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mklotz
05-02-2007, 10:44 AM
Chuck spiders can take many forms. This one consists of a 1/4" aluminum plate that slips over the jaws of the chuck. Spacers of different heights (two sets are shown in the photo) hold the plate away from the chuck front surface at the desired distance.

http://i81.photobucket.com/albums/j234/mklotz/tools/shop010.jpg (http://s81.photobucket.com/user/mklotz/media/tools/shop010.jpg.html)

The advantage of this type of spider is that thin workpieces are fully supported and less likely to deflect away from the cutting tool's pressure.

Lest the safety Nazis get upset, the spacers have tenons that fit into holes in the spider plate, thus making it impossible for them to come free when the chuck is rotating.

BadDog
05-02-2007, 11:18 AM
Tell me that's not all brass? I can't imagine making stuff like that out of brass with current prices. I any case, nice work. I may have to make something like that from aluminum. But being me, it won't be till I need it. Still, better than face cutting my soft jaws, and not having pie jaws, still leaving most of the plate unsupported.

mklotz
05-02-2007, 11:28 AM
No, it's aluminum. The warm color is an artifact of the incandescent lighting used to take the picture.

pcarpenter
05-02-2007, 11:42 AM
Marv-- thats simple but ingenious and I am grateful for the tip. I have that on a long list of tooling to make. I was going to make about 3-4 traditional looking chuck spacers but this could cut the work immensely and make it easy to make a custom thickness as needed by merely making another set of spacer buttons.

I have seen an idea for a sort of spindle plug with an adjustable center rod shown here before. What other means do you guys use for say facing off cut washers? It would be neat to see some of the variety of ways of hanging on to and holding parallel various thin objects. I've seen round magnetic chucks....are these really a viable option for holding something you want to face off like that? A lathe makes a lot of force compared to say a grinder.

Paul

mklotz
05-02-2007, 12:00 PM
Marv-- thats simple but ingenious and I am grateful for the tip. I have that on a long list of tooling to make. I was going to make about 3-4 traditional looking chuck spacers but this could cut the work immensely and make it easy to make a custom thickness as needed by merely making another set of spacer buttons.

I have seen an idea for a sort of spindle plug with an adjustable center rod shown here before. What other means do you guys use for say facing off cut washers? It would be neat to see some of the variety of ways of hanging on to and holding parallel various thin objects. I've seen round magnetic chucks....are these really a viable option for holding something you want to face off like that? A lathe makes a lot of force compared to say a grinder.

Paul

Before I made a collet chuck and gained the ability to use pot chucks, I made my own pot chucks from aluminum rod stock. These had an unslotted section that was held in the chuck and a hose clamp was used to force the three slotted jaws together to grasp the workpiece. I still use that technique for certain oddly shaped parts.

Supergluing or soldering washer shapes to a backplate works fairly well. Keep in mind that superglue has little shear strength so initially rough workpiece surfaces will require very fine cuts.

Mcgyver
05-02-2007, 01:14 PM
i've made them from solid but like your idea of adjustable depth, good one

RPease
05-02-2007, 01:31 PM
Marv..........Help me out.........I'm having a "brain freeze"......

How does the "thin workpiece" mount to the "spider"??

Can you show an example......like maybe mounted to a chuck? I'm have difficulty "picturing" it in operation.

Thanks and best regards.........Rodg

mklotz
05-02-2007, 01:41 PM
Marv..........Help me out.........I'm having a "brain freeze"......

How does the "thin workpiece" mount to the "spider"??

Can you show an example......like maybe mounted to a chuck? I'm have difficulty "picturing" it in operation.

Thanks and best regards.........Rodg

When the spider is mounted on the chuck, the spacers hold the surface of the spider close to the outer edges of the jaws. It's analogous to moving the face of the chuck forward (or alternatively, grinding most of the jaw away). The work is pressed against the spider plate and the jaws are clamped down on the work in the ordinary fashion.

RPease
05-02-2007, 01:49 PM
Thanks Marv...........I understand now..........The actual
facts just seemed to evade me for a while...........It's HELL to get old............I'm lucky I can find the floor when I get up in the morning..........If it wasn't "hard", I probably wouldn't recognize it.............LOL

Regards...........Rodg

cybor462
05-02-2007, 01:56 PM
I too am a bit slow these days. I was hoping for a pic in action as well but the details I hope I have grasped. Basically the spider is a work stop? Allows for a flush backstop to hold the work squarely.

Am I on target or off the map?

Scishopguy
05-02-2007, 01:57 PM
Marv,

That is a great little tool. I was wondering if it would be worth tapping the centers of the spacers and putting a stud (#10-32?) that screwed into threaded holes in the spider plate. You could make thin shims or washers to make the fine adjustments to the depth from the face of the chuck. I have also added this to the ever growing list of tooling that I need to make. I am always having to chuck up washers to bore out or make spacers. This will be a great help.

