Marking out a PCD using dividers - the old-fashioned way

Marking and layout of engineering pitch-circle-diameter (PCD) bolt hole circles using the old-fashioned method using a set of dividers (or compasses)

[@EvoKeremidarov]

The radius of the circle divides the circle into 6 even parts.. I was playing with my divider once and totally by accident discovered that.. I'm sure people a lot more clever than me have known this for centuries but I felt quite proud of my little own light bulb moment..

[@y2ksw1]

If you found out by yourself, you are a clever b***d 😄

[@zanezakai5240]

You probably dont give a damn but does any of you know of a way to log back into an Instagram account? I stupidly lost my account password. I love any tricks you can give me!

[@colecase7537]

@Zane Zakai Instablaster =)

[@zanezakai5240]

@Cole Case i really appreciate your reply. I got to the site thru google and I'm trying it out now. Takes a while so I will reply here later when my account password hopefully is recovered.

[@zanezakai5240]

@Cole Case it did the trick and I now got access to my account again. I am so happy:D Thanks so much, you really help me out!

[@stevo3644]

Exactly what I need for marking out a PCD of 114.3 mm and 5 equally spaced 13mm holes without all the bs. You sir are a legend !

[@AdeSwash]

Thank you Stephen, regards Ade

[@LatheBits]

The simplest ideas are always the best. Thank you.

[@terrybailey2769]

Hi Ade, You don't need to do any of the tweeking, if you scribe the radius of the circle from the centre with the dividers and then chose your starting point, without adjusting the dividers they will step around the circumference exactly 6 times. Its a well known geometrical construction. If you want just 3 points then use each alternate mark.

[@oh8wingman]

You got it. They teach this in most trade schools in the first year.

[@aries6776]

Even simpler! Thanks for sharing.

[@MechInvent]

I NEVER have luck with this. Why not ??

[@robertlewis4666]

Lovely! No batteries to go flat when needed most, no expensive reference books, no complicated hi tech tooling....the list goes on and on. Shows we can exist without all the new age B.S. Nice one thanks for posting!

[@AdeSwash]

Thanks Robert, I wonder what victorian engineers would have made of an iphone

[@robertlewis4666]

@@AdeSwash Probable wonder why the hell we need one.

[@gordonyoud5975]

Where have you been all my life? I wish I had known about this simple "no math" technique. 😢❤👍

[@Laya077]

I'm India working Kuwait oil company ship maintenance work my whatapp namber [phone] welder

[@pauln1557]

Excellent! Many of us newbies to home machining never had basic training in the use of simple workshop equipment like this. Regards Paul in NZ

[@AdeSwash]

Glad it was helpful Paul :)

[@aries6776]

So simple and elegant. Thanks for sharing.

[@samcoote9653]

Hi Ade, love the humour and really well explained ideas in your videos, thanks so much for all the hard work, love it all, cheers, Sam

[@AdeSwash]

Thanks Sam :) Regards. Ade

[@pritpalsingh4729]

Very happy to learn PCD finding with help of diveder. Thanks sir

[@AdeSwash]

Thanks and welcome

[@bustednuckles2]

This is a great video. I have now watched several of your videos, I thought for a while that you were new to me until I stumbled back on to your 4X6 horizontal bandsaw modification vid. I had actually seen that a few months ago when I finally bought one. You do some real pretty work sir and I enjoy your easy going teaching method. I added you to my long list of subscriptions.

[@AdeSwash]

Thank you Phil

[@VintageGearMan]

I have a beautiful set of vintage 3" Starrett dividers coming in next week.

[@AccidentalScience]

Beautifully narrated useful information. Thank you.

[@davespringate5469]

Thanks Ade nice simple technique just what i need being new to this hobby

[@VintageGearMan]

A massive thank you sir!

[@Dj688toneo]

Thank you so much Ade i would be using your way to make my Schmidt coupling part, hope that went well😅

[@CleaveMountaineering]

great trick, I didn't know that one. for a 6 hole or a 3 hole, you can also set your circle radius, scribe the radius. The edges of the hexagon are the same as the radius. So just walk that around the circle. If you only want 3 holes, just drill the 3 you want. But this trick works for any number of holes I suppose~!

[@AdeSwash]

Yep. any number, up to infinity :)

[@johnkinnane547]

G'day Ade your work bench looks like mine, it's interesting you using the old callipers I have a set of DRO on the mill and lathe and I sometimes still use the old way, especially locking in measurements. Thanks for the vlog regards John

[@AdeSwash]

Hi John and thanks for the comment on my video, I have a DRO on my mill but it is cheap and I find it unreliable, so I rely on the old fashioned ways to work things to my needs, and at least this way I can guarantee the precision. Kindest Regards. Ade.

