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Thread: My easter project
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24th March 2008, 10:47 PM #1.
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My easter project
Last Easter buying and fixing a big chainsaw was the big project, this year with SWMBO away I thought of getting up to the same level of mischief but decided on something milder.
Some time ago I pulled an old X-ray machine out of the dumpster at work and got a lot of useful materials out of it, mainly a heap of black powder coated ally plate and small bars but also a lot of hex bolt fixings and bits and pieces.
Anyway - here's what I made over easter. I had nothing particular in mind when I started and sort of made it up as I went along. I made a few mistakes and that caused a design change several times along the way but I'm really pleased with the way it works and runs very smoothly. You may see a number of holes drilled and threaded that are not used - some were there from the x-ray machine, the odd stuff up or I eventually decided to not use them.
The C-shape is made from 6 mm ally plate. I used the rotary feed table on the mill at work to cut it out but it would have been quicker using the bandsaw and then a belt sander which I had to end up using anyway. The base is made out of a couple of sections of 12 mm ally plate.
Here's a shot of the back. You can get a idea of how the arms are held.
This shot also shows the extent of the movement. The straddling idea means the wheels can't retract that far but I could gain another 1" by completely removing the solid bit between the slots - the arms will still hold together
The arms are made of 19 mm ally bar and have slots cut in either ends. The short slot holds a wheel, the longer slot is part of the clamping mechanism. I tried drilling out as much as I could of a slot and then milling out the rest but I found that was too slow so I just used a TS (with special ally cutting blade).
The shed was about 1cm deep in ally flakes by the time I finished - I should have take a photo - but I have 90% cleaned it up
Here's a close up of the contact points.
The bearings were also in the X-ray machine. They are standard (1/2" arbor) size bearings so can easily be replaced if needed. The "tyres" are PVC tubing which stretches to fit over the bearing. I was going to use roller blade wheels but as I do mainly small stuff I wanted a less physically interfering steady with a smallish contact point. I will probably make a bigger steady another time using some rollerblade wheels.
I experimented making different bearing arbors. This one has 5 pieces, a full brass arbor and two narrow spacers on the inner part of the arbor to hold the bearing proud of the arm, and a brass washer and brass countersunk holding it all together
The other 2 arms have a simple all-in-one spacer/arbor, and another spacer and screw. This was much simpler arrangement.
The long slot in each arm straddles the C-section.
Two U-shaped clamps then ride atop each arm and are held together with 2 x 5 mm hex bolts that pass thru the C section and are threaded directly onto one of the clamps. This works really well and the arms slide in out in a positive manner after only 2 turns of each hex bolt. It would be a pain if one was adjusting the steady all the time but should be OK for what I do.
If I was making it again I wouldn't bother with the slotting - I'd just use two pieces of 6 mm ally bar and insert spacers in between at appropriate places.
The base is made out of 12 mm ally plate that slides smoothly on the lathe bed.
So - one X-ray machines turned into a lathe steady. All of the hex bolts were also from the X-ray machine. The only thing not on the machine were these particular bits of brass (because I did get some brass plate out of the machine!), the nylock nut on the base, the PVC tyres, and the bearing brass screws.
I might make a cam locking mechanism for it if I get excited.
No the big question is - should I pretty it up or not? I'm not sure - I'm kinda partial to the scratched black paint and silver look?
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24th March 2008, 10:52 PM #2You've got to risk it to get the biscuit
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looks better than a shop bought one
how does it lock to the lathe bed?S T I R L O
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24th March 2008, 11:05 PM #3.
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Thanks Stirlo.
RE: How's it lock.
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24th March 2008, 11:07 PM #4You've got to risk it to get the biscuit
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ah, thats pretty simple
S T I R L O
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25th March 2008, 12:16 AM #5
Congratulations on your success with the pvc "tyres," Bob. I guess they were enough undersize to secure a good grip on the bearings. I tried something like that a while back, but the "tyres" slipped around too much and I removed them to let the metal ride directly on the wood; sanded the wheel print away without drama. I used it only once, and built a new one with roller-blade wheels:
http://www.woodworkforums.ubeaut.com...ad.php?t=68735
I used a flat bar on top of the bed to maximise the diameter of the workpiece, and added a tie across the bottom of the bed for more robust purchase. It looks like we're on the same wavelength for the wheel supports; much stronger this way, I think.
JoeOf course truth is stranger than fiction.
Fiction has to make sense. - Mark Twain
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25th March 2008, 12:32 AM #6
Bob, you are a talent. I like the black and silver look as is.
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25th March 2008, 12:39 AM #7.
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Thanks Joe,
I saw your very impressive 4 wheeler a while back - it looks pretty big and strong and built to take big bowls etc. The ultimate size of my C section was limited by the size of the ally plate I had available although I guess I coudl use your flat plat base Idea to gain a bit more capacity. Even though it looks big, mine is really meant for small stuff. I deliberately did not go looking around at too many steadys because I am a notorious subconscious copier and find it very hard to get previous images of devices out of my head so this time I deliberately stayed away from looking.
The PVC tubing I used for tyres was quite undersize and had to dunk it in hot water to get it soft. Then by squashing the tube opening flat I could just push the bearing into the tubing opening (like a letter going into a letter box) and then I used a metal rod to twist the bearing inside the tube till it was sitting square across the tube. Then I trimmed off the excess tubing. I guess I've run the steady for about half an hour and the tyres seems to stuck on firmly. My experience with PVC is it will eventually go hard and probably fall off - at that point I will just replace the tyres. The PVC is a fairly common size so that should not be a problem
I will need to get sealed bearings though as the exposed bearings like those ones I fitted seemed to fill up with WW dust.
Cheers
Bob
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25th March 2008, 06:34 AM #8
Bob way to much time spent in throw out bins instead of working
hope you checked for radiation levels
It looks a job
now with those new tool rests and steady your going to show some fine turning
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25th March 2008, 09:25 AM #9.
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I agree! For example last saturday I spied an old sprung double bed frame on the verge for council pickup day about 5 km from home. These old frames have good solid double angle iron frames useful for all sorts of projects so I went home to get my newish HIACE van but the frame still wouldn't fit because the legs are welded on so I had to go home to get a hacksaw. All in all - it took way too long!
hope you checked for radiation levels
It looks a job
now with those new tool rests and steady your going to show some fine turning
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25th March 2008, 06:23 PM #10Skwair2rownd
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Steady as she goes
Good one Bob! really great use of recycled material!!
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25th March 2008, 11:07 PM #11
Nice work Bob, trash makes treasure!
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26th March 2008, 01:26 PM #12
Awesome steady rest! Well done!
I like using junked stuff to make good stuff.
Looks like you do too!Al
Some minds are like concrete thoroughly mixed up and permanently set.
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28th March 2008, 06:21 AM #13New Member
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What is SWMBO?
Sorry new here and fraid I'm missing a good joke.
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28th March 2008, 08:33 AM #14.
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29th March 2008, 06:48 AM #15New Member
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