Veritas - Generator’s Pricker Replacement

Discussion in 'Fettling Forum' started by AussiePete, Jan 6, 2020.

  1. AussiePete

    AussiePete Australia Subscriber

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    Those of us who fettle or have fettled Veritas lanterns are often faced with the pricker wire damaged or missing.
    To my knowledge there are no “off the self” replacements. Usually, any replacements require modifications to similar prickers from different makes of lantern to fashion a workable replacement.

    The other alternative is to fabricate a new pricker replacement from scratch.

    The following is the story of my fabrication of a new pricker replacement for a Veritas 350 lantern.

    First of all, the crime scene .....

    BB79B546-BD22-4B71-BD4F-27C42B823363.jpeg
    The above photo shows the tip of the pricker wire is missing, an all too familiar discovery while fettling these beasties.

    The broken pricker can be unscrewed from the lanterns pricker rod, as seen in the next picture.

    DDBC8BB6-22B0-46F8-BD94-23DC5E81A41F.jpeg

    The thread of the pricker head is a metric M2.0.

    I sourced 1/8” brass tube from a hobby materials supplier. The benefit of the 1/8” brass tube is that it’ll take a 2.0 mm thread, and because it’s a tube, I can insert the new pricker wire inside.

    DC85B65B-A9D1-4D60-A5C1-035D0D479801.jpeg

    The brass tube took the thread very well as seen below. Whilst being threaded, the 1/8” brass tube was held in my miniature vice, using copper keepers on the jaws.

    A42DA412-575A-43DA-80D0-CED45A4EA4CA.jpeg

    The new threaded tube shown along side the original broken pricker.

    6269AEE1-2CC7-42EC-979D-60E4B8723783.jpeg

    A .0006” stainless steel wire was then selected and a knot tied into its middle. This knot will be crimped within the pricker tube thus preventing it from being pulled out.

    4CB40052-027D-4377-BFAC-BE239E4AAFA7.jpeg

    The new pricker unit was then cut from the brass tube stock. The knotted pricker wire is shown ready for assembly to be crimped within the new pricker’s brass tube using the vice.

    428AA680-697C-4574-B648-1A6469DB7370.jpeg

    The final pricker with the wire crimped in using the jaws of my miniature vice. The brass tube’s end was then shaped to fit nicely into the rear of the jet to prevent any chance of catching.

    75450CFC-F841-4FB1-86FB-95BEBE039892.jpeg

    The proof of the pudding. The generator and valve body were assembled to test the new pricker’s operation using the Veritas pricker control lever.

    I’m please to say, it’s a worker. The following picture shows the pricker wire appearing through the generator’s jet.

    702456FA-B42E-4C78-93F8-16B1339FF476.jpeg

    You have to look closely, but the pricker wire is there doing it’s job.

    Thank you for looking

    Cheers
    Pete
     
  2. ColinG

    ColinG United Kingdom Subscriber

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    Excellent and informative post. I have 2x Superbs and I'm sure the time will come when one or both of them will need replacement pricker wire tips. Having read this post I've already decided to buy some brass tube stock and and wire to make a few test tips ahead of time.

    Thanks
     
  3. ColinG

    ColinG United Kingdom Subscriber

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    Can I ask where you purchased the 0.0006" wire from?
     
  4. JonD

    JonD Subscriber

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    There's an extra zero in there Colin. It will be 0.006" I reckon or 0.15mm.
     
  5. JEFF JOHNSON

    JEFF JOHNSON United Kingdom Subscriber

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    Well fettled!:thumbup::clap::clap::thumbup:
     
  6. BigStevie

    BigStevie United Kingdom Subscriber

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    Always a pleasure to see your work Pete...
     
  7. Emiel

    Emiel Netherlands Subscriber

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    That's impressive. Well done.
     
  8. AussiePete

    AussiePete Australia Subscriber

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    ERROR
    Hey guys there is an error in the wire size.
    The wire used is 0.006”(0.15mm) not as I originally stated .0006”.
    I put the decimal point in the wrong place.
    Thanks @JonD for the catch.
    Cheers
    Pete
     
  9. ROBBO55

    ROBBO55 Subscriber

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    Nice work Pete. :clap::clap::clap:
     
  10. Alex Smith

    Alex Smith United Kingdom Subscriber

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    As ever a engineering master class. Thanks for sharing Pete.
     
