The trial in making the wheels started on Saturday and Sunday for a couple of hours each day.  Some pix were taken but I didn't have the time to update the blog till now.  Just returned from the A&E of Changi General Hospital which we spent the last 4 plus hours waiting for the doctor to administer treatment to my poor little Ruth.  Her fever went back up Monday night and she started bleeding from her left nose.  We panic and drove her straight to A&E after midnight.  The wait was rather long with more time spent waiting for the result of her blood test to be out.

Ruth is such a brave girl.  Despite the pain and discomfort, she allowed the doctor to draw blood from her without once pulling back her arm.  I'm so proud of her!

As I was to send our helper to the airport in about 2 hours time for her trip back to Myanmar, I gave up the idea of sleeping - and so this blog entry.

Terrace provided me with a length of delrin of about 28.6mm diameter.  I felt bad as it will be such a waste of the expensive plastic as the final diameter of the wheels will only be 15mm.  He explained that it was meant for another project of his which didn't happen and so using it for this purpose - felt so much better after learning this.

On with the pix.  

The next ops is to turn the chamfers on each side of the wheel so that it seats nicely in the slot of the aluminium extrusion.  The plan is to cut all the 18 pieces needed for the mini kossel and turn a shaft to hold them each at a time.  I've yet to think of how to turn the chamfers accurately for it to balance itself in the slot like the cross section pix below.

I'll figure that out when I feel better.  A little under the weather myself...

Be blessed!

Took a day off after sending Alicia to the airport for her CCA trip to Bandung, Indonesia.  Going to miss this big baby of mine.

After having a good sleep, I started working on the aluminium extrusions.  From the wiki, I need 9 x 240mm and 3 x 600mm for the frame.  I thought through the process of getting them to equal length.  Once I decided on the approach, I went to work.

For the 240mm length, the endstop on the bandsaw was used, after marking out the first piece.

I just love this machine; it cuts through aluminium like butter without much of a mess.   The Proxxon chop saw I have is too messy and noisy to be of use in my humble flat.

In no time, I've the 9 pieces done with some left over from the 2 x 125mm I started wiith.  I've still the other 2 pieces of the 125mm left for the 3 x 600mm pieces.

All required length rough cut.  The left overs are on the left of the pix.

Using a 20x40x80 block and clamp, I started milling off the first edge 2 pieces at a time.

Using the combination square, the required length of 240mm was marked out with a scriber.  I'm not looking at accuracy for the extrusions, just need them to be of the same length, plus minor a little.

The parts were then flipped over.  Several rough cuts were made and when I'm getting close, I crept up to the marked line.  Once there, I measured the length again with the measuring tape (my mitutoyo caliper can only measure up to about 150mm) for confirmation.  The DRO was then zeroed.

All 9 pieces done.

The iGaging DROs are of great help here.  Considerable care was taken for the first set.  Once the reference point can be established with the DRO, the rest were easy - merely cutting to zero.

I'm unable to use the same approach on the 600mm length, of which 3 are needed for the vertical of the frame.  So I lined them up as close as possible and as flat as possible to the bottom of the vise and milled off the first side.  A clamp was then used to hold the 3 pieces together.

Though not necessary, I still check the setup on the surface plate.  they're at the edge because of the overhang at the top of my bench where the surface plate sits. 

The other side was then milled, leaving a little short of the final 600mm length.  Call me paranoid, I want another clamp to be put on and flip the part over to clean up the other end again.

Now both sides done and the 3 extrusions to length.

stacking them up for photo shoot.  I know I shouldn't be leaving the ER16 collet around like this.  Forgotten to keep it in the box.

The pattern formed by the extrusions looks nice...

It seemed that it wasn't very messy from the pix but I've chips everywhere...

I'm rather pleased with the result I get from the few hours I spent today in the shop.  Terence will be sending over the balance 2 pieces of the connecting pieces.  The frame should be up by then. 

He will also be bringing over a short section of delrin rod.  I'll be making the wheels for the carriage to ride between the slots of the extrusions. 2 x flange bearings will be press in to the wheels.  There are a total of 15 wheels to make: 3 sets of 3 for the 3 carriages and 3 sets of 2 for the idlers where the belts will ride on.

From the sketch he drew, this should be a simple lathe job.  Looking forward to start working on it.

Back to my day job tomorrow.  Hope  to have some time next few days to do some work in the shop.

Be Greatly Blessed!

I finally decided to ditch the Portabee, not being able to tweak it to print out the quality I want. I spoke to Terence about it and he shared that he has been doing his research on delta printers. After much deliberation, we settled on the Mini Kossel based on Terence's suggestion - he knows what he is talking about while I don't... lol...

This is how a Mini Kossel looks like (please click on the link to view the pix on Johann's Fllickr album as I've not gotten permission to post it here):  http://www.flickr.com/photos/jcrocholl/8730999022/.


From the description, he was using 15x15 aluminium extrusions for the structure.  Terence managed to find a source for the exact type but it seemed that the dealer in SG doesn't like to deal with personal purchases.  My email to them went into twilight zone...

I know a few places selling almost the same and so went checking.  The smallest I can find is the 20x20, which we bought 2 sets for our project.  The shop at King George's Avenue will only cut to shorter sections for ease of transporting the 5m length.  Good enough for us as we both own a horizontal bandsaw.

This was the first lot of 5m length of 20x20 aluminium extrusion cut into 4 short pieces for each of transportation.

Back home, while waiting for Terence to amend Johann's model to cater for the different size extrusion, I gave the Portabee another shot to see if I can print out something decent for use.  The result was not as bad as previous trials but I don't feel comfortable using the printed parts.  Here are some pix on the attempt:

If you wonder why is the part much shorter than the actual, I accidentally touched the USB cable connecting the printer to my notebook causing it to disconnect after an hour of printing... frankly, no point to finish the print from what I saw, and so the lost in communication was timely.

I received a good news from Terence just yesterday; he has completed the modification of the extrusion connectors and did a test print.  Result was good.  He went on to print some for me in blue.  I've just gotten back from his place with the parts.  They are so much nicer and the fit astonishing well!

Some pix to show off his work from his tweaked Replicator 2:

For our project, Terence will be the one doing the printed parts.  Mine will be turning the delrin wheels that ride on the slots of the aluminium extrusion.

More stuff to acquire the next few days.  We'll try to make whatever we can and buy the rest.  Once we have the basic Mini Kossel up and running, we'll be looking at modifying it.

That's all for now.  Be blessed!