Author Topic: Tapping help  (Read 3869 times)

Offline Jo

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Re: Tapping help
« Reply #15 on: November 16, 2017, 08:18:44 PM »
I recognise that casting  :embarassed:

Sorry Pete, the Eclipse 244 tap wrench is not longer made  :disappointed: they turn up every now and then on Fleabay.

Jo
Usus est optimum magister

Online 10KPete

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Re: Tapping help
« Reply #16 on: November 16, 2017, 09:37:16 PM »
I recognise that casting  :embarassed:

Sorry Pete, the Eclipse 244 tap wrench is not longer made  :disappointed: they turn up every now and then on Fleabay.

Jo

Rats! It never fails... I'll be trolling eBay!

Thanks,
Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
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Offline gerritv

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Re: Tapping help
« Reply #17 on: November 17, 2017, 03:04:06 AM »
Or make one? Looks worth while spending an afternoon on. Perhaps a separate thread where Jo and Ramon could post photos of a dismembered one with a scale (preferably metric) beside it. That should be enough to reverse engineer the thing.

I would be interested myself as working with small taps are in my near future!

Gerrit
Programming is like a Hit-n-Miss engine

Online 10KPete

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Re: Tapping help
« Reply #18 on: November 17, 2017, 03:36:19 AM »
Or make one? Looks worth while spending an afternoon on. Perhaps a separate thread where Jo and Ramon could post photos of a dismembered one with a scale (preferably metric) beside it. That should be enough to reverse engineer the thing.

I would be interested myself as working with small taps are in my near future!

Gerrit

I'm in Gerrit! If we can persuade Jo and/or Ramon to post some close up pics I think that would be enough. It looks pretty simple....

Jo?? Ramon???

Thanks,
Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline Robert Hornby

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Re: Tapping help
« Reply #19 on: November 17, 2017, 04:42:53 AM »
Thank you gentlemen, and Jo for all the suggestions. I think Ramon's take on it will suit me best, so a little tool making time is needed between boat building.
Robert
Age and treachery will always overcome youth and skill

Offline Jasonb

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Re: Tapping help
« Reply #20 on: November 17, 2017, 07:26:09 AM »
And once you have made the 244 you will be wanting the 245 to go with it ;)

Offline engjas

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Re: Tapping help
« Reply #21 on: November 17, 2017, 07:27:05 AM »
Hello  Robert
Re the tap wrench have a look at patent GB670663A available on line I believe (Google patents or Espace)
Best wishes
John

Offline Ramon

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Re: Tapping help
« Reply #22 on: November 17, 2017, 07:42:19 AM »

Hi Guys -

I have to go out first thing but not for too long - once back I'll take some pics and dimensions for you. But at it's simplest form, a flat piece of 3-4 mm thick steel with a through hole and a 2.5mm grub screw in the side would easily handle up to say 4BA. That could be refined as far as you want to take it. You need a 'Trevor'  ;)

Back soon - Ramon
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Offline Jo

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Re: Tapping help
« Reply #23 on: November 17, 2017, 08:13:27 AM »
Re the tap wrench have a look at patent GB670663A available on line I believe (Google patents or Espace)
Best wishes
John

Yes that is the beastie  ;D

Jo
Usus est optimum magister

Offline Ramon

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Re: Tapping help
« Reply #24 on: November 17, 2017, 01:18:57 PM »
Hi guys, further to Jo's info here's a bit more as promised



The wrench  measures 12.8 wide x 3.6 thick and is 95 .6 long OA. Dimple centres are apx 82.

The slot has a width of 5mm  opening to 6.9 mm wide where the knurled nut is.Knurl diameter is 6.3 and is 9.3 long.
From the point of the vee to the end of knurl is 32.8

The screw is L/H and looks 3/16 BSW but that's an estimate as there's not much to see. It has flats each side where it has been machined for the two guide plates

I do use the other two types in the same fashion but being thicker they need a longer flat ground on the shank - okay for the larger taps. I haven't found the CROZ one to be as good as it looked on the shelf! A nice looking piece of kit but not much use in this particular method of use!

