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.

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.

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.

Rambling about Greensand

Allow me to ramble.   There are several variables associated with greensand.   Six people can make greensand from the very same ingreediants and come up with six different sands.     It gets even more complex when the ingrediants vary.   The ratios you seen on the net are a starting point.  Take the time to ram up test flasks while varying the sand, Eventually you will discover what works.  Then ram up your pattern and light the furance.

If you have the time watch olfoundryman and sandrammer ram up a flask.  Both of these dudes are way better than me and maybe most of us.

Sandrammer uses shallow layers and takes care to scratch the surface of each layer prior to adding the next.  Oldfoundryman puts a lot less effort into it with fewer layers not scratching and less ramming in general.(edited)

Sandrammers's techinque makes for a stronger mold and will work with larger flasks.   Oldfoundryman's works for the relatively small flasks he uses.  But largely they cast about the same sized parts in their vidoes.