Messages

I use a small platform bolted to the base of the scissors jig to sharpen all of my knives. About the only thing I use the SVM-45 for is lawn mower blades or the like.

Herman,

It probably doesn't really matter, but I am curious how long your platform is.  I am making one and the material that I have that is best suited is about 130 mm wide (5 1/8"). 

Rick

I found a reference in one of your posts that the stock you started with was about 10", for making two of them and having something long enough for cutting the concavity along the front edge.  I think my piece of aluminum will do.  I only have 3" drum sander for making the concavity.  Not as pretty, but at least it provide the relief needed.  It's actually more convex than concave, but I think it will go better when I put the metal cutting belt on it. 


A different question.  Why all the way to one side of the scissors jig base?  Why not in the middle? 

Thanks,

Rick

I use a small platform bolted to the base of the scissors jig to sharpen all of my knives. About the only thing I use the SVM-45 for is lawn mower blades or the like.

Herman,

It probably doesn't really matter, but I am curious how long your platform is.  I am making one and the material that I have that is best suited is about 130 mm wide (5 1/8"). 

Rick

Misalignment of the shafts can be fixed by a flexible coupling (simple as a piece of tubing, or custom made things) or you could have a wheel on the motor and then drive the shaft or knob with it. Kind of like how the grindstone is driven by a wheel.

If you can remove vibration you can determine if it's the vibration or something else causing it.

Yes, I have a flexible coupling coming from McMaster-Carr.  I'll give it another try once it arrives.  I also have some SS M10x1.5 threaded rod coming that I'll use to make a replacement TT screw to get away from having to attache the motor/coupling on the existing M6 threads.  It would also help if I got my knee mill back together and running so I could be a little more accurate when drilling holes, etc. 

Rick

I have gone back to hand turning the Truing Tool. 

After trying motorized version on my black stone, it left those angular wavy lines about a third of the width in from the outer edge.  I think without the dampening effect of the hands on the TT and USB, it is too free to vibrate.  I tried holding it while it was running and going as slow as possible, but I could not prevent the waves from forming until I disassemble the TT from motor, reinstalled the knob and trued the wheel by hand. 

It was fun trying.

Rick

After getting the intended fitting off and putting the threaded sleeve on it and checking runout with it in the lathe, there was less than 0.010" runout. 

Apparently not good enough.  Still too much wobble to bolt it all down snuggly. 


It would work as is, with not all the screws snugged up, but I'll pursue this some more to see if it can be resolved.  I ordered some M10x1.5 SS threaded rod and will turn the motor end to mate with the motor shaft.  I also ordered an M6x1 threading die to be able to put that on the free end to get that knob back on.

If that all doesn't do it, I'll probably just use it not snugged down.  I believe it would work just fine.

Rick 

I think the wobble is due to too few threads engaged between the screw and TT shaft.  If I can get the brass threaded/press on fitting off of the TT shaft, I might have a chance at getting things lined up. 

Yup, that is the issue.  I tried getting the threaded fitting off the motor end of the shaft, but the other end came off first. 


After getting the intended fitting off and putting the threaded sleeve on it and checking runout with it in the lathe, there was less than 0.010" runout. 


I will modify the design/assembly to rely on this method of connecting the TT shaft to the motor shaft.  I'm hoping this will work satisfactorily. 

Rick

Issue solved.  I got the knob off of the TT screw. The knob mounts on the shaft via a threaded insert.  M6x1.

Issue NOT solved.  I cut down an M6 screw and machined a sleeve to mount it all up.  Used a couple nuts to lock the screw in place. 


There is huge wobble in the assembly.  I tried taking a video of it, but it was massively large and I won't post it.  I think the wobble is due to too few threads engaged between the screw and TT shaft.  If I can get the brass threaded/press on fitting off of the TT shaft, I might have a chance at getting things lined up.  Otherwise, I'll see if I can press on a length of delrin to serve as the connection between the motor and TT shaft.

If you look at the photo, you may notice I've added the zip-ties, ala Wootz, to steady the cross travel.  Those  ties are impinging on the added motor mount bracket, so I'll have to shorten the bracket.  I'll also have to shorten the screws that mount the motor mount as the do-hickie that holds the diamond tip will impinge on the screws sticking out underneath. 

This is all part of the design/implement/discover issues/redesign/reimplement/repeat...  process that I enjoy so much about making things. 

With this motor, I get a traverse time of 24 sec. at 100% power on the train controller.  60 sec. traverse time at 25% setting and 100 sec. traverse time at 20% setting. 

Rick

I'm still thrashing about trying to figure out how to connect the motor shaft to the knob.  I'd like to drill a hole in the center and thread it to insert a screw of some sort and lock it with a nut.  My concern is being able to adequately find the center of the knob. 

Rick

Issue solved.  I got the knob off of the TT screw. The knob mounts on the shaft via a threaded insert.  M6x1.


There is about one turn of thread exposed, which is enough to get an M6x1 screw locked in place as a drive shaft for the motor.  Now all I have to do is make a sleeve to fit over the motor shaft and thread the other end. 


I have an M6x1 tap, so I should be truing via motor control very soon.   

Rick

Here are some photos of the first stage of fabrication on the motorization of the truing tool.  My layout skills are a bit rusty, so I had to enlarge the holes to get the motor mounted and the bracket square on the TT.  I believe it will require further enlarging of the motor mount holes and the bracket holes so the motor/mount can float and find its own center on the knob.






