Modified 'Spindex'

[jhe.1973]

Hi Everyone,

This is just a quick post to show that I have not fallen off the earth! I was all set to post this in the 'Shop Made Tools' thread & then I thought that it would be better here seeing as how I may not be able to get back here on a regular basis for progress reports etc.

I never liked the ‘spindex’ fixtures because the index plate is so close to the spindle nose & it is often in the way of the milling/grinding spindle. I always thought that they were designed backwards for the small stuff I often do.

Long ago I had the idea of turning the spindle around, but finally had the chance to do it & incorporate a dividing worm while I am at it.

Here it is before the worm wheel/index assembly is pushed all the way on:



I also slotted the top & added the clamp screws so that the center height doesn’t change when clamped. In the new front there is a needle thrust bearing w/hardened washers. This is covered with an aluminum cover sealed with an O-ring.

The back of the spindle is threaded for a bearing adjusting nut so can I obtain zero endplay:



After today’s work, this mock-up shows the how the worm will engage the worm wheel:



This is a photo of the CAD drawing to show how the mounting bracket for the worm will allow it to be disengaged for quick spacing with the index plate. I change the drawing as I make & fit the items:



This setup is going on a small horizontal mill for cutting clock gears & I didn’t want the heavy dividing heads that are on the market today. Plus, this will allow the use of 5C collets & even will now have a threaded nose for chucks, faceplates etc.

I have more photos & will add more, but I am still pressed for time w/work required on my house

[1200rpm]

now that`s awesome!
pretty slick!
and i`m am glad you put it here, i may not have seen it otherwise.

[skooter]

Very nice.

[Doozer]

Hey I am very impressed! I agree, the division plate works better
on the other side. I may be inspired to do the same to mine.
I can't say how very much I like this!

--Doozer

PS- I wish this forum has LIKE buttons like PM and others.

-D

[Toolguy]

I like this a lot! I may do one of my spindexes this way. It makes much more sense than having the indexing plate in the way of the spindle. Are you going to post drawings of the worm mechanism? Also, how about a part # for the thrust bearing? Great idea!

[jhe.1973]

Hi Everyone,

This spindex has to be finished & go with me on a trip near the end of the month. It is part of a trade I am making with a friend who repairs clocks. I was going to do 2 of them together (one for me) but had to concentrate only on this one due to serious problems that came up with my house.

So, if I don’t get photos of some detail I will have another chance later on.

The thrust bearing is a 45mm bore metric one from McMaster-Carr. Their part # is 5909K19 & the thrust washers are 5909K79. I also used a third washer between the bronze worm wheel & casting at the other end.

Also from McMaster:

The worm shaft is a hardened & ground 5/16 X 5 inch dowel pin # 98381A601

Bearing locknut # 6343K22 – more on this later!

O-ring for spindle cover # 9452K149 per pack of 50 – anyone need an O- ring?

The 40:1 ratio worm & wheel are standard Boston gear items that I bought off of Amazon. The bronze wheel is # G1044 & the hardened, ground & polished worm is # GLVH1. These gears aren’t cheap, but I wanted a smooth & precise action. The shaft will run in drawn cup needle bearings from VXB Bearings also on Amazon. Their part # SCE59.

The 3 dividing plates are part of a conversion for a small rotary table & come with the brass sector arms, the crank, handle & plunger & the spring retaining clip from Wholesale Tool Co. part # 1990-0063.

Of course most of the above items could be made in your own shop, but to save time I decided to buy whatever I could.

That’s all I can think of at the moment – have to get out to the shop for the day!

[Dr Stan]

Excellent work. Glad to see you removed the "Made in" tag as that no longer applies.

I also recommend copyrighting your drawings. You could then market you design to one of the MT accessory companies. The CR would give you some legal protection against theft of your intellectual property.

[macona]

His drawings are automatically copyright.

[dp]

I'm in awe of the versatility and malleability of that lowly spindex device. Not to mention the cleverness of the people who use them. Nice work.

[Rosco-P]

How do you intend to mount a threaded chuck? I realize that small (2 or 3") chucks with 5C stubs are available. What will it use for registration?

[firbikrhd1]

Your stole my idea! OK, maybe stole is too harsh, let's just say great minds think alike.

I've been planning a similar modification for several years, gathering parts along the way, but haven't gotten around to actually modifying it. The outcome looks great as does your work and your drawings!!! Please keep us posted on how well it works when finished.

[dp]

Will Arc Euro Trade pick this up? They seem to fancy clever mods like this.
http://www.arceurotrade.co.uk/default.aspx

[Toolguy]

It would be great if they did. John.......John S.? Are you listening?
They have some cool stuff that no one else has.

[jhe.1973]

How do you intend to mount a threaded chuck? I realize that small (2 or 3") chucks with 5C stubs are available. What will it use for registration?

I intend to use the original register for the index plate which is just behind the threads cut at the collet end. I will use these same threads (for the original locknut) for a backplate etc.

Thanks to all of you for the kind words!

Dr. Stan:

Thanks for the copyright suggestion. I posted a photo of the CAD drawing, rather than the CAD file itself, so that all the info couldn't be 'stolen'.

I've had quite a few long nights, as this one is geting to be, but it has been worth it. Here is how things are now:



The worm bracket in the foreground is showing the template I cut from a printed CAD view to rough saw cut the outline leaving plenty of finishing material. This was done before I located the worm shaft. For any of you who don't already know it, rolled aluminum/steel have stresses built up in the metal & things move around when this much cutting has to be done.

By cutting the majority of the metal away first, any movement wouldn't affect the bore alignment.

This view shows the shoulder screw I am using for a pivot in the mounting bracket:



Here is how the mounting bracket is fastened with screws & dowel pins:



There is still lots of shaping to be done so that the worm bracket has the required travel. but this shows pretty well what is going to happen:



Its 2:40 AM - I need some sleep!

[jhe.1973]

Another good day

Hi Everyone,

I got all the necessary trimming finished to allow the worm bracket to have all the travel needed to engage & disengage fully. Here it is w/the worm engaged.



And here it is w/the worm disengaged:



I mentioned that I used a third hardened thrust washer between the worm wheel & the casting. I wanted a harder & smoother surface than the casting would provide. This appears to be fairly ordinary cast iron - not particularly fine grained. The washer had to have a flat notch to clear the the worm or have the O.D reduced. I chose the notch.

I found I had to keep the washer from turning so it wouldn't catch the start of the worm 'thread'. I located 3, 1/16 dia. dowels & pressed them in about .008 below the top surface of the washer like so:



I ground the notches by hand w/a thin cutoff wheel in a die grinder.

Then I got the nicest surprise!

Right now I am using a drill blank for the worm & it is about .0005 smaller than the dowel I will use w/the needle bearings. It is in the correct location. but is just in reamed holes for now. The worm doesn't fit the drill blank as tightly as it does the dowel. However, even though you can move the worm sideways on the shaft w/o much effort, it turns the worm wheel & spindle easily & smoothly.

This action should only get better w/o the friction of a rather snug fit in the reamed holes.

Now I'm even more impatient to finish this!