Author Topic: Tufnel gear  (Read 2539 times)

Offline benet

  • Moving Up
  • **
  • Join Date: Feb 2011
  • Posts: 13
  • Karma: 1
Tufnel gear
« on: 26.08. 2012 10:23 »
Hi Guys, I have replaced the tufnel gear on the auto advance with a new one and all appeared in order untill installation. The new gear seems to be binding excessively with the camshaft gear. I guess my first question would be if there are different profiles for the teeth on the tufnel gear's. It seems to match quite well with the old one and has the correct number of teeth, the OD of the old gear is about 0.5 mm greater then the old one but i expect that may be due to wear. It's difficult for me to measure the actual teeth as my vernier won't reach evenly into the bottom of the teeth cavities. Any ideas? Ben

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5414
  • Karma: 61
Re: Tufnel gear
« Reply #1 on: 26.08. 2012 10:43 »
Hi Ben
I had the same thing when I replaced the A/A unit with an alloy pinion, it was a fairly tight fit on the cam pinion.
However it all turned over ok so I figured I'd run it for a while and then check it, the "while" is still in progress so can't tell you what it's like yet, but nothing seems amiss noise or running ways.

Possibly just a repro part tolerance thing, however with tuffnel there's the added thought of teeth breaking, not sure what others might recommend but if it is not much a very slight easing of the three magneto mounting holes might give you enough to let it engage better, but go easy with the file.
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1482
  • Karma: 20
Tufnol gear
« Reply #2 on: 26.08. 2012 10:56 »
I think I've heard that a Tufnol gear needs backlash.

Try another one from Price, if still in business.

Offline benet

  • Moving Up
  • **
  • Join Date: Feb 2011
  • Posts: 13
  • Karma: 1
Re: Tufnel gear
« Reply #3 on: 26.08. 2012 11:30 »
Yea Hi Guys, thanks for the feedback. I had initially thought that maybe running it will wear it in, however what is happening is that the pressure to the side seems to be fouling the auto advance and the mechanism is not operating freely. I'm concerned it will just stay in the advanced position. Ben

Offline a10gf

  • Wise & Enlightened
  • *
  • Join Date: Sep 2006
  • Posts: 2769
  • Karma: 42
  • West Coast, Norway & Alpes Maritimes, France
    • A10 GF
Re: Tufnel gear
« Reply #4 on: 26.08. 2012 11:53 »
(sorry, slightly offt.)

What is it really: tufnol, tufnel, tuffnel ? Nigel Tufnel? > http://en.wikipedia.org/wiki/Up_to_eleven
Ok. I guessed tufnol (as TT had a go at fixing the topic title) > http://en.wikipedia.org/wiki/Up_to_eleven
"Tufnol is made from phenolic resin and woven cotton or linen fabric"




A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1482
  • Karma: 20
Re: Tufnel gear
« Reply #5 on: 26.08. 2012 12:33 »
There is a little tolerance on the magneto mounting holes and studs. Try levering the magneto away from the engine as you tighten the nuts. That might free it a bit.


Online lawnmowerman

  • Resident Legend
  • *****
  • Join Date: Dec 2009
  • Posts: 612
  • Karma: 8
  • 1959 Super Rocket. Kent, England
Re: Tufnel gear
« Reply #6 on: 26.08. 2012 13:23 »
(sorry, slightly offt.)

What is it really: tufnol, tufnel, tuffnel ? Nigel Tufnel? > http://en.wikipedia.org/wiki/Up_to_eleven
Ok. I guessed tufnol (as TT had a go at fixing the topic title) > http://en.wikipedia.org/wiki/Up_to_eleven
"Tufnol is made from phenolic resin and woven cotton or linen fabric"





Hi A10gf

According to this it is tufnell:

 Novasteen is an industrial laminate material with both electrical insulating and mechanical properties.

Novasteen is available in both natural and graphite impregnated (black) sheets or rods.

Novasteen possesses high load bearing characteristics which makes it an ideal material for silent gears, rollers and bearings.

