# Gifkins small cutter diameter



## S Bolton (Mar 5, 2007)

am wondering if anyone can tell me the diameter of the small Gifkins dovetail cutter as shown in the attachment. I will try to convert MM to inches.

Also, the variable spacer is a puzzle to me as to how it works. 

Grateful for any input.

Steve Bolton


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## Roefa (Sep 14, 2007)

Hi SB -
I'm not sure how close you need your answer to be, and some assumptions must be made regarding the drawing of the bit you posted, but here goes:
Bottom Line: 4 mm or about 15/32". If you need and answer fast, I'm posting this now... I'll add a bit about the "assumptions" on my next post to this thread (and tell you how I arrived at my answer).
Hope this is helpful.

Roger
(roefa)


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## Roefa (Sep 14, 2007)

Roefa said:


> Hi SB -
> I'm not sure how close you need your answer to be, and some assumptions must be made regarding the drawing of the bit you posted, but here goes:
> Bottom Line: 4 mm or about 15/32". If you need and answer fast, I'm posting this now... I'll add a bit about the "assumptions" on my next post to this thread (and tell you how I arrived at my answer).
> Hope this is helpful.
> ...


If I'm reading your drawing correctly, the bit has a 13 degree Included Angle or 6-1/2 degrees per side off of the centerline. I'm also assuming that the 
10 mm dimension is along the centerline to the undercut and NOT along the angle. (I based the upon the view if the rabbetting bit drawn next to the dovetail bit). I'm also assuming that the dimension you are interested in is the diameter of the bit at the very end where the undercut begins.

I'm sure that the CAD guys can do this much better, but I don't have it on this computer (not to mention I don't know how... Ha!)... but here's what I did: I drew it out on the drawing board 10 inches high and 6.2 inches across the nose (flat) end. Here's where some inaccuracy can creep in... Using and aircraft mapping protractor, I plotted the angles at 6.5 degrees per side and drew those sides in. Then, using a digital micrometer caliper, I measured the each radius at the small end (undercut). My answers were 2.086" on one and 1.975" on the other or 2.031 average... 4.062" dia. That converts (in mm) to 0.1600". 5/32" is .15625" so there about 0.004" difference... pretty darn close. It might be interesting to plot this on CAD to see how close my "crude" method turned out. 

Roger
(Roefa)


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## bobj3 (Jan 17, 2006)

Hi Sb

The one I have is ▼


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## Roefa (Sep 14, 2007)

More ....
This site:

http://www.datapowertools.co.uk/acatalog/Dovetail__gifkins__bits.html 

is showing the TGHD 12 with a 7 degree bevel... 14 degrees included angle.
This would calculate to a different diameter at the undercut shoulder.
 
Shall we start over? i.e. do you trust the 6 1/2 degree angle on the first drawing?
What are we really trying to find? You would rarely try to use all of the bit to cut a dovetail. Right?
???
Roger
(Roefa)


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## Bob N (Oct 12, 2004)

I just went out and measured mine and I got 4.66 just like Bj. It is from Gifkins in Oz.

Roger, you are a whiz with that math, I am still learning my additions and subtractions before I move on to my multiplication tables


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## Mike (Nov 22, 2004)

Bob? You will run out of fingers and toes when you jump to multiplication. Better ask Corey over and tell him to take off his shoes and socks...


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## Roefa (Sep 14, 2007)

Obviously, we're not talking now about the same bit as S Bolton is asking about...
even if the angle were 7 degrees instead of 6 1/2, the shoulder diameter would be LESS, not greater... i.e. where I calculated about 4.062 using 6 1/2 degrees, 7 degrees would result in a smaller diameter, not 4.66 mm or about 0.183".
I'm gonna' quit workin' on this 'til the thread-starter (SB) gets back and tells us what the heck we're tryin' to do !!! LOL. Besides, i gotta get ready to go to choir rehearsal. I'll be back in a few hours... you guys have fun !

Roger


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## S Bolton (Mar 5, 2007)

Roger Gifkins replied to my email and said it was 3.9 mm and he tried to talk the manufacturer into making it smaller. 3.9 mm would be about 5/32 of an inch I think. Bobj3, do you have the smallest Gifkins template?

sb


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## S Bolton (Mar 5, 2007)

My interest is that I have not seen a dovetail that small at the bottom of the bit, except for perhaps some Woodrat bits. It would seem to make it look more handcut.

sb


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## bobj3 (Jan 17, 2006)

Hi SB

"do you have the smallest Gifkins template?"= No

I have Katie jig and the one below that has a 1/4 dovetail template..

http://www.routerforums.com/attachments/general-routing/9377-first-attempt-dovetail-jig-7926.jpg

The Katie jig can take on the small dovetail bit without the need to add on a template...

http://www.katiejig.com/

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S Bolton said:


> Roger Gifkins replied to my email and said it was 3.9 mm and he tried to talk the manufacturer into making it smaller. 3.9 mm would be about 5/32 of an inch I think. Bobj3, do you have the smallest Gifkins template?
> 
> sb


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## Bob N (Oct 12, 2004)

Roger better check again because his supplier is sending out 4.66. That is where I got mine (from Roger) and I just re-checked and still get 4.66.




S Bolton said:


> Roger Gifkins replied to my email and said it was 3.9 mm and he tried to talk the manufacturer into making it smaller. 3.9 mm would be about 5/32 of an inch I think. Bobj3, do you have the smallest Gifkins template?
> 
> sb


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## S Bolton (Mar 5, 2007)

Bob, you have the TGHD 12 dovetail bit and it is 4.66 mm in the smallest portion of the bit? You use the smallest template?

sb


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## bobj3 (Jan 17, 2006)

Hi SB



I'm not sure if you are asking me or not BUT
http://www.routerforums.com/59572-post4.html

The bit I have is not made by Gifkins it's one of a set I got off eBay.

"You use the smallest template?" = Yes

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S Bolton said:


> Bob, you have the TGHD 12 dovetail bit and it is 4.66 mm in the smallest portion of the bit? You use the smallest template?
> 
> sb


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## Roefa (Sep 14, 2007)

Re 1st reply to post :
"Bottom Line: 4 mm or about 15/32". If you need and answer fast, 
I'm posting this now... " was a typo 5/32 not 15/32!
I had it right on paper and typed it wrong ... 
*sheepish grin* Sorry! I typed it correctly on the next post. 
We did get to the answers eventually anyway. Fun !

Roger


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## S Bolton (Mar 5, 2007)

Acutally I mean Bob N. But all replys have been interesting.

I feel very attracted to the ease of the Gifkins. I bought a Marc Sommerfeld DVD and I think he was using the Katie. Both jigs seem quite similar.

Oh well, have to do some thinking.

sb


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## Bob N (Oct 12, 2004)

Steve,

I was running late this morning and did not have time to answer your email. I will send you a reply when I get in later today.


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## bobj3 (Jan 17, 2006)

Hi SB

The bits below will work in the Katie,Gifkins,MLCS,and some of the HF type jigs..

At about 1/3 of the Mfg.price for the bits.. 

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