NSW 'B' class mogul

[Roger]

Jul 9, 2020 11:27:53 GMT David said:

That's not really an option with the Tormach. It uses special toolholders on 3/4" shanks with a land to sit against the spindle nose.

I changed cutters this morning, went back to a 1mm depth of cut, and slowed the feed to 25mm/min and after about 4 hours when the cutter got to the depth the old one gave away at sparks started showing. So I stopped it and put a brand new cutter in and reduced the depth of cut to 0.5mm and a few hours later finally got through.

So by trying to save some time yesterday I ruined my mill table and had to take all of today! Something about never having time to do it right, but having time to redo it comes to mind.

The damage was more extensive than I thought, but it's done now so no point worrying about how long the gouge is. The discolouration must have been caused by the smouldering wood backing, it wasn't there when I started the job.



The question now is how do I smooth down the huge burrs either side of it - they're way too big to start with stoning.

Can't say I'm feeling terribly chirpy right now having just caused such damage to the most expensive thing I've ever bought other than my house. I was even trying to be careful - I moved the tool to each extent of the toolpath to check clearance so I didn't crash the head again, I cleaned all the chips off the table and the clamp stands so I wouldn't mark the table (HAH!) It seemed to do exactly the same job a couple of weeks ago with no trouble at 1mm doc

Still, work again tomorrow and I won't be listening to the damned machine droning on all day behind me and the compressor kicking in and breaking my train of thought, and then back to uni next week, so that's all a bit of a relief!

Hi David,
Now that's annoying, but not the end of the world. It's more annoying that you get reminded of it every time you use the machine, even though it's not going to make the slightest difference to the usefulness of it. I'd use a needle file on the burrs and then stone them.
I don't know what collets you use, but I've never had a tool pull out of my ER32 collets.
I know most people think I'm way too conservative with my feeds and speeds, but it's the only way you can leave a machine unattended. What seems to work just fine when you start, can soon go pear shaped when the tool loses its initial sharpness. I tend to work with speeds and feeds and are probably a third of what you might get away with using a new tool. I've learned the hard way, breaking tools and having jobs shift when the cutting forces became too great.
Just put it behind you and move on. You can't change it, so don't let it upset you any more.

[David]

Yes, the constant reminders are annoying.

The very first real cut I tried to take on the mill plunged straight into the vice jaw of my shiny new milling vise. I see it every time I use the vise.

There is a shallow 20mm wide cut in my manual mill table. I see it every time I use the mill (unless I cover it up with the vise).

I'll do the same with this one, I'll have the vise sitting over it most of the time.

I know it doesn't make any functional difference, but it's damned annoying all the same.

It ruined the collet, and maybe the toolholder. It raised burrs on the toolholder shank so I imagine it's damaged the special R8 collet in the spindle. I haven't had the heart to check the inside or run-out on that yet. If it has I'll have to get another from Tormach because I think they modified the collet nose so it's flush with the end of the spindle.

A lot of damage for no gain!

In an attempt to do something simpler I'm making the steam turret now.

[racinjason]

David
have a look at this ER Collet Essentials  there is some good info
cheers Jason.

[David]

The attempt to do something simpler is having mixed results!

#1 I made the square body of the manifold, drilled through 4mm, with 6mm couterbores at each end to sit the 1/4x40 threaded parts in that take the steam pipes to the injector valves. I sat the first one on and clamped it for soldering. I don't have machinists clamps that open wide enough that would have given the correct clamping direction so I used a G clamp. While red hot and soft the clamp bent the threaded part like a banana. I'll try and recover this part for use on the red train's manifold.

#2 On the next attempt I was drilling 1/4x40 tapping size through the body into the 4mm through hole, holding the part by hand. Of course it snatched, the drill broke, the part was thrown into my stomach and then onto the floor where it managed to land on one of the already done end threaded pieces. The thread cleaned up with a die, the cone for the nipple might need a look with a centre drill if it was marred.

#3 I figured the straight 3/8 threaded part that screws into the boiler bush should be easy enough... while turning down the brass hex at 1000rpm the camlock chuck came off! The quick change toolholder on the compound slide took the brunt of it but it was damned scary. I didn't think to hit the emergency off and used the lever on the carriage which was ok, but somehow the vibration managed to kick the level into reverse so it started again.

