The Sherline's gettin' some love

[ddmckee54]

I'm sorry about that last post, my computer locked up in the middle of actually posting it, and the post got hosed up. I re-booted the computer and it's playing nicer now.

The post should have looked like this:

It doesn't show in the model I posted, but one of the screws I kept forgetting to model is directly under the slot in the cross-slide. There IS room there, I've got 40mm of separation between te top of the cross-slide and the top of the carriage scale. But it would need a major redesign of at least three of the brackets. Still, it's something to keep in mind for the future.

OK, good news - bad news.

The good news is that when I came downstairs this morning I found this rather unimposing pile of parts on the build-plate, instead of the rats nest I was afraid I'd find.
View attachment 165848
You gotta love those magnetic build-plates, all the parts just popped loose when I pulled the plate out of the D6. Initial inspection showed that all of the parts looked good, and all of the holes lined up like the model said they would.

I did a little sanding on the surfaces that needed to mate together, just to be sure the printed surfaces were flat. There are only two parts that I couldn't build any adjustment into, the cross-slide scale mounting bracket in the upper RH corner of the photo, and the carriage read-head mounting bracket in the lower LH corner. The cross-slide bracket slides into the T-slot on the slide and uses the slot as its' anchor point. The carriage bracket uses those two screws that I kept forgetting to model as its' anchor point. The bad news is that neither one of these parts actually fit.

The cross-slide bracket did not fit in the slot. Since this part is supposed to fit in the T-slot so it has a complex cross section. To avoid the need for supports I print this with its' RH side, as you see it in the photo, on the print bed. This orientation also makes it the tallest part. With its' small cross section at this point in the print there's not much time for the plastic to cool between layers, even with the cooling fan at 100%. So I got a little sag, not unexpected, so that was attacked with the files - still didn't fit. I checked the thickness of the web that fits in the slot. The slot is 6.4mm wide, the web is 6mm thick, I checked the depth of the slot the flanges fit into, it's 2.6mm - the flanges are 2mm thick so they're OK. I checked the overall width of the slot for the flanges and it's 10mm, ish. The flanges measure ... 11mm? WTF, how'd that happen? Oh well, I can always mill 0.5mm off each flange - Easee-Peasee.

On to the carriage bracket problems. Remember those two screws? Well there weren't two, there were three. I forgot about the 8-32 SHCS that secures the tapered gib for the carriage. I modeled them last night, LATE last night. I wanted to get the print started before I went to bed. I hand drew a sketch of the screws and their sizes/locations. The 3D model "Sketch" I was working with was inverted to my hand sketch, so I flipped my hand sketch over. I didn't want to model a mirror image of what I actually wanted. That SHCS is one of the problems with the bracket. The head of that screw is 7.62mm in diameter, I only allowed an 8mm slot. With my FDM 3D printers that ain't enough clearance fo r comfort Clarence, it's WAY too snug. The other problem with this bracket is the location of the slot for the existing screw at the tailstock end of the cross-slide, it's off by about a mm. This one needs a re-print.

Oh well, since I've got to fix and re-print the carriage bracket, I might as well fix and reprint the cross-slide bracket too. To avoid any further issues with the cross-slide bracket I attacked the flanges with the belt sander, just as a sanity check to be sure there weren't anymore problems - fits like a glove.

 

[SmithDoor]

I'm sorry about that last post, my computer locked up in the middle of actually posting it, and the post got hosed up. I re-booted the computer and it's playing nicer now.

The post should have looked like this:

It doesn't show in the model I posted, but one of the screws I kept forgetting to model is directly under the slot in the cross-slide. There IS room there, I've got 40mm of separation between te top of the cross-slide and the top of the carriage scale. But it would need a major redesign of at least three of the brackets. Still, it's something to keep in mind for the future.

OK, good news - bad news.

The good news is that when I came downstairs this morning I found this rather unimposing pile of parts on the build-plate, instead of the rats nest I was afraid I'd find.
View attachment 165848
You gotta love those magnetic build-plates, all the parts just popped loose when I pulled the plate out of the D6. Initial inspection showed that all of the parts looked good, and all of the holes lined up like the model said they would.

