversion of the mill and the trips the family made.  Further, my beautiful wife wasn't impress with the price tag.

The last resort was to call in my buddy, Mike Kong of SG Tooling.  He is the local distributor of Sherline and Proxxon stuff.  Being an electrical engineer by training, he assured me that the bandsaw can be salvaged.  He did and delivered what was promised.

I heard from him a day after the New Year celebration.  He said that the motor has burnt.  Replacing the motor will get the bandsaw going again.  I picked up the bandsaw yesterday at his shop.  He was telling me that the blade I was using was blunt to a point where its not even cutting his fingers; I've worked the less than 1 year old bandsaw to death by pushing it beyond its limit on a blunt blade...

Next, he took out the burnt motor and opened it up.  Burnt smell filled the shop immediate.  I have not seen the internal of a working motor before but I can see that it was rather bad.

Some pics of the motor:



You can see soot all around the housing and whatever you can that in the foreground with the windings.



Closer look at the interior.  The 2 black halves are magnets.

Mike said that the stuff isolating the windings were burnt off. Soot can be seen at the bottom.

The electronics.  Don't know if it is still working.

Anyone out there know if I can make this motor to work again?  I can see if I can use it on some projects if it can be revived.

Anyway, I've a working bandsaw now.  Just cut a piece of wood to make a sacrifical board to continue my work on the leadscrew mod.

A2ZCNC Leadscrews Upgrade - Fabricating the Z-Axis Antibacklash Nut Mount Part 2

Happy 2011!!!  I'm happy indeed as I get to spend around 4 to 5 hours in the shop, not mentioning the 2 to 3 hours yesterday night!  In fact, I just cleaned up the shop and decided to work on this post before I retire for the day.

Some update on this mod.  Finally managed to complete the Antibacklash Nut Mount and will be starting on the Motor Mount.




Starting the slot with a 1/2" endmill. 0.25mm per pass at 60mm/min.



Done finally.  Took a long time to open up the 38.5mm. I started milling down to the required depth of 13mm and move right at 0.25mm per pass.  Spindle speed set around 2000 rpm with feed of 60mm/min.

No radius on mine as I don't know how to create them yet.

Flipping the part on its side to mill out the shoulder.  Quite some vibration milling this side with same feed and speed. The part was standing too tall.  Should have use 2 taller plates to hold the parts between the vise to dampen vibration.

Major work out of the way.  Next with be the clearance and tapped holes.

After the mounting holes were drilled and tapped, the nut was inserted and fastened to check if the hole positions are correct.  Looking good.

Laying out the holes for alignment grub screws.  The center hole is for fastening the nut mount to the saddle.

Drilling from the bottom.  I just had my mill trammed and so decided to drill from the bottom to 1) test if my mill was properly trammed and 2) easier to clamp in the vise.

The 2 grub screw holes (or set screws as they are known here) were tapped 10-32.  Center hole drilled 5.5mm by mistake.  wanted 5mm...  On the far side, the hole was drilled and tapped for M5 per the plan.

Test fitting with the nut and the A2Z leadscrew. 6" caliper as reference.



From another angle.


As I still have some time left, I started preparing the stock for the motor mount.  The motor mount given to me free of charge by Tim of A2Z cannot be used as it didn't offset the stepper motor enough to use the nut mount with the bigger leadscrew.

2 options were available to me at this stage; I can either follow what Graham shown  on his pics by working on a piece of round stock in the lathe or to use CNC to profile out the part.  I went for the latter as I do not have aluminium round stock of 65mm diameter.  What I have on hand is a piece of 100mm x 160mm x 13mm aluminium rectangular stock.  Once the decison was made, I took out the hacksaw and started cutting out the stock.  Would have used my bandsaw if not for the blown motor (or controller).  Mike of SG Tooling is kind enough to volunteer to see if he can fix it.  I'm counting on him for that but, on the other hand, was hoping he can't fix it... why? because I saw a Taiwan bandsaw (Waytrain UE100S) which I like.  This little machine (in fact, it is bigger than all the stuff I have in my shop) can be used vertically and horizontally.  It comes with auto-feed and auto power off, features that make cutting up stocks to required size easier.  But it is going to cost me SGD837 including tax to bring it home.  Maybe I should just postpone this purchase and pray that Mike can fix the Proxxon bandsaw.

Lots of elbow grease was used, only to realize that the blade was blunt.  Changed it and the managed to cut through the 100mm stock.

Preparing for fly cutting.

It looks so much better now.  I'll be bringing this piece of stock down from the current thickness of 13mm to 12mm before drilling holes to hold the stock down for the CNC work.  The drawings were done in BobCad 2 nights' ago.

This is how the Stepper Motor Mount will look like:

48 passes for each feature... I'll standby my coffee and ebooks.

I'll find some time to finish up the conversion as soon as I can.  Got to shift my focus back to my day job since holiday is over.

A2ZCNC Leadscrews Upgrade - Fabricating the Z-Axis Antibacklash Nut Mount Part 1

After fixing up the Touch Plate Probe yesterday night (see A little mishap), I completed the squaring of the aluminium block and laid out the required dimensions.  This little block will be fitted onto the Antibacklash Nut from A2Z so that the precision leadscrew can be mounted on the z-axis to complete the conversion.  With the little time I had, I've to stop right after I completed boring the 23mm hole where the nut slide in to fit.

