Author Topic: Eureka form relief tool  (Read 37556 times)

Offline PekkaNF

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Re: Eureka form relief tool
« Reply #25 on: December 20, 2012, 02:30:58 AM »
Presumably, the relieving tool has to have the same profile (or at least a mirrored/ double sided profile - IYSWIM) as the originating threading/forming tool - does it?

Bill

Is this part of an aswer to your question?:
http://mikesworkshop.weebly.com/designing-gear-cutters.html
Rather interestingly:
http://metalwebnews.com/howto/gear/gear1.html
and:
http://mikesworkshop.weebly.com/making-gear-cutters.html

Pekka

Offline rotorhead

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Re: Eureka form relief tool
« Reply #26 on: December 20, 2012, 03:52:13 AM »
reynard,

I owe you an apology for not realising I'm not the only Chris on here.

In my enthusiasm at finding reference to the Eureka tool, I blundered on, thinking I was initially being replied to, until Rob qualified the Chris with (rotorhead).

So apologies to all actually.

Rob, thanks for the scan, and yes it is my intention when time permits, to make one.
My thinking already, is with the suggestions on here, that I'll go the double size route.

Chris(the other one)

P.S. How does one get the smilies to show where you want them?
« Last Edit: December 20, 2012, 05:23:56 AM by rotorhead »
Chris
Sunny Scunny,
North Lincolnshire.

Offline SLM

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Re: Eureka form relief tool
« Reply #27 on: December 20, 2012, 09:24:46 AM »


Chris(the other one)

P.S. How does one get the smilies to show where you want them?

Either directly  add the code where you want the smilies or click the one you want with the mouse keeping your blinking cursor where you want it. Hopefully that makes sense.

Offline BillTodd

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Re: Eureka form relief tool
« Reply #28 on: December 21, 2012, 07:24:53 AM »
Thanks Pekka :)


Presumably, the relieving tool has to have the same profile (or at least a mirrored/ double sided profile - IYSWIM) as the originating threading/forming tool - does it?

Bill

Is this part of an aswer to your question?:
http://mikesworkshop.weebly.com/designing-gear-cutters.html
Rather interestingly:
http://metalwebnews.com/howto/gear/gear1.html
and:
http://mikesworkshop.weebly.com/making-gear-cutters.html

Pekka
Bill

Offline raynerd

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Re: Eureka form relief tool
« Reply #29 on: December 21, 2012, 03:30:15 PM »
Hi guys, interesting conversation this has started. I`ve just become a dad again so I`ve been away for the last few days! I`ve enjoyed reading all the links and attachements. Thanks.

Rob - I could remake the part but it is so poorly made I`d be as well remaking the entire thing!

Chris


Offline raynerd

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Re: Eureka form relief tool
« Reply #30 on: December 21, 2012, 03:31:02 PM »
Rob - one more thing. On the cutters you made, how do you get such crisp even stamping ?  Are they just standard letter punches?

Offline John Stevenson

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Re: Eureka form relief tool
« Reply #31 on: December 21, 2012, 03:33:50 PM »
Rob - one more thing. On the cutters you made, how do you get such crisp even stamping ?  Are they just standard letter punches?

Photoshop...................
John Stevenson

Offline raynerd

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Re: Eureka form relief tool
« Reply #32 on: December 21, 2012, 03:36:54 PM »
I couldnt get them like that photoshop!

Think I need to invest in some new ones. All mine are second hand sets.

Rob.Wilson

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Re: Eureka form relief tool
« Reply #33 on: December 21, 2012, 03:52:58 PM »
First off congratulation Chris  :clap: :clap: :clap: :clap: :clap: nice one :thumbup:


Is it that bad   :palm: , sure it just dose not just need the part that you mount the cutter on re-made .

Yes just stamped with normal hand stamps ,,,, here a few photos to show how , nowt flash just made a small stamping guide.




 :lol: :lol: Photoshop my secret is out  :palm:

Rob

Offline PekkaNF

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Re: Eureka form relief tool
« Reply #34 on: December 22, 2012, 03:43:14 AM »
..... I`ve just become a dad again so I`ve been away for the last few days! .....
Rob - I could remake the part but it is so poorly made I`d be as well remaking the entire thing!
Chris
Congratulations Chris!

I think that a lot can be learned from nonworking scale size model. Least that what I usually end up producing first almost every time. The bright side is that metal objects are faster to remake than babies - they have certain set up times. :)

Pekka

Offline rotorhead

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Re: Eureka form relief tool
« Reply #35 on: December 22, 2012, 05:08:15 AM »
Chris,

Congratulations, well done lad.

Pekka, you'll get the hang of it, if you keep trying mate.

Chris(the other one)
Chris
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North Lincolnshire.

Offline raynerd

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Re: Eureka form relief tool
« Reply #36 on: December 22, 2012, 08:58:06 AM »
Thanks guys!

Rob, that guide is bloody genious!!   

Currently sat with my son over one shoulder, my daughter pulling my toes and Peppa Pig on the TV - time free in the workshop seems a time off!
 