Just how bad can one be at this game? I really should video my attempts, they'd make great comedy/safety warning videos.

After #1 I've been threading all the little threaded bits into the body before soldering (a) so they are kept in place while they are getting soldered in and (b) so they don't come out again when their solder melts while the next one is going in. That seems to be working. I cover each previous joint with flux to try and keep them clean and allow their solder to stay where it should.

It's tricky soldering these fine threaded bits into 1/2 square brass. It takes a lot of heat to get the square up to temperature and you just can't keep the flame away from the smaller threaded bit. I've been putting threaded caps on them to try and protect the useful end where the pipes attach. I know you're meant to be able to make new joints without melting the old ones, and I am sure I've done so, but I can't do it on this part unless the joint is at the other end of it.

Anyway, it's nearly killed me a couple of times but it's nearly done. One more solder joint after I've put it in the pickle for a bit tomorrow to clean off the existing flux residue.

Will the pickle eat the fine threads if I leave it in there too long?

[ettingtonliam]

Answering your last question first, possibly. I usually finish the threads to size after soldering and pickling to prevent any sizing issues.

How in the world did the camlock come off? I thought that wasn't possible, at least I never managed it.

[springcrocus]

You do seem to have more than your fair share of misfortune, David.

Whatever else you do, please do not take up knitting as an alternative. I dread to think of the harm you may do to yourself.

Kind regards, and (try to) keep up the good work.

Steve

[Roger]

My best advice is to never take short cuts, assume something is simple or it can't go wrong.
You have to be patient, invest the time and pay attention to details. None of this is hard if you do it carefully and methodically step by step. Don't focus on getting the job finished, focus on doing the next operation carefully and as accurately as possible. The job will be done soon enough and you will save a lot of heartache.

[steamer5]

Hi David,
And here’s me going to spend the afternoon in the shop!

I hope you have a supply of Jim’s cure all elixir at hand to calm the nerves & steady the hand after that little lot!

Deep breaths & calm thoughts, it is after all the journey that’s important! Besides which I want to see a video of your first run.......with all your bits intact!

Cheers Kerrin

[David]

The manifold or turret is done now (assuming no leaks and nothing falls off). But I can't show you a photo because I lost my phone a couple of days ago! Really not my fortnight.

I was going to ask this before but thought it was a stupid question, however I can't look much dumber now.

Is there a particular direction you should turn the cams in a camlock chuck?

On mine two of them are happy to turn counter-clockwise, but the other will only go a tiny way like that and prefers to go clockwise. They also seem to want to turn different amounts which seems odd.

Could this be due to the cutouts in the studs on the back of the chuck not being at just the right height?

I have particular trouble with the 4-jaw coming loose, but the 3-jaw does it too. Given they're not meant to come off at all I must be doing something wrong.

[uuu]

Camlock instructions at the bottom of page 1 here.

And a video YouTube

It's clockwise to lock.

Note the description of the "V" indicators, showing if your studs are correctly adjusted.

Wilf

[Roger]

Jul 16, 2020 5:31:06 GMT David said:

The manifold or turret is done now (assuming no leaks and nothing falls off). But I can't show you a photo because I lost my phone a couple of days ago! Really not my fortnight.

I was going to ask this before but thought it was a stupid question, however I can't look much dumber now.

Is there a particular direction you should turn the cams in a camlock chuck?

On mine two of them are happy to turn counter-clockwise, but the other will only go a tiny way like that and prefers to go clockwise. They also seem to want to turn different amounts which seems odd.

Could this be due to the cutouts in the studs on the back of the chuck not being at just the right height?

I have particular trouble with the 4-jaw coming loose, but the 3-jaw does it too. Given they're not meant to come off at all I must be doing something wrong.

Locking is clockwise, and if you can't turn one enough, it's probably because the leg is screwed in too far. You can remove the locking screw and unscrew the leg a whole turn and try again. Maybe they have been removed in the past and screwed in too far?

[David]

We pressed the new dummy backhead today using a friend's press. It went well. Now I have to figure out how to put a wrapper around it and solder it on without distorting the whole thing. At this point I can't see how that's going to happen.

Here it is just through the formers.



Plenty of crinkling but there is a good amount of clean corner there.



With the former taken out.





Because this is slightly thicker brass there's now no room for the reverser wheel so I'll have to see if I can move the whole screw bracket back a bit.

