# Buying involute gear cutters



## Swifty (Mar 8, 2013)

Have any of the Australian members purchased a set of involute cutters? I would like to know which company you purchased them from, there are a few on the Internet, just not sure who to use.
I am after a set of mod 1 cutters.

Paul.


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## hi speed scrap (Mar 8, 2013)

Hi Swifty,
While I have not purchased full sets of gear cutters for a few 
years, I have purchased individual cutters from 2 ebay suppliers
more recently. One in Wandong Nth of Melb, the other is a well
known S.A. supplier.
Reminder that H & F big 3 day sale coming up next weekend, you
may be able to do a deal there. Worth calling them.

I have found for myself, that it is cheaper and quicker to buy 
finished gears off the shelf, some are just ridiculously cheap and
the quality is superb, and the range is huge.  9300 odd gears!
There is a 60mb PDF download catalog on the web at
http://www.khkgears.co.jp/en/catalogs/index.html

There is a dealer here in melbourne who generally carries good 
stocks.

Dave.
Boronia.


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## Swifty (Mar 8, 2013)

Thanks for the information Dave, I am aware of the H & F sale next week, although I haven't seen that they carry any gear cutters. Have cut my own spur gears with a home made hobbling cutter, they came out great. The trouble is that I want to cut some bevel gears which require a single point cutter. I realise that I can make my own, but thought a set of cutters might be handy.

Paul.


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## aarggh (Mar 9, 2013)

I've bought quite a few sets off this seller on Ebay and I'm very happy with them, they seem as good quality as I've seen anywhere else, and I just wasn't prepared to spend 3-4 hundred per set:

http://www.ebay.com.au/itm/FULL-SET...020?pt=LH_DefaultDomain_0&hash=item19d905330c

There is also an Aussie distributor (at nearly 3 x the cost!) but I don't know if these are worse or better than the ones I bought:

http://www.ebay.com.au/itm/GEAR-CUT...15?pt=LH_DefaultDomain_15&hash=item19c93245eb

cheers, Ian


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## Davo J (Mar 9, 2013)

CTC is good and you can see what the postage is strait away.
When you go to the link click on the blue drop down next to "All products" in the search bar and it will drop down a list of everything including the gears you after. I have not heard any complaints with them since he has been selling them and I am on most of the forums around.
http://www.ctctools.biz/servlet/StoreFront

Dave


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## Mbusha (Mar 9, 2013)

hi speed scrap said:


> Hi Swifty,
> While I have not purchased full sets of gear cutters for a few
> years, I have purchased individual cutters from 2 ebay suppliers
> more recently. One in Wandong Nth of Melb, the other is a well
> ...



Dave,

Followed the link above and there also is some nice reference material available as PDF as well.

http://www.khkgears.co.jp/en/gear_technology/guide_info.html

English translation, mostly not so bad, and I think well worth the read. I am a tech manual junkie. 

Thanks for the post.


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## Swifty (Mar 9, 2013)

Mark, a lot of technical advice on the site below, I have requested a metric catalogue, hoping they will post it to Australia, should do as it appears on their list when I entered details.

http://www.sdp-si.com/D805/D805cat.htm#MB1

Paul.


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## Swifty (Mar 9, 2013)

Thanks Ian and Dave, I have ordered a set from CTC direct. It was $26 cheaper than buying through their eBay site. Beats paying close to $300 for a local supplier, most likely comes from the same factory.

Paul.


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## ShedBoy (Mar 9, 2013)

I have bought plenty of gear from CTC. Always seem good quality and service is fast. Their diamond lapping paste is a mint buy too.
Brock


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## rodw (Mar 9, 2013)

ShedBoy said:


> I have bought plenty of gear from CTC. Always seem good quality and service is fast. Their diamond lapping paste is a mint buy too.
> Brock



I can also vouch for CTC. I have for a couple of orders from them and the service has been excellent and included some QC tool holders not on their web site and they just sent me a PayPal invoice for the balance required.


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## ruzzie (Mar 9, 2013)

A couple more sellers in Aus
Mcjing - Sydney
http://www.mcjing.com.au/searchresult.aspx?keyword=gear cutter
Minitech - Brisbane
http://wic043u.server-secure.com/vs4487_secure/find.asp?q=gear+cutter


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## ROBERTBRUCE (Mar 9, 2013)

In reply to the original question, why not make a hob . I have had very good results using a home made hob on steel and cast iron (part of a rayburn and as hard as XXXX). I needed the gears to make a rotary table and a dividing head
for a myford both of which work fine.
Robert


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## Swifty (Mar 9, 2013)

Hi Robert, I already have a hob that I made to cut some spur gears, the problem is that I want to cut some mitre gears, and these need to be cut with a single tooth cutter, as the hob interferes with the previous cut. Found out the hard way!

