Hi John, sorry for the slow reply I've just found your note in my spam folder. Silly people at KZfaq! I agree, I'm totally in awe at the engineering when I work with tools like this that often pre-date CNC. Sadly tools like this are becoming rare due to CNC. I have very dear friends in Melbourne, love your Country and people. Brad, Canada.

All good Brad, I wish you well. I like to know where things come from and as a result I think to myself about those that made the first machine tool. They are True Craftsmen! Thanks for your reply and enjoy your warmer months, it will become cooler here, however not as cool as you have in your Winter All the best from John Australia.

Bevel gears are great for going around corners! Thanks for watching and commenting.

I'm continuously amazed by the knowledge of people I perceive to have basic tools. Very inspirational! Glad the video was useful. Thank you!

Glad it was helpful.

I'm glad it was helpful and appreciate you saying so.

Glad to, thanks for taking the time to say so!

Thank you

I'm glad it was helpful. Thank you for watching and leaving a note.

I'm glad it helped. Congratulations on your exam. Thanks for taking the time to let me know.

My pleasure, that you for your post.

My pleasure, thank you for watching.

+do or die Glad it helped!

I'm glad to hear you learned something from it. Thank you.

+Nacer Ziani Do you have enough of the gear left to get a diameter and number of teeth

+machiningmoments Yes I have , The number of teeth is 15 tooth , and the outside diameter is about 54 , and this is a pic of it i.imgur. com / 0YMlizT . jpg

Ok, take the OD and subtract the depth of the tooth (this will get you close to pitch diameter(PD) unless you know the DP (in your case Normal Diametral Pitch)). Once you have pitch diameter multiply by pie(3.14) to get circumference. Now divide the number of teeth by the circumference this will give you circular pitch (distance from one tooth to the next at the PD) this is side opposite. Next measure the gears thickness at the tooth, this is side adjacent. The helix angle is only a trig function away. Note: both gears in mesh will have the angle and NDP. Good Luck!

machiningmoments ... Thank you again! I just watched this again after a few years, and found it just as fascinating as the first time. Actually, hi schoo shop class was the first time I was able to understand the geometry I was also studying. I became a wiz at making gears.

One thing I learned when I started this is it easy to miss something. Thanks for catching the inconsistency. I appreciate you watching and posting.

@@machiningmoments It is a fantastic video, you did a great job explaining it. I am just getting started in machining and have much to learn, people like you are what will make it possible to learn this new skill.

Thank you for your kind words. Welcome to machining you are going to love this trade!

I'm glad it helped, I think this is one of those concepts that is helpful to see. Thanks for posting.

Thank you!

+Morris Gallo It is called a universal dividing head

My pleasure, I'm glad it was easy for you to understand.

I'm glad it helped. Thank you for your note.

Glad you liked it, thanks for watching. I appreciate you taking the time to leave a message.

+Chris Anderson Hi Chris, differential indexing is not that common but kind of neat. Yes I cut helical gears. I use a horizontal mill with a table that swivels (universal) and a bore mounted full form involute gear cutter. You need to know the gear tooth's DP and number (tooth size and number of teeth per inch of pitch diameter) to select the proper cutter. You also need to know the lead of the helix and the lead of the machine to calculate the gearing between the milling machines lead screw and the dividing head. Finally you need the helix angle of the gear to swivel the table to the angle. If your cutting a pair of gears and they are different diameters the lead of helix will change. Also if your gears are on parallel shafts one will be cut with the table swiveled right the second will need the table swivelled to the left (you also need to add a gear so the dividing head turns in the opposite rotation)(right and left hand helix). Crossing shafts have the same helix. Thanks for your question and comment.

I am also stumped as how you would center the part .can you demonstrate how you would setup a job like this haven't found one on KZfaq.

