Involute Gear - Revision history

Colin at 02:05, 2 May 2011

2011-05-02T02:05:56Z

← Older revision		Revision as of 02:05, 2 May 2011
Line 1:		Line 1:
	{{~~Under Construction~~}}		{{under construction}}

	There are several methods to cut an involute gear, but I will focus on hobbing techniques, as a simple hob can be made with the most basic lathe. (see [[Hob]])		There are several methods to cut an involute gear, but I will focus on hobbing techniques, as a simple hob can be made with the most basic lathe. (see [[Hob]])

Colin at 02:05, 2 May 2011

2011-05-02T02:05:24Z

← Older revision		Revision as of 02:05, 2 May 2011
Line 1:		Line 1:
	~~This page is very much a work in progress-improvements are forthcoming.~~		{{Under Construction}}

	There are several methods to cut an involute gear, but I will focus on hobbing techniques, as a simple hob can be made with the most basic lathe. (see [[Hob]])		There are several methods to cut an involute gear, but I will focus on hobbing techniques, as a simple hob can be made with the most basic lathe. (see [[Hob]])

Syk0 saje at 09:03, 30 April 2011

2011-04-30T09:03:04Z

← Older revision		Revision as of 09:03, 30 April 2011
Line 5:		Line 5:

	=Things Needed=		=Things Needed=
	1. A vertical milling machine (horizontal will probably work as well, but I will focus on vertical here)~~<br>~~		#A vertical milling machine (horizontal will probably work as well, but I will focus on vertical here)
	2. The appropriate gear-cutting [[Hob]] for the dimensions of the gear desired (this can be machined from carbon steel and this process will be documented in the hob article~~<br>~~		#The appropriate gear-cutting [[Hob]] for the dimensions of the gear desired (this can be machined from carbon steel and this process will be documented in the hob article
	3. An indexing head attachment for the milling machine [http://en.wikipedia.org/wiki/Indexing_Head]~~<br>~~		#An indexing head attachment for the milling machine [http://en.wikipedia.org/wiki/Indexing_Head]
	4. A mandrel matching the inside diameter of the gear (where the shaft will be mounted when finished; this too can be machined on the lathe)~~<br>~~		#A mandrel matching the inside diameter of the gear (where the shaft will be mounted when finished; this too can be machined on the lathe)
	5. Appropriately sized round stock of a material no harder than the material of the hob~~<br>~~		#Appropriately sized round stock of a material no harder than the material of the hob
	6. An engine or benchtop lathe and appropriate attachments (3-jaw chuck, 4-jaw chuck, dial gauge, simple cutting tool, chuck attachment for tailstock, center drill, drill bit, reamer)		#An engine or benchtop lathe and appropriate attachments (3-jaw chuck, 4-jaw chuck, dial gauge, simple cutting tool, chuck attachment for tailstock, center drill, drill bit, reamer)

	=Blank Preparation=		=Blank Preparation=

Syk0 saje: /* Post cutting cleanup */

2011-04-30T09:02:10Z

Post cutting cleanup

← Older revision		Revision as of 09:02, 30 April 2011
Line 36:		Line 36:
	Now the head (again, rotary table or indexing head) should be locked in a known position, and proceed to cut .005" into the blank. Now rotate the work before cutting again by 1/N rotations or 360/N degrees where N is the number of teeth on the gear. Cut .005" from this location. Repeat this process of cutting and turning until the first cut is reached again. You'll continue this process .005" at a pass until reaching the depth of cut (which is the tooth depth) which is determined by the formula above (2.157/Dp).		Now the head (again, rotary table or indexing head) should be locked in a known position, and proceed to cut .005" into the blank. Now rotate the work before cutting again by 1/N rotations or 360/N degrees where N is the number of teeth on the gear. Cut .005" from this location. Repeat this process of cutting and turning until the first cut is reached again. You'll continue this process .005" at a pass until reaching the depth of cut (which is the tooth depth) which is determined by the formula above (2.157/Dp).

	=Post cutting cleanup=		=Post-cutting cleanup=
	After finishing the gear form, it is advisable to return it to the lathe and file away any burrs left behind from the process. After this, the gear form should be complete, and all that is required for service is to cut a keyway and provide a shaft on which to mount the gear. If a "double-wide" gear was cut for a hydraulic motor, now would be the time to return to the lathe to part the gear into two halves. Following this, It would be advisable to either end-mill .001-.002" from the cut sides (if so, be sure to include additional thickness in the blank before cutting) or very carefully face the cut ends using the lathe.		After finishing the gear form, it is advisable to return it to the lathe and file away any burrs left behind from the process. After this, the gear form should be complete, and all that is required for service is to cut a keyway and provide a shaft on which to mount the gear. If a "double-wide" gear was cut for a hydraulic motor, now would be the time to return to the lathe to part the gear into two halves. Following this, It would be advisable to either end-mill .001-.002" from the cut sides (if so, be sure to include additional thickness in the blank before cutting) or very carefully face the cut ends using the lathe.

Syk0 saje at 16:11, 29 April 2011

2011-04-29T16:11:27Z

← Older revision		Revision as of 16:11, 29 April 2011
Line 40:		Line 40:

	=External Links=		=External Links=
	http://en.wikipedia.org/wiki/Involute_gear~~<br>~~		http://en.wikipedia.org/wiki/Involute_gear
	Helpful Videos [http://www.youtube.com/user/Hobbynut~~]<br>~~		Helpful Videos [http://www.youtube.com/user/Hobbynut]
	~~[[Category:Hydraulic Motors]~~]

Colin: /* Prepare to Mill */

2011-04-27T04:51:25Z

Prepare to Mill

← Older revision		Revision as of 04:51, 27 April 2011
Line 28:		Line 28:
	In this article, I will focus on using the so-called 'parallel hob' mentioned in [[hob]].		In this article, I will focus on using the so-called 'parallel hob' mentioned in [[hob]].

