Member postings for Pete Gilbert 1

Yes, the thread is not so important, because it doesn't specifically align the prop.

The critical areas of the prop adapter are the reamed bore for the motor shaft, the taper and the plain section and step before the thread. Those absolutely must be machined at the same time to maintain concentricity between the motor and alignment the propeller's own central bore.

It will be preferable for me to get the final saw slit prety central too. I may have to make up a similarly M6 threaded chunk of scrap to mount on the toolpost and run a fine circular saw in the lathe chuck.

Also, if I am forced to make my own female taper section, that will be critical too. Mind you, I'm using plastic propellers that are mostly injection molded. So I do have to pre-balance check them off the plane as well, then see if there's any vibration once mounted.

It's all fun in the end. If it's wrong, I launch the plane, the prop vibrates like all hell and then either the motor burns out, the speed controller fails, or the prop shatters.

Hehe! But seriously, it's never nromally that bad.

I recently had to knock up a different type of adapter at work due to my cheap Chinese one being visibly wobbly, and all is well now, with a vibration free flight .

That's the right part Oliver, but yes, it's pretty basic and will only take a few minutes to turn up from a short piece of 16mm bar.

If I was going to make a spare for my tool post, it would go like this.

Clamp bar in chuck.

Face off end,

Center drill to suit thread (M5)

Drill 4.2mm to approx 16mm deep

Start the M5 tap a few turns in by holding it in the drill chuck and gently turning the chucked workpiece by hand. (you have to leave the tailstock free to slide and apply light pressure towards the work) Use tapping grease.

Then release the tap from the drill chuck without disturbing it in the work. Slip a tap handle onto the tap and add a few more turns to the thread so that it can be finished later and will self align.

Remove the tap.

Turn the 10mm diameter

Form the 7mm 'waist'

Start the part off

Withdraw the part off tool and deburr sharp edges. BEWARE OF GETTING TOO CLOSE TO THE LATHE CHUCK WITH A HAND TOOL!!! IT WIIIIIIIILLLLLL BITE !!!!!!

Part off.

Form flats to clear inside your T slot..

Just re-read that and wanted to say that I have no way, at the moment, to cut threads on this lathe, so I'll have to thread my propeller adapter collets manually with a die.

Hmm , no. Actually I will be forming the body of the collet and drill/reaming the centre bore, but not parting it off to the correct length immediately, so that I can turn it around and use the per-pated large diameter to hold on while die cutting the thread with the die holder backed up against the tool post for stability.

This is a prop adpter collet, the thread is M6 on this one. The 'top hat' thing has the matching 'female' taper to compress the collet and the split part of the collet will have a reamed internal bore to fit whatever motor shaft.

Sorry, just thinking out loud there.

Check out this "Info" page I just found on the Home Model Engine Machinist website.

I agree with everything you've said except the shellac stuff. I've never heard of that till now. But it's verrrry interesting and I've found this thread on homemodelenginemachinist.com And now that I've seen it, I agree with that too! I can see the benefits!!

Thanks for opening my eyes Michael. I owe you one!

Edited By Pete Gilbert 1 on 02/02/2015 21:21:57

Not sure where in Aus you're located, but Andrew Newton is an epic maker and flier down in Victoria, where it always seems to be windy! He doesn't seem to do scale planes or much balsa wood stuff. Foam rules!!

Aluminium can be hardened/toughened and a deep anodized layer will be harder still, but it isn't steel after all is said and done.

Edited By Pete Gilbert 1 on 02/02/2015 20:56:20

Heh, those are way too expensive for aluminium parts. In my humble opinion. Why can't they just make 'em in mild steel? It'll last longer than the ally for starters and it should be cheaper as they won't need anidozing.

At Adaero Precision, we make our own work holding fixtures and vice jaws for milling , when normal plain or step vice jaws aren't suitable and special chucks and collets for turning. And I often complain when a fixture gets made in ally. Yes it's easier to machine, and we do install helicoil inserts to the threads, but the clamping faces don't last too long and we have to make another.

But yes, if all you need is a basic tool post, a made up one is super simple. in the near future, I intend to buy or make up a mini sliding vice for small milling jobs. I may even take my saddle to work and drill/ream a few dowel holes for positioning accuracy.

