HOME
What's New

 

Workshop Stuff

Workshop

Moving the mill

Spindle Noises

ShumaTech Digital Readout

ShumaTech DRO Continued

ShumaTech
DRO-350 Repairs


South Bend 9" Lathe

South Bend 405 Lathe Bench

Grizzly Mill Revisited

Surface Grinder Rebuild

Surface Grinder Continued

Grinder April 6, 2008

Grinder April 20, 2008

Grinder August, 2008

Grinder September, 2008

Grinder November, 2008

Grizzly G3103 Mill
Rebuild

Grizzly G3103 Mill
Rebuild - Part 2

Moving the Shop

Moving the Shop 2

Bringing Home a Sheldon 12" Shaper

Sheldon 12" Shaper 2

Sheldon 12" Shaper 3

Sheldon 12" Shaper 4

Sheldon 12" Shaper 5

Sheldon 12" Shaper 6

Sheldon 12" Shaper 7

Sheldon 12" Shaper 8

Sheldon 12" Shaper 9

Way Alignment Tool

 

 

Email Jim


 workshop.gif

Sheldon 12" Shaper - pg. 6
October 14, 2015 - November 9, 2015

When I finished the last installment, I had taken a test cut. The test cut was pretty successful considering that I hadn't used a very good method of holding the cast iron test block to the table. I had seemingly solved the problem with the tool head creeping downward during cuts. The tool head lock was also working as it should. However, I had run into another issue. Two steps forward and one step back. The stroke made by the ram, which can be set from 0" to 13.5" was increasing in size as the shaper ran. I had set the stroke to 7" and by the time the table moved 4" laterally to finish the cut across the width of my test block, the ram stroke had increased to 10". Obviously, something wasn't right.

Looking at the stroke adjusting rod in the parts breakdown (below left), I noted that part #44 was labeled as a tension nut (expand the image for the names of the parts). Since it had a spring behind it, I was hoping that this nut would be able to make the adjusting shaft a bit harder to turn and solve my problem. To get at this nut, I pulled off the two arms (#5 and #33 in the second picture). I also removed the two screws that appeared to hold the cover in place. At that point, I didn't realize that the parts image I was looking at (below left) didn't have all of the parts shown. The screws are part #21 on the second image. With everything I could see that appeared to hold the cover in place, it wouldn't budge. I messed with the cover for about an hour and called it quits for the night.

The next day, I looked through the parts drawings again and found the second image. This time I saw there were also two taper pins (#20). One next to each of the two screws. I measured both ends of the one taper pin I could easily get to and found that the small end was on the back side of the housing. There was no way I could get a pin drift and hammer in that small space to knock out the pins. What to do? I cobbled together a C clamp with a pin on one end and a socket on the other to try and press the pin out, but knew that the effort would be futile. It was. These pins were stuck in place.

stroke_adjuster
table_indexing
Page 6 from the Sheldon Shaper parts manual.
Click to enlarge and show the part names.
Page 8 from the manual.
Click to enlarge and show the part names.

I had noticed that there were two studs with locking nuts on the top of the cylindrical housing that attached to the rear housing of the cover I needed to remove. These are not shown on either of the parts drawings. When I was cleaning the shaper and trying to understand the purpose every nut and bolt, I had assumed that these were for some sort of adjustment, but what that adjustment could be I didn't know. Each of the studs had a socket for a 1/4" Allen key and the lock bolts took a 3/4" wrench. You can see one of the studs with its lock nut on the 6th image on top of the housing on the right. With nothing left to try, I decided to mark the position of each of the studs so I could return them to their current position and see what happened if I loosened them up. This attempt solved the problem of removing the cover. With both studs backed off by 1/2 turn, the whole housing assembly was free to be pulled off of the machine. The two studs press on the inner cylindrical housing that attaches to the shaper body and hold this housing in place. To replace it, it appears that you just push it back on and position it so that the two arms fit and tighten the studs and lock nuts.

stroke_adjust1
stroke_adjust2
The stroke adjuster rod is the lower squared shaft.
The upper domed knob lets you adjust the amount that the table advances per stroke.
Once the whole assembly is removed, you are looking at the stroke adjustment nut and the gear that drives the table advancement.