Novasteen is known by various trade names for example SRBF, Auspeton, Micarta, F3 and Tufnell.

Novasteen is fully machinable and can be supplied in whole sheets/rods or cut to size and if required machined to your requirements by Modern Engineering.

Applications:

    Gears
    Stern tube
    Tension wheels
    Scraper blades
    Insulating pads
    Pulleys
    Bearings
    Slipperpads
    Bushes
    Rollers
    Insulating sleeves
    Mountingpanels
    Mixingpaddles
    Wearstrips

Jim
1959 A10 SR
1938 Wolseley 14/60
1955 Ferguson TEF20 tractor
1965 Ferguson 135 tractor
1952 Matchless G80 rigid
1960 BMW R60
1954 Matchless G80S
1955 Ariel 500 VH
1951 Sunbeam S7DL
1960 Matchless G12 with Watsonian Monza
......and loads of lawnmowers

Too old to Rock and Roll but too young to die  (Jethro Tull 1976)

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 4997
  • Karma: 48
Re: Tufnel gear
« Reply #7 on: 26.08. 2012 14:40 »
If diameter is the only issue,  and it seems as good a place to start as any,  why not reduce the diameter to that of the original? Then,  if tooth profile still leaves it too tight,  you could dress each tooth down a tad with a jeweler's file,  using due caution not to overdo it.

Richard L.

Edit: This seems to me far less agressive and,  possibly,  damaging than altering the mag mounting holes,  which may not help anyway if the problem is tooth profile.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1482
  • Karma: 20
Re: Tufnel gear
« Reply #8 on: 26.08. 2012 16:47 »
A fibre gear with hand formed teeth will promptly fail in service, I'd almost bet.

Offline Goldy

  • Warwickshire, England
  • Resident Legend
  • *****
  • Join Date: Dec 2008
  • Posts: 619
  • Karma: 9
Re: Tufnel gear
« Reply #9 on: 26.08. 2012 18:15 »
Correct gear cutting is quite complex and that is always going to be a problem with re made parts. If its binding I would not run it because it will put extra load onto the magneto bearings which will lead to other problems.
56 A10 Golden Flash - Restore, ride, relive.                                          
56 C12 BSA project ongoing

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 4997
  • Karma: 48
Re: Tufnel gear
« Reply #10 on: 26.08. 2012 20:20 »
I don't believe reducing the O.D. would amount to reforming the teeth.  I would agree that any major reforming would probably lead to failure.  If it were I,  I would examine the fit between gears with the tufnel gear in hand (not mounted) and decide if
 the problem is just a matter of a couple thou of an inch. If that was all that had to come off,  I would try hand-dressing the teeth; however, I might still fail. Success,  if it's to be had,  would feel good.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1482
  • Karma: 20
Re: Tufnel gear
« Reply #11 on: 26.08. 2012 20:54 »
They don't cost much.

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 4997
  • Karma: 48
Re: Tufnel gear
« Reply #12 on: 26.08. 2012 21:09 »
OK. I was going with the theory that all the new ones might be oversized; but,  no clue,  really.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Offline benet

  • Moving Up
  • **
  • Join Date: Feb 2011
  • Posts: 13
  • Karma: 1
Re: Tufnel gear
« Reply #13 on: 03.09. 2012 09:23 »
Hi Guys (by the way, are there any women on this forum?) Just to give you all an update on what happened to my binding gear. I took the advice to loosen the mag fixing bolts and then wedged it a little away from the binding gear. This made a significant improvement and the advance mechanism is now also operating freely. I was told by an engineering friend of mine that by soaking the gear in oil for 24 hrs, which i did,that the tufnel was slightly absorbant and might swell. Anyway thanks all for your help. Ben 

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5414
  • Karma: 61
Re: Tufnel gear
« Reply #14 on: 03.09. 2012 10:03 »
Quote
(by the way, are there any women on this forum?)

There was one once, If I recall she was after something for her Dad or something.

No offense guys but after the photo of that curry I think a lady might bring a bit of culinary realism  *fight*
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco