Help with 'Speedy' valve gear and other issues...

[Roger]

Apr 1, 2023 6:45:57 GMT jasonb said:

Regarding your lubrication, I run my 4mm Pneumatic down the inside of some cheap LocLine which makes it easy to reposition and you don't end up with a load of lub in the lockline that will drip out when machine is off. I have a brass reducer at the end but you could shape something to take your needles.

I know your noise issues prevent the use of air but I got one of the "quiet" compressors which can't be heard outside my workshop and also run air down the same line, that and a peristatic pump give a good fogbuster type system though really need fully synthetic fluid. I grafted a geared motor to the pump and e-bay variable speed so have it down to a couple of drips per minute if needed.

Hi Jason,
That sounds similar to a system we used to import for use on machines that cut Aluminium Heatsinks. That used something similar to Paraffin for the cutting oil.
An alternative is to use a Pneumatic lubricator and a product like Boelube which is a Red lubricant developed for the Aerospace industry. I supply that to one of my customers and it's amazing how little they use considering the machine is used daily. You can run that down to a drop every couple of seconds, and if you hold a piece of card near the nozzle, you have to wait ages to be able to see that it's delivering any liquid. The machines are not designed to run wet, and you end up with sticky dust for swarf.

[uuu]

I've sometimes wondered if it would be feasible to fit vanes to the spindle nose, to draw in air and blow it down over the tool. Or, perhaps easier, to suck air up from the tool and exhaust it sideways.

So no separate compressor required.

Wilf

[uuu]

Wacky idea number two. You have an oil reservoir that has an air space above the oil and can be pressurised before the job starts. There's enough air to exhaust all the oil if required.

Then a needle valve to control the drip rate.

At one end of the machine carriage is an air release valve. At the end of your G-code you program a move that hits the release, so letting out the air and stopping the oil flow.

This idea doesn't squirt the oil, so won't deliver it from the other side of the room.

Wilf

[jem]

Thanks Roger, you are right, for my set up no problem, but I was forgetting that you run your machines for many hours at a time, unattended,

best wishes

Jem

[Roger]

Apr 1, 2023 14:22:57 GMT uuu said:

Wacky idea number two. You have an oil reservoir that has an air space above the oil and can be pressurised before the job starts. There's enough air to exhaust all the oil if required.

Then a needle valve to control the drip rate.

At one end of the machine carriage is an air release valve. At the end of your G-code you program a move that hits the release, so letting out the air and stopping the oil flow.

This idea doesn't squirt the oil, so won't deliver it from the other side of the room.

Wilf

Interesting ideas Wilf. Dripping the oil sounds ok, but getting it onto the tool or tool shank is problematical. I wonder if a pressurised system that used a Petrol fuel injector would work? That could deliver a very short pulse of oil that would bridge the gap.
I fitted a small cooling fan on a high speed motor, and that turned it into a siren, so that idea might be challenging.

My hope is that my setup will be able to launch a small amount of oil over a 5-10mm gap.

[jasonb]

You can get the spindle fans, have a google for CNC chip fan

[Roger]

I'm looking over the application form for the Midlands Exhibition, and it's asking for an estimate valuation. Frankly I have no idea what that might be, so any suggestions would be welcome. I presume this is for insurance purposes.

[92220]

Hi Roger.

Yes it is for insurance purposes.

Your loco is way above the quality of normal 15xx models. Find the cost of buying a top-of-the-range model, and at least double, or even treble, the cost, as an insurance value. You have to consider what it would cost the insurance company to have a replacement made if your model was stolen.

Bob.

[Roger]

Apr 3, 2023 11:09:01 GMT 92220 said:

Hi Roger.

Yes it is for insurance purposes.

Your loco is way above the quality of normal 15xx models. Find the cost of buying a top-of-the-range model, and at least double, or even treble, the cost, as an insurance value. You have to consider what it would cost the insurance company to have a replacement made if your model was stolen.

Bob.

Thanks Bob, I'll do that.

[Roger]

With a very long commercial job out of the way, I've finally got back on the machine to finish the Pannier Tank infills.

Here I'm making a drilling jig for the 0.75mm tapping size for the M1 fixing bolts. It's a piece of scrap 3mm Aluminium plate, so not exactly ideal material, but good enough since it hasn't got to last.

PXL_20230401_103229405 by Billy Roberts, on Flickr



PXL_20230401_110735901 by Billy Roberts, on Flickr

I carefully lined up the end holes as accurately as possible, eyeing up the positions with the Shim then tapping M1. The drill jig was bolted on using those, and the rest drilled through using the jig. This may seem a bit round the houses, but the clearance holes in the shim are 1.1mm, and I want the bolts to be in the middle of those. You can't spot a 0.75mm hole through a thin shim with a 1.1mm hole, even with a 1.1mm drill. The shim simply isn't thick enough to guide the drill.