Once the housing assembly is removed, I found that I didn't need to remove the cover that I had been fighting to get off unless I wanted to take a look at the gear that drives the table indexing for its side to side travel. This is another case where experimenting can lead you to a discovery. Even though it wasn't necessary for the current repair, I decided to go ahead and drive the old taper pins out and remove the front cover. As long as I had the assembly out, I might as well clean the rust off of it and check the gears for wear. After all, this is a 60+ year old machine and I am assuming that this is the first time it has been disassembled this far. The taper pins came out with a couple whacks with a hammer on a pin drift. The pins were a little rusty and the small ends had been mushroomed a bit by my knocking them out. Contrary to my usual situation of not having the correct pins in stock, I happened to have a good supply of the correct taper pin - #2 pin, 1" length. I have more of these than I could ever use. If you need a couple, send me an email and I'll drop a couple in the mail for you.

With the adjuster nut exposed, it was time to see if I could increase the tension on the adjusting shaft so that the shaft wouldn't turn on its own. The adjuster nut takes a 1 1/8" wrench and I had assumed that I would need to tighten the nut a small amount to add some tension to the shaft, but I was wrong. To be on the safe side, I again marked the position of the nut on the shaft so I could return it to the position I found it in and then tried tightening the nut clockwise by a quarter turn. Tightening the nut took tension off the shaft. OK, no problem, let's try turning the nut counter-clockwise. I turned the nut back a quarter turn, then an additional quarter turn. The shaft appeared to get a little harder to turn. I went another quarter turn and the shaft was now locked up from rotating. I backed off (turned clockwise) about a 1/16th turn and tried cranking the adjuster rod again. It seemed to have more tension but wasn't too hard to turn. I will try it here. If the truth be known, I have no clue whether my adjustment will solve the problem. However, it seems like it should. I guess I will know soon enough.

Since there is a fair amount of dirt and rust on all of the parts in this assembly, I decided to clean things up a bit before I reassembled and tried another test cut. While I would like to reassemble the machine and take a test cut right now, I know myself too well. If I don't take the time to clean up the rust, it will not get done until I decide to strip the whole machine for painting. Since that's not on my agenda right now, I might as well do what I can to get rid of the rust.


stroke_adjust3
stroke_adjust4
A 1 1/8' wrench fits on the tension nut. It appears that turning the nut counter-clockwise makes the adjustment shaft harder to turn.
The parts of the housing and cover that I was having trouble separating. I have some new #2 taper pins along with the old ones.

It turned out to be well worth my time to strip down the housings to clean the parts and give the painted parts a better coat of paint. I ended up finding a couple parts that might have been lost if I wasn't paying close attention. The two studs with lock nuts that secure the housing assembly to the cylinder on the side of the shaper do not bear directly on the cylinder shown above right. There are two wafer thin bronze shoes that sit at the end of each stud that fit between the studs and the cylinder they bear on. One fell out while I was cleaning up the rear cover housing. As soon as I saw it, I knew what it was and scolded myself for not checking the bore of the housing more carefully. I was lucky it didn't end up on the floor to be vacuumed up later in the day. The other disk shaped shoe was still on the end of the second stud. I removed the shoe and both studs and continued cleaning the housings so I could give them a coat of paint. I got one coat of paint brushed on in the late afternoon and another coat later that night. Hopefully I will be able to reassemble everything tomorrow and test to see if I have fixed the issue with the stroke increasing on its own.

To get the eccentric off (lower left photo - the part with the divisions), you need to remove another taper pin. This one is driven out from the gear. The size of this one is a #1 - 1 1/4" in length. This pin came out easily and can be reused, but I have some of these in stock also. I may not have all sizes of nuts and bolts on hand, but I have an excess of taper pins. All of them received from a guy who was down-sizing his workshop. With the taper pin out, the gear pulls off from the rear and the eccentric pulls out from the front with the attached shaft. I cleaned and buffed all the shiny bits and added a coat of paste wax to help to keep them from rusting. I wax pretty much everything that is bare metal after finding that just wiping parts with way oil every few months wasn't enough to stop the surface rust I get in this shop. I have only been using the carnuba paste wax for a couple months, but it seems to protect the bare metal very well. I put it on thick and don't buff all of it off. A quick wipe with a rag or shop towel on parts like squares of parallels gets them ready for use. So far, I like this a lot better than way oil or the spray on anti-rust coatings, but I have yet to go through the worst part of the year for rust. Spring and early summer seem to be the rust seasons in my shop.

