Compressors Compressors

 The compressor head and 220V motor are not original.  But it seems to work well. Took it up to 125 PSI.  I generally run my compressor to max out at 100 PSI which is easier on the unit.  But not good when using air tools.  Maybe set this on up for air tools and use another for lower pressure needs.

Obtained another junked compressor with 1.5 TECF motor.  Wired for 115V.  Changed the front bearing.  Did not look much at the compressor but it seems find.  Did not get an image of it as it arrived.

one and a half horse motor from old compressor

Picked up a scraped air compressor without a tank.  1.5HP TEFC motor.  Bearing on the output side was bad.  620414ZZ,  Purchased a bearing puller set in addition to the new bearing.

Cost
$1 Air Compressor
$10 Bearing
$59 Bearing puller

The internals of the motor are very clean.  TEFC is nice.

After cleaning the motor shaft I installed the puller and applied pressure.  A few taps on the puller and the bearing started to move.   Drilled out a bit of pipe to make a tool to drive the new bearing on.   Motor is back together and runs nice.  Old bearing might have been OK with some grease.  I don't know if one can remove and then replace the metal shield.  Should have tried on the old one then greased the new if it worked.  Maybe next time.

The compressor head is cast iron and looks good.  I will pull it from the base and put it up in the loft for now.  When I get setup for sand blasting I may want an additional compressor to up the SCFM.

Kittens

VBLOG 17 Test Furnace Demonstration.

Maybe i should have made a video on the why an wherefor's of the test furnace first.  Its been a while and there are new subscribers.






OBSERVATIONS

1. I should have arranged the mold to make more room for a decent pour basin.   The aluminum escaped and ran into the top of the cylinder I was pouring.
2. Need to judge pour temperature better.  I am new to casting aluminum with gas.
3. Surface could be better. But it was just a billet for machining and I did not properly blow out the mold.
4. Would like to improve how the spru connects to the runner.
5. Would like a model for the pour basin.
6. I could have poured at about 30 minutes but added more aluminum I did not need then waited too long.
7. Additional melts would be shorter.  Need to batch work.  I don't like this part.

The new flask and shank worked well if a bit difficult to lock closed.  The cobbled together cheek worked well.

The refractory in the cylinder seems to be holding up.   Will need to see how it is after extended use.

Green Sand Binders, speciffically dextrin

Optimizing the green compression strength and permeability of green sand made from Epe silica sand

Effect of varying binders (bentonite and dextrin) and water on the properties of recycled foundry sand made from silica sand mined from Ilaro Silica sand deposit in Ogun State Nigeria and have been used in several cycles for production of cast iron was examined. The used sand was washed in hot water, dried and the sieved for grain distribution. Varying bentonite and dextrin contents were added together with water to portions of the silica sand and thoroughly mixed. The moulding sand properties (permeability, green strength, compatibility, shatter index and moisture content) of the recycled foundry sand were determined. It was observed that the recycled Ilaro sand (after several cycle of usage) has grain Fineness Index (GFI) of 50 and that it can still be reused by minimum addition of binders. It was concluded that the optimum green strength and permeability for the recycled sand was achieved when 12g of bentonite, 8g of dextrin and 12cm3 of water were added to 200g of recycled sand.

I think the key here is 8 parts dextrin to 12+12+200 parts by weight.

Elsewhere I have read the ratios for such binders is .5 to .75%.   The above ratio is 3.6%. 

Currently I am having problems with edges and plan on trying to mix a small quantity of facing sand by adding dextrin in the 8/224 ratio.  Then applying this sand where I think it is needed.

Adding this tiny amount of dextrin should not significantly effect the sand in future castings.  

Placed 262 of green sand in the toaster oven to dry it out.  The dextrin will mix better in dry sand.  It will be interesting to see what the water ratio is.  Have not looked at that in a year.  Have been 'adjusting to taste'.

262g x 0.005 = 1.2g

Well that did not got well.  The new scale has a 1 gram resolution.   Need to use the little precision scale if I make another tiny batch.  But its made and it smells like dextrin.  Works and feels different.  Put it in a zip lock.

New steel cruciables

My friend dropped by on request and welded my new crucible, on the right,  that fits the test furnace.  He was also kind enough to fix the leaky one I welded some time ago.

The crate behind contains rockwool.  Its a bit nasty having spent a few years outside.  Still good enough for testing, maybe more.

Refractory on Rockwool

<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgZRxN5Dki8p9aiTykoy0fUjjf-bOB20uP_b2RiDN1wIVgR6G-i61XURx2YLFjh6cV1EgB4uMX14GwEtlQhHcMQe63ciKV5nE5pKFzJ_-usD-r1oa24wFeLcGBSoDHAwk5Z8uXwB2yCkyPW/s1600/IMG_8323.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgZRxN5Dki8p9aiTykoy0fUjjf-bOB20uP_b2RiDN1wIVgR6G-i61XURx2YLFjh6cV1EgB4uMX14GwEtlQhHcMQe63ciKV5nE5pKFzJ_-usD-r1oa24wFeLcGBSoDHAwk5Z8uXwB2yCkyPW/s320/IMG_8323.JPG" width="240" /></a>About a week ago I coated this sample of rockwool with my refractory.&nbsp;&nbsp; The goal is to test how well it bonds to the fibers.&nbsp; If this works maybe it will make a good hotface for ceramic blanket. Much tougher and thicker than satanite.<br />
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This morning I removed the refractory on rockwool test sample from its zip lock bag.&nbsp; The bottom side is smooth from resting on the paper.<br />
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Its easier to cure the concrete in a zip lock bag with a tablespoon or two of water then the larger chamber I was using.<br />
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Lathe tool bit trays

Figured it would be nice to organize the carbide lathe bits.

This was made using the top from a project TV.  The material is best described as paper fiber with a wood grain veneer.  The sides are plywood.

The large tray has 49 compartments the smaller has 28.

The pockets are 0,4 inches.   The space between pockets are large enough to prevent the its from touching.

I have about 6 1/2 inch bits that will not fit.  Making the pockets large enough to accomadate them would have made them too large for the smaller 5/16".

I am not sure about the use model.  Maybe keep the larger one in a tool cabinet and the smaller near the lathe.  Will have to see what works.