Nozzle fabrication/ordering (Nov '17)

[Mike]

For holes it should help to at least have a central dimple in the 3D print to centre the drill.
Pity  you can't (easily) make the theta motor spin continuously - you could just use a vertically mounted drill bit to at least start the hole.

[alanambrose]

... the RVxS as accurate x/y drilling machine - like it

Good point re dimples - have sent in another batch with them, also versions which may not need the brass bush, a Tool 3 as mine is beaten up, and tests of little holes in various materials. Arriving around the new year.

A.

[spiyda]

Drilling on a lathe should be reasonably easy but needs patience

My lathe is a quite big ( about 7 feet long ), but very ancient belt drive job with an 8" Taylor chuck and it was fine drilling down to 0.4mm

I don't have any tools or fittings to do very small stuff so i winged it.

I put a bit of scrap in the chuck and turned it down to the same diameter as the RV toolholder stub
machined a groove in it for the  O ring
fitted an O ring

then mounted a small pin vice in the Jacobs chuck in the tailstock ( this is the weak point in the process, I bought the parts to make a proper collect chuck miniature drilling jig, but like many things, never got round to making it.)

I spend most of the time getting the tailstock set up properly so that the drill was on centre..

I didn't drill too deep, finishing off with a 0.8mm from the inside as it felt a but safer..
but if they were printed with a slightly hollow conical section, it would solve that problem

just a shame I only had a couple of nozzles to drill at the time ( and no, I'm not volunteering to do them all !)

[alanambrose]

Thanks for the hints - lack of machinist skill / subtlety / accuracy on my part I think Just checked again and the tailstock centreing is actually better than I thought - maybe 0.5mm low, but that needs to be fixed before I can accurately get a 0.4/0.6mm hole in the end of a 1mm nozzle I was using a tiny 0.3-1mm chuck mounted in the normal tailstock chuck.

I'll give it another whirl - in fact if that's all it does, that'll be fine.

Alan

[alanambrose]

Ah I think I have a way to do this accurately without sorting the tailstock out - which is a side project I would rather not engage in atm. Will order in a few more bits...

@spiyda - when you're making the brass nozzle inserts - do you normally start off with bar or tube?

Alan

[spiyda]

@spiyda - when you're making the brass nozzle inserts - do you normally start off with bar or tube?

Alan

I depends on what you are chucking it up in..
a three jaw chuck can quite easily crush and distort tube..

I'm lucky that the jaws on my three jaw chuck actually grip the tube at six places, so tube is fine..

When I made a few I reamed the inside of the tube, them machined the outside, then parted them off.

Chris

[ColinBarron]

If size is critical why not pre drill 0.8mm part way from the back as suggested then drill under size from the front and then ream to size.  Then use a drill blank to confirm size.  If the size is slightly out you can use a tapered diamond file.   

[alanambrose]

>>> then drill under size from the front and then ream to size

you can actually get 0.4mm reamers e.g.

https://www.accu.co.uk/en/machine-reamers/444469-221450-0400

but I think that's well beyond my machining ability / capabilities of the equipment I have to hand.

A bunch of new nozzle tests have come in plus a nozzle cup (I'm missing one) / a replacement 'light cover plate' for the Z-axis / a test of a new size nozzle for a 5050 led / a nozzle base to take an off-the-shelf 3D printer 0.4mm brass nozzle / some more material tests. I can already see the dimples have not worked out so well so far - too little resolution, but one of the material tests looks like a big improvement. I'll do some more drilling / lathe work / testing later in the week.

I noticed a reference to 'RVT01.5' and 'RVTMELF' nozzles in the Versa price lists. Anyone seen any drawings or have one?

A.

[Mike]

I have a nozzle marked "Melf", which just looks like a T2 with a semicircular groove filed into the end.

[trev]

I just bought a bag of new/old nozzles from Grove. I cant see any markings on them so I do not know which are which. Is there an easy way to tell?

Trev

[Mike]

Big holes T1, Small T6

[spiyda]

I have a nozzle marked "Melf", which just looks like a T2 with a semicircular groove filed into the end.

Mike, what is the orientation of the groove compared to the flats on the flange ?
I need to place some melf type zeners so I'll need to modify a nozzle

and once modified, how do you rotate it when setting up the feeder ?

Chris

[trev]

I seem to have a few spares, it would be useful to make up a melf nozzle from one of them if possible. Do you have an image of the nozzle?

Trev

[Mike]

I seem to have a few spares, it would be useful to make up a melf nozzle from one of them if possible. Do you have an image of the nozzle?

Trev

I seem to have a few spares, it would be useful to make up a melf nozzle from one of them if possible. Do you have an image of the nozzle?

Trev

Just had a look & seems I repurposed it into another special so can' tell slot direction - shouldn't be hard to figure out though by marking a nozzle, and picking a part with run-time test.

[spiyda]

I just did a quick test ( not entirely accurate ) but at least a sanity check

marking the orientation on a plain nozzle picked from position 1

picking from right hand side  feeder nearest the front, slot nearest the back

the component seemed to be about 10 degrees adrift from the flats on the nozzle..

quick sketch showing what I mean



I don't have any spare nozzles to try at the moment, having had a couple of head crashes at the weekend  ( see other post)

Edit....  I measured using several nozzles and the angle is actually closer to 16 degrees.
that is what I will work on for my first attempt at making one  ( when this flu is gone  :-(  )