Is it a Spider? Is it a Mandrel? Is this my worst-ever coffee-fuelled machining project?
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- čas přidán 16. 07. 2024
- I made a Spider/Mandrel thingy to help with machining a large thick-wall tube to make antenna support rings on my lathe. Coffee and brainstorming resulted in an internal mandrel fixture that works a treat. I can now hold large heavy tube and machine the outside and both ends with ease. No steady-rest to get in the way, and it's a very solid, safe and adjustable way to hold big tubes on my ancient Colchester 1800 manual lathe. This is Part One. Please consider subscribing to the channel so you'll get notified about the next part and other rambling nonsense that I come up with.
To be clear, I am not saying that THIS is how to make a tube-holding spider mandrel thingy, I am saying that this is how I made MY tube-holding spider mandrel thingy. Making the thing was a huge pile of fun, and the fact that it works really well is a bit of a bonus.
Absolutely no originality is claimed for this fixture. It's probably got a proper name but I don't know what to call it. "Expanding Tube Mandrel" will have to do. [Update: Toolmaker51 at Homemadetools.net suggests it's a type of Spider]
Before anyone says "why not use a steady rest?", I haven't got one (yet) but more importantly, I need to machine the outside of the tubes and both ends, which is a bit of a faff with a steady rest.
Disclaimers apply: I have literally no idea what I'm doing when it comes to machining.
Also I'm an idiot, so don't copy what I do or what I say. My redeeming feature is that I give myself permission to fail and have no fear of failure. That seems to mean I get a huge amount of fun from playing with microwave ham radio and all of the electronics, maths, physics, electromagnetic simulation and propagation studies. I also have a jolly time messing about in my home machine shop making stuff.
SAFETY DISCLAIMER
On occasion, I wear flimsy nitrile gloves to help reduce the impact of allergic dermatitis from coolant, lube and fine metal shavings . That seems to trigger some folks who are sensitive to a purported (but not evidenced) physical safety risk to my life and limbs. Please don't bother commenting if you see me wear a glove sometimes.
Chapters:
0:00 Why I need a tube mandrel
1:15 Design ideas
6:55 Machining the shaft
14:01 Making the studs
26:00 Collars
35:55 Test fit!
37:48 Drilling the hole pattern
41:04 Haimer Time - Věda a technologie
absolutely love the humor.
this is some extreme high level s**tposting while still being incredibly informative
This is what happens when I have a Hard Day at the office. My revenge against the unfairness of, well, everything and another salvo in the battle against entropy in a vain attempt to delay the eventual heat death of the Universe. Normal sort of day in fact.
It's a joy to be invited into your shop. Thank you.
It's nice to be able to share the fun I'm having, despite not having any idea what I'm doing.
Looking forward to your contraptions build. Happy New Years! Enjoyed watching.
28:20 Oh that's fun, you're getting _four_ spiraling chips off that drill there for a moment: two from the main flutes, but then another two miniature curls off the edges of what I'm assuming is a split point. That's a sharp, well-ground and well-centered drill right there.
I get those from Drill Service in Horley. Super grinds on them, at least until I decide to refresh the grind, then it's all downhill. My father was a tool and cutter grinder, he could grind freehand split points just by feel.
Max Grant did a tailstock chuck recently and this seems like a good counterpart. There's no welding for this which makes it the easier one to start with too.
I enjoy watching Max making things. A rotating tailstock chuck is on my list of things to make next, but a steady-rest is a higher priority. A surface grinder would make life better, so would a proper bandsaw. I need to retire from the day job so I can play harder at my hobbies!
I did the same with a 4 jaw--I went 4 jaw because of the adjustment for accuracy--I have no regrets and vevor chucks have quality and are cheap and no kick backs for me.
I can't wait to see the rest of the build!!!
Heh heh, I'm too busy making things with it to do the editing!
Happy new Year!
And the same to you and yours!
Great work! Very entertaining !
I have such a lot of fun messing about making things, it seems churlish not to share my enjoyment on the Intertubez!
Love the #Abom79 reference. Good work as always sir. Thank you for the videos
Excellent work . Thanks for sharing
Nice work Neil. Happy New Year
Thanks Howard, I need to get on with those heatspreaders. This fixture if for a job that's been waiting EVEN LONGER, if you can imagine that. 122 GHz parabolic dish mounting rings from Oct 2020. What with the backlog of work AND the very busy day job AND family stuff over the hols, catching up is tough. The pile of 3kW watercooled UHF PAs is cluttering the place up as well. Wondering seriously about tearing the pallets out of one and using it for a big 23cm SSPA. They have 3 x 48V PSUs and all the water plumbing for a rack mount chiller. Easier than building a rack enclosure perhaps. Loud as a loud thing on 432 MHz obviously!