  11. Norman

    Norman United States Subscriber

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    Well done Pete.

    Thank you for sharing.

    Cheers,
    Norman
     
  12. JonD

    JonD Subscriber

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    No problem @AussiePete I am admiring your set of taps and dies for the small sizes!

    We still wonder where you found the wire? I have been looking at music strings for guitar etc and 0.006" is rare as hen's teeth. Custom shops will make them for you but generally they are not on sale in string sets or as single strings as far as I can tell.

    You can bulk buy 0.006" music wire but they are selling long lengths which means high prices.

    I found soft stainless steel wire, 304 grade. wires.co.uk stock # SS0150-050
    Price of that is not too bad. The 50gm reel about 320m long will last a life time of making prickers.
    It's about £7 here inc tax but not shipping.
     
    Last edited: Jan 7, 2020
  13. ColinG

    ColinG United Kingdom Subscriber

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    I found some 0.15mm (that's metric equivalent of 0.006") stainless wire on Amazon for £3.70 for 20M. Should last me years!thereaare w different grades: 304 and 316... 316 is the best grade.
     
  14. Mackburner

    Mackburner United Kingdom Founder Member Subscriber

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    Hmmm! You say the thread is M2. That is the same thread as a Petromax needle. Seems to me it would be easier to modify one of those rather than make a complete new assembly. Brilliant work though it is. We have done that successfully for some Nulite and AGM prickers and they work fine. ::Neil::
     
  15. JEFF JOHNSON

    JEFF JOHNSON United Kingdom Subscriber

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    Hello Pete, a similar method was used by a fellow in Western Australia/Perth, to make prickers for the Australian Aladdin lanterns.
     
  16. AussiePete

    AussiePete Australia Subscriber

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    @ColinG
    That’s similar to the stuff I bought. It works well and as you said it’ll last a lifetime, many more lifetimes I suspect.
    Cheers mate
    Pete
     
  17. Darryl Durdin

    Darryl Durdin Australia Subscriber

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    Excellent display of being resourseful, i have tried making prickers for various fettles with some succes, but the best bart of your story for me is the knot in the wire, ive been finding it hard to crip and keep the wire from being pulled out,
    Great tip. I used an OHO #3 cleaning needle (tawian), i had to carefully file it round and to shape to fit my 350 veritas.:thumbup:
     
  18. Damien

    Damien Australia Subscriber

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    Brilliant thread... thank you. I've been stuffing around with copper wire, quite obviously too soft. Snipped off 1 thread/wire from a brass bristled brush I just bought thanks to tips from this site. Going strong!
     
    Last edited: Apr 11, 2020
  19. Damien

    Damien Australia Subscriber

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    The following is some brass tube I can get. Just wondering if the wall thickness would work for cutting a thread? I'm just trying to work out a way to make my own pricker rod, whilst borrowing Pete's brilliant ideas.
    O.D: 3.18mm (1/8)

    I.D: 2.4638 (.097")

    Wall Thickness: .3556mm (.014")
     
  20. ColinG

    ColinG United Kingdom Subscriber

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    Well, I tried with some 2mm brass tube (I don't know the exact wall thickness, sorry) but I couldn't get it to work. My problem is I don't have a lathe so I can't keep the die central to the tube and the die keeps popping off sideways - drove me nuts! I tried so many times but I had to give up in the end! Actually now I have more time on my hands I might try to rig something up and try again.
     
  21. AussiePete

    AussiePete Australia Subscriber

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    Hi @Damien and @ColinG
    I don’t use my lathe to centre the die. I just thread the 1/8” brass tube, held in a for purpose clamp, directly with the die. I’ve not had problems with the die wandering. Once the thread has started, and using care, the die tends to self centre as it cuts further down on the brass tube. I don’t use any lube.

    3031D456-D036-47FD-97A7-28E8347C140C.jpeg

    Cheers
    Pete
     
  22. Matty

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    This is a great topic brilliantly presented. Thanks Pete.

