Friday, May 25, 2018

Perlite and Sodium Silicate Cake

Made a test puck today.  The roll of pink tape was used as a form.



Its not acting like it should.  It is hardening over a period of days.  I attribute that to drying rather than the wanted chemical reaction.

Looks like I need to make new stuff.   Not sure maybe this is contaminated.

Thursday, May 24, 2018

Base for Master Mill Electronics

Pattern for the base plate that will hold the Master Mill's DC motor.  The V groove rests over the lathe rear way.
























On the first cast attempt everything seemed to go wrong but the resulting casting was useable with a some milling for cleanup.     But I do not have a working mill.   Although the center pocket has sufficient draft it was fragile. The worst was a breakout in the upper right corner of the pocket.   And for some reason the left edge of the rectangle came out tapered.  Not sure how that happened.




So on the second attempt I may add some mails to hold it into the sand below it.   Actually sheet rock screws.   This pour let me know how much aluminum was needed and that there are no noticeable shrinkage issues.   This is most likely because the hollowed out back side reduces the volume.

This time I am going to attempt to feed the mold cavity from the left side so I can cut most of the gating with the band saw.

Rammed up the 2nd but never poured it.  Even with the screws the center section fell apart.  Three choices here.  The 1st is to use the other sand for the center and faceing sand.  The 2nd is to make a core.  The 3rd is to just live with the casting I already have.  Its not show piece but it works and I think that is the better choice.  I can chase this problem while making the pulley.

Not sure why I messing with this 2nd string sand.  I have good stuff but I wonder if adding a bit of bentonite to it will help.  Hmmm






Tuesday, May 22, 2018

Lathe Carriage Stop

Two videos on this small project.


Constructed a carriage end stop.  The top half is cast aluminum and the bottom is  0.42 hot rolled steel.

The original plan was to have a bolt extend out from the stop and hit the carriage.  When I was about to drill the hole for that I noticed the bolt hole in the carriage.   Unfortunately it only contacts half the stop but that's OK`


Bolts are both 3/8".   Most other frequently used on the lathe use 1/2" wrenches.  At some point the top bolt head needs to be machined down to take a 1/2" wrench too.  Maybe even square ?

I still need to setup a DTI and bump the stop a few times to see if it creeps.  If so I may need to do some crude scraping on the V groove.   Other than that its good enough for now.   At some point I may make another one with a DTI and or multiple adjustable stops.



Saturday, May 19, 2018

Master Mills on Ebay

Mostly been doing VBlogs over on YouTube.  Made a new cube crucible for the Kerr 666 oven out of 0.42 " steel plate.   Weights 12.5 lbs empty.  It should stay warm longer than the thin wall one I first made.



Found some Master Mill pics on ebay.  



This box looks familiar.  Wonder if its being sold a 2nd time.












They are asking $10 K for this rather extensive setup.



 This looks like it is the lathe adapter.  Need to look that up in the manual.





Monday, April 30, 2018

More Casting

I have mostly always been disappointed with the bottom side of my aluminum castings.  The sand has been on the fragile side.   As an experiment I tried using wetter facing sand.  It worked.

The 3D printed pattern.

The cast with the sprue and gates/

After it was cut.

A close look at the reproduction of the features on the 3D print.

OK yeah I see the lump too but this is the bottom side and but for the lump it is very good.


I tried smoothing this with a propane torch.  The top sunk.  Again you can see the pattern in the 3D print.  The face you see is the bottom.  It looks nice too.

Sunday, April 15, 2018

Sundry

Been cleaning and rearranging the shop. Moved this bench left to make room for the compressor but the outlet for the welder has to  move to the other side of the service entrance.  While I am doing that I will tie in the circuit for the lathe.

 


Tuesday, April 17, 2018

Lathe is now wired save for the 15A 2 pole breaker needed.  In the short run it is using a 30A.

Knocked the top bearing out of the cap on the rear of the lathe.   The way I cut the felts they are interfering with the two bearing halves.  Strange I did not catch this.  I know I checked.  I think I checked.  Oh well.

Saturday, April 7, 2018

The lost is found and other random bits.

A month or two ago I moved things between shops to make room for the lathe.   In the process I mistplaced my square aluminum casting crucible. a mold pattern,  a new set of silver and demming drill bits, and a numbered drill bit set.   A few days ago I found the crucible and today both drill bit sets.   The magic key was cleaning the shop.

I have been thinking about motors to power the versaMil attachment.  The one HP motor I purchased for the sand processor is too heavy as is a 3/4 HP I have on hand.    Current thinking is to use a DC thread mill motor which will also give speed control.

When I first assembled the lathe the cross shaft was OK.  It seems to have gotten worse.  I don't know if that's do to repositioning the lathe itself or something else.   Iphones have apps that record vibration.  Plans are to use it in an attempt to better balance the counter shaft but maybe I should get new belts first.