For just over $100, I have ordered a set of 8 cutters in the module that I wanted. Just thought that by the time I mucked around and made a single point cutter, which only covered a small number of teeth, it was easier to buy a set in HSS.

Paul.


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## Davo J (Mar 10, 2013)

If your cutting steel gears use plenty of coolant and the right speed and feeds and they will last you a long time, well worth the money in my eyes for the ease of cutting gears.

Before we had these Chinese sellers there is no way we could afford a gear never mind a gear set for hobby use. A lot of people go on about Chinese stuff, but for a lot of us hobby guys (especially in Australia) there is no way we could afford this as a hobby without them, they have made tooling obtainable at reasonable prices for a lot of us on small budgets.

Don't forget to post up your gears when your doing them, going on experience you should have them by the end of the week or earlier.

Dave


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## ROBERTBRUCE (Mar 10, 2013)

Is it just me ? but i get a lot of pleasure in producing something from nothing. I would not spend money on somthing that i can produce (and learn ). There have been articles on how to produce
invalute cutters, can dig them out if you are interested. 
Just before you all jump down my throught and say you have to buy somethings I will retreat to my shed to play with my portable forge, need to make pullys for a 7x12 moter went bang some time ago.


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## Fluffy (Mar 10, 2013)

G'Day Paul,
I have bought a number of individual involute cutters from Tracy Tools in the UK. Their service is excellent & goods are delivered in 7 to 10 days. All of the cutters have been good quality & are massively, cheeper than any of the quotes that I obtained from local suppliers.
Regards,
Don.


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## Davo J (Mar 10, 2013)

I can fully understand what you mean there, and I also get great enjoyment out of making something from nothing, but there is a cut off point for me.

It all depends on the member, his time, and how much of a project he wants to make it. On one end of the scale you could pour your own metal into sand castings to make the gear, then on the other end there is going and buying a gear, so it's up to the individual to work out how much work he wants to do for a set project.

If someone is looking for something he has already made up his mind he wants to buy them instead of making it another project to make the tooling, and this way he will have the full set for years to come for other projects where it will save time.

I bought a mill years ago with a NT30 spindle and after looking locally and seeing collet chucks for around $180 each I thought I would make my own, then I see Chinese sellers selling them with a nice hardened and ground finish for $17, I couldn't make them for that and don't have a way to heat treat or precision grind them anyway.

Dave


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## radial1951 (Mar 10, 2013)

Swifty said:


> Hi Robert, I already have a hob that I made to cut some spur gears, the problem is that I want to cut some mitre gears, and these need to be cut with a single tooth cutter, as the hob interferes with the previous cut. Found out the hard way!
> 
> For just over $100, I have ordered a set of 8 cutters in the module that I wanted. Just thought that by the time I mucked around and made a single point cutter, which only covered a small number of teeth, it was easier to buy a set in HSS.
> 
> Paul.



Hi Paul,  If you are making bevel gears, there are a few methods. Many moons ago I milled the diff gears for a couple of large scale traction engines using the "correct" offset and roll method. The cutters are special for bevel gears, having the correct form on the sides, but are thinner to fit through the gap at the inner small end of the teeth. There was a total of 7 cuts per tooth space AND the tips of the teeth had to be filed towards the small end!! A real PITA.

After doing all that, I discovered the "parallel depth method", using standard involute milling cutters. Would have saved me literally weeks of work. Ah well, live and learn...

BTW, CTC prices and service are fine, but don't _expect_ good quality. A mate and I have been testing some R8 collets and frankly most of them are ru**ish. The Bridgeport's taper indicated under 0.0002" TIR, but some of the collets have up to 0.003" or more runout, depending on how far from the collet. Not simple parallel runout, but wobble. Hmm.

The form on an involute cutter probably doesn't matter as much as collet accuracy, but it would be nice if the teeth are concentric to the bore...

Where did you end up buying the involute cutters?

Regards, RossG
radial1951
_____________


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## aarggh (Mar 10, 2013)

ROBERTBRUCE said:


> Is it just me ? but i get a lot of pleasure in producing something from nothing. I would not spend money on somthing that i can produce (and learn ). There have been articles on how to produce
> invalute cutters, can dig them out if you are interested.
> Just before you all jump down my throught and say you have to buy somethings I will retreat to my shed to play with my portable forge, need to make pullys for a 7x12 moter went bang some time ago.


