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KO-Lee Cutter/Grinder Revamp

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Perhaps you've seen this from other photos... It's a KO-Lee cutter grinder. It's a good platform and the table and all mechanisms are in excellent condition. I don't think this machine was used much in it's lifetime as there are very few signs of wear (hardly any at all really).

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The motor is the weak link. The bearings are going bad and vibration can be felt in the short shaft. The long shaft is OK. The seller told me about this when I got it. I'm guessing someone bumped a wheel really hard and damaged the bearing on that side.

Anyhow, I once had a B&S #2 surface grinder but, sold it a few years ago. It needed too much work. It took up too much space, and I rarely worked on parts more than a few inches in size. Also, the things I make do not need sub-ten-thou tolerances. I've used the KO a couple times to do some grinding on small parts within a half-thou and it works out fine. My plan when I sold the B&S was to modify the KO-Lee to handle the simple grinding tasks that come my way.

The time as come...

I'm tackling this in a couple ways and doing the work simultaneously as I go. The plan is to address a travel issue with the KO. It's got about a 12" horizontal travel which stays true the whole way. The vertical travel is about 4" and falls-off at the extremes. I'll see what I can do about that. The other idea, is to remove the old motor and replace it with a small 3 phase and design a new spindle. The spindle design will just be a larger version of the tool post spindle I dreamed-up and posted here several years ago. It's proven to be a very good design but I want to improve a couple things to handle heavier grinding wheels possessing more rotational energy.

This will be an ongoing project that I hope to finish by spring.

The drawing for the spindle is being recreated from the ground up. Here's a sneak preview. The design is still in my head and no dimensions are shown because I'm still making rough measurements of the KO-Lee platform and also, I have not settled on a convenient way to terminate the business end of the grinder shaft. Kicking about 3-4 ideas around. Here's what we have so far. You can upload the .pdf and see it in 3D.


SpindleConcept.JPG

As with the last project (https://www.hobby-machinist.com/threads/bull-nose-live-center.64859/) all the machining shots along the way will be shown and described (so you can butcher-up metal just like me).

Regards

Ray C.
 

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OK, we're making-up for lost time now...

When I made grinder hubs in days gone by, I would always take the raw (warped part), bore a basic hole then bore the taper. I always would make an arbor shaft with the same taper then, finish all the dimensions by spinning on the tapered arbor. Well, that's basically what I did here but I just used the actual shaft.

Pictures are worth a thousand words. Remember now, this hub was hardened. I don't remember for sure but think it's at RC 35 or so. Also, sorry but, I forgot to take pictures of boring the taper. I stuck the raw/warped piece in the 6 jaw with the disk (back) part facing the carriage. The taper was cut from the large diameter to the small diameter, as the cutter moved from right to left.

The good thing about doing it this way, is that the centerline is the reference axis for the completion of the entire part. Once setup like this, you can get the spindle shaft and all sides of the back plate all in one shot. Totally ideal situation. (I've made dozens of hubs this way).

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The only thing I'm a little disappointed about, is the small welding void. It was not an inclusion but rather, I just had a couple low spots in the filler. I didn't want to chase it out on the lathe because it's only a cosmetic error.
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Upon measuring this thing in every possible way, it is Dead-Ba11z-On.

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Only a few more features to go which I'll catch some other day. It needs LH threads and I need to make the pushplate and LH nut.


Ray
 
OK, the fun begins on some of the other parts.

We're going to start on the front bearing cap. Here it is. If you'll recall, it was 1045 and heat treated to somewhere in the RC 30 range. In all honesty, I forgot exactly where it was set to but, for a part like this, somewhere about 35RC would be good. That is very pleasant to work on and gives an attractive and durable finish. When I say pleasant to work with, my real message is that it cuts evenly, cleanly and predictably. We're going to need that when get to a couple critical dimensions for the slight negative tolerance bearing fit.
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The first thought, is how to chuck it up. I always consider two things: 1) Where are the critical dimensions and 2) how many features can be addressed w/o needing to remove the part from the chuck.

Here's the profile of the part and it's pretty clear that I can catch the back of the plate (right side of the drawing), the side of the plate and all of the various bore diameters w/o needing to remove the part. It's important for all those features to be concentric and the right side back needs to be perpendicular to the axis of the bore. On the left side of the diagram, the outer surfaces are not critical because they will not prevent the shaft from being perfectly straight during the assembly process.

