Bearing Thrust Collar for Y Axis - Rectification

I was given 3 days medical leave from yesterday to Friday and decided to stay a day more at home to nurse the swell.  But I will return to office on Friday to clear my work; I've a client coming by tomorrow noon to sign our offer.  Come to think about it, unless its school holiday, I rather be at work.  Its strange, I know, but... got to learn how to let go.

Anyway, spent some time in the morning trying to find ways to rectify the error in my calculations.  I was looking at Graham's drawings on the Z axis mod and saw that the mounting holes he is using were slotted to allow adjustments.  So I went back to my 3D CAD file and put on the slots to derive the locations and the amount of material I need to removed.

The part was put back in the vise and tapped down.

After clocking the part to find the centre of the bore and edge from the flat surface, I dialed to the new hole location and start off with the bigger slot mill to cut the counterbore.

Lots of chatter during the cut. I was feeding the tool very slowly to form the slots after milling to 6mm deep. The 5mm slot mill was used next to mill the through holes.

Slot done - the ugliest around...

From another view.

I tap the mounting hole deeper to avoid having to shorten the #8-32 capscrews, taking the opportunity to clean up the holes.

If you enlarge the pic, you can see that I cut the right slot a little too long.  No harm done.

The thrust collar is now ready to accept the handwheel.

You can see that either I had the leadscrew adaptor a little too long or the thrust collar a little too thin, the handwheel couldn't seat in properly causing huge amount of backlash.  Two thick washers were employed to see how much I missed.  Looks like I've measured the length of the leadscrew adaptor that extends out of the thrust collar wrongly...

I went back to measure the amount of adaptor protruding from the stock thrust collar.  The difference was about 2mm.  Time to go back to the lathe...

I carefully trimmed off 2mm from the end. The wall of the counter-bored hole is rather thin. I was worried about it going out of shape.

The micro boring tool was up next to increase the depth of the counter-bore by the same 2mm.

I brought the table forward to avoid alignment problem later. Time to see if the shortened adaptor works.

Beautiful!!! The handwheel turns free and smooth.

I went ahead to tighten up the anti-backlash nut till the wheel is hard to turn and slacken it a little.  The handwheel still turns smoothly.  Finally... I DID IT!!! (giving myself a pat on the back...).

From the exercise, I know what I've gone wrong and what I need to take note of for future projects.  This has been a very rewarding learning experience for me.  The bearing thrust collar for the X axis is up next.  The hole locations are the same as the Y axis except that they're upside down.  I'll be starting with the thrust collar first before working on the leadscrew adaptor as the length of the adaptor depends on the thickness of the thrust collar.  This will give me some room to play after boring the small recess for the flange bearings to seat in.  Not sure if I want to start working on it today.  I've slight discomfort (not amounting to pain. kind of sore...) at the place the dentist operated on.  It can be a little distracting especially when counting handwheel turns.  I started over twice this morning when dialing in the distance after finding the edge.  Maybe I'll just rest a little while and read the George H Thomas' "The Model Engineers Workshop Manual".

I've Mike Kong of SG Tooling (http://shop.sgtooling.com/) to thank for teaching me the centering method used in the bore. It works really well.  I dare not say that I'm right on centre but I should be very close.  Thanks Mike!

Ball Bearing Thrust Collar - Completed but...

In less than an hour's time (at the time of writing this), I'll be going for stage 2 of my dental implant.  I've been fasting since 6.30am and are feeling very hungry and thirsty.  I was told to fast 6 hours before the surgery as, this round, I opted to be sedated during the process.  This is my third time going through this - hope this is the last.  I have to remind myself not to bite on sweets that, I was told, causing tooth fracture.  Kind of hard to rid of this bad habit...

To distract myself (excuses excuses excuses), I went to my shop after having my mandatory 2 cups of coffee just before 6.30am, to complete the thrust bearing mod on the Y axis leadscrew.  It was a good session as I made no mistake and was rather proud of myself to be able to find the centre of the bore with the DTI using the method Mike taught me.  Though completed successfully based on the drawings I did (with slight modifications due to the size of the stock I started with), I'm not able to mount the bearing holder with the leadscrew adaptor inserted.  My measurements and calculations of the distance between the leadscrew and the stepper motor mount's screw holes was off by quite a fair bit.  I thought I was getting smarter when I did the measurements and project the numbers using the stock thrust collar - I am obviously not.  But I'm still happy as I managed to fabricate the parts with quite a good level of accuracy from the plans I drawn.