 
Hmm, I used to approach everything like that too, for no other reason that I could, but as I get older my time is becoming increasingly limited and valuable, so while I'm happy to waste time on projects simply because I really enjoy them, some things, like re-creating precision tooling that I can buy better than I could make, for a fraction of what it would cost me, I just buy now. That free's up more time to be spent on things I want to spend time on, and sometimes things I don't!

cheers, Ian


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## Swifty (Mar 10, 2013)

Thanks everyone for your comments, I have ordered a set of cutters from CTC, cheaper buying direct from them at $100 a set of Mod 1. Works out at $12.50 per cutter, can't beat that. I have always been keen on making my own tools etc, but the time and effort put into making 1 cutter was not worth it, especially seeming that the cutter would only cover a small range of teeth. I will have to make an arbor to hold the cutters anyway. By the way, it took 3 attempts before getting the hob right, hob 1 did not heat treat well, hob 2 tooth form not quite deep enough, hob 3 perfect.

I have been taking pictures along the way, making the hobbing cutter and cutting some spur gears. When I have the mitre gears ready to cut I will take more pictures and post about it.

By the way, mitre gears work in sets of 1:1 ratio, bevel gears work in different ratios. The spur and bevel / mitre gears are for a couple of projects that I have in mind for the future, as I haven't done any gear cutting before, I thought that I would see how I go making them first.

Paul.


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## Swifty (Mar 10, 2013)

ROBERTBRUCE said:


> Is it just me ? but i get a lot of pleasure in producing something from nothing. I would not spend money on somthing that i can produce (and learn ). There have been articles on how to produce
> invalute cutters, can dig them out if you like.



I feel the same way, although a lot of effort and it could still not work. I could have bought the gears quite cheaply, but decided to make them instead, so have put in some effort.

Paul.


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## parisharma (Mar 16, 2013)

Great post I appropriate your post.  I want to buy gear cutting tools. Can you please suggest me where I can get good quality of tools.


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## Swifty (Mar 22, 2013)

The cutters arrived from CTC a couple of day ago, very happy with price and delivery time. The cutters look great, made an arbor to hold them and then cut one mitre gear. Before cutting, I re read Ivan Laws book a couple of times and used his 3 cut method. Before I go any further, I turned the blanks after researching on the Internet, and after finding the same sizes on a few sites, I was happy that I had the correct form. I cut the gears to the theoretical depth for the module, but when I checked the gear it looked as if the depth was too deep. 

I'm still trying out different ideas, but not happy yet. One thing, I'm getting very good at turning the blanks. Anyone with any ideas would be appreciated.

Paul.


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## radial1951 (Mar 23, 2013)

Swifty said:


> ... making the *hobbling* cutter and cutting some spur gears. When I have the mitre gears ready to cut I will take more pictures and post about it.
> 
> By the way, mitre gears work in sets of 1:1 ratio, bevel gears work in different ratios...
> 
> Paul.



Hi Paul, with all respect, the typo error "hobbling" needs to be corrected. A newbie to the art of gear cutting may not realise that "hobbing" is the term used for one of several methods of generating a gear tooth profile, based on the theoretical rack of the same tooth size/shape, and the cutter is called a "hob".

No offence intended, but also  ....  By definition, any pair of gears connecting two shafts, whose axes intersect, are BEVEL GEARS. A pair of IDENTICAL BEVEL GEARS, with 45 degree pitch cone angles, are known as MITRE GEARS i.e. 1:1 ratio and shafts at 90 degrees.

As I'm sure you know, the correct tooth profile for Bevel Gears cannot be produced with a milling cutter.

BTW, parallel depth bevel gears do look a bit strange, maybe because the Module size of the cutter suits the small end of the teeth. As a _rough_ guide, for Module 1, the pitch line is 1mm down from the top of the tooth, and the tooth thickness at the small end, on the pitch line, is about 1.57mm. Guesstimating with a vernier caliper will give you an idea if you are within cooee (that'll throw 'em).

This link was on HSM: http://www.archive.org/stream/americanmachini00logugoog#page/n148/mode/1up  - Good info, see page 144.

Regards, RossG.
radial1951
______________


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## rcaffin (Mar 23, 2013)

I've bought a fair bit from CTC, direct. 
The runout on the ER25 collets was less than the runout on the mill.
Some carbide cutters are specified for wood, plastics and Al. Fair enough, don't use them on steel.
Some of the cutters specified for steel are truly wicked!

