Dividing head problem with angles.

[Brian AbbottParticipant @brianabbott67793]

Hello all.

I apologies if this subject has already being covered.

I own a small vertex 6” dividing table ( HV6 I think ) and am looking for a way to be able to use the 3 supplied plates to turn the table a certain angle..

Ie.. how many turns + holes to rotate the table say 33.5° or can I not be that exact ?

Maths is not my strongest subject so ideally a simple solution if there is one..

Thanks in advance.

Brian

[Brian AbbottParticipant @brianabbott67793]

[D HannaParticipant @dhanna35823]

1 turn of crank on your Vertex = 4 deg = 240 minutes

33.5 deg = 2010 minutes

Turns of crank = minutes/240 = 2010/240 = 8 3/8

3/8 =6/16

You have a 16 hole plate

8 complete turns of crank+ 6 spaces in 16 hole circle = 33.5 deg exactly

Note: that will be 7 holes between sector arms on your 16 hole plate

 

Hope that helps

Edited By D Hanna on 17/10/2016 13:16:04

[SillyOldDufferModerator @sillyoldduffer]

Not sure if I'm answering the question but this site (search 'HV6' has a link to this table.

I'm too busy at the moment to think about how to calculate angles like 33.5 degrees but I'm sure it's possible provided there's actually an approximation close enough given a particular table and wheels.

If no-one else can provide the answer I'll have a go later.

edit: And D Hanna posted the answer while I was typing!

Dave

Edited By SillyOldDuffer on 17/10/2016 13:13:01

[Brian AbbottParticipant @brianabbott67793]

Thanks both for replying, understand now what i need to do.

[Brian AbbottParticipant @brianabbott67793]

Hello all.

Could i ask for some advice please.

Based on the info above, I need to rotate the table 3.6 deg.

is this 18 holes in a 20 hole plate?

Thanks

[Martin ConnellyParticipant @martinconnelly55370]

If your table does 1 revolution for 90 handle turns then yes. One handle turn is 4 degrees, 3.6 degrees is 90% of this. Any set of holes that allow you to use 90% of them will work. 18 of 20, 27 of 30, 36 of 40. Use whatever is available to you, small numbers are less error prone, 9 of 10 being the easiest but it's an unlikely hole count in a set of dividing plates.

Martin C

[JasonBModerator @jasonb]

Posted by Brian Abbott on 06/04/2020 23:14:23:

Based on the info above, I need to rotate the table 3.6 deg.

is this 18 holes in a 20 hole plate?

Yes, 18/20 x 4 = 3.6

[Brian AbbottParticipant @brianabbott67793]

Thanks both.

[Howard LewisParticipant @howardlewis46836]

If you need to rotate the table by a set number of degrees, I would suggest that you do not try mixing degrees and use of division plates, for fear of confusing yourself.

The Division Plates and an accurate chart will make it easy to produce the number of divisions that you want, IF it is possible with the three plates supplied with the HV6.

Use one of two methods.

Either use the vernier scale on the handlewheel, and work in degrees;

OR

Divide the required number of degrees into 360. That will tell you how many divisions are required. Then use the Division Plates to produce that number of divisions (Angular spacing )

I made up an EXCEL spreadsheet which tells me if that number of divisions is possible with the Division Plates for the HV6. When an extra number of divisions is needed, the required number is added to the spreadsheet, and hopefully a set number of Turns and a whole number of Holes results. If this does not happen, then that number of divisions is not possible with any of the three plates supplied.

One day I will get around to making at least one extra plate to increase the number of divisions possible.The road to hell is paved with good intentions!

Recently I needed a whole number of turns and 10.04 holes for a job. I decided that when the error had been reduced by a factor 90, I could live with the discrepancy!

ONE WORD OF WARNING

If you have a fairly old HV6, the supplied chart contains errors, and omissions. I found 8, hence the spreadsheet. I wasted a week trying to produce a 13T gear, but kept getting 12 thin teeth and one fat one. For a while it seemed that I could not count. Eventually, I made up the spreadsheet, and the errors came to light.

Needless to say, one of the errors was for the 13 divisions that I wanted!

H T H

Howard

 

Edited By Howard Lewis on 07/04/2020 21:48:10

[Brian AbbottParticipant @brianabbott67793]

Hello Howard, thanks for the reply and my apologies for the delay it coming back to you.

I have downloaded a copy of your table now and all seems to be working out ok ( on the second attempt )

I can see a world or ward on the horizon i think.

Thanks again,

Brian

[Howard LewisParticipant @howardlewis46836]

Brian,

Am glad that you have now got things sorted out. Another window opening onto the world of model engineering!

Keep mat it!

Howard

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