Rockwell Mill, Head Stock worm gear?

[38super]

Anyone have a source for a 7/8-5 acme tap? My aluminum worm gear is cracked, have made a gear blank. If I can't find an acme tap, will have to make one.

TIA
super

 

[machPete99]

Sorry,but no help on the tap.
I may need to do something similar at some point, was thinking that something other than aluminum should be used for the ring gear (brass?).
Any thoughts?

 

[38super]

Making a 7/8-5 cutter, hope I have enough propane for kasenit treatment. Might be time to build a furnace/smelter and melt all the aluminum shavings into ingots. Aluminum (6061 - 7075) is OK, who ever used this machine before did not understand the headstock clamps have to be loosen to rotate the head. Seems like one job begets another.

 

[T Bredehoft]

Is the gear stripped all the way around? Can it be rotated 180º and reused?

 

[38super]

Gear and cast gear housing are both cracked. Serious gronk was applied. Will post a few pics of work in progress. Got a lead screw prob with SB13 gear box, gotta fix that to finish the 7/8-5 tap blank. $h*t snowball.

edit: The original worm gear has the look of cast aluminum, crack looks grainy. Bet it made noise when it cracked.

 

[38super]

Original gear and housing 7/8-5 tap hob in progress Worm gear blank

 

[38super]

Bad and good news. SB13 gear box SNAFU, lost the feed in the middle of making the hob (0.078" thd depth, need 0.115"). Milled 4 cutting faces and applied Kasenit. 12 minute heat up with a propane weed burner. Gear blank rotated on used M/C wheel bearings (mistake). First try was very hard for the hob to rotate the gear blank until a cut is established. Inconsistent tooth profile on gear blank, suspect a bad (stretched) bearing cage.
Good news, the hob will work but needs improvements. Bad, need a better way to hold the gear blank.
Set up. Bad teeth. Cutter / gear blank engagement.

I'm sure experienced machinist are enjoying my rookie escapades, can't pass up a learning experience no matter how bad it looks.

 

[markba633csi]

Looks like you are nearly there, one more blank on some better bearings should give a good part
What about the housing? Braze? (I assume it's cast iron)
mark

 

[38super]

Was watching Jody on Welding Tips n Tricks, trying to source aluminum/bronze filler rod.

FYI: Gear blank base metal machines like 6061, stringy. For SoCal hobby machinist, try Max Industries in Gardena, best source for aluminum sheet, plate & round (all extruded, no cast). Not associated with this business.

 

[jwmay]

Still got that hob laying around somewhere? I need to try to make a replacement gear for mine too.