Another interesting thing I found is that the two bronze bushings that support the eccentric's shaft have no provision to be oiled. Page 8 of the parts manual says that they (#9 & #15) are bushings. Other bushings on the same page are listed as Oilite bearings. From their appearance, I believe these are the Oilite type also. Oilite bushings are made from sintered bronze and are oil impregnated, but I would prefer to be able to oil them when I use the shaper. Since there is no way to oil them without disassembling the housing, I will recharge them with oil. To recharge them, you soak them in mineral oil that is heated to 80 to 100F and let the bushing cool to room temperature. I have also read that they can be recharged by placing the bushings in oil under a vacuum. I will soak them in heated oil and let it go at that. The shaft that turns the eccentric spins slowly and after 60 years, there is very little play between the bushings and shaft. The gears are also in great condition. There is virtually no wear, just a nice even polish to the face of the teeth.


stroke_adjust5
stroke_adjust6
Two bronze shoes that fit on the ends of the two locking studs that hold the assembly to the shaper. I am starting to clean things up a bit.
The assembly is back together and I am ready to test it. This didn't go so well, but I learned a few things that helped me make it right.

After heating up some ISO Grade 32 turbine oil and soaking the bushings in it for a couple hours, I cleaned up the mess and reassembled the housing. I used some grease to hold the bronze shoes in place and reinstalled the housing. The whole process went pretty quickly and I was soon ready to reattach the two arms. The rear arm secures the housing to the back of the table advance mechanism which is connected to the cross rail. The front arm connects the eccentric to the front of the advance mechanism and is responsible for moving the ratcheting cogs that move the table either left or right.

When I had initially checked the tightness of the studs on the housing, I had found that the two studs were not all the way tightened down. Once I found that loosening them allowed me to remove the housing, I didn't give their tightness much more thought. When I reinstalled the housing, I cranked the studs until they fully seated the shoes against the cylinder they pressed against. I reinstalled the two arms and figured that I was ready to take a test cut. I mounted the test block on the table and started to raise the table into position. After one or two cranks, the table wouldn't elevate any more. After a couple moments thought, I realized that the rear arm (below right) tied the housing to the cross rail. The cross rail is what moves when you raise and lower the table. Instantly, the signs of wear on both the shoes made sense. The housing was supposed to rotate as the cross rail was raised and lowered. If the housing couldn't rotate, it bound up the cross rail. It was one of those "Duh" moments.

I backed off both the studs by enough that the housing could rotate and I could now raise and lower the table. I was set. Or so I thought. I started my test cut and by half way through the 4" wide cut, the stroke was advancing on its own again. I removed the arms and pulled off the housing once again. I checked the tension on the stroke adjusting shaft and it turned a little easier than I thought that I had set the tension to. I would try again. This time, I turned the adjusting screw counter-clockwise until the stroke adjusting shaft had a good deal more tension while turning with the crank. If I get it right this time, I will put a constant reading torque wrench in place of the crank to check the amount of resistance when I turn the shaft. Hopefully having a reading in inch or foot pounds will help in case I need to go through this again.

stroke_adjust7
stroke_adjust8
The two studs with lock nuts on the rear cylinder are not meant to hold the housing stationary. The housing needs to be able to rotate.
The rear arm is attached between the shaft on the table advance and the housing. If the housing doesn't rotate, the table height won't adjust.

I reassembled all of the pieces I had removed and tried cutting my test block. I had a better outcome this time. I was able to cut the whole 4" wide surface without the stroke straying from where I had set it. At this point it is a little early to say that I have fixed the issue. I will try some more cuts tomorrow. If it holds the adjustment without the stroke increasing, I will then be a bit more confident in saying that it appears to be fixed.