Looking at the pic of my tool post, it's dimensions in that view are as follows:

40 x 40 mm and 35mm across

The cut out starts at 16mm from the base is 16mm high (under the screws) and 10mm deep. Presumably for 10mm tool steel.

At the back is an 8mm through hole, 26mm up from the base, 6mm in from the back edge and paralell to the cutout. This has two short screws for clamping round shank boring bars or maybe as cigarrette holder or whatever.

Hope that helps Oliver

The central hole for the 'T' slot bolt is by no means a close fit on the bolt and no precision should be imagined when adjusting the post by this means.

- - -

Unfortunately I just measured the eccentricity of my main chuck centering (with a dial micrometer borrowed from work) and found an average 0.15mm run out at the workpiece! It's the chuck and not the spindle, so I need to think how I'm going to sort it out. I knew it was out from the first time got it home and turned something, but now I know just how bad it is.

I shall have to correct it before I go much further, as one of my tight tolerance requirements for this lathe is turning parts for propeller adapters for my RC planes. And with a prop rotating at 10000 rpm or more, any imbalances must be minimised.

Hmm, I really need a collet holder for increased accuracy.

Oliver, that thing inside the tailstock is a brass bush/thrust washer and that's all there is to it. It stays on one side of the circlip and stops movement in one direction and the handwheel does the other. Nice and simple, and even if we break the circlip I'm sure it'll be a stock size.

Separated. The handwheel turns this coarse left hand thread.

Here's my recommendation for your stuck chuck. (let's not forget that this is a micro lathe and the casr iron parts could be damaged by heavy handed hammering )

Soak the drill chuck and tailstock slider in whatever easing oil you have overnight at the very least. And, if you feel like it, apply a flame to the slider to heat it up, not to red hot, but hot enough so that water evaporates instantly.

Then, re-assemble your tailstock without the handwheel. Use a couple of M6 nuts and lock them together on the thread at the back. Then, wind back a bit of pressure, as if to pull the slider away from the chuck with your 10mm spanner, then put a 17 or 16mm spanner behind the chuck. Use that to lever against the chuck and tap it with a hammer at the same time.

You could also try a brass drift and a few good hefty taps at the back of the chuck.

If that doesn't work realitively easily, you'll need to make up something that looks like a ball joint splitter out of steel, which will apply more pressure as it's also a wedge shape which you will have to tap in to the join before tapping it sideways. Once again, beware ot damaging the cast iron tailstock body.

-------------

And this is my original toolpost.

There's an M5 machine screw through from the top and the heavy sleeved 'T' slot thingy measures just under 7mm at the 'neck' and has flats machined to 14mm wide on the 16mm flange. The 7mm 'neck' is 5mm long, so it's actually 2mm clear of the saddle once locked by the screw. The fat part of this one is just under 10mm to suit the hole in the post.

I'm certain that the proxxon one will be close to these sizes, and if slightly bigger, any alterations shouldn't be a problem since you've found a friendly machinist.

Yes, it's a self ejecting type, but I had to 'encourage' mine because it was a bit tight. So I used an open end 13mm spanner placed over the back of the chuck taper and then angled it towards the lathe chuck so that it pushed the little chuck away from the tailstock. I then gave it an enthusiastic thump with the heel of my hand and it popped out. From then on it has worked well.

We shouldn't be hammering this little chuck into it's taper by the way, just a quick slide in to wedge it into the taper is enough. Although mine takes a 7mm drill of, I would use very light drilling pressure to avoid stalling the spindle.

Yes, your handwheel is almost fubared, with a domestic electric drill badly by the looks of it. It definitely needs to be bored and sleeved, then a fresh M6 can be tapped through.

((LOL! Forget "Through A Glass Darkly" Let's hope someone publishes "With A Domestic Electric Drill, Badly" !! ))

Here's a toolpost fron Axminster Tools that wil probably suit as it's for the Proxxon. I think that's the current, rebranded, updated, (haha ), version of the ML210.

I'd really like to have a quick release tool post and tool holders. Maybe later as I'm really skint after xmas..

Good to hear that Oliver. The lack of density of the rust probably indicates that it wasn't in damp conditions for too long and, obviously the good quality of the metal.