Next step is to do all the holes again so I'll have to redo the transfer punches because the originals have had their points turned off and replaced with centre dimples for scribing the big circles. I have an idea of how I can reuse them by drilling a hole in them and making inserts.

[David]

I redid some transfer punches last night and did the cut-outs on the dummy backhead after work today. On the last one I used a step drill and filed out the last few mm for the two big holes. This time I decided to use the CNC machine to do them and it was a lot easier, and didn't take much more time if any.

I used a 2.5mm endmill with a 4mm entry hole. 2000rpm, 0.5mm depth of cut, 30mm/min feed. Slow, but after last time I didn't want any hiccups. I also checked there wouldn't be any collisions with clamps.



I'll make a new firehole ring because the current one looks pretty tatty now and those 3 holes don't need to be there. They were an attempt to rivet it in place on the old one.

I'm planning to make a former from wood to bend the wrapper around to try and avoid twisting it. I'm pretty sure the last one was badly twisted as I soldered in place.

Perhaps I'll screw the wrapper in place as soldering was such a bad road last time. Using 10BA brass screws with the wrapper threaded and clearance holes in the backhead I'm hoping will allow me to screw from the inside and file the threaded part of the screw flush with the outside of the wrapper. If it's not much good and needs filling at least the screws will hold the wrapper in place if I then decide to solder it after all.

[David]

I didn't have a piece of wood big enough to make a former and didn't want to cut and glue a bunch of MDF so I went without.

I used strips of paper to measure the length of the wrapper, marked it about 10mm longer, and cut it 20mm shorter :-\ I missed my mark somehow, but none of us are surprised by that by now. I only discovered that after carefully straightening an edge on the manual mill. I'm hoping the floorboards come up far enough to hide it.

I annealed the strip very slowly to try and minimise distortion, seemed to work. Then I bent the strip around the backhead with the backhead sitting face down on the bench and the milled edge of the strip on the bench to try and avoid introducing a twist. I think I held the strip to the top of the backhead with a welding clamp, that will be seen in a later photo. The backhead has been flipped over in this photo.



I decided to try soldering using as many clamps as I could find or borrow. Using bakers fluid, 965 unleaded solder, and an extremely gentle flame it worked pretty well. There are gaps in the solder where the clamps were but it seems to be stuck on ok. I'm very happy with the shape.





The 1mm brass holds its shape a lot better than the 0.4mm I used for the wrapper in the previous attempt.

I have turned a new fire hole ring but I can't fit it until I've drilled a hole in the top for the steam manifold to go through. I've marked that tonight but it's late and I've pushed my luck far enough for one day. Still probably going to use JB Weld to stick the ring in - I'm going to quit soldering while I'm ahead and it has to be fixed while in place on the boiler.

[suctionhose]

Looks perfect to me...

[Roger]

Very nicely done, that's a cracking job.

[David]

I was using the step drill to make the hole for the steam manifold and it drifted as it usually does for me.

I made a 'reverse' transfer punch so I could use dividers to scribe where I needed to move the circle and then filed it out, finishing with a tapered reamer to get it back close to round.

I had to make a couple of these scribing aids when I did the first attempt because I started drilling the bigger holes before I thought to scribe their final size.

[jasonb]

Bit late to this but I can't see the point of using a roughing cutter on a job like that which is not making use of the side of the cutter where the flute form comes into play. On a shallow ap you will only get one flute cutting right to the bottom of the slot so that will be getting 4 times the chip load and as it is doing all the work will wear quickly. particularly with that slow 30mm/min feed which is making the tool rub. Keep the roughers for deep profiling where they come into their own eg where ap is at least the cutter diameter or more and chip thinning comes into play with the lower ae.

I'd be running a 3-flute cutter at 5000rpm (my max) and feeding at 250-300mm/min for a similar cut in steel with a 6mm tool.

[simplyloco]

Jul 28, 2020 12:23:38 GMT jasonb said:

SNIP

I'd be running a 3-flute cutter at 5000rpm (my max) and feeding at 250-300mm/min for a similar cut in steel with a 6mm tool.

Jason
A 6mm tool at 5000 rpm? You'll have people on here in a fit of fear and apoplexy if you suggest they do that!
John

[ettingtonliam]

Even I run a 3/32" cutter at 4250 (my maximum). I think its the feed rate that I'd be way down on, more like 25mm/minute.