Anyone have a Britool EVT3000A torque wrench?

[Wedg1e]

...or one from the same series... the type with the red knob you pull out and twirl to adjust? Not the later type with the plastic handle, this one has a chromed steel one with knurled bands.

I have had one in bits for some time now because an internal part broke... I came up with the idea of turning a new part but when I extracted the wrench from its place of repose (in the loft ) I found that the cluster of bits that were with it, are no longer with it, so rather than scrap a potentially useful tool I'd like to have a crack at replacing the parts, if only I can identify what they look like, how big they are and what they're made from
Needless to say, Britool themselves no longer exist (that I can find) and anyway, what's the point of owning a lathe and not using it?
And yes, I have looked under the loft insulation...

 

[normspanners]

yep i have one

 

[RonA]

I have the one displayed plus two smaller versions which covering the range from 4lbs-ft to the version shown which goes upto nearly 300lbs-ft. Great kit & as you say another quality manufacturing company gone to the wall.

Suspect you may be able to remanafacture missing parts but not sure how you can determine the correct grades of steel to use or the heat treatment the finished pieces may require.
RonA

 

[pedrobedro]

I've got a smaller one similar but it's got a 4" nail instead of the bit with the red knob on the end, still works though.

 

[Wedg1e]

Ah good: anyone fancy a stripdown?

I guess if the part that broke had been made from a better grade of steel, it wouldn't have broken (stripped thread as I recall).
Heat treatment not an issue: we have a 1200 degree oven at work...

 

[graffian]

I've got a smaller one similar but it's got a 4" nail instead of the bit with the red knob on the end, still works though.

I have one, hasn't even got a nail but still works fine;-) It's marked in grams-metre and I have another similar size marked in kg-cm!
I always wanted one like in the pic to do bike flywheels up, I just do them **Language**ing tight.

 

[normspanners]

we have a 1200 degree oven at work...

bet that does the pies quick !

yeah will have to look where it is, i think I know, mine is the long series one about metre long ? 250 ftlbs IIRC

 

[RonA]

Just took mine apart to measure up the internals, which part has broken on yours.
Below the spring is a round edge flat piece of steel with a turned ball end shaft, that mates with a cylinderical component which has a half cylinder indent (on one end) to match first component, (& on the other) it has a reduced cylindrical tailpiece which in turn mates with the spring. At the top of the spring sits a further component with a tailpiece which sits in the spring, the main body of that component is cylindrical but the end is cut away to form a tang. The tang mates with a screwed component which screws into the tubular body of the torque wrench & exerts the force on the spring which opposes the turning moment of the wrench
RonA

 

[Wedg1e]

Just took mine apart to measure up the internals, which part has broken on yours.
Below the spring is a round edge flat piece of steel with a turned ball end shaft, that mates with a cylinderical component which has a half cylinder indent (on one end) to match first component, (& on the other) it has a reduced cylindrical tailpiece which in turn mates with the spring. At the top of the spring sits a further component with a tailpiece which sits in the spring, the main body of that component is cylindrical but the end is cut away to form a tang. The tang mates with a screwed component which screws into the tubular body of the torque wrench & exerts the force on the spring which opposes the turning moment of the wrench
RonA

Cheers Ron, sounds about right... it's the threaded piece that screws up to preload the spring (complete with its pull-out tommy bar) that has gone AWOL... let me take a quick pic...

I assume the little spring-loaded pin is in there to indicate minimum setting so you don't screw the thing apart every time...

Errr, hang on... am I as thick as a diplodocus buttie or what? I also have this beast, the same tool but later version, I bet the internals aren't too dissimilar...

 

[RonA]

Cheers Ron, sounds about right... it's the threaded piece that screws up to preload the spring (complete with its pull-out tommy bar) that has gone AWOL... let me take a quick pic...

View attachment 60983

View attachment 60984

View attachment 60985

View attachment 60982


I assume the little spring-loaded pin is in there to indicate minimum setting so you don't screw the thing apart every time...

Errr, hang on... am I as thick as a diplodocus buttie or what? I also have this beast, the same tool but later version, I bet the internals aren't too dissimilar...

View attachment 60986

Hi Wedgie,
Attached is a small drawing of the part which is faulty on your wrench. Just a thought is the internal thread on the wrench tube in good order or you could be wasting your time. Also dont think this piece is quite as critical for hardness/steel quality as the components toward the action end of the wrench. Sorry its only a rough sketch, my other computer with AutoCad on it has just packed up. Also just noticed the small hole in the middle (0.275" dia) isn't shown on side elevation but is right through the middle of the component, not sure what its for but may only for manafacturing purposes

I suspect that you don't reside too far from me, for although I'm down as North East for location , I live on the outskirts of Teesside.