	The hob should be mounted in a collet and then on the mill spindle. The quill should then be lowered so that one of the inner teeth of the hob is roughly centered on the horizontal diameter. Lock the quill feed. the table should now be raised or lowered in .001" increments until centered within .001". Lock the ~~table z-axis~~.		The hob should be mounted in a collet and then on the mill spindle. The quill should then be lowered so that one of the inner teeth of the hob is roughly centered on the horizontal diameter. Lock the quill feed. the table should now be raised or lowered in .001" increments until centered within .001". Lock the knee.

	=Formulae and Cutting Details=		=Formulae and Cutting Details=

Colin: /* Formulae and Cutting Details */

2011-04-27T04:50:51Z

Formulae and Cutting Details

← Older revision		Revision as of 04:50, 27 April 2011
Line 31:		Line 31:

	=Formulae and Cutting Details=		=Formulae and Cutting Details=
	The final depth of cut into the blank should be equal to the tooth depth which is determined by the formula 2.157/Dp where Dp is the diametral pitch, or number of teeth per inch of pitch diameter. Diametral pitch is determined by the ratio of the number of teeth to the pitch diameter. These three factors also determine the dimensions of the [[hob]] you'll require.		The final depth of cut into the blank should be equal to the tooth depth which is determined by the formula 2.157/Dp for Dp>20 and 2.2/Dp for Dp<=20, where Dp is the diametral pitch, or number of teeth per inch of pitch diameter. Diametral pitch is determined by the ratio of the number of teeth to the pitch diameter. These three factors also determine the dimensions of the [[hob]] you'll require.

	=Just Start Cutting already -or- Hurry up and wait=		=Just Start Cutting already -or- Hurry up and wait=

Colin: /* Things Needed */

2011-04-26T03:13:54Z

Things Needed

← Older revision		Revision as of 03:13, 26 April 2011
Line 8:		Line 8:
	2. The appropriate gear-cutting [[Hob]] for the dimensions of the gear desired (this can be machined from carbon steel and this process will be documented in the hob article<br>		2. The appropriate gear-cutting [[Hob]] for the dimensions of the gear desired (this can be machined from carbon steel and this process will be documented in the hob article<br>
	3. An indexing head attachment for the milling machine [http://en.wikipedia.org/wiki/Indexing_Head]<br>		3. An indexing head attachment for the milling machine [http://en.wikipedia.org/wiki/Indexing_Head]<br>
	4. A mandrel matching the inside diameter of the gear (where the shaft will be mounted when finished)<br>		4. A mandrel matching the inside diameter of the gear (where the shaft will be mounted when finished; this too can be machined on the lathe)<br>
	5. Appropriately sized round stock of a material no harder than the material of the hob<br>		5. Appropriately sized round stock of a material no harder than the material of the hob<br>
	6. An engine or benchtop lathe and appropriate attachments		6. An engine or benchtop lathe and appropriate attachments (3-jaw chuck, 4-jaw chuck, dial gauge, simple cutting tool, chuck attachment for tailstock, center drill, drill bit, reamer)

	=Blank Preparation=		=Blank Preparation=

Colin: /* Things Needed */

2011-04-26T03:11:34Z

Things Needed

← Older revision		Revision as of 03:11, 26 April 2011
Line 6:		Line 6:
	=Things Needed=		=Things Needed=
	1. A vertical milling machine (horizontal will probably work as well, but I will focus on vertical here)<br>		1. A vertical milling machine (horizontal will probably work as well, but I will focus on vertical here)<br>
	2. The appropriate gear-cutting [[Hob]] for the dimensions of the gear desired<br>		2. The appropriate gear-cutting [[Hob]] for the dimensions of the gear desired (this can be machined from carbon steel and this process will be documented in the hob article<br>
	3. An indexing head attachment for the milling machine [http://en.wikipedia.org/wiki/Indexing_Head]<br>		3. An indexing head attachment for the milling machine [http://en.wikipedia.org/wiki/Indexing_Head]<br>
	4. A mandrel matching the inside diameter of the gear (where the shaft will be mounted when finished)<br>		4. A mandrel matching the inside diameter of the gear (where the shaft will be mounted when finished)<br>

Colin: /* Prepare to Mill */

2011-04-26T01:49:39Z

Prepare to Mill

← Older revision		Revision as of 01:49, 26 April 2011
Line 28:		Line 28:
	In this article, I will focus on using the so-called 'parallel hob' mentioned in [[hob]].		In this article, I will focus on using the so-called 'parallel hob' mentioned in [[hob]].

	The hob should be mounted in a collet and then on the mill spindle. The quill should then be lowered so that one of the inner teeth of the hob is roughly centered on the horizontal diameter. Lock the quill feed. the table should now be raised or lowered in .001" increments until centered within .001". Lock the table z-axis. This can be checked by placing a machinist rule against the work and moving the table to push the work against the hob. The rule should be perpendicular to the table if the hob is at the proper height.		The hob should be mounted in a collet and then on the mill spindle. The quill should then be lowered so that one of the inner teeth of the hob is roughly centered on the horizontal diameter. Lock the quill feed. the table should now be raised or lowered in .001" increments until centered within .001". Lock the table z-axis.

	=Formulae and Cutting Details=		=Formulae and Cutting Details=