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eightball

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#91
I would see no need to ever disengage the rollers once there set to move freely with minumum play. I would have at least 4 rollers(one on each corner) and the locking mechanism seperate. That way when it locks it wouldnt be putting any forces on the bearings, in fact just the opposite. Just my 2 cents worth.
 

Ray C

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#92
Yep, I agree. I left 1" of space in front and behind the locking plate to possibly put another plate below it that has rollers or bearings. If the undersides of the ways are both parallel and coincident I'll go with one roller in front and one in back. Each roller will contact both sides of the ways. If the undersides are not coincident, I'll go with 4 individual bearings. Anyhow the plates will work independently. I did for a while think I'd put the rollers on the existing locking plate and just have them swing out of the way when not needed. There's plenty of clearance for either method.

EDIT: And I fully realize this is not an ideal way of holding down a drilling mechanism. It's perfectly safe but there will be some tendency to lift-up maybe a thou or two -but it's manageable. When I want to do precision drilling, it's done on the mill or if on the lathe, it's rough drilled first followed-up with a boring bar mounted on the QCTP. -Bases are covered.


Ray

I would see no need to ever disengage the rollers once there set to move freely with minumum play. I would have at least 4 rollers(one on each corner) and the locking mechanism seperate. That way when it locks it wouldnt be putting any forces on the bearings, in fact just the opposite. Just my 2 cents worth.
 

Ray C

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#94
Will do... the last couple days, I've been working on some other parts for folks and also, the day-job has got me kinda busy too...


Ray

Keep us posted Ray, facinating build!
 

eightball

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#95
Its been a while since i adjusted a carriage Ray, but every thing we do in this business is a give and take. drills and reamers push off, just a fact of life. I feel certain you set your turrett up like a carriage and everything willl be more than acceptable.
 

Ray C

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#96
Yes, thanks... I think/hope it will be fine. I guess if I wanted the performance of a Hardinge or Monarch, I'd buy one. Drilling is a "crude" operation in the first place. For the kind of work I do and foresee doing, as long as the starting hole is within a couple thou of where I want it, other operations (such as endmill or boring) can fix the rest. -That's my story and I'm sticking to it :whistle:.

BTW: With any luck, later today, I plan to work on the push/pull mechanism for the top plates. It will be a single, internal screw whose position is fixed (and not engaged) with the bottom of the two top plates and top plate will have a threaded semi-hole. As the screw is turned, it pushes the top plate a desired amount.

One of the reasons I built this thing like a brick xxxxhouse is that I really hate trying to adjust sideways motion of the TS to get a shaft centered. This is also why I put two dovetail guides in the top plates. The traditional tailstocks have a lot of slack and wiggle and even though you push it in the proper direction, it seems to go the other way until the slack is pulled-out. Heaven forbid you overshoot and need to backtrack the direction. I'm hoping (fingers crossed) this mechanism is more precise. Later on, I'll make an attachment to accommodate a DI to see exactly how much the adjustment is.

All these little improvements (if they are successful) are real time-savers in the longrun. Aside from that, this is just a fun project that makes you feel like a hero :)

Ray



Its been a while since i adjusted a carriage Ray, but every thing we do in this business is a give and take. drills and reamers push off, just a fact of life. I feel certain you set your turrett up like a carriage and everything willl be more than acceptable.
 

eightball

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#97
Never ran a harding, but i fell in love with monarchs 1/4 century ago. We i was an apprentice we had 2 monarchs 2 colchesters 2 leblonds A planer a big shaper a horizontil cincinatti, a big verticle cincinatti milatron a supermax and a brand new bridgeport had a surface grinder, a big drill sharpener two radial arm drills belt sander several bench grinders we had a big lathe with a 50 inch swing and bout a 200 inch bed but i dont remember the name. I really miss that old shaper.We have a couple of TOS lathes now and they are pretty good lathes, Still have both the monarchs, the small colshester and the chinese boring mill. We have a sharp mill which is a bridgeport clone and i like it better than the bridgeport.
 

Ray C

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#98
In case that description of the push/pull mechanism wasn't clear, here's some pics...

First, a center hole (1/2x13) was drilled and tapped right between the two plates. Not shown (but you'll see later) a 1/4" hole was drilled at the bottom of tapped hole. The area around the hole was milled flat to later accommodate a metal retaining plate for the adjustment screw.

Center Hole.JPG


Once the tapping was finished, the plate that's fixed was milled to remove the threads from that half of the hole. The semi-circle was bored to 9/16".