@@MachiningandMicrowaves Always great to see your work. Haven't seen the amps that you bought. Do you think the MRF13750 pa's will fit..?? Sounds like it would save a lot of work. No snake cooling plates...
This is the best kind of nonsense. I'm fascinated. Good show.
High quality nonsense guaranteed! Thanks
Could you accomplished the sam thing, but easy to adjust, by making 4 center pieces to fit the shaft, with the inner ones fitted tight with grub screws, they make a wedge shape that fit a disc that is beveled on both sides, and split into 4pieces, the disc fits inside the tube, with the shaft through it, then the opposite side wedges fitted,. When tighten the center shaft is threaded, the wedges spread the disc against the inside of the tube, similar to an exhaust pipe expander tool, it maybe easier to make, and can easily fit different size tubing! I know I'm rubbish at explanation but hopefully you get it! 😜👍
I use something similar to your idea for smaller tubes up to about 80 mm ID, with a six-way split using conical wedges from each end. The jaws are made from Acetal or Nylon. Works very well, especially if I turn custom rings to fit inside round tubes. The close fit means the expanding jaws don't distort even thin tubes At smaller sizes, I have an expanding mandrel set for up to about 28 mm.
The only thing I know about microwaves, is it warms my food, but I dig the machining part,
Enjoyed it all
Thanks for watchin', as a particular Old Tony would say.
I had approximately the same problem with an oversize piece of stock. But, while you were showing off your skill with your CAD program, I cut a hole in some plywood to support the length of the piece, then shimmed and clamped my wooden mandrel onto the lathe bed using a dial indicator. With a light cut to establish center, I then drilled for a live center and I was in business. Granted, this was a one time setup using what I had available in my garage.
Perfect engineering solution! Love it!
I like your mandrel thingy. I probably would have gone with 4 adjustable screws, but seems like it's working for you.
Thanks Chris, I had an idea in the back of my mind about drilling and threading six holes in the collars, with four at 90 degrees and two at 120 degrees from one of the first four. There's enough clearance for that. The trick with three is to tighten or loosen one jaw, then loosen or tighten the other two by exactly half as much. It does take longer than it would with four jaws. Next time I need to use it, I'm going to make two extra studs and drill/tap three extra M12 holes, then I'll have the choice of three or four. If I'm using thinner tubes, I'll make up quadrant-shaped soft-jaws to fit the tube ID rather than the brutal ones in this original. Now I just need a 63 inch VTL and I'll be able to make PROPER parts...
For the final version, I added four holes in the collars at 90 degrees and made two more studs and jaws, so it can now be used with three OR four jaws. Thanks very much for the inspiration.
Neil
I'm glad you made this comment, and glad M&M mentioned it. I've been watching your videos ever since.
Good work & very good camera work & editing. Much better than my video's. Subbed you. Thanks for posting.
Steve.
Thanks Steve, I'm a rank beginner at this video nonsense. I've just started uploading the final part of the Spider Mandrel video, so that should hit CZcams in the next few hours.
I think you missed a trick there. You had the 3 studs on the centre axis. If you moved the 3 studs to the side of the centre axis (like an Isle of Man flag) you could have made the studs longer and the adjustment range much larger.
That would have made the tool more useful on future jobs. Sure you would have needed to change the teeth design but with 6 points of contact you probably don't need big sharp teeth anyway, 6 roughened "nubs" expanded out would grip a tube quite well. 👍🙂
Good thought. Also if the studs were at a tangent, the forces from turning would tend to make the teeth dig in harder. The collars could have cutaways like the teeth on a ratchet. Not sure if it would liberate much extra adjustment though, as the radial movement would stay about the same, and I'd have to think carefully about spanner access. Might be worth considering using eccentric cams that can be adjusted from the side. Certainly worth considering if I use soft jaws on thinner material. My original thought was that I'd make multiple sets of studs, but for larger material, I'll probably just make longer jaws. For smaller material, I could indeed just remove the studs and jaws and use bolts with raised nubs in the centre of their heads, running in the M12 threaded holes. The expanding plugs work well for the smaller items up to about 80 mm, but I have some upcoming jobs for antenna feedhorns where the body is a 160 mm dia tube made from aluminium sheet 1/16 inch thick with TIG welded seams. There's a 250 mm dia ring flange attached that will need turning at the edge, so I will need to come up with a solution for that. Plus of course, I get the fun of making yet another fixture.
Those are some tasty looking chips, hope you have some fish to go with them!