Hope this helps
RonA

 

[Wedg1e]

View attachment 60989
I suspect that you don't reside too far from me, for although I'm down as North East for location , I live on the outskirts of Teesside.

Hope this helps
RonA

Thanks Ron, very good of you... now you mention it, the internal thread is looking a bit rounded at the crests, not as bad as the adjuster was though... is the hole through the centre not there to allow the tommy bar to be dropped in from inside so it can't pull out? I recall mine was very stiff and the red plastic knob would come off the end if you yanked it too hard (sure there's a euphemism in there somewhere...).
I might turn up a 20tpi thread on a bit of round scrap and see how it feels.
You can't be far away, I split my time between Norton (home), central Stockton (the office) and the girlfriend's place just outside Yarm (and wherever in the world the job takes me, of course... )

 

[normspanners]

(sure there's a euphemism in there somewhere...).

WHO WOULD EVER THINK THAT???
if you have one of those in there maybe thats what went wrong with it?

 

[RonA]

Thanks Ron, very good of you... now you mention it, the internal thread is looking a bit rounded at the crests, not as bad as the adjuster was though... is the hole through the centre not there to allow the tommy bar to be dropped in from inside so it can't pull out? I recall mine was very stiff and the red plastic knob would come off the end if you yanked it too hard (sure there's a euphemism in there somewhere...).
I might turn up a 20tpi thread on a bit of round scrap and see how it feels.
You can't be far away, I split my time between Norton (home), central Stockton (the office) and the girlfriend's place just outside Yarm (and wherever in the world the job takes me, of course... )

Hi Wedgie,
Never thought about about fitting the adjusting Tommy bar, yes sounds about right. I've checked my Zeus book & the 20 TPI thread against a range of standard threads but it doesn't seem to match up, so I guess it must have Been a special just for this wrench.
Shame about Britool going to the wall, I have a range of their torque wrenches, along with ordinary sockets & wrenches, they are good kit built to last. Hope your repair goes Ok. if you're like me I hate to bin what had been a good tool.
Actually you live closer to me than I guessed.
RonA

 

[Wedg1e]

Right, by way of avoiding socio-political comment I thought I should get back to what I do best... bodging so I rooted out a buckshee length of something steely and set to work with the lathe. As usual my Finepix can be relied on to have flat batteries when I need it and to compound matters I'd left the charger at work, so to summarise a fair bit of fannying about, there's this:

Why was there some fannying about? As the thread in the wrench body didn't look too clever, I made a trial piece with a short length of thread on it and kept tickling it with the 55 degree tool until it would screw in stiffly (I once worked in a pub and a leggy blonde asked me for a double entendre, so I gave her one ) and used that to clean out the thread: I think the shredded remains of the original adjuster was mixed with the grease and filling the thread roots, making it look worse than it was. From that I established (a) that it was indeed 20tpi and (b) that I could go a few thou" larger on the major diameter for a snugger fit. Then I turned another piece, this time using a 60 degree tool, just in case it was a better fit, but it wasn't.
So I got stuck in and made the beast you see above. It's not finished of course: it needs the slot milling across the thread end and a smaller slot for the retractable tommy bar to swing in - and that brings me to the tommy bar itself. It's a rod about 6mm diameter and 4.6" long (mixing my measurements there) with a ball formed on one end (to keep it captive whilst allowing it to swing to perpendicular while adjusting the wrench) and threaded at the other for a knob.
The circlip groove was entertaining: I ended up slimming-down a parting-off blade on the grinder and by pure luck hit 42 thou", close enough for Government work as they say
Internally the adjuster 'body' must be a little more involved than Ron's depiction as there seems to be a plastic or rubber insert that grips the tommy bar whilst it's 'stowed'; I'll have to give that some thought once I've cracked the t-bar itself... I don't have a ball-turning widget for my lathe... yet
However, what I DO have for this lathe as a result of this little project, is a Thread Dial Indicator... somehow lost by previous owners as often seems to be the case. Someone on here posted a tip-off that Bede Machine Tools were breaking a couple of Mk.2 Students so I gave them a bell... but the lathes were long gone. So I turned to Ebay and found a TDI for a Mk.1 Student for sale. A manly bid secured that, hoping that Colchester hadn't changed the mounting just for the hell of it: with some trepidation I offered it to the lathe and... it fits! Not only that but it works perfectly, so next time I need a 20tpi thread I won't have to leave the clasp-nuts engaged and keep reversing the lathe...