Tapping these with a new tap proved to be surprisingly difficult. 0.75mm is definitely the right tapping size, and it's only Brass, but I had to be very careful and use lube to prevent the tap from breaking.

The Tank is held in place by a big G-Clamp and a pencil eraser under the foot. I don't want to risk crushing anything.

PXL_20230402_114832760 by Billy Roberts, on Flickr


PXL_20230402_150536655 by Billy Roberts, on Flickr

With this last thing done, I'm almost ready to paint the tanks. There's a fair bit of hand finishing to be done, rounding off the very sharp corners so they don't thin the paint too much.

I made these 3D printed supports for the painting spit some time ago, but had to reprint the arms about 15mm shorter because it was soo out of balance. The Aluminium extrusion was left over from a shower installation. 

PXL_20230404_204522884 by Billy Roberts, on Flickr

It still needed a small counterweight to get it nicely balanced though. It's supported on the pads that will attach the bottom of the Tanks to the Locomotive. There's a decent clearance underneath them so I can spray from both sides and cover the back of the tank. 

PXL_20230404_204512955 by Billy Roberts, on Flickr

We haven't had a Wobbly Video for a while, so here's one showing how that moves around. It's fiddly spraying all around the Steps and handles, so being able to turn this over back and forth while spraying it will make life a lot easier.

Obviously doing it this way means I've got to do them one at a time. Still, I'd rather stack the odds in favour of getting a nice finish.

PXL_20230404_204550172.TS by Billy Roberts, on Flickr

[Roger]

Success! Here's another wobbly video, this time of the Oiling system sending a small but forceful slug of oil across the reservoir. I just tried it on the Lathe to see how far it goes, and it's around 100mm.

I think this is going to work really well, but it needs some refinements to see the Oil level and a better method of attaching the springs. The needle mount needs redesigning to use a metal taper to get a better seal too. The top needs a lid and filler as well as a mounting arrangement to hold it on the column. Actually, I could curve the body and use magnets to hold it. I'll chew over the options.


PXL_20230406_192217066.TS by Billy Roberts, on Flickr

[terrier060]

That tank is looking really good Roger. I am still battling with the test boiler - should be putting up some pictures soon when I have finished the thermocouple electronics.
Ed

[Roger]

I was hoping to paint the first of the Pannier Tanks this weekend, but I guess that's not happening.

I prepared everything in the usual fashion, but this was the result. Initially I thought that it might have been due to me cleaning off the surface with White Spirit, so I used thinners and tried again, with the same result. I also tried it on a piece of Steel, and that turned out the same.

I've had similar issues before with this primer, but not this bad, so I think it's because I'm getting to the bottom of the tin and it needs throwing out. It's a two pack product, and it's very watery, so getting it to wet evenly isn't the easiest to achieve.

Anyway, I've ordered some of the Craftmaster Single Pack Etch Primer and their thinners specific to that product. With delivery, that's over £50, but it will finish the locomotive.

I might consider very lightly shot blasting the tank, just to get rid of the sheen and give it a better chance of biting into the surface rather than running away from spots like you see below.

These sorts of issues are why I hate painting so much, it's a lottery.

PXL_20230408_104620366 by Billy Roberts, on Flickr

[92220]

Hi Roger.

I must warn you. Single Pack Etch primer has a life. Because the acid is already mixed in with the primer, unless thi9ngs have changed quite dramatically since I retired, and I don't think that is possible chemically, it will be OK for about 9 months from date of manufacture, then it will start to lose it's etching properties because the acid will be neutralised. This is typical of all single pack etch primers...they have a short working life. Two-pack etch primer has an almost infinite life as the acid is kept apart from the primer until mixed for application, but the primer must keep near it's formulated consistency.

Your problem with the 2-pack that you have, may be because you are getting to the bottom of the tin, but you cleaned the surface with white spirit. I'm afraid that is not strong enough to get rid of ALL greases. The ideal solvent, available to the public, for degreasing is cellulose thinners, which will get rid of all oil and grease. Ideally, wipe over the surface with a clean lint free cotton cloth, wetted with cellulose thinners. Then when dry, wipe over again with a lint free white cotton cloth, just dampened with cellulose thinners. If you have any rivetted parts or bolted up parts that are going to be painted, put the parts to be painted, in a warm atmosphere, to get quite warm, to drive any solvents out from between the rivetted/bolted surfaces, otherwise, when you paint, any trapped solvents in the joints, will come out by capillary action, and ruin the paint surface.