I did a little sanding on the surfaces that needed to mate together, just to be sure the printed surfaces were flat. There are only two parts that I couldn't build any adjustment into, the cross-slide scale mounting bracket in the upper RH corner of the photo, and the carriage read-head mounting bracket in the lower LH corner. The cross-slide bracket slides into the T-slot on the slide and uses the slot as its' anchor point. The carriage bracket uses those two screws that I kept forgetting to model as its' anchor point. The bad news is that neither one of these parts actually fit.

The cross-slide bracket did not fit in the slot. Since this part is supposed to fit in the T-slot so it has a complex cross section. To avoid the need for supports I print this with its' RH side, as you see it in the photo, on the print bed. This orientation also makes it the tallest part. With its' small cross section at this point in the print there's not much time for the plastic to cool between layers, even with the cooling fan at 100%. So I got a little sag, not unexpected, so that was attacked with the files - still didn't fit. I checked the thickness of the web that fits in the slot. The slot is 6.4mm wide, the web is 6mm thick, I checked the depth of the slot the flanges fit into, it's 2.6mm - the flanges are 2mm thick so they're OK. I checked the overall width of the slot for the flanges and it's 10mm, ish. The flanges measure ... 11mm? WTF, how'd that happen? Oh well, I can always mill 0.5mm off each flange - Easee-Peasee.

On to the carriage bracket problems. Remember those two screws? Well there weren't two, there were three. I forgot about the 8-32 SHCS that secures the tapered gib for the carriage. I modeled them last night, LATE last night. I wanted to get the print started before I went to bed. I hand drew a sketch of the screws and their sizes/locations. The 3D model "Sketch" I was working with was inverted to my hand sketch, so I flipped my hand sketch over. I didn't want to model a mirror image of what I actually wanted. That SHCS is one of the problems with the bracket. The head of that screw is 7.62mm in diameter, I only allowed an 8mm slot. With my FDM 3D printers that ain't enough clearance fo r comfort Clarence, it's WAY too snug. The other problem with this bracket is the location of the slot for the existing screw at the tailstock end of the cross-slide, it's off by about a mm. This one needs a re-print.

Oh well, since I've got to fix and re-print the carriage bracket, I might as well fix and reprint the cross-slide bracket too. To avoid any further issues with the cross-slide bracket I attacked the flanges with the belt sander, just as a sanity check to be sure there weren't anymore problems - fits like a glove.

The lathe looking great

Remember the old days everthing work great.

I found this workers ever time and never need power or batteries. Take off shelf day night and works

This on my desk and used it too.
Works by candle light too

This off the internet looks new

https://sliderulemuseum.com/VirtualSR2/react/nestler_23r.html

Use C & D SCALE

Dave

 

[SmithDoor]

Just case you see how great side here ap DIGITAL SLIDE RULE.

 

[ddmckee54]

Yup, remember them well. I've still got my 10" engineering log-log slide rule around here somewhere.

 

[SmithDoor]

Yup, remember them well. I've still got my 10" engineering log-log slide rule around here somewhere.

Here site for real working sliderule

https://sliderulemuseum.com/VirtualSR2/react/nestler_23r.html

https://sliderulemuseum.com/VirtualSR2/react/hemmi_versalog_ii.html


I use C & D scale

Dave

 

[ddmckee54]

I finished the fixes on the cross-slide and the carriage bracket models. They're re-printing now and should be done in a couple more hours, it takes a while to print 50mm in height with 0.2mm layers. It's done with the flat part of the carriage bracket so the layers will go faster. I really need to get my resin printer set up and running.

Meanwhile, I can at least take the old scales off the lathe and start installing the new scales.

 

[ddmckee54]

The print completed, but they still didn't fit right off the printer. The carriage bracket still isn't right on the headstock end, the slots aren't deep enough. But ya' know what? A Dremel and a rotary burr fixed that problem REAL fast, I am NOT printing that sucker again. I am going to modify the 3D model though. That way if I ever DO have to re-print the bracket it will be a little closer to accurate. The cross-slide bracket was fitting too tight. A few licks with a file and some sandpaper fixed that problem. I powered up the new scales with the AC adapter, to verify which way the scales read. Then I marked them with tape as to which end went where and which direction was up.

Now I just need to install some heat set inserts, drill and tap a couple holes in the base, and do the final install. I also need to find my micro screwdrivers so I can open the battery cover. That way I can at least use the scales with batteries until I can get another plug and make a Y connector for the AC adapter.