Anyhow, for this piece, it's pretty obvious how it should be held. The point is, not all pieces are this obvious! It's really easy to ruin the elegance on the execution of a part if you box yourself into a corner and need to re-chuck it while in the midst of critical cuts.
FrontHousing.JPG

So, without further delay, we start making chips... It cuts wonderfully and the machine sounds and feels great during the cut. It's what we strive for and it's nice when things go our way. Here's the very first pass on the backside; just enough to remove the scale. The next pass will look like chrome. The outer edge was taken to the final diameter and that's some pretty sexy looking metal under that first 1/8" of outer surface.
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It's late now and we'll do more this weekend...


Ray
 
Only a few more baby steps on the front bearing housing today as I got a late start. It was almost one of those days where I was going to stay out of the shop but, decided to jump in and let the shop work take my mind off the earlier part of the day. The trick worked.

I'll tell y'a, digging these grooves is a bit of a white-knuckle operation -but it had a happy ending.
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The O-Ring fits.

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I did all the other features before the O-ring groove. That very first lip that looks like an accidental dig in the part, is actually a clearance area so the bearing can be lined-up before being pressed in. It's called-out in the diagram.

Despite what I though was going to be a dicey day in the shop, all the dimensions came out really well. Everything cleaned-up with just a few moments of clean-up with emery cloth. Wheeew! I've gotten to the point that it's pretty rare for me to over-shoot a dimension (although it does happen once in a while). It's usually a question of "will it take 30 seconds of emery cloth or will it take 3 minutes of emery cloth to bring it to size"... Luck was on my side today.

BTW: That little step all the way inside the bore is clearance for the bearing cage.

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After this, we'll do the other side. No critical dimensions there. FWIW, when I design these things, I do not put formal tolerance specs in the drawings. The only place that tolerances are specified are for where it's really needed such as bearing race fitments, intentional interference areas etc. I self-imply that all other tolerances are +/- 1 thou and I don't cry or beat myself up if I blow it a little. Sometimes, I try to nail non-critical dimensions dead-on only for the practice of doing it. I tend to do that on about 1/3 of the non critical dimensions -but it varies from project to project. It's good practice but can really slow you down.
 
As promised, we're doing the other side. Once again, a little thought goes into how this should be held. If absolute, perfect concentricity were needed on the outside dimensions, I would build a a mandrel of some sort and spin it on the same axis as the bore. No need for that here.
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We'll need to carefully hold this one with a partial bite from the chuck. This will be a good test of the new 6 Jaw chuck. The chuck was purchased specifically for parts like this.

Look closely... machinist parallels were placed against the chuck (between the jaws) and the part pressed flat against them. This is good enough in this case. CAUTION: Remove the parallels from the chuck before spin-up. They will go flying just like a chuck key.
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The TIR was checked on the outer lip and the exposed bore. I did in-fact need to loosen the chuck bolts and bump the body a tiny bit. The difference TIR between the two surfaces was adjusted well within 1/2 thou by bumping the chuck body. -Close enough!
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There it is, fresh naked metal to behold.
IMPORTANT: With the part held this way, all the cuts must be fairly light. A heavy cut could dislodge the part from the chuck -not good!

FYI: The part is on the order of 2.5 to 3.5" diameter. The lathe was set to base RPM of 360 and the VFD was used to tweak speeds up/down as needed. Feed rates were around 2 thou/rev and DoCs were kept around 20-25 thou.
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All done except the holes. ...And a big Hooray for the 6 jaw chuck. Not the slightest bit of damage or scratching on the part.
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The piece came out very nicely. I happen to set it down (gently) on the granite table and it sits nice and flat and almost has that nice "suction" feel when it's lifted off the plate.

OK, I'm going to knock the other one out quickly and there won't be any write-up because it's almost the same part. Obviously, I'm writing this up in hopes that someone new to this gets a feel for how to make this kind of stuff.

Later...

Ray
 
A few more pieces of the puzzle to show here.