Hope that helps - I'm in the throes of drilling and tapping an excessive amount of holes (200 plus) at the mo - 7 and 8 BA for the better part. Most will be done the way described above.

Hope that helps a little further

Regards - Ramon

Oh Yes - A 'Trevor'.

We had a rather recalcitrant member of the workshop who possessed few tools. Caught going through someones tool chest one morning and challenged he replied he was looking for a tap wrench. Told in no short order to buy his bloody own he disappeared to return with a length of 5/8 x 38 GFS in hand - a quick hole through and one through the side for a 6mm cap head and Trevor had his tap wrench. Used once it was thrown on the bench to remain there - left as a display by his colleagues as a reminder of his craftsmanship and belligerence. A tap wrench  (and a bodge ) was hence forth known as a 'Trevor'
« Last Edit: November 17, 2017, 01:27:20 PM by Ramon »
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Offline Ramon

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Re: Tapping help
« Reply #25 on: November 22, 2017, 08:49:57 PM »
Guys, Just a short addition to the previous posting.

Just finished off 224 7and 8BA holes in this fashion in two cylinder blocks.






The cylinder blocks are allowed to float but are prevented from rotation by the 'fixed stop' (angle plate left for previous op) and the magnet which helps do the same when backing the thread off.

This method does have something going for it - a small flat ground freehand on the tap is all that's required. The tap can be held by either gently closing the chuck to just support it or, as here, floating in a brass bush

As usual, hope that's of help and interest to someone.

Regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Online sco

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Re: Tapping help
« Reply #26 on: November 23, 2017, 08:02:26 AM »
Ramon,

I really like the idea of this method - quick to move from hole to hole to start the next tapping operation and very economical on Z-height!  224 tapping operations though - do you use 2nd and then plug or straight to plug - that's a lot to do whichever!

Simon.
Ars longa, vita brevis.

Offline jadge

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Re: Tapping help
« Reply #27 on: November 23, 2017, 08:49:18 AM »
Ramon: I admire your patience. I'd have been idle and dug out my Tapmatic reversing tapping head. To partially answer Simon's question I often use spiral flute taps, even for hand tapping. You only need to buy, and use, one tap and they cut closer to the bottom of a blind hole than many bottoming taps.

Andrew

Offline Ramon

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Re: Tapping help
« Reply #28 on: November 23, 2017, 10:08:24 AM »
Hi Simon, Andrew,

I do have a Tapmatic under the bench Andrew but wanted to be absolutely in control of these small taps for as you can imagine I really did not want to break one in these two cylinders.

The taps I used were Blue Wizard HSS Spiral Point Taps. The immediate point of these were ground off and the holes drilled deep enough for the lead in taper not to have any effect on the stud thread. The points of these taps are very pointed and serve only for sharpening purposes. It can cause cracking/breakage of the tip if hitting the bottom of the hole too sudden, grinding the point back to a flat reduces this possibility immensely.
I have spiral flute taps too but I always feel they are are a much weaker tap due to the fluting so prefer to use SP when possible.

Had I had no choice but to use to use carbon taps I would have drilled the holes slightly larger diameter for less engagement, used the second tap as shown above, then, if necessary, gone back in with a plug tap using a chuck type wrench free hand.

As a matter of interest Simon this idea was borne of the need to overcome the lack of Z height on my old Linley machine  ;)

As you can see there's been a lot of holes to tap on these two parts and hope this will help those with limited kit overcome any doubt about taking on such a task.

Regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline ShopShoe

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Re: Tapping help
« Reply #29 on: November 23, 2017, 01:35:37 PM »
Who among us has been using the Starrett tap handles? I keep wondering whether to add one to one of my orders when they turn up on sale. I have been considering making a copy of the older one as MrPete222 did. I have seen AvE compare the large one with a cheaper brand, but we use the smaller ones. I get by with the collection of cheap ones I have, but I also upgrade things as I go forward in this hobby.

I like a tight grip of the wrench to the tap so that the "feel" of the cut transfers to my fingers.

--ShopShoe