The next evening, I spent a few hours running the shaper. The issue with the stroke increasing by itself appears to be fixed.

images/sheldon_test_cut1
sheldon_vise_body8
The first test cut. I am using some milling hold-downs and wedges to hold the block in place. The results were only fair.
Planing the rails of the vise body. This is a much more secure setup and the accuracy of the cut reflects this.

I planed a few pieces of different sizes and materials, all of which were mounted directly to the table with studs and wedges. I had given up on using the two piece vise and was now using blocks and wedges. These have their own problems, but I will get to that in a moment.  Each piece, after being planed on two opposing sides, was then transferred to the surface plate and checked for being parallel with the plate. My worst case readings were about 0.001" per 6" out of parallel in the X axis. The Y axis measurements were always about half the error of the X axis.  Not bad, and certainly better than before I started scraping, but not as good as I thought it should have been. I have read that being able to plane to around a thousandth is thought to be pretty good for this size of machine. Remarks like "the shaper isn't a surface grinder" come to mind, but I am sure that with some time to refine my setups, my planing errors will come down a little.

sheldon_vise_body9
sheldon_vise_body10
Checking for parallel between the vise rails and the bottom scraped surface.
The surfaces came out pretty close to dead on. I am very pleased with the results.

Since the stroke was now staying put, it was time to plane the rails of the shaper vise body. With the bolt holes in the vise body to allow me to hold it to the table securely, I thought that this would be the first good test of how accurate the shaper was. The bottom of the vise body was scraped flat and I had rechecked the table with a straight edge to make sure that there were no burrs. Due to the vise jaw and the need to under cut the bottom of the vise jaw a small amount, I decided to use a tool bit mounted directly to the clapper. Not the best setup due to a lot of extension on the tool bit, but it ended up working very well. The vise rails came out almost dead flat and parallel with the bottom of the body. The finish came out nice enough that I don't feel the need to scrape it. I think that my test blocks were coming out a little less true than the vise body did due to the poor method of holding the test blocks to the table. With the test block only being held by the side forces from wedging against some hold down clamps, I wasn't getting as much downward force as with the vise body. Even though I had tapped the block with a mallet to seat it, it's hard to come close to the force exerted by bolting something to the table.

sheldon_vise_body11
sheldon_vise_body12
The vise has been mounted to the swivel base and I am now checking parallel for the whole assembly.
Again, the results are very good. The time spend scraping the vise surfaces has paid off.

I mounted the vise body on the swivel base and measured again on the surface plate. It appears that I did a pretty good job on my scraping. The rails are withing a couple tenths of being parallel everywhere I put the DTI. I am happy with the outcome. The next step was to test and grind the vise jaws or make some new ones. I will probably end up doing both. The vise jaw faces were pretty scarred up and were both a little bowed. The worst one allowed me to slip a 0.010" feeler gauge under the center. I took the jaw pieces to the hydraulic press and set up a couple blocks to try and get the bow pressed flat. This is tricky work, but after an hour or so, I had both jaws flat enough to put them on the magnetic chuck of the grinder. I ground 0.007" off of one side of both jaws, then flipped them over and ground another 0.008" off the other side. I printed them on the marking surface plate and they looked good.

sheldon_vise_jaws1
sheldon_vise_jaws2
The jaw faces are not in the best of shape. That's a 0.010" feeler under the jaw on the right.
The jaw faces are attached for a test fit. Some testing revealed that I still have some work to do.

I mounted the jaw faces on the chuck. I then stacked two, half inch thick, one inch wide, by six inches long parallels on the rails and tightened the vise jaws snug. The bottom parallel held tight, but the top one could be moved. There wasn't a lot of slop, but there was enough that the top parallel wasn't trapped by the jaws. Hmm, this isn't good. The jaw faces don't seem to be parallel.