Roast salmon for supper tonight!
@@MachiningandMicrowaves can I come?
good job on that
I need to get the final part of the video finished, but I'm too busy actually USING the mandrel to make mounting rings right now.!
Respect!
Great job amigo!! Greetings from El Paso, TX 🇺🇸 USA! SUBSCRIBED
Thanks for the sub! I have relatives in TX, but they are at the other end of I10 near Houston, 750 miles away, still in the same state. I'm always impressed by how absolutely enormous Texas is.
@@MachiningandMicrowaves It sure is! Keep up the great videos with the humor as good as Tony's!
What kind of camera do you use for filming purposes? AMAZING QUALITY
I really hate this camera, it's the second-worst camera I've ever owned for usability, creative control and dynamic range. It's a Sony ZV-1 and the manual focus is almost unusable, the autofocus is horribly slow, inaccurate and impossible to lock using follow mode or anything at all really. I feel like I've just burned a slab of cash. It can't even be plugged in to power while you are using it, so if the battery runs out mid-shot, that's the end of the scene. It's utterly hateful. On a cold day, if I take it out from the warm house to the cold workshop, the lens actually steams up on the inside. The lens cover is flimsy and you can't fit filters, but also, there isn't a protective gorilla glass outer lens. The only thing it does well is capture what's left of the image after the lens, focus things and user controls have munged it up. The worst camera was a tenth of the price and wasn't much worse. This dreadful bit of fashion accessory tech is probably fine for folks who make CZcams videos, but, er, oh, wait....
I bought it because I could pop it in my pocket and just use it without any faffing about, but after you'd got a task light and two colour-mixed LED illumination panels and a tripod to set up, any benefit is lost. It can't even run with a simple remote switch, unless it's connected to some device, but then I'd need two hands. The control buttons are stupidly small and... well I could go on, but you get the drift. The decent-looking scenes are made despite the camera, not because of it. Avoid at all costs! Unless you're a vlogger doing pieces to camera on a gimbal, then it might be a *really* good choice
Not sure I can ever unhear the jazzy b comment. Absolutely unexpected
Caron Wheeler... whew. czcams.com/video/TB54dZkzZOY/video.html One of the comments says "We had no idea of what good times we were living in back then". Maybe. That hit me right in the feels. I'm not usually afflicted by nostalgia, but it's 3.30 am and I'm watching Jazzie and Caron laying it down and my eyes are full-on leaking. "A happy face, a thumping bass for a loving race". I'd been married to Caroline for two years and was totally blissed out.
@@MachiningandMicrowaves you know you're my hero now right?
Would love to come across the pond to have a pint. You must be a hoot
@@drewcagno I'll be in MA and CT for a few days next month. America, I'm gonna be in ya!
You could have just wrapped some tape around your live center...
Brilliant, I have six rolls of gaffer tape. That'll get 'er done
@@MachiningandMicrowaves Great... next video down one digit. Guess you shipped from the factory with plenty of extras! LOL
Do you have a video or plans for your tailstock indicator. I plan to make something similar, just got a mitutoyo scale.
There are a few designs out there, I made this one in 2019. It's a simple split collar and bolt-on tab, then a magnet glued to a block at the free end of the scale. The scale body is screwed to a weirdly-shaped block and has more magnets to hold it to the edge of the tailstock body. I found an old blog post about it, at www.g4dbn.uk/?p=1035 www.g4dbn.uk/?p=1045 and www.g4dbn.uk/?p=1055 so there must be a CAD drawing for the body somewhere. Might be worth doing a short vid about it. The scale I used isn't sealed, and it's gradually filling up with cutting oil, but it was very cheap and I keep a spare just in case. It's been immensely useful.
Can't find the original of the angled mounting block for some reason, I'll have a proper look later. The drawing of the ring and tab shows a 28mm wide tab, I think the real one is more like 20mm. Sounds like I need to go measure it and refresh the Fusion model www.g4dbn.uk/wp-content/uploads/2022/01/Tailstock-DRO-collar-Drawing-v3.pdf
Have you considered using a set of spherical washers under the brass teeth to compensate for offset?
That's a great idea! I was trying to work out how to do something like the ball joint on a G-cramp, but machining a spherical mating surface on the nut and a matching concave surface with a larger hole would be a useful upgrade, especially for cast material and welded hollow sections. Thanks for the tip.
Happy to help
Are those tiger paw gloves?