Here's the rear bearing housing; very similar to the front housing...
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And now for the the pieces of the center housing. Started out making two flanges and cutting the oil seal groove that mates with the bearing housings. It's too hard to dig a 1/8" groove on just one of the pieces so, we'll dig roughly half on each side. Can't remember for sure but, the depth is about 15 or 20 thou shy of 1/8" to compress the seal.
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The center body is a piece of schedule 80 pipe. Cutting to rough size and will trim to precise length on the lathe.
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Putting a taper on the end for a weld groove.
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Here it is just roughly setup as a sanity check.
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Coming up:
  • Drill the 6-hole patterns in all the flanges.
  • Tap the two flanges for the center piece.
  • Clean the scale off the pipe in the sandblaster.
  • Weld the flanges to the tube.
  • Toss it in the lathe, true it up and take it to final size.
The inside of the pipe has no significant seam like some pipes do so, we won't need to bore the inside.

That's a rap for today...


Ray
 
Here's where we are after a few hours in the shop... Sticking to the plan with only a minor detour.

All 4 of those flanges needed drilling and 2 of them drilled & tapped. Fortunately, the mill has DRO with the bolt/circle function which is right up there with sliced bread, food, water and oxygen.

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And yes, I can understand why you might think otherwise but, I do in-fact own a mill. This is one of Matt's early machines.
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... A few close-ups. By the way, I really like that Shars dial caliper. They have 2 versions; one is the base model and this one is a step-up. IMG_20180211_091820.jpg IMG_20180211_092022.jpg

Lot's of tapping... By the way, that tap handle is my favorite style. Here's a thread from 4-5 years ago that gives a blow-by-blow on how to make them: https://www.hobby-machinist.com/threads/my-favorite-tap-handle.20186/#post-172788
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Here's where things deviated a little bit... I didn't want to bore the inside of the pipe but, the sandblaster just wasn't doing the job at getting the inside clean. The boring bar got the job done. Didn't take too long and only a few thou was taken off. Also, I happen to notice that the pipe was amazingly straight and had an even surface on the inside. It didn't think it was DOM pipe but it sure was good quality. I didn't think it was possible for schedule 80 to be Drawn Over Mandrel.
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Now for welding... The scale and grease were cleaned way back from the weld zone. That's very important with TIG. Fumes burning off of nearby slag, oil, scale etc will mix with the argon gas and screw-up your bead in a heartbeat. The pipe and flange were pre-heated to about 500F.
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On one side, I did a basic TIG. I have no idea what metal the Schedule 80 is but, the flange is 1045. Of course, filler selection is critical so, I did the right thing and used the most appropriate one for the job... The cheapest stuff I had! -Which happens to be 70S2. (For a job like this, coat hanger wire would work fine).
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So, everybody likes this "Walking The Cup" technique. This is the first time I ever tried it -and as you can see, it will probably be my last. Darn near set my fingers on fire. Way too much motion and thinking going on. I'll stick with the boring jab & dab style.
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So, the center piece is sitting in the heat treat oven at 600F and I'll gradually cool it down over the next several hours. That 1045 connected to a big thermal sink (hollow tube) will self heat treat at the junction in a heartbeat. Pictures of that will come in a few hours after it transitions through the "Martenizing" phase.

There you have it for a few hours... Any thoughts, comments, questions, stock tips etc?

Later

Ray
 
We're getting there...

The heat-up and cool-down worked great. The 1045 flange plates ended-up being about the same hardness as the other two pieces. Very easy to work with; has a nice clean, snappy feel when it cuts. I've made the mistake of work-hardening or weld-hardening things and that can be a real problem.

Just cleaning-up the surfaces here. Hardly taking anything off to speak of.
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The welding caused a small amount of warpage; not much, but enough that a light pass was needed and the grooves adjusted accordingly.
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It's taking shape... What'ya think, should I toss it in the luggage, grab the passport and see which of the FVEYs stops me at Customs? Hello, State Department, this is Ray C. Can you come and help me?
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Look Ma, all the holes line up!
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We're over the hump I think. OK, that's about it for now...


Regards

Ray
 
I wanted to be further along by now but, #3 son called, stranded in a local parking lot with a dead battery. We took care of that without issues.

So, it has a left handed tread now and the nut fits just fine.

Threading Quick Tip: If the chuck and leadscrew are rotating in the same direction, you will cut a right hand thread. If the leadscrew and chuck are spinning in opposite directions, it will cut a left hand thread. It makes no difference what directions they are actually spinning, it only matters which direction relative to each-other.