Enlarging.JPG

Now it might start making sense why the extra hole was drilled. I'll make a special screw that has a leading piece on the end that will support the end of the bolt; otherwise, it would just drop down into the 9/16" side of the semi-circle.

End Support.JPG

Here are the mated pieces. The special screw thats made will be held in the front by the fixed plate. I'll put some collars on the front of the screw and a metal plate will support the front part of the screw. I though it would be nice to use an ACME thread but, I don't have ACME taps on hand -and they're quite expensive. A 1/2-13 will have to do. When the adjustment screw is turned, the bottom/fixed plate will remain stationary and the top plate that supports the Morse holder disk will slide in the keyed grooves.

Mated Pieces.JPG


Taking a step backward in time, here's a shot of tapping the holes for the plate that will support the front of the screw. What I really wanted to point-out here is how the mill spindle is used to hold the tap straight. There's a pointy piece in the chuck that either fits in the divot in the end of the tap or, it fits well enough into the opening of the tap handle. I apply light pressure with the spindle for the first few turns. BTW: I made that tap handle when I was about 13 years old in my dad's garage shop. One of my favorite tools in the shop and everyone who uses it wants me to make them one -and I usually do. I can make them in my sleep.

Tapping.JPG

Hopefully tomorrow, I'll have time to make the adjustment screw.

Until we meet again...

Ray

Tapping.JPG Center Hole.JPG Enlarging.JPG Mated Pieces.JPG Screw 1.JPG End Support.JPG
 

Ray C

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#99
So, I came-up with an idea for the rollers under the way rails to keep the TS down when drilling... What do you think of this? How about a heavy piece of band steel that would act similar to a leaf spring? I could mount the bearings/rollers to the piece and it would operate just like the normal locking plate but, it would have adequate tension to keep it flat on the ways.

Thoughts? Any ideas for a suitable piece of metal that could serve as a "leaf spring". I have proper heat treating equipment so, I could make something with a cutom temper. The piece will need to be about 3.5" wide and 5-6" long (roughly). Ideas about what would be a good metal to start with are greatly appreciated.


Ray
 

Ray C

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A few more visuals on the push/pull adjusting knob.

Roughed it out pretty much by eyeball and cut the collar with the parting blade.


Adjusting Knob Parting.JPG

Here's a few views of it in place. It's a little stiff but a few moments on the wire wheel and some grease will fix that. I need to form a knob or a hex or just drill some holes through to put put a little leverage bar so it can be turned by hand. It works though. Now I just need to make the front plate that retains it by the front collar. We'll take care of that after dinner.


Adjusting Knob 2.JPG Adjusting Knob Profile.JPG Adjusting Knob In Place.JPG

PS: We just had the most intense 20 minutes of rain that I can recall in years. The skies clouded up all the sudden and wham! The dog bowl in the front lawn, which is about 4" deep, was empty and 20 minutes later it was full. -Weird!...


Ray

Adjusting Knob 2.JPG Adjusting Knob In Place.JPG Adjusting Knob Parting.JPG Adjusting Knob Profile.JPG
 

DMS

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So, I came-up with an idea for the rollers under the way rails to keep the TS down when drilling... What do you think of this? How about a heavy piece of band steel that would act similar to a leaf spring? I could mount the bearings/rollers to the piece and it would operate just like the normal locking plate but, it would have adequate tension to keep it flat on the ways.

Thoughts? Any ideas for a suitable piece of metal that could serve as a "leaf spring". I have proper heat treating equipment so, I could make something with a cutom temper. The piece will need to be about 3.5" wide and 5-6" long (roughly). Ideas about what would be a good metal to start with are greatly appreciated.


Ray
1095 or 5160 steels come to mind. 5160 is more fatigue resistant IIRC, but I don't think this is going to be a high cycle use, so 1095 would probably work fine. In fact, any high carbon steel would work. If you know what force you need, should be relatively easy to figure out what thickness/length you need.

I don't think the temper is that critical, basically you want to increase your yield strength so that the material doesn't deform plastically. You also don't want it to be too brittle. I think a "blue" temper with a rockwell hardness in the high 40s or low 50s is common for carbon steel.
 

Ray C

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All done with the push/pull screw...

The threads were a little tight so the piece was remounted and threads cut a few thou deeper. I probably should have just chased it with a die but for some reason, I didn't think of that -Duh! The retainer plate was easy and everything fits together just peachy. It spins easily with fingertip pressure and the plates slide with no side play at all. I put a little way oil between the plates and had my son stand on it. Still easy to work the adjustment with fingertips but, I'll probably put a screwdriver slot on the face of the screw (assuming I can find an endmill small enough -pretty sure I have one...).