Thanks,

mklotz
05-02-2007, 02:13 PM
Cybor: Yes, you've got the idea.

Scishop: I thought of threaded stops when I made it but dismissed the idea because I didn't want to have to fiddle with it each time I used it.

However, I threw this up for the idea. There's no law that says you have to duplicate my design. That's the beauty of the informality of this hobby.

pcarpenter
05-02-2007, 02:33 PM
Marv-- as I stare at your design further, it looks a bit like the squarish bottom of the jaw "slots" may restrict just how far closed the chuck can go with the spider in place. As I stare at it however, I wonder if the plate would have enough strength if you were either to cut the jaw slots deeper (leaving square) or make them v-shaped at the bottom. On the other hand, its a bit hard for me to tell much about scale so maybe I am wrong. The only dimension I know is that the plate is 1/4" thick and that's a hard one to translate to the rest of the picture.

Paul

mklotz
05-02-2007, 02:53 PM
Paul,

Yes, it has a minimum size workpiece limitation due to how far the jaws can close. I have other spiders and pot chucks that accommodate workpieces smaller than this minimum size.

This design is meant for somewhat larger items, most especially flywheels for small engines.

mklotz
05-02-2007, 04:44 PM
Ok, for the visualization impaired :), here's a picture of the spider mounted on the chuck. Normally, the workpiece would be thinner than the one shown, but that was lying around to hand so I used it.

http://i81.photobucket.com/albums/j234/mklotz/tools/spider-1.jpg (http://s81.photobucket.com/user/mklotz/media/tools/spider-1.jpg.html)

miker
05-02-2007, 05:02 PM
"Ok, for the visualization impaired "

I ressemble that remark!! :)

Thanks for the pic Marv.

Rgds

tattoomike68
05-02-2007, 05:17 PM
Ok, for the visualization impaired :), here's a picture of the spider mounted on the chuck. Normally, the workpiece would be thinner than the one shown, but that was lying around to hand so I used it.

http://i81.photobucket.com/albums/j234/mklotz/spider.jpg

I like the little chuck wrench in the picture, thats a slick idea too.

Bill Pace
05-02-2007, 05:33 PM
Yep, youre just full of em, --- tried to slip that neat little chuck wrench right by us didnt ya!! But being the sharp eyed machinists we are, we spotted it right away, hah!........course we WERE having trouble visualizing the spider set-up----

madman
05-02-2007, 05:57 PM
Instead of spacers of aluminumn how bout spacers out of magnets ground flat after assembly. They stick to chuck nicely. Just a thought Mike aka Madman

pcarpenter
05-02-2007, 06:06 PM
Hmmm....grinding magnets...now that sounds messy:D

Still, there is no reason that the spacer "knobs" couldn't include a magnet inset on the chuck side (with no need for grinding). The Royal branded chuck spacers of the more standard variety have magnets imbedded in them. A design for that type was in a recent edition of one of the magazines. I still like Marv's design....you could make those spacer knobs any size you want and only make one plate. My only reservation is with the ability to hold something small diameter.

paul

mklotz
05-02-2007, 06:07 PM
I change jaws, remove jaws to clean scroll, and do complex setups with the chuck on the bench. I have a spinner on the regular chuck wrench but the arms are too long and hit the bench top so something shorter is needed for bench work.

There are matching cranks for the four jaw chucks too.

BobWarfield
05-02-2007, 07:22 PM
Nice design Marv!

For those who want piccies of the Royal chuck spiders (which they call "chuck stops" incidentally), read all about them here:

http://www.royalprod.com/img/category/upload/Page_091.pdf

When you see the price, you will instantly see Marv's wisdom for the home shop.

I'd be tempted to bore those spacers for magnets though. If made of something magnetic, this would also help keep them together as you're assembling them onto the chuck with your workpiece, though if they thread into the spider, that works too.

In any event, I like it!

Now here is a puzzle for ye, something a friend used to call a brain-fart because its a half-formed notion and not necessarily a good idea. I saw your little chuck key, and I do very much like it too. For some reason, I immediately flashed on the idea of a chuck key for 4-jaws that turns opposite keys in unison to make dialing in easier.

Anyone ever see a gizmo like that?

Best,

BW

mklotz
05-02-2007, 07:31 PM
No, but I always make a second chuck key for any 4jaw I have to use. It's so much easier to be able to move two jaws back and forth with two hands.

Fasttrack
05-02-2007, 07:59 PM
"Marv-- thats simple but ingenious and I am grateful for the tip. I have that on a long list of tooling to make. I was going to make about 3-4 traditional looking chuck spacers but this could cut the work immensely and make it easy to make a custom thickness as needed by merely making another set of spacer buttons."



Ditto here - i saw plans in a home shop machinist magazine, but they included casting a blank from aluminum. I though "hah yeah right" :D

I saw the magnet thing in that same article, interesting idea...