I'm still thrashing about trying to figure out how to connect the motor shaft to the knob.  I'd like to drill a hole in the center and thread it to insert a screw of some sort and lock it with a nut.  My concern is being able to adequately find the center of the knob. 

I have figured out how to hold the TT for drilling.


Rick

I've had some time to work on the design of a motorized Truing Tool.  CAD drawings are attached below.  I spent a lot of time trying to work with a piece of U shaped box channel but the space on the side of the TT around the knob is just too confined.  When I went to just an "L" shaped bracket for the motor mount, the design got real simple and even easier to make. 


Also, when I got home, I could not find the 1/8" wall thickness box channel that I know I had before my move a year and a half ago, so I had to use what I had, which is 0.202" wall thickness.  I like it better too.  More rigid.  I have not figured out exactly how I'm going to attach the knob chuck to the knob.  I'm thinking with some drive pins, maybe.  I'd like to come up with something that will break free when (not "if") the screw reached the end of its travel and I haven't switched off the motor.  Limit switched would be good, so maybe I'll give that a go after getting this thing built.

Rick

Are you sure it's rubbing against the plastic?  It looks like there's a thin strip of metal mounted on the face of the plastic that the washer turns on? 

I stand corrected. When I looked at the shaft shoulder and plastic ring, it appeared the ring was higher than the shoulder on the shaft.  And given the scratch marks on the backing washer, I "assumed" the washer was riding against the ring and not the shoulder.  My bad for not looking closer. 



On CB's question, I looked closer and found the ring to be about 0.150" above the housing.  The small shoulder on the shaft is about 0.020" higher than the ring.  And checking the washer's fit, it definitely mounts against the shaft shoulder, but also contacts the plastic ring at some point.  On thinking about it, I wonder if that plastic ring isn't the seal against water getting inside the machine. 

Thanks for the question, CB.

Rick

I do like the looks of that one "more better".      

I do like the looks of that one "more better".      

A while back, during the discussion on "to pivot or not", this notion came up and I liked it so I ordered several extra adjustable stops so that I could turn one round.  I did't know what else might come of it is way I ordered several extras.  I had ideas of trying to make something that would insert onto the USB that the stop could pivot on by some sort of pin to help keep the rounded on on the USB better.  Other things came up so have not pursued it. 

Rick

CB,

Nice work and photos. With the photo on the left of the modified Tormek stop, would it be possible to shape it square instead of rounded? If so, it would combine the surface advantage of the collar stop with the threaded adjustability of the SVM-45.

I have long felt that Herman's platform is one of the most useful and underappreciated jigs for Tormek. The squared off one definitely stays on the USB better than the rounded one.
Ken

Sorta like this?


I left a little bit of a shoulder until I test it to see how well it stays on the USB.  The squared off one definitely stays on the USB better than the rounded one.  With the rounded one, I had to really pay attention to keeping it on the USB.


Rick

Have any of you looked at how the stones mount on the shaft?  I did, expecting to see a substantial steel hub against which the washer would mount.  Instead, I found a non-rotating plastic bearing surface against which the washer mounts and turns against as the wheel rotates. 


I measured the washer thickness.  One that came with my T8 was 6mm +- 0.0002mm in the four quadrants.  One that came with my JS-250 was 5mm, +-0.0006mm in the four quadrants.  At worst, that is two one hundred thousandths of an inch.  I do not think it is an issue with the washer. 

I think it is the plastic bearing surface against which the washer bears while rotating.  I am surprised by this design.  I don't know what to make of it.  I think the procedures described to use a standard approach to mounting each stone, based on first finding the best orientation is as good as we can expect to do. 

Rick

Hi Rick - you don't need either, believe me.
Many had advocated diamond plates for conditioning the wheels after truing and cleaning in between, but it took me time to recognize all the benefits of it.
Don't be like me, and take this shortcut.

#400 diamond plate for the SG or SB wheel graded to #800-1000;
#1000 diamond plate for the #4000 SJ wheel.

A #1000 diamond plate  in the Tormek Square Edge jig is the best solution for declogging SJ.
As the diamond plate I use the cheapest plates I could find on eBay; the one in the picture is 1mm thick  and cost me $5 delivered. Had to clamp it together with a plane iron on the top for rigidity.
The diamond plates do wear with use on the stone, please do not use the expensive DMT or Atoma for this.

IMPORTANT: Make sure the diamond plate contacts the stone by its surface, not the end, otherwise it will chip the wheel corners.

Thank you, Wootz. 

I recall seeing the thread you reference, but as I said, I'm only now really starting to pay attention.  I'll need to go read that thread more thoroughly.  What do you suppose is the physical process that is occurring during the conditioning/cleaning/declogging with the diamond plates?  Especially as it differs from the other solutions proffered.  Are we talking about steel particles that are adhered to the stone surface or embedded in the stone matrix?  I expect both. 

I'd ask the same of others who have advanced methods.  What is happening with the rust eraser, the Nagura stone, the soaking in water?  I'll state my assumption about the stone grader: it breaks down the stone matrix, releasing adhered and embedded steel particles.  There has to be a small amount of wear on the stone. 

I don't get at all how simply soaking the stone in water removes steel particles unless it simply rusts them away, which I would think would leave rust stains. 

I'll offer an example.  There is a brick of soft rubbery material that is used to de-clog wood sanding disks and belts.  It is soft enough to wear away significantly, but it is sticky enough to pull clogged wood particles out of the sander media.  There can hardly be any wear on the sander media, but works very effectively. 

Rick