LOL: When I went to cut these threads, I almost made them RH because... well because I just forgot they needed to be LH. Fortunately, I only got as far an initial scratch to see if the pitch was correct. No harm done. Man, I would have been ticked...
View attachment 256634

Ray
As to the directions of spindle and lead screw, not so in all cases; The Regal Leblond lathes have left hand lead screws, so when cutting right hand threads, the spindle and lead screws are rotating in opposite directions; why they designed it that way, I have no idea.
 
As to the directions of spindle and lead screw, not so in all cases; The Regal Leblond lathes have left hand lead screws, so when cutting right hand threads, the spindle and lead screws are rotating in opposite directions; why they designed it that way, I have no idea.
I'll be darned... I wonder if they're all that way or just some models. I ran my dad's LeBlond for the better part of 15 years. It was a 15-54 gearhead (non-servo) but for the life of me, I can't recall if it was LH or RH leadscrew.

Ray
 
So sorry for the long delay. My day job has been very demanding lately.

I did a course correction and changed the shaft from a taper on the hub end to just straight. I'm "inventing" another mechanism to center the grinder hub. The idea of a steep taper on a thin diameter shaft was not sitting well with me. Quite frankly, it was just bugging me because I'm not all that crazy about friction tapers in the first place and having one on shaft less than 1" diameter was doomed for failure.

Anyhow, another precision shaft was made. When I heat treated the raw stock for the last one, I did 3 others along with it. Without stopping to take pictures and do write-up, it only takes about 45 minutes to re-make that shaft. Tolerances on this one were the same and everything is inside 1-2 tenths.

The shaft was assembled last night and a couple very simple pieces of stock were cut to serve as a precision guide while the bearings were pressed on. There was one fairly big surprise... A fairly large extra spacer was needed to supply spring pressure. My initial calculations were to put 25lbs force on the taper bearing. I calculated that much into the dimensions and also added a good bit of extra on the spring support, with the intention it could be trimmed down if needed. Instead, that extra bushing/spacer (next to the thrust bearing) was needed. Turned-out, 25lbs was nowhere near enough. The calculations and dimensions came-out right as far as I could tell but, I just miscalculated how much force is needed to keep the bearing seated. Now, the force is about 125lbs.


Here's what the assembled setup looks like:

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The indicator is showing TIR inside 1.5 tenths which I suspect is mostly surface irregularities. For now, the bearings were lightly greased and a motor was rigged-up to spin it for increasing periods of time from 10, 20, 30 and 60 minute periods. No heat at all -meaning, ABEC 5 bearings are good things and also, 125lbs is not too much force. Should be fine really because that bearing should be able to handle axial load of 5,000 lbs safely.

So... Here's what I'm working on instead of a tapered shaft. The idea is conveyed in the close-up of the hub attachment assembly. I'm going to use 2 very simple tapers and hardened smooth surfaces to self-center the hub. The added complication is that a couple drive pins are needed. I might change the drive pins to a slot-type arrangement but for now, pins will do. The pins free-float in the back of hub plate.

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And here are some of the prototype pieces...
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So, we're in free-wheeling territory now, thinking on-the-fly -which is how most of my projects are hatched...

So, any thoughts, suggestions? I'm all ears.

Ray
 
In the light of a new day, things are looking OK. Here's a simple roller/balancer fixture that was rigged-up out of scraps many years ago. Back when it was made, I never imagined it would be one of the more useful pieces of equipment in the shop. One of these days, I should touch it up and improve it.

So... As best I can tell, the shaft is has no perceptible bow. Everywhere the indicator looks, it sees no more than 0.0002 TIR. I'm calling it good and time to move on with making those tapered centering do-dads.

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Ray
 
Moving along...

Here's another piece to the puzzle. Just need to drill holes and put the drive pins in there, heat treat it and finish the surface with emery cloth. Heat treating will be done with open flame and all I'm after is the tapered cone. We're solidly in prototype mode here so if this does not work out, we'll fall back to plan B (and at this time, I have no idea what plan B is -may need to skip over to plan C).

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The two tapered do-dads (I'm calling them centering rings for now) fit very snugly on the shaft. The rear one (with the pins) will be affixed to the shaft by some TBD means. The front one will be held in place by a nut by some yet-to-be-cut LH threads.

