We put on a 20 dp hob used on another machine and it cut straight. The 16dp hob I have has defects in the way it was manufactured. I am procuring a hob made in USA.
I will start over and see if any problems are left using the 20 dp hob.
bob
We tried another hob today that has made straight parts before and the part today looks straight. Tommorrow we will indicate and know in thousands if it is staight. Since this is probably a combination of problems, the hob itself is a problem.
No differential. The work between centers is straight within .004 over more than 12 inches, horizontal and vertical plane. The tooth form is making a helix.
by index constant, do you mean a single lead worm on the spindle head or somethingelse? I am thinking that the loose mechanical fits and the angle on the hob slide would make the tooth thinner than required, but not change the helix.
We adjusted the worm gear, we can see the helix is still...
The hob run out is .0008.
I do not understand which direction to swivel the hob. We think we have it done as the manual shows. I do not understand how hob swivel would create a helix. If wrong swivel, right or left, I would expect the tooth to be too thin when the whole depth was reached...
I am making a 16 dp 44 tooth gear on a Barber C #12. I have set the hob slide to 1 degree 47 minutes as is printed on the right hand hob. When I cut towards the spindle I do not get a zero helix. The rough cut had a helix of about .020 per inch. The finish cut did not have the same helix...
A 5c collet closer that mounts directly to your spindle,such as, a2-6, is very common. Search for collet chucks on ebay and you will see several. I bought the s-30 collets and have not used them yet. If you no longer need yours, I might buy them. What is your spindle mount? I might trade you...
How are you going to determine when the bed is straight? I do not allow machines to be set in a twist. The weight on the leveling screws has always been enough to get the machine straight. I would not hesitate to add weight or pull to a leveling screw if I needed it. I would prefer an anchor...
This question is too general. lots of forming is +- .06. Fine blanking is done in .0001. Wire is drawn(not with a pencil) in .0001. Other people would know mold tol if you describe the features in the mold you are making.
Truck loads of liquid nitrogen are delivered everyday. All of the big welding gas suppliers can sell you nitrogen. I have not heard of anyone using it for machining. I did some experiments with aluminum where we tried to get it cold enough to be brittle and fracture on impact. We could not...
I have used things like Paashe air brushes to apply glue(not hot). I work for Advanced Grinding and Machine who has built machines that apply hot melt glue.
Bob webmaster@advanced-grinding.com
The centerline distance is helpful. You may find the exact copies are very expensive and may decide to use stock gears for replacements. Very few gear teeth on old equipment are cast. You could be looking at pitted worn-out teeth. If they were cast this machine...