Cheers


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## Swifty (Mar 23, 2013)

radial1951 said:


> Hi Paul, with all respect, the typo error "hobbling" needs to be corrected. A newbie to the art of gear cutting may not realise that "hobbing" is the term used for one of several methods of generating a gear tooth profile, based on the theoretical rack of the same tooth size/shape, and the cutter is called a "hob".



Have corrected the spelling error, my fat fingers on the iPad caused the extra letter. Will check out the web site.

Paul.


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## Swifty (Mar 23, 2013)

radial1951 said:


> BTW, parallel depth bevel gears do look a bit strange, maybe because the Module size of the cutter suits the small end of the teeth. As a _rough_ guide, for Module 1, the pitch line is 1mm down from the top of the tooth, and the tooth thickness at the small end, on the pitch line, is about 1.57mm. Guesstimating with a vernier caliper will give you an idea if you are within cooee (that'll throw 'em).



According to Ivan Laws book, the cutter number chosen should reflect the large end of the gear. Which, in my case, when trying to cut 20 teeth the cutter chosen should be for 28 teeth. Therefor I should use cutter no:4 instead of cutter no:3. The tooth thickness at the small end is a lot smaller than what you state. It would be better if I could make a cutter to cut the "tooth" instead of the "gap", but not practical. Back to the drawing board for me, and more studying.

Paul.


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## gus (Jun 13, 2013)

rcaffin said:


> I've bought a fair bit from CTC, direct.
> The runout on the ER25 collets was less than the runout on the mill.
> Some carbide cutters are specified for wood, plastics and Al. Fair enough, don't use them on steel.
> Some of the cutters specified for steel are truly wicked!
> ...




Hi RCaffin,

Two sets of Gear Cutters came in from CTC week ago.
Inspected one set that I will using shortly from now to cut Module 0.8 pinion.
Some cutters are very well ID marked with Cutter nos. No of teeth etc,
Some have very faint marking that I cannot read.Emailed CTC and so far no resonse.

CTC end mills are usable.

It is true even Littlemachineshop have quality problems.Been buying from LMS and had one Precision Tool Maker Vice I am not happy.But they gave me refund.I am still buying from LMS. 


Gus Teng from faraway Singapore.


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## rcaffin (Jun 13, 2013)

> Some have very faint marking that I cannot read.Emailed CTC and so far no resonse.



Can take them a few days to reply sometimes. But I have found them fairly reliable.
I have had faint markings on collets, but I found that if I angled them 'just right' to the sun they were quite readable. No, I don't know what is 'just right' - sorry!

Cheers


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## rodw (Jun 13, 2013)

gus said:


> Hi RCaffin,
> 
> Two sets of Gear Cutters came in from CTC week ago.
> Inspected one set that I will using shortly from now to cut Module 0.8 pinion.
> ...



Gus, can you work them out from the detailed specifications on CTC's web site? 
Try http://www.ctctools.biz/servlet/the-629/hss-involute-gear-cutter/Detail

It took me a while to realise in their listings there is another tab with more info. Click on the "Detailed Description" tab to see it.
 I am not really ready to tackle any gear cutting yet so in this case it does not make much sense to me..


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## Swifty (Jun 13, 2013)

The set of cutters that I purchased fron CTC also have hard to read markings. But one positive thing was that the greasy paper that the individual cutters were wrapped in had the cutter number written on it in marker pen. Will get around to engraving the cutters with correct details one day.

Despite that, they are very good cutters.

Paul.


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## aarggh (Jun 14, 2013)

All the involute cutters I've bought off CTC have been very good quality, and very cheap! The markings on my sets are quite fine to read.

cheers, Ian


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## gus (Jun 14, 2013)

Swifty said:


> The set of cutters that I purchased fron CTC also have hard to read markings. But one positive thing was that the greasy paper that the individual cutters were wrapped in had the cutter number written on it in marker pen. Will get around to engraving the cutters with correct details one day.
> 
> Despite that, they are very good cutters.
> 
> Paul.



Hi Paul,
I agree with you. The grease paper is ID marked. Will be cutting a Module 0.8 Pinion gear for the Webster Engine Timing Train in two weeks time.

Your expertise is seeked.The wrapping will sooner or later go bad.How do I etch or engrave on hard steel.

Gus Teng.


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## gmac (Jun 14, 2013)

Gus;
Try a chemical etching pen, similar to this;

http://www.etching-pen.com/index.php?id=11&L=13
http://www.flexbar.com/shop/pc/METAL-ETCHING-PEN-p3113.htm

There must be something similar in your neck of the woods.