Anyhow, they fit very snugly now and will "stay-put" once squeezed into place. Testing TIR on the hub shaft showed absolutely no sign of needle movement so, it looks like the centering technique stands a chance of working.


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Time to grab some grub and walk the dogs...

Ray
 
The rear hub centering ring (with the drive pins came-out OK. It's not the prettiest thing in the world and is still a little ugly from the flame hardening. The rear of the hub (which has a 30 degree chamfered edge) centers on the taper of the smaller piece. The pins are TIG welded to the small piece and extend to fit very loosely into the back of hub to transmit power. The little centering assembly is made of 1045 and is intentionally quite hard so it will not bind-up with the softer metal of the spindle. The spindle was also 1045 but only RC 35-ish.

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Here it is, positioned on the shaft. It will be pushed a little further back later on.

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In case you're interested how this is all coming together, here's a sneak preview. The new spindle is just (precariously) sitting atop that column for now but, a suitable bracket will be dreamed-up sometime between now and probably tomorrow morning. I have a 3 phase motor to drive it and that will sit above the spindle, also attached to the TBD bracket. There will be a flat drive belt and sheaves transmitting power at the rear of the spindle, similar to how a toolpost grinder works. -Matter of fact, this thing is nothing more than a gigantic toolpost grinder.

The KO Lee base will be used for now, as a proof of concept. If I like it, I've had ideas circulating for a while to make an X-Y roller bearing table and some day, I might get around to making my own mini surface grinder.
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Ray
 
Just so you know, I have not lost interested in this project. The motor spindle and motor brackets are the next big items to work on however, two things are slowing down progress. I ordered a 1 HP, 3 phase motor and the wrong one was delivered. Until the motor is here, I'm holding off on drawing-up the design that's floating around in my head. Also, I'm basically working 2 full time jobs these days and have been doing 12 hour days at the office for a couple months now. In all honesty, I'm tired. I check in and BS on this forum to relax but, have not been able to muster-up the extra energy it takes to finish this off. Soon, I'll get my second wind.

Here's a tiny little piece today related to the motor bracket that is OK make w/o the finalized design.

I had a piece of 316 stainless laying around in the shop for several years now. It's been put to use for a bunch of things and now, it gets a permanent purpose. It's about the size of a hockey puck.

Here's something I use all the time. It's a ram bar that fits in the ram of the tailstock. Make one sometime. They're very handy for this purpose. The SS block is lightly held in the jaws and a couple of parallels between the jaws to prop-up the part. The ram bar does a great job of applying even pressure to hold the piece nice and flat. Of course, it can be pushed by hand but, it's very easy to apply uneven pressure. REMINDER: Remember to remove the parallels before spinning-up the lathe.

When you press on the part by hand, when tightened, the jaws overpower you and the part shifts. This is less likely to happen with the ram bar. I used the ram bar when facing-off both sides of the piece and the width varied within 0.0003" measuring all the way around. You could tap on it with a dead blow hammer but, instincts tell me that the spindle bearings would prefer not to be pounded on.

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Speeds and feeds are critical with stainless steel. This part was spun at 250 RPM and increased to around 400 (controlled with the VFD) as it reached the center. The finish is beautiful. Too bad stainless scratches just by looking at it too hard.

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The part needed some holes and recesses to clear a bolt head. Once again, cutter RPM was critical here. FWIW, I drilled the thru-holes first then, cut the counter-sinks. This way, the center of the endmill does not take such a pounding even though it is a center-cut endmill.

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It came out looking nice. I went way over-board with the detail on this part but, the time spent in on this was pure relaxation time.

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And this is the purpose it serves... It sits atop the grinder column and will be held to it by 2 bolts. The recess in the center will accommodate a matching feature on the bottom of a plate that sits atop the stainless puck. The plate will later hold the spindle and motor assembly. A bolt in the middle can be tightened/loosened to let the spindle/motor assembly have a full range of motion. The OD of that puck fits the ID of the column perfectly. The diameter of that recess is 1.2505". It's important that the matching feature on the bottom of the plate fit perfectly and I'll be shooting for 1.2500".

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All that work on that pretty piece of stainless will be covered-up completely when the matching part covers it up. Say goodbye...

So, that's it for today.