Next I'll probably start making the gear and handle to drive it.

Retainer.JPG Working Well.JPG

Ray

Retainer.JPG Working Well.JPG
 

eightball

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you'll be using this turrett b4 long, Everbody i know that worked in job shops hated them lol.
 

Ray C

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Don't know if you saw the other posts about the mill tool and the pinion gear... Those were part of this project. I'm also scrounging around for for some 1095 for the flat spring. Also, last Sunday, I took the off from shop work -which is pretty rare for me.


you'll be using this turrett b4 long, Everbody i know that worked in job shops hated them lol.
 

Ray C

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Quick update... I started making the rack pinion gears but, the cutter was getting dull way too quickly and also, I dislike banging the spindle gears to such an extent so, I've ordered some small endmills and will cut the slots first then, just cut the pressure angle with the rotary doo-dad. Everything is documented in the threads called "Multip-purpose mill tool holder" and "Making a Pinion Gear". In the mean time, I've done the scraping on the bottom of the slide plate. I simply used a roto-dremel tool with a cutoff disk and with a light fine touch using the tool at an oblique angle put a scalloped texture on the surfaces. Using the edge of the cutoff disk, oil grooves were made. With a hand tool, notched a small channel to allow oil to seep from the top and enter the oil grooves. When tested on the lathe with oil, it slides much easier.

Also, here's another possible way to apply tension to the underside for the purpose of allowing it to roll without lifting up. The idea is to use a heavy spring at the rear of the unit that will apply downward force on a leverage bar that has a pivot point at the locking plate bolt that protrudes through the underside. The positioning of the spring is shown. A knob on the spring can be used to adjust the force. The spring is a valve spring from a lawnmower engine and a rough check shows it to about a 40lb spring. With pressure on the leverage bar, the teeter point will push upward on a plate that holds the roller bars. If the leverage bar is say, 8" long and has a 1" teeter length on the other end, that should produce 320lbs of force. -I think plenty to hold the unit down especially since the rest of the turret attachment probably weights about 80 lbs (possibly more). If that's not enough pressure, I could use a regular automotive valve spring. This will be very easy to make.... just a plate that holds the rollers, some threaded rod, a knob and piece of bar stock.

How's that sound?

Ray
PivotSpring.JPG

PivotSpring.JPG
 

eightball

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lookinggood ray, unfortunantly the cancer meds are kicking in so im gonna call it a night and take a fresh look tomorrow
 

Ray C

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Thanks but hey, don't worry about me, take care of yourself...


Ray

lookinggood ray, unfortunantly the cancer meds are kicking in so im gonna call it a night and take a fresh look tomorrow
 

eightball

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not so sure about the springs, Would that cause excessive wear on the ways?
 

Ray C

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The spring tensioner would only be used for drilling. The whole tailstock moves when the crank is turned. The spring tension should be just enough to keep the rig plastered down to the ways. I doubt if it will need 320lbs of force. For normal use, the tension is removed and the locking plate is used like a normal tailstock. Also, the ways are hardened to RC 52 (I checked) and the new base is soft 1018 -which is no match for hardened cast iron.

Ray

not so sure about the springs, Would that cause excessive wear on the ways?
 

Ray C

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Oh yeah, for sure. Just haven't gotten to it.

BTW: Still waiting for the little endmills to finish the rack gear.


Ray

Gee Ray, I am a little surprised you didn't knurl or put a hex on the end for ease of turning. Any plans on that upgrade? The project is looking very good, keep 'em coming.
 

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Here's more work on the transit gear mechanism. Normally I like to design things up front but, this was laid out the old fashioned way because there's almost no room to measure the clearances between the rack gear on the lathe and the leadscrew. This thing is driven off the rack gear and must clear the leadscrew. After looking closely at the available space, I decided the main drive gear would have to be smaller than the 2:1 ratio I was looking for and also, I had to double stack the gears to get it to fit. Anyhow, the brass rack gear is 15 tooth and the drive gear was 20. I'm hoping it won't be too slow to operate and also have decent torque. Things are fitting well and the gears are all meshing smoothly but I won't know if I like the feel of it till later...

Here's the gears. The teeth on the large gear are the same angle but the reflection from the chamfer shows-up oddly. The gears mesh nicely. Didn't have a 2" piece of brass so, it was made of 1045 HR.


Transit Gears 0.JPG

Here's the back side of the transit mechanism. A well fitting spacer was made and welded to the plate to give the correct engagement with the rack. The little studs were custom made and have crowns that fit in a recess to hold the gears in place.