Also ditto on the nice chuck wrench - that is great. I think i will make one of those. This has been a most inspirational thread! :D

JRouche
05-03-2007, 01:02 AM
Marv....Another useful tool outta the labratories of Mr. Klotz..Thanks for sharin..JRouche

Alguy
05-03-2007, 02:25 AM
I read the HSM article too , I had no idea what they were for, now i do.
In past when i had to face something small i fiddled cobbled something togeather not alwys with good results. This is lot simpler than the hsm article.

Oldguy
05-03-2007, 04:07 AM
For those who want to use this with smaller parts, make each slot a closed ended rectangle and move the inner end closer to the center point. You could make one of each type and share the spacers between them.

Lots of good ideas. Thanks for the inspiration Marv.

Glenn

John Stevenson
05-03-2007, 04:22 AM
Not as simple as Marv's idea but a variation to do the same job.

http://homepage.ntlworld.com/stevenson.engineers/lsteve/hidden/hexjaws1.jpg

Mild steel hex pieces screwed onto a set of soft jaws.
With 6 sides and three sets of location holes you get 18 unique setups.

http://homepage.ntlworld.com/stevenson.engineers/lsteve/hidden/hexjaws2.jpg


By numbering the jaws and keeping a chart of placing and holes you can quickly rest to hole different jobs.
The pics were taken when I first did these and only one corner of the hex's has been machined but currently I now have about three sets.

One set has been screwed tight and then drilled, bored and tapped in common sizes as i can hold on threads without damaging.
One jaw has been bored and then opened up behind so I can hold some very short clevis pins for reworking.

They take a bit of initial machining but soon pay off, what would 18 sets of soft jaws cost ? or even if remachined how long would they last ?

.

cmiller231
05-03-2007, 09:12 AM
Marv ;Great idea , I like it Chris

Scishopguy
05-03-2007, 11:57 AM
Marv,

As for the issue of holding smaller diameter washers and such, you could make a spider plate that was connected on the outer edge and open in the center. I was thinking about this and just had one of those "DUH" moments. This has been a very thought provoking thread.

Thanks for the inspiration.

pcarpenter
05-03-2007, 12:13 PM
It has indeed been thougt provoking. I like Marv's idea and may go that route for something that would hold thin, larger diameter stuff. I *really* like your idea John...but alas I compromised on my deisre to get a chuck with two-piece jaws and now I regret my decision.

I still keep thinking about how to make them so they would hold smaller stuff and kept going back to the Royal design. Then, last night I took a look at my 7.something inch three-jaw chuck. I have a d1-4 camlock spindle and this chuck is really a plain-back chuck on a D1-4 backing plate. If you have another chuck mounting method, don't tune out yet as this could apply to others of similar construction.

I noticed that the bore in the backing plate is at least as big as the spindle bore (as you would want it) , but not as large as the bore in the center of the chuck. In a sense, this forms a sort of "pocket" behind the jaws. My idea is to turn a plug that would drop into this pocket and precisely long enough that the back side of the chuck jaws (the thread-ground face) would trap the plug as you close the jaws. This plug could have a center hole that is threaded and into that you could screw various length or diameter spacer plugs....down to some pretty small diameters. These could even be made up quickly to any needed size with a small scrap of round bar and a die to thread the back end.

I took a picture of the chuck last night so I could post it but its not here now. I am hoping the description is adequate. I really wanted to run the idea past others here so they could check my thinking for safety and functionality. Its a variation on a theme I saw here some time back that involved a split tube with a wedge-type fit in the spindle bore. Same deal there...you ran it into the spindle bore and locked it and then threaded pieces into it cut to length to serve as a stop.

Paul

h12721
05-03-2007, 10:13 PM
<< I have seen an idea for a sort of spindle plug with an adjustable center rod shown here before.>>

What would this ting look like?
Hilmar.

Ausserdog
05-04-2007, 01:10 PM
Geez Marv -
You post a really neat solution to something I've wanted to do for a while - just before I go on vacation. Now I won't be able to enjoy vacation because this will be on my mind the whole time. Thanks a lot! :D

I like Oldguy's and Scishopguy's solution to the small diameter issue. And the magnets.

Dang. I hate you all. Vacation's ruined.
Keep the ideas coming! :D

lazlo
05-04-2007, 05:58 PM
Not as simple as Marv's idea but a variation to do the same job.

Mild steel hex pieces screwed onto a set of soft jaws.
With 6 sides and three sets of location holes you get 18 unique setups.


Very cool idea John! I especially like that you can set the three jaws asymmetrically for odd-shaped parts, like a casting.
So 18 positions on each jaw x 3 = 54 different setups.

The only downside that I see is that you have to drill the bottom jaws. Can they still grip the normal two-piece top jaws
with those holes drilled in them?