Ray
 
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that came out beautiful. I hear you on the limited time, it sucks. During the semester I rarely have time to work on anything and when I do bike maintenance takes priority. Still little jobs keep the flame alive - made a hamster powered LED light with my daughter this weekend (and a gerbil habitat with the other daughter), so I got my fix that way!
 
Great project Ray, I'm enjoying watching your progress. Wondering how you are liking the 6-jaw, and if it's doing everything you hoped? Cheers, Mike
 
Hampster powered LED and a gerbil habitat? Did you post pictures here? That would put a smile on my face.

Ray
I have to get the pics from my daughter as I forgot my camera at work. She presented it at her science fair last night and people seemed interested. Unfortunately the LED stopped working - I think the reverse voltage when the wheel was spinning the other way killed it, should have put a diode in series with it.
 
Great project Ray, I'm enjoying watching your progress. Wondering how you are liking the 6-jaw, and if it's doing everything you hoped? Cheers, Mike
Hi Mike,

The chucks are beyond my expectations and they get a lot of use. Those two new chucks are my primaries now -along with the 5C collet chuck. I'm using the collet chuck less these days because the others are doing so well. I'll probably keep the existing 8", 4 jaw but may sell off the other two 3 jaw chucks I have.

The new chucks hold zero within about a thou over the full range of usable diameter and they hold parts in a pretty nice straight line; usually within 3 thou over 20 inches.

I had to develop a little technique to tighten them -not complicated. First snug the part up followed by backing-off about 1/4 turn then, wiggling the piece so it settles the jaws into position. A firm tightening after that and the part is usually right on. Since the shoulder was cut back on the backplate, I can do precise centering in matter of moments if needed.

Really good buy for the money...

https://www.hobby-machinist.com/threads/ordered-a-6-jaw-lathe-chuck.65884/

Ray
 
Look what showed-up today. It's very nice and small for a 1HP unit; lightweight too, at only 15 lbs. From the fan housing to the tip of the shaft, its 10" long. I had another motor that could have been used but, it was a 1.5HP heavy service class 2 device and I really did not want to use it for this project. https://www.ebay.com/itm/1-HP-Electric-Motor-METRIC-3600-RPM-3-Phase-C-Face-Aluminum/332411562201?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I have not wired it up for a test spin yet. Maybe tomorrow.
IMG_20180228_190606.jpg

Ray
 
Here's something I use all the time. It's a ram bar that fits in the ram of the tailstock. Make one sometime. They're very handy for this purpose. The SS block is lightly held in the jaws and a couple of parallels between the jaws to prop-up the part. The ram bar does a great job of applying even pressure to hold the piece nice and flat. Of course, it can be pushed by hand but, it's very easy to apply uneven pressure. REMINDER: Remember to remove the parallels before spinning-up the lathe.

When you press on the part by hand, when tightened, the jaws overpower you and the part shifts. This is less likely to happen with the ram bar. I used the ram bar when facing-off both sides of the piece and the width varied within 0.0003" measuring all the way around. You could tap on it with a dead blow hammer but, instincts tell me that the spindle bearings would prefer not to be pounded on.

View attachment 259830
Ray
I tried this today but couldn't get the parallels out after tightening.
 
I tried this today but couldn't get the parallels out after tightening.
I do not use a lot of force with the ram bar; just enough to hold it firmly. Once the jaws are tightened, I can wiggle them out of there without too much fuss. Similar problems like this arise when using parallels in the mill vise. Eventually, you'll develop a knack for how much pressure needs to be applied. Also, you can try to snug the jaws up firmly (but not tight) then remove the parallels then, give it the final tightening.

One other thing, when I tighten chuck jaws, I do not go ape-man on the t-bar. A quick push of body weight is all it takes. Don't pile-drive it with muscle -not necessary. Firm, yes. Gorilla -no.

If ever you're uncertain about tightness of a part in any jawed fixture, stop your work and check it.

Ray
 
Here's another odds&ends piece of metal now donated to this project. The metal was unmarked and judging by the way it cut, it's almost certainly 1018 or 1117. Couldn't pull a finish out of it to save my life. Anyhow, it was cut very unevenly and just barely the right diameter; also, it was just a little longer than needed. Make lemons out of lemonaide... When it was chucked-up, it was not pressed flat against the backside of the chuck. Instead the piece was positioned to minimize the amount taken off the outer diameter. The front/back was wobbling like crazy but the OD was running evenly.