I had already measured and machined a step into the two rub plates on the underside of the rails that hold the moveable jaw tight against the vise rails. I did this to adjust for having planed the rails. Planing the vise rails had introduced more of a gap between the rub plates and bottom of the vise rails.  I had relieved the portion of the rub strip that mounted to the moveable jaw so that I had less than a thousandth clearance between the rub strips and the bottom of the rails. The moveable jaw was as tight to the rails as I could get it without making the jaw hard to move. It was now time to do some measuring to see where the problem lies. I had hoped that the jaws would have been perpendicular with the rails, but knew that this probably wouldn't be the case. While I've rebuilt a Kurt clone import mill vise with good success, this vise wasn't quite the same. Not to shift the topic, but Kurt has some good instructions for rebuilding their D series vises here. The mill vises like the Kurt D series have a removable fixed jaw aligned with a key. The Sheldon vise has the fixed jaw cast along with the base. From what I have read, for the best holding ability, the fixed jaw should tilt a bit inward rather than being machined or ground at exactly 90 to the rails. This is done so that when the vise is tightened, the fixed jaw flexes into a state of being very close to 90 rather than obtuse and past 90 by some small increment.

sheldon_vise_jaws3
sheldon_vise_jaws4
Scraping the fixed jaw so that the top of the jaw is angled toward the rear jaw by a couple tenths.
The moveable jaw's first print after knocking down a few burrs with a coarse stone.

Since I need cut the stationary jaw to be a bit less than perpendicular, I thought that the following operations could do what I needed: from least to most accurate. Plane it on the shaper, if I shimmed the vise base on the table to the correct angle. I wouldn't want to try and set the tool head to cut a fraction of a degree. Using a cup wheel on the grinder would also work, again by shimming the vise to achieve the very slight angle I needed. Last, I could scrape the fixed jaw. This would be a little more time consuming than grinding, but since this is not a sliding surface, the points count doesn't need to be very high. I chose scraping. Since scraping takes metal off more slowly, I stood a better chance of getting the angle where I wanted it. I clamped the vise body to an 8" angle block and clamped the block to the bench. I checked my progress with a precision square backed by a bright light. When the jaw was flat and I could just see a hint of light at the bottom of the fixed jaw, I stopped scraping. It took less than an hour to complete.

I reassembled the vise with the hard vise faces and again tested the holding ability. It was better, but not quite there yet. Time to check the moveable jaw. Once the jaw was on the bench. I did what I could to knock down the high points with a rather coarse grit stone, then cleaned it, and put it on the marking plate. Aside from a ring around the large hole where the screw resides there were only a couple of burrs touching the plate. A couple cycles later, I got to see something interesting. In the picture below left, you can see that there is a hollow area across the top center of the moveable jaw. Since the jaw face still showed the machining marks from a large face mill, at one point in time it was fairly flat. Now, not so much. I am always interested in trying to figure out how surfaces get out of alignment. If I had to wager on this one, I would put my money on compression/deformation of the top center of the jaw from years by having smaller objects held in the center of the vise and then cranking the jaws very tight. When I first checked the vise, there was a lot of slop between the moveable jaw and the rails. This meant that the top of the jaw was tilting away from the fixed jaw when tightened.  I'd guess that some operator kept tightening the jaws to try to overcome the fact that the work wasn't being held securely. The top center of the moveable jaw is dished by about a thousandth. Time to do some more scraping.

A couple sets of step scraping passes and some finish scraping to even out the points count a bit and I was ready to check the holding ability of the jaws again.

sheldon_vise_jaws5
sheldon_vise_jaws6
The top center of the jaw is a bit hollow. I have more rough scraping to do.
After another round of step scraping and some work to get a more even bearing, I was done.

This is the first time that I have tried stacking parallels to check if the vise jaws were true with each other. I don't know if I read about this procedure somewhere or I came up with it on my own, but it seems to work very well as a test. Out of curiosity, I checked my milling vises using the same method. All of them passed the test with only a slight snugging of the screw.