Great question. With the gear blank in the dividing head I will either touch a square sitting on the table to the OD of the gear blank and measure from the square to the cutter. Repeat the procedure on the other side of the blank. I've also seen pinching a straight edge (rule) between gear blank top and cutter. If the cutter is centered the length of rule will be horizontal. You could measure to the table on both sides to straight edge.

I Don't quite understand

Sorry Chris, I will try to put a short video together for you.

Honestly Rico the answer is it was what fit in between. The number on teeth on the idle means nothing, it could be 10,000 teeth, all it does is provide a drive between the driver and driven gears. Good question!

You need to know the lead of the helix on the gear, in other words how long would the gear be if one tooth made a 360 deg rotation.

+Aswin Narayanan Glad it helped, thanks for the note and watching!

It is more about creating a ratio that will allow the hole plate to move so it can mathematically correct an error introduced allowing use of the device. On a side note the 127 T gear can be used for metric conversion.

+Jeremy Hall Once the crankpin is dropped back in the holeplate nothing moves.

Thank you for watching.

+Rasheed Senior My pleasure, I like things simple!

It is connected to a gear train inside the device.

@@machiningmoments Thank you very much

Can you explain to me the way?

Hi Blair, great question. This requires differential indexing so (A-N)40/A Try A=120 (120 - 127)40/120 your indexing 40/120 becomes 1/3 not sure which dividing head you have but lets say 11 spaces on a 33 hole plate. Now used the full formula for the gear train which works out to -7/3. Multiple this fraction by 8 and you get -56/24 so your gears are 56 (driver) and 24 (driven). You need two idlers to satisfy the negative fraction (opposite rotation). Good Luck!

@@machiningmoments Thanks My Mill is a Parkson 2N Universal, with the 12" Parkson Universal Dividing Head, Only Problem now is all the Change Gears are Missing. I am going to get a price on a set of gears made by 3D printing, they should be fine for Indexing. It also came with a Cam Milling Attachment, that is quite a piece of equipment, today you just need to write a program and push Rum My Plate is double sided with the holes 1st Side 24,25,28,30,34,37,38,39,41,42,43. 2nd Side 46,47,49,51,53,54,57,58,59,62,66, The list of Change Gears Listed is 24,28,32,40,44,48,56(2),64,72,86,88,100 Teeth Do you have any suggestion's on extra change gears I should get besides what's listed? I can use 22 spaces on my 66 hole plate Thanks Blair

+Nacer Ziani OD = (N+2)M So, outside diameter divided by (number of teeth plus 2) should give you the module.

+machiningmoments Thanks for responding , but i think this equation works just with metric spur gears , or am i wrong ?

+Nacer Ziani The formula is for metric spur gears which is the "module" same as addendum...if you have OD and teeth you should be able to calculate the module with this formula. The helix angle allows you to set the cutter angle (table).

+machiningmoments thanks man for your help

+Nacer Ziani Glad to, good luck!

Hi Dana, sorry for the slow reply busy weekend. So I assume you have your gear ratio fraction worked out. For argument sake let's say that ratio is 1/4 and you can't find two gears to satisfy this fraction. 1/4 is the same as 1/2 x 1/2 now look for gears to satisfy each fraction the first 1/2 gears are 24/48 and the second fraction is 32/64. The 24 gear is on the spindle it meshes with the 48 tooth gear. Stack the 32 gear on top of the 48 tooth gear (compound) the 32 gear meshes with the 64 tooth gear that is on the worm shaft. This is compound gearing satisfying the original 1/4 gear ratio. I hope this makes sense. Good luck.

machiningmoments didn’t get things worked out. Even if you did the 53 divisions and showed the math would be great. I tried different scenarios for factor A and just got confused using (A-N)x40/N.