Transit Gears 1.JPG

Here's how it fits with the gear rack. A handle drives the steel gear which then drives the brass gear. I could have gone with one gear but I wanted the handle to spin and move the same way as the carriage. The top view shows how their double-stacked and the side view show that things are clearing the leadscrew by almost 1/4". Also, with this angled mechanism, the new tailstock will be able to enter fully into the rear U-shaped section of the carriage and neither the transit gears or drive wheel will interfere with the thread chaser. Matter of fact, the transit gears fit well behind the chaser. I'll use snap rings and washers to keep the studs snug. I still need to broach the steel gear and cut a keyway on it's corresponding stud.

Transit Gears 2.JPG Transit Gears 3.JPG

Just a few more details to go on this -not much. Need to rig-up a bracket to connect the transit mechanism to the tailstock then make a wheel. I'll probably incorporate that tensioning mechanism (discussed in an earlier post) to this bracket.


That's it for now...

Ray

Transit Gears 0.JPG Transit Gears 1.JPG Transit Gears 2.JPG Transit Gears 3.JPG
 

Ray C

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We're getting there. The bracket is all done. Just need to install the snap rings on the axle studs and make a wheel. It glides back/forth nicely so far with no sticking at all. Gotta cook Sunday vittles on the BBQ now. Probably will finish this later this evening. After that, it's just the tensioning bar and some alignment of the turret taper blocks...

Base1.JPG Base2.JPG Base3.JPG


Ray

Base1.JPG Base2.JPG Base3.JPG
 

Bill Gruby

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Great work so far Ray. At this point I would have done only one thing differently. It looks as if you have already bored the tooling blocks correct? If so now you have to align them to the chuck. I would have waited till they were all mounted and the last operation to complete the Turret would have been to use the lathe chuck to bore the holes. Perfect alignment that way.

"Billy G"
 

Ray C

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Thanks Bill but there's a setback on this... Everything works and rolls fine but, there's not enough gearing leverage to drill holes. The hand crank works very smoothly but, it takes way too much hand force to drill so, I'm going to fall-back to plan-B (which I had to hurry-up and invent). Plan B-1 is to put a wheel crank in one or more of the blocks or, plan B-2 is to devise a leverage bar or an ACME screw mechanism to drive the whole unit forward. ...Going to sleep on it to help make the decision...

On a positive note, when drilling, the unit did not lift up at all so, that tensioning mechanism might not be needed.


Ray
 

Bill Gruby

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Use a spider type handle. A 3 0r 4 inch hub with 4 arms sticking out of it. The arms must be at least 1/2 inch dia. The length of them will determine the amount of force you have available. The longer the more force you can apply. Put a ball on each of them.

"Billy G"
 

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Ray, have you considered moving the drive train to the outside of that bracket? (brass gear stays where it is, but is driven from the other side). That would require some refabrication too, but would solve the problem of the gear size limiting your available ratio.
 

Ray C

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Thanks...

Bill's idea worked. Complicating matters, I happened to grab a bit that was a little dull. 20 seconds at the grinder and it wasn't dull anymore and drilled through no problem but... I want a cleaner solution and think I'll abandon the gears and drive it with an ACME rod from underneath and between the ways.

Here's a piece of 1" stock (pretend it's an ACME rod) laying in the intended location. Plenty of space with room to spare. There's already a drilled/tapped hole at the end of the bed which served a stop-bolt to prevent accidentally pushing the TS off the end of the bed. That hole will serve as a good mounting location for the thrust plate. I'll make a small fixture with an ACME nut welded to it that will attach to the bottom of the TS. The TS can now be moved with either a hand crank or a motor at the end of the lathe. If I feel like getting fancy, instead of an ACME nut, I could make a half-nut doo-dad so I could optionally disengage the half-nut and slide the TS by hand as desired.

Threaded ACME rod is cheap... 20 bucks for a 3' piece... Clean approach and drilling depths can easily be estimated by counting the number of turns once contact is made.

What'ya think?

Acme Thrust location .JPG Acme rod location.JPG

Ray

Acme rod location.JPG Acme Thrust location .JPG
 

Ray C

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Well, I think this will be much better. It was just made this morning... I decided to try a drive rod mechanism with a half-nut clamp.

Here's the half-nut clamp. I just made it out of a couple 5/8" nuts and a simple door-hinge like closing bracket.
HN 1.JPG HN 2.JPG

And here's how it looks. It's not all assembled yet -we're just a few steps away from that.
HN Drive Bracket.JPG HN Drive Rod.JPG

Time to have lunch and walk the dogs...

Ray

HN 1.JPG HN 2.JPG HN Drive Bracket.JPG HN Drive Rod.JPG
 
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