Author Topic: A quickie 'Nudger'  (Read 13178 times)

Offline Bogstandard

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A quickie 'Nudger'
« on: February 25, 2011, 05:20:14 PM »
This is by no means my idea, I saw one demonstrated a few years back and decided it would go onto my tuit list

Up until now I have used a bit of hardwood mounted into a toolholder, but decided the other day I needed to make a proper one.


The things required were a lump of bar that will stick out either side of the toolholder (if using a QCTP) or you would make it single ended if using a normal toolpost, a couple of reasonable sized ball races, mine were 3/4" diameter, a couple of bolts, mine were 6mm, you need something fairly substantial to take the strain, and a bit of bar to make the top hat spacers from.
The bar was cut down for a nice fit in my toolholder, 16mm square. It was then machined down by the thickness of the bearings and across by about 3/4 their diameter

The top hats were made to a couple of thou longer on the part that goes thru the bearing and the flange was just larger than the diameter on the bolt heads. It was drilled thru the middle 6mm, to fit the bolt. You could use two top hats for each bearing, as long as they didn't meet in the middle. Anything to stop the bearing becoming 'trapped'.

Holes were drilled and tapped 6mm in the position where the bearing didn't quite hit the back shoulder and hung out of the end of the recess, half way across the width of the square bar.

It was more difficult to describe it than make it. Just have it so the bearings stick over the end bit. I also reduced the thickness of the bolt head to about half, just to give a little more room if things get tight.




This is how it should look when assembled.




Mounted in the toolholder, with a bearing either side.

It should be set to centre height when working, but I am showing how it is used.

With the part mounted into or onto the chuck, with the jaws just 'tweaked' tight, the ball race is brought into contact with the face that requires straightening up. With a slight nudge from the tool, the part should move into a much truer running position, then you tighten up the jaws. If say you were holding a disc in the jaws, by nudging, you should be able to get it running fairly true, if not spot on.




By swinging the toolholder the other way, the other ballrace can be brought into operation to true up those wobbly bits of metal held in the jaws, before fully tightening up.




Please don't try it with square or hex bar, it won't work very well.


Bogs
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Rob.Wilson

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Re: A quickie 'Nudger'
« Reply #1 on: February 25, 2011, 05:28:24 PM »
Hi John  :thumbup:


I must get around to making one  :dremel: 


Rob

Offline doubleboost

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Re: A quickie 'Nudger'
« Reply #2 on: February 25, 2011, 05:45:31 PM »
mine is just a bearing pressed on to a silver steel bar
it has a paint mark on it so it can be used as a edge finder on the mill (once it touches the job it stops spinning )
works great

Offline doubleboost

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Re: A quickie 'Nudger'
« Reply #3 on: February 25, 2011, 06:14:59 PM »

Offline Bogstandard

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Re: A quickie 'Nudger'
« Reply #4 on: February 26, 2011, 12:18:57 AM »
Any which way John, as usual, I think mine, most probably, is a little over engineered.

As long as it does the job.


John
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Offline Brass_Machine

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Re: A quickie 'Nudger'
« Reply #5 on: February 26, 2011, 12:40:08 AM »
Nice looking 'nudger' Bogs. I have one like DB's that I salved from a gear/belt swap. I am going to make one like yours... I like the way it looks.


Eric
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Offline raynerd

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Re: A quickie 'Nudger'
« Reply #6 on: February 26, 2011, 03:46:46 AM »
John, I made one of these and posted about it a few months ago. I use mine a lot but your design is much much better. Mine works just fine but the large nut on mine has once got in the way so I may make another to your design.

http://madmodder.net/index.php?topic=3455.0   (http://www.raynerd.co.uk/?p=689)

I`ve just had a look at the madmodder link and cidrontmg's tool was also a great design!

Offline Bogstandard

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Re: A quickie 'Nudger'
« Reply #7 on: February 26, 2011, 04:49:58 AM »
I said that mine wasn't my own idea, if it is good, I will pinch it. Why waste brainpower when somebody has already done so.

I think the only advantage mine has over others is that it doesn't need to be removed from the toolholder at all if you use a QCTP, just swap it to a different position on the toolpost to get both types of nudges.


Bogs
If you don't try it, you will never know if you can do it.

Location - Crewe, Cheshire

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Offline krv3000

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Re: A quickie 'Nudger'
« Reply #8 on: February 26, 2011, 03:14:37 PM »
thats a good tool tip    :nrocks:

Offline Jasonb

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Re: A quickie 'Nudger'
« Reply #9 on: February 26, 2011, 03:42:32 PM »
John, just a query on the tophats. If the part that goes through the bearing is longer than the bearing width is there not the risk of the inner race turning on the tophat? in which case just a steel disc would do the same job, The two tophat method would clamp the race tight. If the tophat were a thou or two less than the bearing it would clamp the inner race firm regardless of any poor fit (not by you) between race and tophat, obviously the flange would need to be on the bar side to stop the outer race rubbing on the bar.