Hi Dana, the formula is (A-N)x40/A. I assume you don't have a 53 hole plate, you could simple index 40 spaces on a 53 hole plate and ignore the gears. So, I choose 60 for an approximate (A) (60-53) x 40/60...if you work that out it 14/3 as an improper fraction (your gear ratio). 14/3 is the same thing as 7/3x 2/1. Now we look for a multiple of each fraction that will give us the gears we need. 7/3 x 8 will give us the first two gears 56/24...The other fraction 2/1 x 24 will give us the last two gears 48/24. 56 goes to the spindle and meshes with 24, 48 goes on top of the 24 (compound) and 48 meshes with 56 on the worm shaft. Your indexing is 40/A 40/60 or 2/3 find a multiple of this that works with a hole plate you have...30 as an example. The indexing is 20 spaces on a 30 hole plate. Note! the index plate has to rotate (driven by the gear train you created) make sure it is unlocked. Clear as mud? ;)

machiningmoments I’ll do the math too on paper and see if I work it out. Thanks.

Okay. I worked out pretty much the same thing as you said only I had to use a 33 holes plate which would be 22 spaces on a 33 holes plate. Only thing is I’m not sure of the meshing of the gears. I’m a visual person so if you could draw the gears in contact with each other would be great. vintagemachinery.org/pubs/2185/5863.pdf this is a link to instruction manual to brown and sharp dividing head. It has some good info.

My pleasure, thank you for watching and your post.

It is not possible to gear a dividing head to the table and differential index. The gear I would have from the dividing head to the milling machine table is used to gear to the dividing head spindle instead. If you want to gear the dividing head to the milling machine you have to use simple indexing. Please have a look at my Cam Milling video. If you can't find it I'll send you a link. If question arise please let me know.

Absolutely, as long as the solution works with available gears and holeplate.

Thank you sir for your video. And reply to my question. I am confuse,can you help me how to get the gear ratio for 87T spur gear. Thank you again sir,

Ok so 87 teeth is what you require. This needs to be done with differential indexing (in the video). A = approximate number and N = your actual number. The formula is (A-N)x40/A I chose 90 as my A...So (A-N)x40/A = (90-87)x40/90 = (3)x4/9 = 12/9 Your indexing is 40/90 or 4/9 and your gear train 12/9 (lowest common denominator 4/3. Indexing first, find a holeplate that is a multiple of the demoninator of the 4/9 fraction. A 27 or a 54 holeplate will work, assume you use a 27 holeplate 3x9=27 you need to use the same multiple for the numerator 3x4=12. So your indexing is 12 spaces on a 27 hole plate. Next you need the gear train, the ratio calculated above 4/3 multiply numerator and denominator by 8 and you get 32/24. These are your gears. The 32 tooth gear goes on the spindle and the 24 tooth gear goes on the other shaft (back into the wormshaft). There will be an idler in between these two gears (any gear will do you don't care how many teeth it has). Remember to unlock the holeplate it has to turn, that's why you made the gear train. I hope this makes sense. Good luck!

Thank you sir, this will help me.

Thank you Henri, nice to hear from you. I believe it is a Walter.

120 can be done with simple indexing. 40/N ...40/120 or 1/3. Look at your hole plate and choose the diameter that is a multiple of 3. Example let's say you have a 30 hole plate, your indexing would be 10 spaces on a 30 hole plate for 120 divisions.

@@machiningmoments Thanks a lot now i get it.😊😊😊

I'm glad, thanks for letting me know. Good luck!

Hello Anup, helical gears are possible if you gear the dividing head to the table lead screw. You also need to be able to swivel the milling machine table.

Thank you

Thank you for watching and making the time to leave a message.

Sorry for the slow reply, busy day. The number of teeth on the idler is irrelevant, all it does is move the power from the driver to the driven. I likely used 44 teeth because the gap was close to that size and I wouldn't have to adjust the setup much. It could have been any number of teeth for the idler.

machiningmoments thanks for the reply. Do you have any video about cutting helical gear? Do you have any good reference books to read about gear and its theory?

I have cut helical gears and have often thought about making a video. I don't have one yet. The problem is it is a very involved topic. The book I like to use is Technology of Machine Tools by Steven Krar. If you would like to leave me your email address I have a power point on helical gear cutting I can send you.

machiningmoments thanks for your reply. Look forward to the ppt slides :)

machiningmoments received your mail. Thanks a lot.