[@jmtx.]

Low-tech at it's best. Thanks for sharing.

[@butterflywing61]

Liked your narration!

[@AdeSwash]

Thank you :)

[@butterflywing61]

@@AdeSwash That 55 Degree tool is for Whitworth thread right? For years us kids couldn't figure out why our North American screws wouldn't work with our Meccano square nuts! :)

[@MrApmotos]

happy to find you with this video

[@SalopianBivvyman]

Genius 👌I’ll throw away my dividing machine, only wanted it for holes!

[@PrussianRedWhiteBlue]

exactly what I needed. Thanks!!

[@AdeSwash]

Glad it helped!

[@larrybarnes3920]

This is how I was taught when I did my time.

[@raymondmarteene7047]

Thanks ADE, Simple explanation well done They say a tidy work space is the sign of a sick mind........mmm easy peasy lemon squeezy?? 😂 Cheers Raymond

[@damienlepan3914]

Good shot saves time I value the advice.

[@AdeSwash]

Thanks Damien :)

[@jeromegutierrez4149]

Learned a lot from this video the i hate doing the math ,

[@AdeSwash]

Thanks Jerome, Regards Ade

[@stanwardoshiro]

This is ultra amazing!!!!

[@AdeSwash]

Simplicity in it's finest, Thanks for watching, Regards, Ade

[@arccraft8583]

this video very informative,tq sir!!

[@AdeSwash]

You are welcome

[@hobbyelectronics6630]

Excellent !

[@tiggywinkle1000]

"Have to tidy up 'round here. Now where's my airline?" And promptly blows swarf all over the place!

[@AdeSwash]

Hell yeah!

[@Man-in-da-shed]

Well explained , as for your bench you must have a better compressor than mine, loved the comedy element

[@EvoKeremidarov]

thank you

[@anuragpandey1455]

Thank you so much for the informative video. How to do the pcd marking on a larger gear wheels of 800 mm diameter. It would be really helpful if you can tell what tools can be used?

[@karlleber7003]

Are there any plans for this, i could print out? Do you have a link? Kind regards

[@jamescole3152]

I love it. But not all of us have a lathe. You could have done the whole thing with the divider if you could find the center.

[@TheGentlemensMotorRacingTeam]

amazing thank you

[@y2ksw1]

We learned that at school.

[@sunnyswazz5876]

Hi there, what happens if your divider dosent go back to refrence point or slightly off what do you adjust

[@AdeSwash]

Hi Sunny, you adjust the divider until it does go to the reference point, only then is it set correct

[@abdulnafeez1259]

divider

[@neiljarvis8911]

Great video but not quite as lemon sqeezy when there are 5🤣!

[@AdeSwash]

It's the same process from 2 to infinity

[@staceynico]

Put back in lathe and scribe using tool, rotate job 120 degree scribe again then repeat?

[@AdeSwash]

How to get precise 120 degree rotation in a lathe without index?

[@Ropetangler]

@@AdeSwash 3 jaw chuck could be used as an accurate index, that said, I really liked your approach to this subject, and the video that you did on using a boring head for ball turning. Have only just found your channel, have subbed and look forward to seeing more of your work. Thank you for all your hard work and the time that you must have put in.

[@ronnieg6358]

I guess this would work for 5 holes too. Don't reply, I'll just try it.

[@AdeSwash]

To infinity - and beyond! ;)

[@y2ksw1]

For any number but 1 or 2.

[@riderlife2571]

❤❤❤❤❤❤❤❤❤😍😍😍😍😍😍😍😍😍😍😍🤩🤩🤩🤩🤩🤩🤩

[@stevehuntley3089]

Or you could just look up the chord length in Machinery's Handbook...

[@AdeSwash]

What page is that info on Steve? would be handy to know

[@aries6776]

Or just use this formula: sin(DEG/2)*2, where DEG is 360/n, with n is the number of holes. Then multiple the result by your radius to give the chord length.

[@grahamwhite1656]

Seven holes? Five holes? Odd numbers are a bit more difficult.

[@AdeSwash]

Actually Graham White, they are not, you can walk any number of points, from two to infinity- and beyond!

[@pommeran211]

vẽ 6 đỉnh lục giác sao kém vậy.vẽ 6 đỉnh thì được luôn 3 đỉnh thôi

[@terrytibs1977]

Such bad practice using your Vernier callipers as a scribe.

[@AdeSwash]

They are my vernier scribes, its their job!

[@larryphelan7122]

Anyone who can,t do that should not be in a workshop to begin with. Six year old,s can do that,it,s no big deal.

[@AdeSwash]

@larry phelan, six year old's also know the difference between apostrophes and commas, just sayin' ;)