    I do have one complaint, your work bench is too clean, it puts me to shame.
     
  23. AussiePete

    AussiePete Australia Subscriber

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    @Matty
    I’m a bit slack lately, I didn’t polish the vice yesterday, but I did dust my drill box.
    :lol:
    Bloody engineers.
    Cheers
    Pete
     
  24. george

    george United States Subscriber

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    You could eat off Pete's work bench, mine you can't even work off it!!! Shame, shame, George!
    :cry:
     
  25. Matty

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    I have a Sidchrome toolbox and the lid is always open to the top shelf. I was going through the draws looking for something yesterday and noticed just how dusty the spanners and sockets were that sit in that top shelf. I've got a new workbench on its way from SuperCheap Autos that I intend to put the toolbox on the bottom shelf of. I'll dust them before I put the box in its new home. I'll probably have to remove the lid of the tool box. Can you see the greeting message?

    20200416_084515.jpg



    [​IMG]


    On the subject of this work bench, I admire peoples success that they can have a need for something and go and buy it without regard to the expense. I'm a bargain hunter and if I decide I want something I'll generally research then I'll wait for it to go on special. This week you can buy this workbench and have it delivered to the metropolitan area for about $115. I got it last week for $69 including delivery.

    Grant you, the delivery was free if you spent over a certain amount. My shopping cart was $729 including delivery but by buying 90% of the stuff on special I paid $378 including delivery. When you consider that if I bought the items individually most of them would have incurred a postage charge, by nullifying those charges, I am very happy with what I bought and what the bottom dollar amount was.

    I had no intentions of buying a sand blast cabinet. When I saw one at SuperCheap that normally retailed for $459 reduced to $189 I decided to give one a home. I've been trying to find a reason to upgrade my compressor and now I have it. Mind you, whenever I use my nibbler it almost drives me nuts waiting for the compressor to catch up.

    Well, I'm a bit off topic, I hope you don't mind.
     
  26. ColinG

    ColinG United Kingdom Subscriber

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    I tried again this evening but the tube wall is too thin. Not only that but the rod may be slightly too large because it's impossible to even get the thread started. It popped out each time!
     
  27. ColinG

    ColinG United Kingdom Subscriber

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    Where do you source your 1/8th inch brass tube from, Pete? In the UK I'm having difficulty finding exactly what I need.
     
  28. Damien

    Damien Australia Subscriber

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    I found hobby stores and modelling stores online with brass tube. The wall thickness, as I've mentioned, seems to be 0.4mm or there abouts. I'm learning the art of patience... with deference to you members! All good things come to those...... etc. It seems such a speciality, ie fettling pressure lamps, that the average punter I speak to has vague memories of pressure lamps, but if I mention thread sizes or BSW, or 47.5 degree angles versus 55 degrees on threads, most people just glaze over.... and as for pricker rods. I am obviously happy to post web sites, but I'm loathe to break this crackling tradition you all have of helping each other. I'm brand new to this, as you know, and I look to this forum with awe and respect.
     
  29. ROBBO55

    ROBBO55 Subscriber

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    @Damien

    Your tube has a ID greater than 2mm, won’t work.

    The calculated min diameter of a M2x.4 thread is 1.57mm (varies slightly from reality)
    Therefore the thread depth is (2 – 1.57) /2 = .215mm
    So you need a wall thickness > 0.35mm and a centre hole ID < 1.3mm dia to be on the safe side. (just my opinion)


    I have used these tubes to make replacements for Aladdin 1A

    1.JPG

    2mm dia with wall thickness 0.45mm ID 1.1mm

    The 1 mm dia tube slides into the 2mm to reduce the centre diameter to approx 0.4mm. If you want to reduce further use a 27 gauge hypodermic needle inside the 1mm.

    @ColinG

    To start and keep the taping running true I mount the 2mm brass rod in a drill press and lay the die flat on the bed. I then turn the chuck by hand.

    2.JPG

    3.JPG
     
  30. Damien

    Damien Australia Subscriber

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    Cheers Tony. All that wonderful knowledge of yours makes sense and has stopped me throwing good money after bad.
    I'm heading out to my little property near Cowra, so I'll be off the air for the next 4 days. Take care.
     

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