The number of teeth on the idler are irrelevant. All the idler does is move power from driver to driven gear.

Thank you

:) Good Luck!

All the idler gear is doing is moving power from the driver to the driven. It could be 12 teeth or 100 teeth. The ratio is determined by the number of teeth between the first and last gear. This is known as simple gearing...a simple gear train not a compound gear train. Thanks for your question and watching.

Hm, very interesting to learn, thank you for that insight. I would have thought it would change the gearing ratio.

I'm glad to hear it was helpful. Thank you

+Nacer Ziani and I have another Q, how should we choose the A value ? is it random and always bigger then the right cuttings ?

+Nacer Ziani Short answer, it's a guess (an educated guess). When I "guess" a number I'm considering how it will factor into my hole plate selection and my gear selection. Some numbers you pick will not work with the hole plates and gears you have. It is a bit of trial and error but with practice you will get it.

+Nacer Ziani This is one of the videos I want to make. Sorry I don't have a timeline but it is in the back of my mind. Life gets in the way. Thanks for your posts.

+machiningmoments Thanks a lot mate , I really learned a lot from your vids

nicely videos

No, Gear ratio in this case will be (48/44)*(44/28) idler gear teeth cancel out

It doesn't matter how many (or few) teeth are on the idler, it is only used to move the power from the first gear to the last.

In simple gear train number of idlers and teeth on idler do not affect the gear ratio. Idlers are used to transmit the from from driver to driven.

That's too bad, spiral fluting on a mill is really neat!

If you have the mill you can make the gears!

+J800613 where could I get information on what size gears to make ? i also have 8 of the involuted gear cutters that came with it .

A Google search on involute gear calculations may be helpful...here is one I found. www.engineersedge.com/gears/involute-gear-design.htm

+machiningmoments thanks , that is very helpful,

Thank you for watching.

Hi Mark a textbook I use a great deal is Technology of Machine Tools. I believe the author is Steven Krar.

+cerberus Thanks for watching and commenting.

Thanks for watching and leaving a note.

The problem with 67 is there is not a 67 hole plate so it becomes difficult...not impossible but difficult.

@@machiningmoments Are the distribution results right ?

40 / 70 / 40= 0.014 turn spindle rigth ?? 0.014 × 48 / 28= 0.024 turn plate indexing rigth ??

Sorry for the slow reply, busy weekend. I would leave your work in a fractional form. Your example 40/70 is the same as 4/7 find a multiple of the denominator that matches with a hole plate you have. Example assume you have a 28 hole plate. 4 times 7 is 28 so it satisfies the denominator. Numerator and denominator use the same multiple. So your solution would be 16 spaces on a 28 hole plate (assuming you have a 28 hole plate). I hope that makes sense. Good Luck!

I'm glad you liked it.

Thank you, I appreciate you posting.

Thank you

No, I think it's just a standard dividing head. Make sure you are able to engage the worm shaft (move the dividing head by turning the index crank) also you want a shaft to come off the worm shaft on the back of the dividing head to add gears to. Thanks for the "hail Mary"1

Thank you

As long as it satisfies the fraction it works so 22/66 is 1/3rd same as 10/30 is 1/3rd. So they both work. Good practice is to choose the multiple on the largest diameter. Thanks you for watching and your message.

Name? I'm not sure I understand what you would like to know.

I'm sorry I don't understand the question.

A 70 Outdia

If you watch my video on Cam Milling you will see the dividing head geared to the milling machine table with an explanation of how it works. Sorry for the slow reply. Thank you for watching.

Great!

?

machiningmoments job cutting

Like direct indexing

मुझे यकीन नहीं है कि मैं आपकी पोस्ट को समझता हूं। देखने के लिए धन्यवाद।

kya main aap ko samajhane mein madad kar sakate hain?

yeah Sir