As usual, pics were taken along the way.  Here they are:

Started with drilling progressively bigger hole after center drilling. My boring tool needs a minimum hole size of 1/4" to start.  Being Singaporean (Kia Su syndrome), I gave it a 7mm.

The HSS boring tool in use.  Here you can see the layout lines and the circular mark on the surface caused by the shank of the tool rubbing against it.  The boring bar is a little short for the 25mm thick block.

Completed the "boring" operation.  The marking are almost gone... This is an inexperience machinist wannabe at work.

Test fitting the antibacklash nut. Can't insert it all the way yet as I couldn't bore all the way through the stock due to the cutting depth of the tool being a little short.  But the fit is rather good.

The back of the mount.  I didn't take pics of how I managed to mill out the portion left behind.  Deburring tool was used to remove the balance material.

Good fit.  I marked the 2 screw hole locations again using the digital height gauge.  They're right in the middle of the 2 mounting holes on the antibacklash nut.  I feel so proud of myself...

The entire process of boring out the 23mm diameter hole started with some fear of the stock moving out of the chuck.  The cut wasn't smooth at the beginning but I managed.  Spindle speed was rather slow to reduce vibration as the hole is not in the middle of the rectangular block.  As the length of the boring tool is less than the required depth of 25mm, I left a few mm at the back of the stock for cleaning up later.  Once I get the diameter of 23mm, I adjusted the tool angle to clean up what I can of the balance.  The rest was left for the deburring tool.



This is the same type of deburring tool I used for the final cleaning up. Mine has a blue and longer handle.


I hope to complete the nut mount by the next session, if time permits.  And if the A2Z horse shoe Stepper Motor Mount can be used, I'll have one less component to make to complete this mod.

When the precision leadscrew conversion is done, I'll move on to wire the spindle to the Gecko G540 VFD so that I can control the spindle rpm using gcode.  Then I'll have full automation (almost) at home :-)

Almost 1am now.  Better get some sleep.  Some appointments lined up tomorrow.

A little mishap

I've been using erniebro's touch plate micro (on cnczone.com) to zero the cutter before starting a job on the mill. It is really a time saver; no more jogging in small little steps of 0.01mm to zero by sight of all the 3 axes.

On Christmas night, it stopped working. Touching the 2 crocodile clips together (my "probes") didn't lit up the Touch Test LED in the Probe section. Couldn't figure out what happened after checking around for a while. So went back to manual zero'ing to complete the facing job to prepare the stock for the z axis mounting adapter for the A2Z leadscrew.

I kept thinking about what could have happened for the past 2 days and decided to check for connectivity of all the wires leading to the probes. Using a multimeter set to continuity mode, I probed the DB9 cable, the DB9 breakout board, and the wires connected to the crocodile clips. All perfect, nothing broken. Then I started connecting them part by part while testing continuity after each part was assembled. No problem found. Strange...

I decided to open up the controller box and look at what I've found:



The little wire (blackish one across the 4 pins on top) came loose from its soldering joint.

The 4 pins on the top row at the back of the DB9 socket is soldered together with a piece of hard wire. The black wire you see in the pic is the ground.

I took out my trusty made in China soldering iron to try to heat up the hard wire to melt the solder underneath it so that they'll stick.  Instead, the black wire came off the slot.  Couldn't seem to heat up the hard wire enough for the solder to stick.  Quite some time was spent trying to remove the solder from the slot using a soldering pump and trimming of the black wire to fit the slot.  Gave up using the hard wire.  A piece of jumper wire was stripped, laid across the 4 pins, and the joints soldered.  Ran some test before closing the cover to make sure it works.




Jumper wire soldered in place and excess trimmed off.


Now I'm back in business!

I've done some further work on the A2Z leadscrew hardware for the z axis.  Will try to post them up tonight if I've the time.

A2ZCNC Leadscrews Upgrade - X & Y Axis Installation

We just returned from HK Disney, reaching home at about 2am this morning.  We were supposed to reach Singapore yesterday afternoon at about 5pm but due to some technical problem with the aircraft, the flight back was delayed for 6.5hrs.  Other than being too cold for most of us, the trip was a good one, especially for the kids.

Spent some time in the shop this afternoon trying to fix up the precision leadscrews for both the x and y axes.  The process was simple enough except for the smaller hole size on the Super Gibs for the fastening wire.  Had to enlarge the holes slightly.  Some play observed on x but let's see if its serious enough after some trial cuts.

As usual, some pics.

Table, saddle, and motor mount were stripped off and the base cleaned.



Placing the new saddle on the base to mark out the new Super Gib.



Sawing off the excess on both ends.



The holes provided are too small for the stock wire.



Enlarging the hole a little.



Another problem encountered: the hole for the wire came too shallow.  It was drilled a little deeper.



As the new leadscrews are much bigger than the stock, adapters are provided to rise the motor mounts on both x & y.



Both screws mounted. I didn't take pics of the installation of the antilash nuts on the leadscrews and the table as I was very frustrated with fixing up the wire and the gibs.

Some videos of tests done:

Moving saddle by hand to see if the gib is set too tight. You can see the cut I have on my middle finger. This was from trying to fix up the cable to stream video from my iPhone to the roof mount LCD player in my car.



Motion test:



Simple backlash test:



I'll be doing more test to see if the play on the x axis would create some problem.