Chris

Offline John Stevenson

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Re: Eureka form relief tool
« Reply #37 on: December 22, 2012, 09:20:41 AM »
Thanks guys!



Currently sat with my son over one shoulder, my daughter pulling my toes and Peppa Pig on the TV - time free in the workshop seems a time off!
 
Chris

Buy a treadmill.
John Stevenson

Offline raynerd

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Re: Eureka form relief tool
« Reply #38 on: December 30, 2012, 05:05:18 PM »
Got a couple of hours in the workshop while my wife`s friend came around.

Eureka worked well and I think I`ve produced a useable cutter however the problem I had was that for this 0.6 mod cycloidal cutter profile I needed a 0.92mm radius "button" profile tool. As suggested in the past, a suitably ground drill bit works so I picked a 2mm drill bit and ground the profile on the end. However, It just isn`t rigid enough and consequently there is flex in the cut. Multiple cuts works but there are problems. I just can`t image grinding a round 0.92mm profile radius onto a larger more rigid bit of tool steel.

Suggestions welcome. However, it has worked!






The picture below shows the steel blank mounted on a mandrel with 12 x 4mm holes drilled as near to the edge as possible. The wheel is then turned down in the lathe to expose the holes. These holes become the back relief and gap between teeth.






Finally the finished cutter, with relief!






Offline philf

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Re: Eureka form relief tool
« Reply #39 on: January 18, 2013, 04:18:32 PM »
Prompted by Chris's efforts to produce cutters for clock wheels and pinions I thought I'd have a go myself.

I bought a Eureka relieving attachment via Homeworkshop.org some time ago and it's sat in a box ever since. It's much better finished than Chris's but still I had to make a few improvements. One problem was that the arbor ran out by 0.2mm. The guy who made it decided on 3/4" bore cutters rather than 1/2". I set up the arbor in the 4 jaw and got the bore running true and then skimmed it down to 16mm. (The clamping thread was 5/8" so didn't need recutting.) The arbor was bushed with, I think, brass and the bush was a very very loose fit so I remade it a press fit in the arbor and a nice running fit on the eccentric shaft.



Many years ago at work we used KE672 oil hardening low distortion tool steel and I managed to get an old colleague to find me 12" of 1.5" diameter. I sawed this into slices and faced them up in the lathe. So I could face the thin disks parallel I made a support which fitted in the bore of my 3 jaw and was just under 3mm shorter than the chuck jaws. I faced this holding it in place with a running centre with the chuck jaws removed. The slots are marked with the jaw numbers so it always goes back in the same orientation so should produce perfectly? parallel parts.



I made 20 or so blanks which were drilled and bored to 16mm. (No 16mm reamer!)

The button method of machining the profile on the cutter for involute gears isn't so straightforward for cycloidal cutters as the flanks of the cutter have to be radial with a radius at the root. I also chose to make the cutters with a radius at the tips so the finished clock teeth will have round bottoms. You can't achieve that with a button tool. (Antique clocks always had square bottoms but modern practice is to have round bottom teeth which are stronger.) As Chris found the button method would require buttons of less than 1mm diameter which wouldn't be stiff enough unless they were tapered. Having a CNC miller, I thought that it would be possible to machine a form tool with the tooth form to put the profile on the cutter. This form tool would also need a relief angle so that it didn't rub on the cutter. I chose 5 degrees as that's what seemed to be specified for the button method. To get the relief I angled the form tool blank at 5 degrees to horizontal. This would give a constant profile which would allow sharpening without losing the profile. I drew the form tool in Autocad and then generated the GCode in Cut2d. With a 0.8mm end mill at 10,000 rpm I cut the form into 6mm gauge plate which was then hardened (in old cooking oil) and tempered (in the deep fat fryer). The top surface of the tool looks dog rough but this was taken through a microscope and is the gauge plate finish before heat treatment and polishing. The radiuses on the tool are just over 0.4mm.





To remove the bulk of the material from the cutters I chamfered either side of the blank which would also help centre the form tool on the blank. The method of slotting the blank given in Ivan Law's book is to drill 12 holes and then saw into the holes. This may be OK for one or two cutters but I thought the CNC could do this job with ease.



The first attempts at forming the teeth on the blanks with the Eureka were very disappointing. I seemed to be getting nice little chips for a while but then the cutting seemed to slow up. I thought that perhaps the form tool was dulling too quickly but, on examination, it looked fine. After a few abortive attempts I decided that 5 degrees clearance on the form tool wasn't enough. The Eureka puts the relief on the cutter and I guess that this was also about 5 degrees. So, once the tooth started to form, it very soon started to rub on the cutter. I remade the form tool with 7 degree clearance and had another go. This worked OK for 8 and 12 tooth pinion cutters but when I tried to profile the wheel cutter (which has a much deeper form) I again had problems and had to make yet another form tool with 8 degree clearance.

Here are a few photos of the finished hardened cutters (just awaiting the deep fat fryer tempering and then sharpening).







I've marked the cutters with an Actograp engraver - not as neat as Rob's method of stamping but much quicker and I don't have any letter stamps. Perhaps I'll engrave them on the CNC if I make any more.