On spoked flywheels I prefer to set the spoke ends to run as true as possible and then machine the rim to them, I find this gives better results than setting one side of the rim true as the back face can be well off, whereas setting to the spokes usually averages out any irregularities in the rim.

J

Offline saw

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Re: A quickie 'Nudger'
« Reply #10 on: February 26, 2011, 03:52:24 PM »
I must find some time to do a tool like that.  :jaw:
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Offline Bogstandard

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Re: A quickie 'Nudger'
« Reply #11 on: February 26, 2011, 05:28:39 PM »
Jason,

I forgot to add that my tophats had a drop of loctite on them. But it wouldn't really matter if the inner did turn a bit. It is the extra couple of thou that is the important part.

I had to use some sort of spacer in the middle anyway, as the thru hole was 3/8" whereas my fixings were only 6mm, so a tophat was the easiest way for me to go.

The main problem is that inner and outer races are invariably the same width, so if the inner race is tightened down onto say a fairly rough machined surface, then the surface under the inner race could collapse even a tiny amount, 1 thou would be enough to cause problems, that then allows the free outer race to bind up on the surface. Hence the need to keep the inner race slightly higher.

The flywheel is already done.

BTW, I never trust spokes at all, they can be almost anywhere, especially if they are tapered like mine were, and can easily dressed up if they are out anyway.


John
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Offline jmshep

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Re: A quickie 'Nudger'
« Reply #12 on: February 28, 2011, 09:14:27 AM »
Made a single ended version similar to Bogs today and already don't know how I have managed so long without one.
Thanks for the inspiration.

John S

Offline PekkaNF

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Re: A quickie 'Nudger'
« Reply #13 on: March 18, 2017, 06:44:56 PM »
Too little pictures here....

Nudger and a diamond dust roller.

Pekka

Offline PeterE

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Re: A quickie 'Nudger'
« Reply #14 on: March 19, 2017, 04:29:15 AM »
My version:

 


/Peter

<edit> Un-necessarily large images now replaced by a couple of smaller ones.</edit>
« Last Edit: March 19, 2017, 10:41:44 AM by PeterE »
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Offline awemawson

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Re: A quickie 'Nudger'
« Reply #15 on: March 19, 2017, 04:58:35 AM »
I saw John Doubleboost use one in one of his videos some while back and it prompted me to make one. Considering how trivially easy they are to make it is one of the most useful simple tools I have near the lathe.

He also showed a bearing mounted on the end of a round bar, as a simple edge finder - brilliant - so simple to use in the milling machine :clap:

All power to your elbow John  :bow:

Andrew Mawson
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Offline PekkaNF

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Re: A quickie 'Nudger'
« Reply #16 on: March 19, 2017, 05:41:17 AM »
I saw John Doubleboost use one in one of his videos some while back and it prompted me to make one. Considering how trivially easy they are to make it is one of the most useful simple tools I have near the lathe.

He also showed a bearing mounted on the end of a round bar, as a simple edge finder - brilliant - so simple to use in the milling machine :clap:

All power to your elbow John  :bow:

Peter, nice one!

Andrew, how it used on the milling machine? Like edgefinder? When bearing rotates, you are 1/2 OD way off center?

I wanted to avoid using screws, ended up making it press tight. Probably have to use glue if I ever disassemble it. made shoulder for inner race.

Pekka

Offline mechman48

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Re: A quickie 'Nudger'
« Reply #17 on: March 19, 2017, 06:50:26 AM »
Too little pictures here....

Nudger and a diamond dust roller.

Pekka

Must have brain fade this morning... Nudger, I have one... diamond dust roller... please explain :scratch: ?

George.
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Offline seadog

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Re: A quickie 'Nudger'
« Reply #18 on: March 19, 2017, 07:39:32 AM »
My simpler version.

Well it would be if I could post the image. Not letting me  :Doh:

Offline Sid_Vicious

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Re: A quickie 'Nudger'
« Reply #19 on: March 19, 2017, 07:51:47 AM »
@Mechman 48 With diamond dust roller I think he refers to an earlier post of using diamond grit as an lapping compound...
Nothing is impossible, it just take more time to figure out.

Offline PekkaNF

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Re: A quickie 'Nudger'
« Reply #20 on: March 19, 2017, 09:01:03 AM »
Yesh....You need some very hard material to pres the grit on softer lap. Often carbide rod is used to charge copper lap. Rotating cast iron lap is easiest charged with a roller type. Ball bearing is much harder than cast iron, it charges lap pretty easy.

Pekka