Brit Progress - Better Fluting!

[Deleted]

Forgive me for placing more posts on this subject, but I was having great difficulty getting the flute start points to line up in the way I wanted: i.e. exactly! Hopefully these photos will assist others to make a slightly better job of what I have found to be a steep learning curve! The advantage of using a side and face cutter instead of a Woodruff is shown here.

I discarded the pair of rods I was working on (and the words and music!) and came up with my own method. I marked out the bathtub, and centre popped the corners. I put the side and face cutter across the rod at full 1/16" depth to achieve the correct rod thickness, and moved the carriage until the cutter just split the centre pops at each end. Slips were placed against the headstock to ensure exact repeatability, as was a production stop at the other end. The rod was brought to thickness over the appropriate area without stopping the cutter or raising it.


I now had to drop the cutter a further 3/64" to machine the actual flute. This meant the length of traverse had to be reduced by .0704 each end, calculated with Autocad. I found a small drill the right size. You can just see the drill in this picture, against the slip. Once again, the cutter was kept at the same setting, and just moved around against the stops.


Job Done! Breathe easier!
JB

The pops are just cut in half...... Am I Chuffed?

[drjohn]

Hi JB

Despite your great pictures, I'm still a little confused - having not actually settled on a definition for "the pops" etc.

I assume you will now mill the rods down to outside dimensions? Does your BMS not "banana" like mine when you cleave metal from one side? ;D

And of course. I have to assume you're making 70000 as all the others had fish-bellies, if I'm not mistaken.

DJ

[Deleted]

I marked out the bathtub, and centre popped the corners.

DrJohn, I hope that answers your question.

On the subject of bendy rods, I hacksaw mine and they appear to remain stable. Final milling/filing gets rid of any minor mis-shape. Here's some I prepared earlier, they are quite straight.


Regarding fluted v. fish-belly, it's dangerous to assume anything. I can show you a picture of 70004 Willam Shakespeare outside Swindon Works in 1960: she is fitted with fluted coupling rods. It gets even more interesting if one cares to research the subject properly. For example, No. 70014 Iron Duke was photographed in 1965 fitted with both: leading plain and trailing fluted. To complete the picture, there's a photo of 70000 around that clearly shows fish-belly rods, so your assumption may need modifying in the light of my research.
I'll carry on with the words and music.....
Cheers
JB

[drumkilbo]

A beautiful bit of work JB, and interesting procedures as well, thanks for posting.

Ian.

[drjohn]

OK JB

No offence intended, I just didn't understand "pops"

The finished product looks great - well done.

DJ

P.S. Wish I could get side and face cutters over here - retricted to woodruffs at present!

P.P.S. Although he wore long robes, I think William Shakespeare might be upset at being referred to as "she" ;D

P.P.P.S. On the ones you prepared earlier (Mrs Bakewell ), I see the fluting is not the same on the two rods. Always a fiddle that without DRO's and CNC!

[Deleted]

They are not yet finished, but the radii are the same as those produced in the 'Better Fluting' procedure for the front rods..
JB

[drjohn]

OK JB, just pulling your coupling rods. ;D Jealous because of my lack of useful tools here.

DJ

[Deleted]

Coupled at last!
After three goes to achieve my desired machining and appearance standards I now have a coupled locomotive. I am most pleased.
It may be of help, but I had serious trouble getting the six to run smoothly without relieving the leading bushes. After careful measuring I found that one previously spot-on rod centre distance had moved by four thou, perhaps during the secondary drilling operation. Dr John was very helpful (what am I saying!) and suggested inserting slightly eccentric leading bushes, held in with Loctite. Worked a treat and the whole lot runs round nice and easy now on two thou (intentional) bush clearance. I'll probably need more than that but for now I'm quite 'chuffed'.
Happy New Year!
JB

[redmog]

Very nice JB
You're catching me up !
Yes it is better fluting - should I start again !!!!
But - what nut do we put on the joining of coupling rods?
because mine doesn't look right.
I look forward to some photos of the making of castellated nuts !
Have I spelt that correctly? think so.

Chris

[Deleted]

Happy New Year Chris! Thanks for the nice words, and yours looks perfectly OK to me. I don't want to be a smart-a*s but 'castellated' might be a more accurate rendering?
JB

[redmog]

Yes you're right - just looked it up.
castellated
Adjective
having turrets and battlements, like a castle.
And a Happy New Year to you also.

Chris

[Deleted]

OK Chris, you wanted Castellated Nuts? This piece of today's work is for you: what do you think?

LBSC specifies an ordinary 1/4"A/F nut and a washer, so this slightly more elegant approach would seem to be in the spirit of the thing!

PB1. 0.090" thick nut to go on 3/32" stud. 0.30dia x 0.025 thick 'built in' washer. 0.25 A/F nut. 0.040 slots.
Regards
JB
PS. The wheels will be painted......

New Castellated Nut


Another View


Slotting the nut.

[redmog]

Very Good ! - No - Excellent JB
What fast work. I like it.
Is that rotary table 4"? Mine's 6" and cannot mount vertically
under the milling head - shame.
I'll find a way round it. Looks like getting a 1mm slitting saw,
but that looks like a fine woodruff cutter.
I'll go down the workshop and have a sort through the odd cutter box tonight, I might have something I can grind to size.
Well Done.
Thanks for the sizes, are they from the Brit 'Words & Music' ?

Chris

[Deleted]

Hi Chris. Yes, it's a 100mm table, perhaps more suited to the type of work that I like doing. I was using the keyway cutter because if a 50mm x 1mm slitting saw is used, even with the small rotary table, there is not enough travel available on the Proxxon milling table. The search for neat little cutters/boring tools is the main reason that I go to the shows.

Nut sizes are straight off the top of my head: as in life, success is just a matter of keeping things in proportion!

Regards
JB

[drjohn]

Is it my imagination / eyesight, John, but the tread/flange radii seem rather sharp?

DJ

I don't have to say that the bits you've done are awffy good!

[Deleted]

Hi DJ. Yes, I think that you are right about the wheels, but I bought them as they are, and a real bargain they were too. However, I'm not sure I can do anything about it without spoiling them!
JB

[drjohn]

I'm not sure I can do anything about it without spoiling them

I can appreciate that John. Maybe others might know better, but if the wheels on the bogie and the lateral springing thereof are OK, it should keep it on the rails - as there is no lateral sprung forces on the pony truck, going backwards will need a bit of care on corners with rusty rails..

Happy New Year, by the way, and to the rest of the folk on the forum

DJ

[mutley]

Hi DrJohn and SimplyLoco,
As I understand it all the Brits started out with fluted rods. Following problems with them breaking they where changed to the fish bellied style. Athough as the photos show there where some intresting matches.
Even to this day in preservation 90775 carries an odd rod from when it had one replaced whilst in Greece.

Andy

[davidimurray]

JB - a quick question. How do you mount your chuck to the rotary table?

I have a very similar rotary table and chuck, but the chuck has through holes and I bolt it down to T-nuts in the table.

Just bein nosy!

Cheers

Dave

[Deleted]

Hi Dave. The table is bored MT2, so it was relatively straightforward to make an adapter to fit the back of the chuck. I just drop it into the table when I need to use it, and the taper provides sufficient holding power. No setup time and concentricity is assured. Hope this helps.

JB