The OD was skimmed just enough to get past the scale and preserve as much OD as possible. Only had to take off 25 thou. The cut was taken as close to the jaws as I dared go.
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The jaws on this chuck are running very true so, the piece was just flipped and the remaining scale was cut off. The OD's of the first and second cuts to remove the scale matched-up remarkably well. I'm loving this new 6 Jaw.

After the OD was trued-up in 2 steps, then finally, the faces were squared-off. This brought the length down right in the ballpark. One side needed this little shoulder to match the pocket in the stainless piece made yesterday.

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Here it is sitting in place on top of the stainless steel thingy from yesterday.
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Next, I'll attach that carbon steel puck to this piece of mild plate steel which is about 0.75" x 6" x 8". Initially I thought I'd weld the carbon steel puck to the plate but, I'll go with bolts to keep from warping the daylights out of everything. Also, if this project crashes and burns in failure, I'll stand a chance of reusing some of the pieces later on.

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I think you get the picture... Some brackets will be made to hold the spindle to the heavy plate. [Not shown: Some other brackets will extend from the plate upward and above the spindle to another plate that will hold the motor. I'll put (TBD) vibration isolators in the upper plate that holds the motor. Oh, BTW, the shaft on the spindle will get trimmed down as soon as the bracket arrangement is worked-out].

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At this stage, we're really winging this part of the project because, everything is coming from available shop drops.

Until next time...


Ray
 
The good news, this is coming along... The bad news, it's coming along at a snail's pace.

The crude housing and motor bracket is made from 3/16 plate steel. The pieces are just big enough that they're a royal pain to cut precisely. I roughed them out in the bandsaw then, squared them up in the mill. In the picture here, there's just a couple tack welds holding the box together.

Here's the front:
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The motor will sit on another plate directly above where it is now and that second plate will be affixed with some adjustable stand-offs. That way, the belt can be tensioned by moving the plate. Some sheaves will be needed but first, I'll need to find a small flat drive belt.

Here's the back:

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Anyhow, this will need to grind along for a while longer. This is what happens when something is being made from shop drops. One part of me loves to improvise... the other part of me hates how much longer it takes to get things done properly when you're "winging it on the fly".

Ray
 
We're getting there.... We're down to the last quarter mile or so.

It' welded-up adequately. I didn't use filler rod, just fusion welds everywhere. The top part bolts to the heavy base plate with some 10Mx1.5x25 socket head bolts. It's in the final position but is just balanced up there. The bolt hold that allows it to attach to the column is not drilled yet.

I've got to focus on determining the proper diameter belt and start tracking one down. ...And all those edges and corners need to be rounded down.

Lot's of steps to go. I should probably make a list...
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That's it for today...

I'm going to chill for a while and listen to the wind. It's pretty bad around here today. 75MPH gusts. My neighbor lost a tree a few hours ago.

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Ray
 
Here's the platform bolted to the column. Once that bolt is tight, the assembly is rock solid.

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Turns-out, I had a 24" OD, 3 groove serpentine belt in the shop. I won't need to order one. So... it was time to make some sheaves.

This bar is 4" diameter and pretty darn heavy. It's giving the 8" chuck a run for it's money.
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To clean off the scale, you don't wear your best Sunday carbide. I keep a few ratty inserts around for just such occasions. This made a mess. It also gave this 1236 lathe a real workout. The motor could handle it just fine but, a large diameter bar like this is pushing the envelope of carriage and compound travel. In all likelihood, I'm going to spring for a larger lathe sometime soon.
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Cruising right along... Here's are two nearly complete sheaves. The grooves match the spacing on the belt.
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Normally, I would have no problem parting but this piece, even supported with the tailstock, is sticking out too far and is too heavy. Over to the bandsaw we go.
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Anyone care to guess how long it took to cut in the bandsaw? Or, if you really want to take guesses, try to guess how many thousandths the width varied after the cut.

OK, more later today...

Ray
 
Two more pieces to the puzzle. One of them needs a keyway which will be taken care of tomorrow. I'll also make a couple temporary shafts and check them for even balance. The diameter should be big enough to not beat the daylights out of the belt. A sharp turn radius and 3600 RPM will wear out belts quickly.

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Ray
 
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