Bob.

[Roger]

Apr 8, 2023 18:36:40 GMT 92220 said:

Hi Roger.

I must warn you. Single Pack Etch primer has a life. Because the acid is already mixed in with the primer, unless thi9ngs have changed quite dramatically since I retired, and I don't think that is possible chemically, it will be OK for about 9 months from date of manufacture, then it will start to lose it's etching properties because the acid will be neutralised. This is typical of all single pack etch primers...they have a short working life. Two-pack etch primer has an almost infinite life as the acid is kept apart from the primer until mixed for application, but the primer must keep near it's formulated consistency.

Your problem with the 2-pack that you have, may be because you are getting to the bottom of the tin, but you cleaned the surface with white spirit. I'm afraid that is not strong enough to get rid of ALL greases. The ideal solvent, available to the public, for degreasing is cellulose thinners, which will get rid of all oil and grease. Ideally, wipe over the surface with a clean lint free cotton cloth, wetted with cellulose thinners. Then when dry, wipe over again with a lint free white cotton cloth, just dampened with cellulose thinners. If you have any rivetted parts or bolted up parts that are going to be painted, put the parts to be painted, in a warm atmosphere, to get quite warm, to drive any solvents out from between the rivetted/bolted surfaces, otherwise, when you paint, any trapped solvents in the joints, will come out by capillary action, and ruin the paint surface.

Bob.

Hi Bob,
Thanks for that. Hopefully I'll be finished with the painting this year, so the shelf life may not turn out to be an issue. I hear what you're saying though.
I'll certainly clean the parts in the way you describe, that makes perfect sense. I have both standard thinners for cleaning the gun, and PQ9 Air Drying Thinners from Phoenix paints, as well as Craftmaster thinners. I'm not sure what those are though, it doesn't say on the containers.

I've just ordered some 99.8% Pure Lab Grade Acetone which I use for wiping down before TIG welding. That ought to be ideal for removing any oily residue.

[Roger]

Here's the second iteration of the Coolant Spray System, this time with a top and filler.

PXL_20230408_092850810 by Billy Roberts, on Flickr

I added a curved flange to the top to match the column radius, and a couple of elbows for the Level Tube.

PXL_20230408_195100862 by Billy Roberts, on Flickr

I bought an adjustable DTI base and fine adjustment to attach the nozzle to the column. I thought that would be more flexible than bolting it on.

PXL_20230408_195215106 by Billy Roberts, on Flickr

The Syringe mount is a modified version of the one that I designed for the Oil Can.

PXL_20230407_205729267 by Billy Roberts, on Flickr


PXL_20230407_211035589 by Billy Roberts, on Flickr

The RH circular 3D printed part has a Hex in it that matches the one on the Brass adaptor, and that screws into the 3D printed holder which is tapped M5. The circular part has barbs that engage with the helix on the outside of the Syringe Needle to stop it popping off.

PXL_20230408_195410763 by Billy Roberts, on Flickr

I bought some clear 4mm Pneumatic hose to I could see if there were any air bubbles. You need it to be completely free of air else it won't shoot a slug of oil, it will just dribble out the end instead. It's taken a while to purge the air all the way to the Syringe Needle, but leaving it running with the pipe held up high eventually managed that. It will be interesting to see how it works in practice. I only really made it for difficult materials, but I'll probably use it on everything since it's not going to use much cutting oil.

[chris vine]

Hi Roger,

I feel your pain with the etch primer.
You don't say which type you are using, but I found that the two pack etch from Trimite to be excellent.
I used their SAP3 product, but it looks as though you will have to settle for SAP2, which is more or less the same but without the toxic Chromates.

All best
Chris.

[92220]

Hi Roger. Acetone is ideal as a degreaser, but take care when using it. Try not to breath in the fumes though, as they are easily absorbed by the body. Acetone was the original basis of cellulose thinners, until they changed to solvents with a higher flash point (Acetone has a flash point of -18C) and less toxicity.

Bob.

[andyhigham]

Have your tanks been anywhere near Mr Sheen or similar? the silicone in them is an absolute b*****d to remove

[Roger]

Apr 9, 2023 9:08:46 GMT andyhigham said:

Have your tanks been anywhere near Mr Sheen or similar? the silicone in them is an absolute b*****d to remove

Thankfully no, they've just had things like tapping compound and cutting oil, and of course finger grease. I'll really go to town on the cleaning when I try again, there's obviously something on there that's preventing it wetting.