Trimming the face with bearing mounted so as to make the bearing sit flushed in the recess. This was done on both sides in the same manner.

Done! Nice...

Marking out the amount to cut off for the witness mark using the stock thrust collar as a gauge of how much I need to cut.

Flycutter was used to flatten the top for the witness mark.

Nicely done. About 6.8mm was taken off from the top.

I was looking around for the 1mm endmill but saw this in the box.  Been there for maybe a year, sealed in its plastic wrapper.

The witness mark engraved.

This was how the part look before the mounting holes were drilled.

First hole done, shown with a cap screw inserted.

The completed part.

Time to test if this works.

The new bearing thrust collar mounted using 2 x 8-32 3/4" capscrews borrowed from the lathe. They're a little longer than needed.

From the back you can see that the distance between the leadscrew and the 2 x 8-32 mounting holes are quite off.  My measurements were off.

Like I mentioned at the beginning, I'm quite pleased with the adaptor and the bearing thrust collar that I made.  They're both accurate to the dimensions I layed out on the plan.  The error in the thrust collar is in my measuring of the distance between the leadscrew and the mounting holes.  This is something I've yet to learn - accurate measuring from existing parts.

More to learn.

Shop closed for the day

I was kept out of the shop today though I've quite a few things to try out.  My little Ruth is having a fever that went off after medication but came back up a few hours later.  Her mommy was out to transport an elderly person to church and her elder sister, Alicia, was stuck with her activities on the Internet.
Ruth was crying when mommy left home.  So I distracted her with the 2 Mr Bean movies I bought last Sunday after church.  We had fun watching the silly fella.  When she was feeling better, she got restless and wanted to play.  So my right hand was transformed to a snake head attacking her while she fended herself laughing away.  She fell asleep when she got tired and drowsy from the medication. I fell asleep too, tired of being the snake...

If time permits, I'll do some work tomorrow.  Otherwise, it will be 2 weeks from now - we'll be going to my dad's factory in Malaysia next weekend.

I read about a gear making software today, written by Art Fenerty, the creator of Mach3.  From the videos I've been watching, it seems a good piece of software for me on learning how to make clocks, especially if it only cost USD75 for a license which I can use on both the computers I'm using for my CNC work.  I'll start with the demo to see if I'm up to using it.

As I think about it, the more I want to start building my first clock, the skeleton wall clock from W.R. Smith, in acrylic.  If I can put all the parts in my CadCam software, I can mill them out using CNC and put them together to form the clock.  I may be thinking too much about the likely problems I may encounter, like do I need a faster spindle with very small endmills and if the cut length of these small endmills long enough to cut through the thickness of the parts called for in the plan.  There is also concern about the speed and feed of the cut on acrylic, a material I've not tried playing with in the mill.  I don't have proper cooling to keep the endmill cool so that it wouldn't melt the material.  More research is required.

Anyone with experience in milling acrylic with smallish endmills, please chim in.  Kindly leave your name with your input so that credit can be given when I've the post up on the build.

I'm going back to check on Ruth with the thermometer.  Until the next session, be blessed.

Picked up some new accessories today

I popped over to Mike's shop to at Fook Hai Building to pick up the independent 4-jaw chuck and the centre turning accessories ordered through him. As usual, I had some fun chatting with him and picked up some idea on the workholding.
I looked at the chuck and was a little disappointed with what I saw. From an untrained eyes' prospective, it doesn't look as well built as the 3-jaw Rohm chuck supplied with the lathe. The little piece of instruction manual in the box is all in German. That had me wonder, are they interested at all to sell their products outside Germany?
Here's a pic:

The centre turning accessories looks as expected except some little chip or dent mark. No big deal there.

Mike is a funny guy. When I text him asking if the order is ready for collection, he forwarded me this pic:

But when I reached there, in less than an hour's time, only the carcass of the box remains.
After playing with the lathe for about a month, I'm wondering if there is a mill in the same size category... Better stop thinking, bad for the wallet.

By the way, anyone can help translate this? It should be the technical data of the chuck.


- Posted using BlogPress from my iPhone

Testing BlogPress

The BlogPress developer replied to my mail this morning asking me to either to repost or reinstall the app. I've been trying to repost many times yesterday and do chose to remove the app and reinstall it.
Let's hope this test post appears... and with this pic...

