It has been a while since I do any serious work on the lathe. After fixing up the scale, the carriage was reinstalled and I took some time to take out some slack in the hand wheels and the screws. Turning is a little tighter now but still rather smooth. To get a proper feel, I chuck up a small piece of aluminum and did some test.
Practicing On The Lathe
Come to think about it, if I'm to make the wheels from scratch, I don't really need to face off the part off side of the wheel. Reason being, most of its face would be recessed and spokes milled out.
Do let me know if you have any suggestion or spotted mistakes. I'm still very much a newbie though I've had my machines for 4 to 5 years.
I spent the afternoon in the shop after I decided to tap the centre hole of the fixture M4. The fixture was completed quickly and I moved on to work on the M4 screw to fit the task.
Being off the CNC mill for so long, I was a little wary. Went through the BobCad simulator several times before committing to the job. The GCode was transfered to the workshop PC, which is still running Windows XP. After painfully setting up the work and checked through several times again, I hit cycle start... Midway through the program, I saw something that shouldn't happen, the wheel was turning in the fixture! I did what I shouldn't do, using my fingers to hold the wheel from turning...
Anyway, the wheel came out bad. I'll have to re look at workholding before continuing with this job.
I was studying the few pics of the Thai hobbyist milling the wheels. I suspect the use of superglue. No screw to hold the wheels in place for machining. Another possibility is the pressing of the wheel blanks into the plastic sheet with the hole slightly smaller than the wheel diameter. But will that provide enough hold to withstand cutting force? I'm already milling at 0.25mm DOC per pass, feeding at 200mm/min. Very very light cut...
Igaging Scale Installed!
Had a "quickie" in the shop before sending Ruth to her class. Whipped out the Bosch power drill and started where I left of few hours ago. I couldn't seem to push in any further after going in a short distance. Tried increasing the speed and finally get to the depth I want.
After this, the rest was a walk in the park...
I've to think of a way to deal with the wire, especially when moving the carriage towards the tailstock end. The wire has the tendency to fold into the chip tray. Another thing to look at is some way to cover the scale from chips and coolant. Can't think of anything at the moment.
Hope I can get back to work when I get home later.
Igaging DRO On The Lathe
Been wanting to fix up the DRO on the lathe, at least on the Z axis, for a long time. The Igaging scales have been sitting underneath the bench for several years waiting to be used. The main reason for the scale? I've been missing count when turning, resulting in inaccurate parts being made. Since I've taken a new job to make some wheels for slot cars, I might as well use the opportunity to get this going.
Being stupid and clumsy, I dropped the Mitutoyo DTI. The problem moved side to side after the accident. When I tried tightening the screw next to the probe, the wiggle didn't go away. So I decided to remove the screw to see what may be the problem. Big mistake! Several micro size steel balls started dropping out... Arghhhh... I've 3 dial indicators but only 1 dial test... Why?!?!?!?!
I'll pray for no mishap tomorrow when I started drilling and tapping the holes for the scale. It was an eventful night (or should I say, morning...) with my broken DTI. I checked Element14 for the price of the same unit, it is listed as almost S$180... I might have to bite the bullet and purchase one as a replacement as I don't know how else to indicate in my vise and parts without it.
Fixture To Hold The Wheel Blank
After a lovely evening out having dinner with my family, I continue with my work on the wheel. I wanted to do up a fixture to hold the wheel blank in place during the machining of the spokes. The fixture will hold a piece of blank for now. Since I've only 4 pieces to work on at this stage, it shouldn't take very long doing one at a time once that part of the job starts.
Looks like I can't carry on tonight. Will have to make a trip down to Chan Man Lee to buy the M3 tap. Problem is, I would be able to get back to the shop till after Tuesday - roadshows on both Monday and Tuesday night.
The Toilet Is Fixed!
Late morning today, I decided to complete the job I started on repairing the leaking water closet. Once again I remove the tank from the bowl and uninstall all the existing components. New flushing system and fill valve mechanism were added to the tank. And with the installation of the spud gasket, I've leakage no more!!!
Enough of words, let's see some pix!
One thing I realized when working on this project - I always don't have the right tools when the need arises. Like for this instance, none of my spanners can be used! I've to rely on the adjustable wrench, which is a pain to use for such tight corner. In fact, I've almost all the spanner sizes from 5mm to 26mm, but not a 20mm... And I've 2 of 18mm and 19mm... Thank God I managed to get through with the job.
Now that I've some confident fixing a toilet tank, call or write me if you need help. For a fee of cause... Lol. Tedious job.
A Day As a Plumber
The leakage of the fitting at the master room's toilet continues after I tried fixing it during my annual leave in June. It irritates me so much that I told myself that I got to get it fixed today. Went out to the hardware store nearby and bought this:
I was told by the hardware shop that I'll need to remove the entire water closet to do the replacement. I was a little hesitant but went ahead with it.
It was a messy job, especially with parts soaked in water for so many years. Managed to remove the water closet and dismantle what's required. Then I realized that the new part is too big to fit I the water closet... *slap head*
Anyway, I tried cleaning the rubber seal as best as I could, hoping it is just the seal causing the problem. Will be heading back to the hardware store to find the right part to complete the job.
This is what I got meddling with something unknown to me...
A Thought on Holding The Rollers
When I was just about to get out of bed, the ER collet holder I bought from Arc Euro came to my mind. So I scrambled to the shop and search for it.
I tried out using the 19mm collet but the little thin disc fell right through. So in tightened the nut and carefully put in the roller till it started gripping. The problem using this method of holding is, I'm not sure how to hold it such that the working surface is perpendicular to the spindle. Further, I'll have problem with those pieces that have the blue plastic ring on their parameter.
Looks to me that holding the rollers via the centre hole is the way to go.
If anyone has any suggestion, please comment. Thank you.
Slot Car Rollers
Been wanting to get back to the shop for the longest time. My last post to this site was about 2 years ago... Anyway, blame Terence, whom has been showing off his work.
A young man contacted me on Carousell asking if I'm also into CNC. He would like to customize some wheels, which are used as rollers on his slot car. From what I understand from him, the rollers would ride against the wall of race tracks, guiding the car along the track.
He forwarded me some pix:
He bought some blanks and would like to have them machines tongue design he wants. We chatted thru Carousell and migrated to Whatsapps with pix flowing to and fro. Based on what was told to me, i put them into 3D models.
But I find the spokes too thin at 1mm. So I reduced the number of spokes to 6 instead.
From his response, I know that he still prefers having 8 spokes than 6. So I went back to the drawing board and made some adjustments:
After having dinner with my girls at an overcrowded Korean BBQ restaurant at SOTA, I went by the young man's place to pick up the blanks.
Don't ask me why some came with the blue plastic ring and some don't. I don't know anything about slot car till now.
I imported the 3D model into BobCadCam and extracted the bottom edges. The features I'll be working on are the spokes since I'm given the blanks. After computing the toolpath, I ran the simulator to make sure.
I'm giving the rapid height a bigger value to clear the cap screw which I plan to use to hold the wheels.
Next will be to find the right sized capscrew to use. The centre hole is slightly less than 5mm, which is to be used to press in a 520 bearings. M5 capscrew seems about right but there is some tiny bit of movement. Also, the capscrew head is a tad too big. I've it turned down to just slight more than 6mm.
Ok. That's all for now. I'll see if I can get some work down tomorrow cutting some blanks to test. Wouldn't want to try it on the actual thing.
Meanwhile, Be blessed!