I reassembled the shaper vise and tried the test without the jaw facings. The parallels were both held tight with only the slightest pressure from the screw. I then cranked the screw tight and there was no change. Both parallels were still trapped tightly by the jaws. I placed the top parallel at the very top of the jaws and repeated the test. Same results and still good. I reattached both ground jaw faces and tested again. I had figured that I would get the same results, since I had checked the jaw faces with a micrometer and on the surface plate and found that the grinding had brought them to within a half tenth of being parallel. However, it was still a nice confirmation that with the faces installed, that testing with the parallels passed with flying colors. Cool. I had succeeded in aligning the jaws. The next step was to get the tops of the jaws parallel with the vise base.

sheldon_vise_jaws7
sheldon_vise_jaws8
I tested the jaw alignment with the top and bottom parallels separated by a quarter inch.
After some time on the grinder and about 50 thou. removed, the tops are parallel within 0.0002".

The tops of the jaws had a fair amount of battle scars. For about 60 years of age, they looked about like you would figure. Not horrible, but the jaw tops showed signs that, at least a few of the operators weren't paying attention during its life. Initially, I was going to true the tops of the jaws with the shaper and finish with grinding, but my surface grinder hasn't seen a lot of use in the past few years and it could do with some exercise. I had done a rough measurement and knew I needed to remove at least 0.035" to get the tops of the jaws lined up and this measurement didn't include the battle scars. I ended up grinding off 50 thousandths and still had a couple divots left. I ground pretty aggressively and was grinding dry, so I introduced a bit of heat in the vise and that wasn't good for accuracy. I decided to stop for the night and do a quick measurement of the jaw tops on the surface plate, then grind the remainder the next day. Even with a slightly warm vise, I measured less than 0.0002" discrepancy over the seven inches of the jaw tops. I hope to improve on that tomorrow.

sheldon_vise_jaws9
sheldon_vise_jaws10
Another 0.009" was removed and it looks nice. A texture difference shows between the cast iron of the body and the steel of the jaw faces.
After putting the vise on the surface plate, I found less than a tenth height difference after loosening and snugging the jaws. I am pleased.

With my grinder coolant pump waiting on a roto-flex seal and the make-shift pump not having enough head pressure to give a decent flow, I again had to grind dry. I ground another seven thousandths off and had finally removed all of the divots. I didn't feel any appreciable heat in the jaws, but let them sit for a while as I re-faced the stone for the final passes. I took a couple five tenth passes, a few two tenth passes and then sparked out. With coolant, it only takes a couple passes until there are no sparks coming from the wheel as it traverses the work. Grinding dry seemed to take quite a few more passes. When the grinder wheel finally stopped making sparks, I was done. I have to say that changing the belt on the grinder made a big difference. I am now seeing none of the patterns on the ground surface that I saw with the old belt. I was quite pleased with the surface finish. The finish of the ground cast iron looks a little darker than the steel jaw faces, but both the CI and the steel look very smooth and uniform.

I moved the vise to the surface plate and was happy to see that I had improved the surface. I was now reading less than a tenth difference in height on the seven inch width of the jaws. It's about a half tenth concave in the center. I was quite pleased that I could open and close the vise jaws and measure no lip when I passed the stylus over the point where the jaws met. If I cranked down hard on the handle, the rear jaw lifts a few tenths, but that is to be expected with the design of this vise. Overall, I think I did a pretty good job. I will be interested to see the outcome when trying to true up my test block.

As seems to be typical for me, on the afternoon I finished grinding the vise, the new roto-flex seal arrived. Hopefully I will again have a working coolant pump on the grinder soon.

sheldon_vise_jaws11
sheldon_test_cut2
After a few months work, the swivel vise is finally mounted back on the table. It is now much more accurate than when I began.
After a couple of test cuts, I learned a few things and was able to get the top surface very close to parallel with the bottom.