The plan was to have the OD of the mount at a diameter of 40mm but the only available piece of stock was 40mm. 1mm was turned away to remove the scale on the surface and to make a round number, hence the 39mm diameter on the final workpiece.

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Adding Bearings to Y Axis Part 3 - Bearing Mounted Thrust Collar

This is going to be a long post, combining what I did for the last 2 sessions. Blame BlogPress, if you want to; for whatever reasons, the 2 posts done on BlogPress, one for each session, cannot be uploaded. I've sent a mail to its developer earlier today.  Hope that they sort out the problem soon.

Ok, with the longer leadscrew adaptor completed, I went on to make the other component that made up the whole assembly.  Not knowing what to call it, it should just be known as bearing mount as its role is to hold the 2 flange bearings to the base of the mill where the handwheel is to be mounted on.

The stock I started with was a piece of 40mm diameter aluminium round stock.  It was cut to about 40mm in length on the bandsaw, catering for the the height of the 3-jaw chuck in its reverse position.  The part is supposed to be 12mm thick and so I thought I can make 2 pieces at one go. If I'm successful, I'll have 1 extra to use on the X-axis.

Here goes:

Cutting off a section of 40mm in length. The straightedge clamp to guide the cut.

The end was faced off to "flatten" the sawn surface.

Turning as close to the jaws as I was comfortable with.

The largest center drill in my toolbox was employed.

Drilling through using the largest drill the tailstock drill chuck can take - 10mm diameter, to prepare for boring.

I was trying to use the set of boring tool from Proxxon but they apparently require a bigger bore to start. So the little boring tool was used instead.  I really love this little beast! Very nice finishes can be achieved. The only regret is its short length though - max at 15mm.

After opening the bore to about 12mm in diameter, I tried using the Proxxon boring tool to see how it performs.

Bad Bad Bad... Just look at it! I must have done something wrong... the mini boring tool was mounted back to clean up the mess created and work continued.

Testing how well the bearing fit.  Not tight enough though no wobble felt. One more chance to get it tight when the recess is done to cater for the flange.

I did it again... the recess is a little too deep for my liking, but it is really tight when I press the bearing down with my finger.  So tight that I can remove it with the L-shaped allen key...

I'm now ready to part off the mount to clean up the other side.  I was so confident of the experience I acquired parting off brass and steel that I didn't expect to encounter problem with this piece of aluminium stock - the lathe motor was stalled twice and I've a bad case of chatter.  The part was so hot to touch that I burn my fingers touching it... ouch!

This was where I left the workpiece to cool off while I think through how I should do.

I was standing at the lathe looking at where I stopped the next morning.  The tool was advanced to almost touching the last place where jam occurred the night before.  I turned the chuck by hand to rid of the chips and chatter marks that caused the jam.  For some reasons unknown to me, I opened up the gear box to look at the belt position and realized that it was set to 1400 rpm!  This is too fast from the experience I gathered.  No wonder the feel wasn't right when I feed the tool into the workpiece.  I changed the belt to 330/660 position and selected the slower speed (330 rpm).  The feel is now back!

All the way through!!!  Well done, Wongster!

You can see from this pic that I didn't bore deep enough.

In fact, I was off by quite some bit!

The workpiece was put back into the chuck and faced off to the targeted thickness of 12mm.  There just wasn't enough "meat" after parting to make 2 pieces of the same so I gave up the idea.

Bearings fitted on both sides.

Testing the mount on the mill with the handwheel installed. Please note that the original thrust collar wasn't removed when the modified thrust collar (now I know its name...) was tested.

There is still the 2 mounting holes for the #8-32 capscrews to be added before I can call the job completed.  I'll be making another one as I'm not satisfied with the bearing bore.  With this experience, I hope to do a better job when starting over.

I welcome any suggestion on how I should approach this.

Have a blessed night.

BlogPress is giving problem again...

I just realized that the 2 posts written over the pass 2 days weren't updated onto blogger. They're about the bearings holder I'm making for the Y axis of the manual 5410 mill.

Of late, I'm getting very reliance on the iPhone app to update my blog.  It frustrates me whenever it went out of action.  I'm too lazy to rewrite the 2 posts again using my notebook and so will have to wait till it is up and running again.

Sigh...