Phil.
« Last Edit: July 13, 2017, 02:34:46 PM by philf »
Phil Fern
Location: Marple, Cheshire

Rob.Wilson

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Re: Eureka form relief tool
« Reply #40 on: January 18, 2013, 04:41:52 PM »
 :thumbup: Very nicely done  Phil


Using the CNC would have speeded the process up a fair bit  :med:


Rob

Offline raynerd

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Eureka form relief tool
« Reply #41 on: January 23, 2013, 04:32:23 PM »
Ahhhhh, I missed this Phil.

These look amazing Phil and you know that I'll be following closely. The CNC profile tool seems the way to go.

Also, I think based on your quality eureka tool for half the price I got mind for, I'm going to remake mine. I paid 50 and it looks like a dogs dinner and fit for the crap bin. It does a job but despite best efforts, it isn't turning true.

Ok, a clock to a least start but I'll be back t this thread.

Phil, please update us how it cuts.

Chris

Offline philf

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Re: Eureka form relief tool
« Reply #42 on: January 24, 2013, 11:34:33 AM »
Ahhhhh, I missed this Phil.

These look amazing Phil and you know that I'll be following closely. The CNC profile tool seems the way to go.

Phil, please update us how it cuts.

Chris

Chris,

I managed an hour in the workshop today and tried a 12 tooth pinion. I did it on the Aciera with the dividing head as my CNC won't run at 60 rpm.

This is the result:



I'm pretty pleased with it - it looks better in real life than in the picture. (I took the picture with a USB microscope as my compact digital has died. It could be better focussed.)

It's 8.09mm OD and was cut in one pass with a 1.49mm depth of cut with plenty of cutting oil brushed on.

Phil.
« Last Edit: July 13, 2017, 02:33:01 PM by philf »
Phil Fern
Location: Marple, Cheshire

Rob.Wilson

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Re: Eureka form relief tool
« Reply #43 on: January 24, 2013, 11:38:56 AM »
I would be well pleased with that too Phil  :thumbup:

Well done  :clap: :clap:

Rob

Offline Simon0362

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Re: Eureka form relief tool
« Reply #44 on: January 25, 2013, 02:55:07 PM »
Very impressive....
Do I understand that you were running the cutter at 60rpm? What feedrate did you use - if you can tell?

Regards,
Simon

Offline philf

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Re: Eureka form relief tool
« Reply #45 on: January 25, 2013, 03:26:30 PM »
Very impressive....
Do I understand that you were running the cutter at 60rpm? What feedrate did you use - if you can tell?

Regards,
Simon

Hi Simon,

Yes - I used about 60 rpm. I can't tell what the feed rate was as it was done by hand. My guess is only about 10mm/minute. I would have liked to use my CNC so I could have used a known feed rate and my 4th axis but that has a minimum speed of about 166 rpm which is a bit too fast for a carbon steel cutter cutting a silver steel pinion.

I've finshed the turning of the pinion now and have hardened and tempered it. I just need to finish polishing it when I get a new tube of Solvol Autosol tomorrow - I have a nearly full tube somewhere.................

Cheers.

Phil.
Phil Fern
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Offline raynerd

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Re: Eureka form relief tool
« Reply #46 on: January 25, 2013, 09:05:44 PM »
Top trumped me there! I was chuffed with my wheel but that pinion is FAB!!!

Offline Boo

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Re: Eureka form relief tool
« Reply #47 on: January 11, 2023, 08:23:53 AM »
Apologies for the thread resusitation but I thought that it would be better to have my question here rather than start a new thread and have the group end up covering the same ground again.

I was thinking of building a Eureka tool to assist in making gear cutters for small gears for model engines but using a 16mm bore diameter to suite my existing mandrels.  I wondered what the group thinks about thickness of the Ratchet Plate and the Anchor plate ?  Scaling from 12.7mm to 16mm gives something like 10mm and 8mm respectively and I can get gauge plate in both these sizes.  Is gauge plate worth using does the group think ?  I can see that the pawls would also benefit from being made from gauge plate but would any other parts benefit ?

On the subject of gauge plate, I've never used it and don't know what it is like to work with in practice in the annealed state - can anyone tell me how it is to hacksaw, file and machine in general ?  I assume there is no prospect of using a jigsaw on it in these thicknesses and retain any degree of sanity ?

Many thanks,

Boo

Offline awemawson

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Re: Eureka form relief tool
« Reply #48 on: January 11, 2023, 09:58:35 AM »
Gauge plate (silver steel) in the anealed state is quite nice to work with hand tools, but hardens nicely.

As for the Eureka and scaling it up, I've only used one years ago, and that was made by someone else but I don't suppose dimensions of plate thickness are too critical after all it's not intended to make massive cuts.
Andrew Mawson
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Offline Boo

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Re: Eureka form relief tool
« Reply #49 on: January 11, 2023, 03:26:46 PM »
Gauge plate (silver steel) in the anealed state is quite nice to work with hand tools, but hardens nicely...
Thanks, I suppose an alternative would be to chop it up with an angle grinder, but would there be issues with hard spots doing that do you think ?

Boo