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View Full Version : Keyway done -- finally!!



TGTool
03-27-2007, 02:11 PM
I had a part that required a small keyway, and after a great deal of ancilliary work it's finally there. The keyway was supposed to be 3/32 wide by 3/64 deep so there wasn't a lot of room to work. The cutter itself is a section from the end of a cutoff tool. It's a T-section 3/32 blade so that part was easy. The holder is slotted to take the blade.

http://i48.photobucket.com/albums/f244/TGTool/KeyCut3.jpg

It's also recessed fractionally since the thick part of the blade is about .100 and I didn't need that much projecting. The bottom that sits in the slot is also ground at about 3 degrees to provide front clearance. No side clearance in this case. A little would be good, but this worked.

This holder goes in the hand shaper on the QC toolpost.

http://i48.photobucket.com/albums/f244/TGTool/KeyCut1.jpg

I don't have infinite stroke, so I made a blind keyway. The cross hole breaks the chips. As usual, getting the tool and setting it up took much longer than the actual cutting. That much was just easy and came out well.

http://i48.photobucket.com/albums/f244/TGTool/KeyCut4.jpg

The final part is a step pulley for a 9mm HTD5 timing belt. Not deburred yet, but it looks like it's going to work.

http://i48.photobucket.com/albums/f244/TGTool/KeyCut5.jpg

tattoomike68
03-27-2007, 02:52 PM
Wow, thats great. You did a good job.

Vinland
03-27-2007, 08:31 PM
That looks great!!!!

BobWarfield
03-27-2007, 08:41 PM
That sort of thing is always a fussy business. Reminds me to add a slotting attachment for the lathe to my list of To Do's. Inevitably I will find I need it and be tempted to take a shortcut since I don't have one.

I like your approach to the timing pulley as well.

Best,

BW

Your Old Dog
03-27-2007, 08:52 PM
Looks like a pretty "up-hill" project but you got thru it anyhow! Nice work coming up with a fix.

Tinkerer
03-27-2007, 09:46 PM
Very cool tool and slick looking pulley to boot. ;)

TGTool
03-27-2007, 10:19 PM
It has been one of those jobs where you have to go all the way around the block just to get a start. I didn't have a division plate with the right hole count for a couple of the hole sets so had to make that too.

A big THANKS to Marv Klotz for the hole program where you can just put in the number of holes you need and the pitch circle and get a printout of all the X-Y locations. Of course there's that bit about subtracting from 100 and taking out backlash in various quadrants. I guess if I weren't doing that I'd be frittering the time away doing something else like improving my mind (or spelling). :rolleyes:

JM

Ken_Shea
03-27-2007, 10:30 PM
Jim,
That is nice work and once again proves that there is always more than one road to success. I always enjoy seeing and learning from the varied approaches others take to accomplish an end result.

Take a pic after you get it cleaned up and belt installed so we can see the finished product.

EDIT:
Jim, where did you get the profile for the belt ?


Ken

TGTool
03-27-2007, 10:38 PM
Ken,

I've got a catalog from www.econobelt.com which is also Quality Transmission Components. Some dimensions I just scaled from the profile in the catalog. I know the pitch of the belt, and the catalog gives OD figures for different pulleys so I worked out the constants. I can't swear that what I have is perfect but I think it's good. If you're seriously interested in doing some I'll dig out the numbers I used.

JRouche
03-27-2007, 10:42 PM
Jan, fantastic....

Looks good and I am sure will de-burr nicely. That would be a good candidate for an abrasive tumbler.


Nice work....JRouche

Ken_Shea
03-27-2007, 11:02 PM
Jan, sorry about the Jim, I saw JM and my eyes just added the "i" :)

If it is not a lot of trouble for you that information could save some time, I am unable to find the pulleys needed for my project and that just may be a solution. I am not looking for perfection only to get it progressing as it has been on hold because of the timing pulleys being unavailable. There's a million things yet to do but with out these pulleys it matters little.


Thanks
Ken

torker
03-28-2007, 12:06 AM
TG, I sure like that little hand shaper of yours. Is that the same one you showed us awhile back?
I have one "in the plans" but may have to do a rethink on it. I never thought of using it in the lathe. My "new and improved" idear wouldn't work for that. Oh ya...I meant to spell idear wrong :D
Russ

TGTool
03-28-2007, 12:19 AM
Russ,

Yes, basically the same device. I'd had in mind that it could be used as a hand shaper, but I hadn't used it that way to make sure it worked.

I made a new body for it a while back. The original worked fine, but I wanted to see if the Turcite slideways would work. That meant machining the space for the square slide oversize and epoxying in the Turcite strips. So far that also seems to be a good procedure. The picture that shows the shaper also shows the glue squeeze-out at the ends. :( It won't win prizes as a pretty face, but it can do the lifting.

torker
03-28-2007, 12:27 AM
Thanks TG! Turcite strips huh? Good idear :D
I was going to use roller bearings running on two milled flats on a piece of ground 4140. It would work well (I'm betting) but would be a bit bulky compared to yours and Evans shapers.
I'm still going to try it. I have the bearings and bushing stock in the "new" pile. That's the pile of new stuff for all the projects I want to do...lol!
Russ

JCHannum
03-28-2007, 11:28 AM
Jan; Nice job on the timing pulley. Another example of a ten minute job that takes three days.

If you are coming to NAMES, could you bring the hand shaper along for show & tell. I admired your original photos, and have it toward the top of my projects list to make one. The QCTP mount adds quite a bit to the usefulness of the tool.

TGTool
03-28-2007, 11:34 AM
If it is not a lot of trouble for you that information could save some time, I am unable to find the pulleys needed for my project and that just may be a solution. I am not looking for perfection only to get it progressing as it has been on hold because of the timing pulleys being unavailable. There's a million things yet to do but with out these pulleys it matters little.
Thanks
Ken

Ken,

With the HTD5, 5.0mm. pitch, Pitch Diameter (PD) is NoTeeth x .1969" / Pi.

The pitch line of the belt will fall closer to the middle of its thickness so:
Pulley OD = PD - .045" (This is verified in catalog pulley dimensions)

The hole circle for the belt teeth = PD - .076"

I believe the teeth on the belt are 3.0mm so a 1/8" or #31 drill would provide some slight clearance for the teeth.

Probably self-evident, but turn the blanks a large enough diameter to drill through solid material, then turn the OD down to size. I used the material for flanges, which may or may not be necessary.

And, since the centerline of the holes falls below the OD, the peaks left after turning down to the holes should have the corners broken (ideally a small radius) so it doesn't chew into the inside corners of the belt. My plan was to make a small scraper form tool and harden it to get the corners.

Jan