The paint on the ML1 seems to be like a Hammerite finish. So any rust that appears to show through is probably just due to the 'spots' that occur as the paint dries.

Both my chuck keys have 12 teeth, a 15mm diameter and a just under 4mm dia pilot (nose). They do look quite different, but both work in the lathe chuck. I'm guessing that the one on the left is the original. I can't imagine that Toyo Sakai would not have followed standard available specs for this sort of thing.

Curse you for saying it's quite silent! Mine isn't.

I have two chuck keys and although they look different they both seem to work the main chuck and the drill chuck ok.

The handwheels have no M6 internal thread?

In that case I would bore them out to around 9 or 10mm, reduce the face that touches the carriage by 2mm and make up a top hat sleeve with a 2mm brim plus M6 internal and press them into the 9/10mm bore, with the 2mm brim replacing the material that was removed.

If you don't currently have access to another lathe, I'd be happy to make 'em for you. We have a small hand press at work, so I can make them a friction fit and press them in. Problem solved mate.

Drop me a PM if you need to.

I think 0000 grade steel wool should be ok. You can add oil to it to reduce it's effectiveness, even engine oil. We use it at work for deburring and polishing precision aluminium parts, so there's no need to worry about your steel bed guides. In fact the steel in the wire wool is probably the same hardness as the steel you're going to clean, so it shouldn't really be able to affect it.

All genuine Scotch Brite, also used at my workplace, has alminium oxide as it's abrasive and only the industrial graded white coloured one is graded as being the same as 0000 wire wool. All scouring pads let go of their abrasive during use, but cheap scouring pads are unregulated and shed their abrasive onto your workpiece rapidly. So you MUST clean off all that grit before you even think of reassembilng your lathe.

Edited By Pete Gilbert 1 on 27/01/2015 12:31:47

This sort of stuff does fade in the public eye quite rapidly these days. I mean, Rosetta was news 3 years before the first iPhone, and Apple have produced a new generation of it every year since then.

I'm not getting involved in THIS part of the thread!!

Bless 'im, he's awesome! And very cute at 14 weeks. I love the enquiring eye of a parrot, you can see their smart mind sizing stuff up and looking for something to eat or play with. They love interaction too and learn from it so much more quickly than a dog/cat/your mate down the pub.

Expensive as a hobby tool, but yes, very neat.

We have a small 'tapping drill' type stand at work that has the same action as that for the table, and a double cone drive for the chuck. It releases the drive as the table rises and the tap meets a set depth then drives the opposite way to screw the tap back out of the new thread as the table is lowered.

Edited By Pete Gilbert 1 on 27/07/2014 16:21:05

Edited By Pete Gilbert 1 on 27/07/2014 16:21:48

Heh, I haven't made enough 'home swarf' to start worrying yet! It's all disappeared up the vacuum cleaner so far.

But any greater build up will probably get taken to work and added to the bins there.

I like the idea of adding it to food tins and drinks cans, that's excellent. Don't forget that 25% of drink cans are still made from steel.

Ouch! Was that unsupervised, or was the guy a setter/operator? Where I work, a setter would be directly responsible for something like that. We don't have operators involved in any part of the set up of any machine, unless they're being trained.

Yeap, softer than the workpiece packing material is good. If you're just working with a bench vice then ally pieces or protectors are good. If you're gripping a finished ally work piece in a bench vice, either use something slightly softer (nylon sheet/block) or use spotlessly clean ally protectors.

But in a 3 jaw chuck that can make the work eccentric if you're holding on a finished dimension. Even Coke cans will vary in thickness. Basically, try to using hard lathe jaws on a finished surface if you can avoid it. I know that home engineering brings cost into play significantly more than at the workplace. But your precious work needs precision and stability at all times, if it's being turned or machined so you're better off pre machining some soft (mild steel) jaws (or collet if you can't match the work diameter) and ensuring a smooth precise gripping face that will do the gripping. A shiny surface in the jaws isn't slippery, it actually means that you've maximised the contact available for gripping the work. Perfect jaws shouldn't mark the work. Reduce pressure in the jaws and take lighter cuts.

So, if you HAVE to use what you've got, make the jaw faces as perfect as you can, or make up precision thickness packing pieces.

Edited By Pete Gilbert 1 on 27/07/2014 14:49:23