I touched up a couple spots on the vise where I had damaged the paint and the next evening, I mounted my cast iron test block in the vise. I added some thin squares of paper under each corner of the block and tightened the jaw. The end of the block nearest the moveable jaw lifted a very small amount. Just enough that I could move one of the papers a fraction before it became trapped again. I used a mallet to tap down the block and snugged the jaw a little tighter. All four papers were now trapped, but as I would find out, not trapped well enough. I set the ram travel and position and turned the shaper over by hand using the Reeves drive pulley. I happened to turn the pulley the opposite direction and the ram didn't move until I had turned the pulley about a half turn. Strange. I hadn't noticed this before. I checked to see that the secondary shaft was turning without the lag and it was. I surmised that the only thing left to check was the shaft that runs the planetary gears that act as the back gear. I pulled off the cover and found the problem. When the lever is shifted into direct drive, there is a pin that is forced into a hole in the shifter collar. There are two holes on the shifter collar with a semi-circular relieved area between them. Apparently when I had shifted into direct drive, I had only seated the pin into the relieved area and not into one of the two holes. This allowed the pin to move a half a revolution without driving the collar. I will need to pay attention and make sure that the pin is fully seated and the shift lever is turned all of the way to its stop.

I set up to take a 0.005" cut and got to enjoy watching the shaper peel of tiny curls of cast iron. With the block resurfaced, I pulled it out of the vise and measured it on the surface plate. The bottom of the block had been surface ground, so I knew that it was pretty flat. The questions was - how parallel was the top surface to the bottom. The answer was that in the X plane, it was as good as I was hoping for. There was more wavering of the needle on the half-tenth resolution DTI due to the surface finish than there was error that I was able to read. In the Y plane, it wasn't as good. The end that was chucked nearest the operator was low by 0.0007". I took this to mean that the moveable jaw had lifted and had raised the rear of my test block a bit.

Trying to get to tenths of accuracy is a fiddly business. Not only does everything need to be spotlessly clean, but with this vise, it means that the amount of clamping force can't be too high. The vise is not designed like a Kurt where the moveable jaw is pulled downward as you crank tighter on the screw. In fact, it's closer to the opposite. When the screw is cranked tighter, the moveable jaw tilts by, at least, the amount of clearance between the jaw bottom sliding surface and the tops of the vise rails. With this in mind, I decided to try the next cut with just enough force on the jaws to hold my test block securely. This was the trick that made the difference. After the next cut, I was still at around a tenth or two in the X plane, but I had improved the Y plane to two tenths. I spent the rest of the evening cutting the four faces of the test block a couple thousandths at a time and checking the results on the surface plate. My measurements over a dozen cuts went from a tenth at the best to a worst case of a half thousandth over the 4.5" X 6.5" test block.

sheldon_test_cut3
sheldon_test_cut4
This is my attempt to measure flex in the over-hanging section of the vise body.
Instead of flex, I am probably reading the machine rocking and need to bolt the shaper to the floor.

Early in the process of working on this shaper, I put up a picture of a shaper vise that had a pair of bosses to support the rear section of the vise. I thought it looked like a good idea to reduce flexing of the vise body. I decided to try and measure if there was any flex when taking a light cut. I mounted the DTI magnetic base to the side of the table and placed the stylus under the vise. I then cut the surface of the test block again. What I saw convinced me that I need to bolt the shaper to the floor. The DTI needle was bouncing between about a half and full thousandth. I took a couple pictures that seem to show that there could be some flex, but I don't think that's what the DTI is showing me. It is more likely that the needle is bouncing due to the fact that the shaper is rocking on each stroke and the DTI needle is bouncing rather than reading flex in the vise. I won't be able to confirm this until I secure the shaper to the floor.

Time to wrap up this installment. I am close to accomplishing the goals I set when I took my first cuts and found that the shaper wasn't as accurate as I had hoped it would be. I think I have been successful in helping this shaper produce a little more accurate work as well as taking care of a couple problem areas that I found. The shaper now runs as I figure it should and produces fairly accurate cuts. The next projects are to bolt the shaper to the floor and to try and recreate the missing ball handle that is used to lock the ram position. As far as the ball handle is concerned, my shaper currently has a single nut in place of the missing ball handle. I posted a message on the Yahoo Metal Shaper group asking for the dimensions of the handle and a nice gent in Washington state supplied me with the information I needed. All I need to do now is to build the radius turning attachment for my lathe so that I can make the ball handle. Sounds like fun to me.


Shaper 1
Shaper 2
Shaper 3
Shaper 4
Shaper 5
Shaper 6
Shaper 7
Shaper 8
Shaper 9


Fager November 9, 2015