Anyway, back to the wrench... I 'reassembled in reverse order' as car manuals always say, and wound the adjuster up by hand - here it is at about 164 lbf. ft. by which time I needed hands like Steve Austin to grip it any harder:

I'll need to check the calibration of it once it's back together and I have a cunning plan involving another torque wrench and the rear hub nuts of the TVR, which just happen to need 250 lbf. ft. on them

 

[RonA]

Hi Wedgie,
Glad to see you're getting somewhere with making up the missing piece to your torque wrench, although by yor script it appears to have been far from plain sailing. I'm not sure about the plastic grip you think should be there, as far as I could see I had all the parts out of mine when I disassembled it. I know where you're coming from with the comment about needing arms like Steve Austen, once you get up to a certain torque setting you definitely the Tommy bar to go any further. Good luck with the final sorting out & testing, they are a very good tool. As I said before I have three in my toolbox from a few pounds ft upto 250 pounds ft
RonA

 

[Wedg1e]

Cheers Ron: I may have solved the riddle... I think it's the knob on the end of the tommy bar that has an internal O-ring or something to grip the end of the adjuster and keep it retracted. That simplifies things a bit - maybe!

I did contemplate cheating and just milling a hex on the bottom end of the adjuster so you could wind it up with a spanner, but if a job's worth doing...

 

[Wedg1e]

So, the next thing to do was make a tommy bar. I decided it wasn't too dimensionally critical so went with a 6.5mm diameter bar with a 8.5mm ball on one end - but how to make the ball? Just for a laugh I thought I'd see if I could rough cut a ball on a spare bit of bright mild (at least, I think that's what it is)...

and once I'd tickled it a bit with a file it didn't look TOO shabby:

so I decided to press on and see where it might lead...

and it eventually led to this:

(the groove about a third of the length from the right is what's known in machinists' parlance as a cock-up - but I didn't fancy starting again so let's call it a decorative feature ).
Anyway, next it needed threading at the other end to take a knob so I reached for the 60 degree tool and pushed and pulled levers on the lathe...

Tried an M6 nut on for size and all was good. Fired-up with no enthusiasm for gardening I figured I could crack-on and mill the slot across the end of the adjuster whilst Nursy wasn't looking, so I scratched my head for a while until I figured out how to set the thing up on the mill...

...and I was just about to take the cut when Nursy turned up with some lunch. Haven't seen the bloody mill since

 

[Wedg1e]

Right, where was I? Oh yes... to make sure the cutter was on-axis with the threaded adjuster clamped in the vice I measured from 'top dead centre' of the chuck to the table and the same point on the adjuster to the table. Then I subtracted half the diameter of the respective components to arrive at their respective centre heights and adjusted the knee until the axes were concentric - or at any rate, level.
Then it was time to get jiggy wiv me tool, innit:

Doubleboost would probably pick me up for climb milling or improper use of V-blocks or some such but what the hell...

As the cutter was a bit narrower than the required slot I had to go up and down a few thou and take a shave off either side, trying the bit it mates with until it fit about right...

Then I turned the adjuster around in the vice, poked the cutter up the bore to make sure it was about on-centre ...

lined the cutter up at the required depth of cut...

and cut the slot that the tommy bar will wiggle in:

Tried the t-bar and it's a nice fit in the slot...

I know, I know... I should have cut the slot with the cutter perpendicular to the work so that the blind end was radiused but that would have taken longer and I'd have had to rejig the vice on the table... and it was cold... and I needed a poo... [insert plausible excuse ad infinitum ]

Now I have reached something of an impasse; I need to drill or bore the adjuster 150mm deep at 8.5mm but even my longest long series drill won't do that. I found one for sale that will but I could almost buy another torque wrench for that price!
No way am I going to get a normal boring bar down there which leaves boring between centres... and I'd have to make the boring bar first!

More rum needed...

 

[graffian]

More side clearance wanted on the on the pointy threading tool;-)

 

[Wedg1e]

More side clearance wanted on the on the pointy threading tool;-)

You're probably right, it's a cheap brazed carbide job so who knows. Mind you this steel doesn't machine particularly nicely I've noticed: under a magnifier even a straight cut looks a bit 'tearey'.