Not sure of the make, they are very flimsy nitrile for safety, I only use them occasionally because I get really bad contact dermatitis from some metals and fluids, but the Glove Police give me absolute hell when I use them. I mute their accounts in a heartbeat of course. I used to get a lot of really awful finger-wagging about how I would lose my arm or cause thermonuclear Armageddon or something. I don't need their advice, I have my own risk appetite and do my own risk assessments and I wouldn't want to work in their shops, so there's no need for them to try to browbeat me. Of course, now they're muted, they are probably tapping venomous missives sitting in their armchairs doing their Mister Angry impressions. Oh joy. One friend of mine has some Tiger Paw gloves, but he has the whole suit as well. He works in IT. He can't type with them on though.
that's some kind of machine porn. thanks for the vid...
Heh heh, glad you enjoyed it.
It's hard to tell in the vid but what size is your lathe?
It's a Colchester Student 1800, 6.5 inch over the bed, 25 inch between centres. Not exactly in the @abom79, @CuttingEdgeEngineeringAustralia or @bcbloc02 class, but it was cheap and it's compact. It has an inverter and electronic braking and DRO, and it makes decent enough parts. Limit on long tube diameter is the height over the cross-slide, so max 8 inch diameter. The tube in the pics is 6.5 inch outside diameter.
at about 10:15 it looks like your tail DRO is running low on fluid.
The downside of not using IP67 rated scales! There's a level where the oil getting in is balanced by the oil leaking out. Sadly. most of the fine metal dust in the oil stays inside and eventually, the scale electronics board decides it's had enough and goes off to DRO heaven. Usually they last 2-3 years, which at £25 is definitely a bargain!
It was easier to make a plug of 3-5 different diameters, like a stepped drill
Tricky bit is how to support the tube so it can be machined on the outside, end and a little way inside, and then parted off safely. I wasn't sure how safe it would be when the parting broke through if I was supporting the tube using plugs in the ends. I do have lots of those stepped plugs where I only needed to machine the outside of a tube. They start off one size but then get modified and added to. "Easier" isn't always "More Fun" though, at least for me. If I was doing this for money, I'd have paid the £0.50 per cut to have it bandsawn by the metal supplier! I totally get it that I'm able to take advantage of my financial privilege by not costing in my time, or rather by discounting the time against the amount of jolly machining and design and general messing about that I got to do. Might have been rather shorter video if all I had to say was "Ordered some custom-cut rings from Aluminium-R-Us". Not a lot of dramatic tension or potential for comedic commentary in that. I'm just a sucker for doing things the complicated way for the sheer joy of making stuff. Yeah, privilege.
@@MachiningandMicrowaves
the processing inside to some extent justifies your decision, but I still think that you do not cut pipes every day :)
@@patevm4435 I think "Decision" is rather overstating the amount of logic involved here. Perhaps more like "whim" or "flight of fancy" or "totally daft idea to make a dank winter evening a bit less tedious", or even en as a counterblast to the inevitable march of entropy towards the eventual heat-death of the Universe, but yeah, you are right!
@@MachiningandMicrowaves I understand you, I was also an electronics engineer for 35 years, and now I have bought several Chinese machine tools. Computers are tired .. But again you need them for making complex shapes.
@@OtripleXY I have a 750W servomotor that I will be fitting to my lathe so I can make complex curved surfaces, parabola, hyperbola, ellipse etc. I prefer PIC as a microcontroller. Should be interesting to build the interfaces and drivers. I might even make it standalone and parameter-driven rather than using a computer
Growing old is compulsory, growing up not so much. :)
This channel is way too advanced for lathe newbies like me.
Enjoy your private hang out.
I'm only a beginner myself. There are so many really good educational channels for folks new to lathes and mills that it's hard to come up with content they haven't already covered in great detail. I learned almost everything from CZcams channels, but I don't feel the tiniest bit qualified to tell other folks how to use a lathe or mill properly. For me, the lathe and mill are just another part of my toolset, like the CAD software, electromagnetic modelling apps, metalcasting, electroplating, MATLAB, microcontroller programming, electronic phase locked PLL frequency references, spectrum analysers, 3D printers and (cough) welders.
I wouldn't feel qualified to tell anyone how to use any of those other than perhaps the E-M modelling and microcontroller stuff and specans.
My focus is solidly on doing interesting things with practical applications in microwave and mmwave radio using that wide range of tools. Maybe in ten years I'll know enough to teach folks a little about machining. Maybe.
@@MachiningandMicrowaves I'd love to see something on the EM modeling, but I'm enjoying it all.
Cheers!
@@martinmckee5333 That will be quite soon as I have some new dual-mode Pickett-Potter feedhorns that need modelling then making. I did consider trying to model this 1296 MHz low pass filter in OpenEMS, but life is too short sometimes!