Cheers Garry


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## Swifty (Jun 28, 2013)

gus said:


> Hi Paul,
> How do I etch or engrave on hard steel.
> 
> Gus Teng.



Hi Gus, I was intending to engrave the cutters with a diamond coated bit or a fine pointed mounted point in my dremel.

Paul.


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## gus (Jun 29, 2013)

Just came up with a way to mark the gear cuttter no 4. Number stamp the arbor. Looks like I have to all 8 arbors and stamp all arbors. Will make a small wooden box to house and display
 Module 0.8 Gear Cutters.Will be another thread.

Meanwhile I am very happy with my private gear cutting lessons.
Instructor-----------Gus Teng.  Student-----------Gus.
Cut a good gear after three practice cuts. See fotos.
Ten days to make Dividing Head and Tail Stock Centre. And only half day to come up with a 
good looking mini Spure Gear. Harold Hall's design was good and strong.


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## Philjoe5 (Jun 29, 2013)

Gus,
I'm watching the gear cutting and appreciate your posting.  I'd like to buy the CTC set of cutters but I contacted them about getting the proper arbor to hold the cutters and they don't supply them.  Where did you find the abors to go with these cutters?

Cheers,
Phil


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## rcaffin (Jun 29, 2013)

> I'd like to buy the CTC set of cutters but I contacted them about getting the proper arbor to hold the cutters and they don't supply them.  Where did you find the abors to go with these cutters?



Bit of silver steel (aka 'drill rod'). I make them up regularly for mounting diamond wheels and CBN wheels.
Actually, heat treating them afterwards is probably optional. I have not done all of mine.

Cheers


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## Swifty (Jun 29, 2013)

Same as rcaffin in the above post, just make your own. I use mild steel mainly, or whatever odd bit of steel that is lying around. Seems that Gus is making a holder for each cutter, just make the one and change cutters as required.

Paul.


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## Philjoe5 (Jun 29, 2013)

Paul, Rcaffin,
Thanks for the tip.  The metric thread drawbars on arbors for this set of cutters, won't mix with the Unified threads on my machine.  It seems like the best way to go...make 'em myself.  

Cheers,
Phil


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## gus (Jun 30, 2013)

Philjoe5 said:


> Gus,
> I'm watching the gear cutting and appreciate your posting.  I'd like to buy the CTC set of cutters but I contacted them about getting the proper arbor to hold the cutters and they don't supply them.  Where did you find the abors to go with these cutters?
> 
> Cheers,
> Phil



Hi Phil,

The Arbors were DIYed using Grade 5 Hex Bolt. 
Grade 5 does not cut well when turned dry.I used Tapmatic Tapping Fluid applied in dobs with a tiny brush. The fastener to secure cutter and spacer to arbor is M6 Hex. Did not provide for keying cutter to arbor.

Gus.


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## Philjoe5 (Jun 30, 2013)

Hi Gus,
Thanks for your advice.  I caught your other thread about "Poor Man's Dividing Head" where you made the arbor and I was wondering about whether you keyed it.

I'm about to go where you were about 1 month ago...buying the cutters from CTC this week.  Making gears seems like a nice thing to do.

Cheers,
Phil


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## gus (Jul 1, 2013)

Swifty said:


> Hi Gus, I was intending to engrave the cutters with a diamond coated bit or a fine pointed mounted point in my dremel.
> 
> Paul.



Hi Paul,

Good idea. Might try doing same.
I have a cheapy China Rotary Endraver. Will look for a diamong coated bit in at Tokyu Hands,Osaka. Taking my better half there for a cheapy holiday.
Nowadays even regular airlines like SIA would have special offers cheaper than budget airlines if you out on frequent bargain hunting. Osaka ** and ***
hotel room rates are cheap basis you book on the net.

Meanwhile all set to stamp number "4" on the very first arbor mounted gear cutter.


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## gus (Jul 1, 2013)

Philjoe5 said:


> Hi Gus,
> Thanks for your advice.  I caught your other thread about "Poor Man's Dividing Head" where you made the arbor and I was wondering about whether you keyed it.
> 
> I'm about to go where you were about 1 month ago...buying the cutters from CTC this week.  Making gears seems like a nice thing to do.
> ...



Hi Phil,

I got away w/o keying it but I did put Loctite on the mating faces for some cheapy assurance. Did help for now. Backup would drill into arbor and put a pin. Not so sure I get away with Module 1.0 cutters.


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## doortoh (Jul 4, 2013)

Hi..can you still purchase electric engravers...12 volt.....i have had one for years and it works fine for marking  any hard material...especially those taps that you cant read after using them a few times....Wayne


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