MadModder

The Shop => Tools => Topic started by: Joules on December 08, 2017, 01:31:31 PM

Title: Santa Came Early
Post by: Joules on December 08, 2017, 01:31:31 PM
But a couple of wet wipes cleaned that up...

As most may know, my 3D printed Quorn has been in the doldrums for the last couple of years.   Work has taken more of my free time and the demand for cutters and regrinds in the workshop has increased.

I would never really have considered one of these grinders had I not been addicted to Stefan Gotteswinter's YouTube channel.



Now here's a guy that knows his onions on these machines.  I have read and seen the gumph talked about these grinders and bought into it for many years.   However similar to Stefan my work involves prototyping and a current run of parts had me taking a Dremel to some wood router bits to make form tools.   Arrrrrrg, enough of that, bite the bullet and get something to do the job properly.

She isn't a thing of beauty and initial inspection would suggest a complete strip down and clean (the grinder that is) would be prudent to a long and productive life.   The thing weighs a ton so the strip down will also allow me to rebuild it in its intended position.  Don't worry the 3D printing hasn't left the scene.   I intend to print a number of accessories, like vacuum dust collection and some Quorn style prints to allow me to cylindrical and surface grind in miniture using this machine.

And following in Stefan's footsteps make up some tapered carriers for the various diamond/stone wheels to be aquired.

Oh, the printed Quorn is still on my bucket list.
Title: Re: Santa Came Early
Post by: kayzed1 on December 08, 2017, 03:09:58 PM
Hi Joules, i have one of those grinders.....offered it on here cheap as i have no real use for it..apart that is, i have a
box full of blunt milling cutters that need a touch up but i do not have room in my shed for it. It sits on the bench i made
for it in another garden shed again with no room to move..
 I will watch with interest.
Lyn.
Title: Re: Santa Came Early
Post by: Joules on December 08, 2017, 03:17:17 PM
Oooh, I missed your advert and did a look round before I ordered.   Can't you make a window box for the shed that will accommodate the grinder.   If not, maybe renewewd interest will get you a buyer for it, but take a look at Stefan's video on his first.
Title: Re: Santa Came Early
Post by: NormanV on December 08, 2017, 04:22:04 PM
The thing about Stefan Gotteswinter is that he makes it all seem so easy. I love him and hate him!
Title: Re: Santa Came Early
Post by: Joules on December 08, 2017, 07:18:04 PM
LOL the more you do Norman, the more you forget about the lack of confidence you had when you started.  Keep practising, and learn that good enough, can be good enough.  I no longer aim for perfection but what I am comfortable with that will get the job done.   Suddenly you find you take away all that peer pressure.  OK so somtimes your work isnít as good as the next guy.  Well if your life doesnít depend on it, so what.  That isnt to say you should be complacent, but always try your best, be humble and learn.
Title: Re: Santa Came Early
Post by: Joules on December 09, 2017, 04:08:04 PM
Managed to sit down and loose 5hrs fettling today.   My other half, bless her, let me setup the B&D Workmate in the kitchen to do the work on the grinder.  Having put the plug on it and made sure nothing fouled the wheel, a quick run to see how it sounded and how much vibration.   Not at all noisy and the mass of the thing meant almost no vibration, I guess the grind stone is pretty close on, but a later job is to pull it off and rebalance.

I've started by stripping down the tool post/head assembly.  You can see in the springs picture the new finger hammer has had some use tapping parts loose and removing pins etc.  I had to clean off the thick grease with included abrasive particles, I replace this with LM2, making sure everything is cleaned.  You can see the diamond stones and drill I used to remove burrs and clean mating surfaces.  You don't need to de burr, but I would rather they didn't work loose sometime in the future so for me it's a job worth doing now.   The horizontal motion of the grinding wheel is nice and smooth, however the lower tool post bar is gritty and has some tight spots, they will be dealt with later.

Last picture is some of the casting defects I found, nothing serious but I like to pick the loose stuff out and fill them with JB Weld.  This serves dual purpose, to seal in any further loose bits and stop dirt finding its way into a hiding place for later escape.



 
Title: Re: Santa Came Early
Post by: Joules on December 09, 2017, 04:21:35 PM
On the subject of using JB Weld, for applications like this, I prefer to heat up the casting to 40℃ or there abouts.  This helps the JB Weld flow better, pushing it into the hole with a toothpick and the heat lets any bubbles expand and pop on the surface.  Finally it reduces the cure time some, but still allows working time with the small amount mixed.  I did 2 peas worth for filling.   The JB weld will be left for a few hours to partially cure and be levelled with a razor blade.  Tomorrow I will just tickle it with a riffler file to make sure its not proud of the surface.   A few other places need some filling, which wasn't a problem as I had plenty left over from the mix.

Final part of filling for tonight was on the tool post horizontal bar.  They but a bolt though that holds the tension spring for the bar, but then rough grind the bolt to get it below the surface.  This is down right ugly and pretty much defeats the bar seal on the tool post, so I added filler and will carefully blend it back to the bar profile.  I hope that will preserve the seal as it won't get ragged or pick up grit from the afore mentioned hole.


 
Title: Re: Santa Came Early
Post by: Joules on December 10, 2017, 07:06:35 AM
Some 6hrs after applying the JB Weld, I use a razor blade to carefully scrape back and get things flush.  Extra care is taken on the horizontal bar so you don't scratch it.  The results are very pleasing on the bar, the finish is flush and you can't feel an edge.  With a nail you can feel the transition from metal to filler but I don't want to buff it and risk marking the bar, time will polish the surface.

The cross slide top once filled and some dirty oil rubbed over it, the filler nearly disappears.  However I managed to break a small bit of filler off the dovetail edge.  I will fix it if I need to use anymore filler, otherwise leave it as is.

I fixed the bar adjuster, it was the dial that had grit in it.  Clean and re grease solved the grittiness, the tight spots are reduced but I can still feel them, maybe they will disappear with time as things bed in.   Just some work to do on the collet holder and the head will be done.  Then design and print some dust covers for the larger threaded bosses.  I will probably use hot glue to plug the grub screw holes as it's easy to pick out when the time comes.

   
Title: Re: Santa Came Early
Post by: RobWilson on December 16, 2017, 07:57:28 AM
Very nice cutter grinder Joules  :thumbup:


I have same made by  Alexander  :dremel:


All the best , Rob
Title: Re: Santa Came Early
Post by: tom osselton on December 16, 2017, 03:33:01 PM
They did the same thing at work when the odd wrench fell into the printing press they used some sort of epoxy I belive.