Quick-step

[philjoe5]

Bjorn,
When I started making gears I made some of the same mistakes that you have, ie, wrong cutter etc.  I'd say keep those gears because I've found that in some applications they will work just fine.

Cheers,
Phil

[Bjorn_B]

I hope that top gear is the one you made a mistake on Bjorn. The teeth tips are quiet small compared to the inside diameter. It may just be a photo illusion. You have been doing some very nice work and I have been following quietly.

Don

Hello Don! If you are refering to the smaller gear, i is cut with the correct infeed and correct #cutter, on a correct diameter blank. I had to double check that a couple of times as I allso believe the teeth are a bit thin. It is a 32t gear and it could be just the matter rhat this is very near the end of the range for that cutter (next cutter starts at 35t). It could allso be due to the well known chinese quality control.

[tangler]

Bjorn,

I've noticed that my Chinese module cutters are numbered the other way round from the standard Brown & Sharpe system where #1 cuts 135  and above.  On my Chinese MOD cutters that's a #8....

Anyway, very nice work so far.  I'm a big fan of milling in the lathe even though I have a perfectly good milling machine.

Rod

[jadge]

I've noticed that my Chinese module cutters are numbered the other way round from the standard Brown & Sharpe system where #1 cuts 135  and above.  On my Chinese MOD cutters that's a #8....

I'll stick my neck out and say I think that is true for all module gear cutters, not just the Chinese ones.

Andrew

[Don1966]

I hope that top gear is the one you made a mistake on Bjorn. The teeth tips are quiet small compared to the inside diameter. It may just be a photo illusion. You have been doing some very nice work and I have been following quietly.

Don

Hello Don! If you are refering to the smaller gear, i is cut with the correct infeed and correct #cutter, on a correct diameter blank. I had to double check that a couple of times as I allso believe the teeth are a bit thin. It is a 32t gear and it could be just the matter rhat this is very near the end of the range for that cutter (next cutter starts at 35t). It could allso be due to the well known chinese quality control.

Hi Bjorn, it does look like something is wrong with the gear if it isn"t a photo illusion. I have attacted somes sheet for you. I did an Autocad drawing using the Button method and the difference from the inset and outside tooth is about .008" smaller. I attached my Button calculation sheet and a DWG and DXF drawing for you to see. I do hope I have the PA, and DP correct.

Regards Don

[Jasonb]

Have you mixed up the 0.8 and 1.0 MOD cutters by any chance?

[Bjorn_B]

First, thanks for all your input, it is still a bit of a mystery why the 32t gear got a bit wonky

A shadowgraph of some sorts or a usb microscope wuld perhaps be useful here, a 26 to 34t cutter witch is what I used, in module 1 form with a 20 degree pa should accomodate gears that in theory have a aproximate gear flank radius from 4,45 to 5,81mm. I do not know in what end of the scale they make theese cutters but a guess is that they are formed for something in the middle of the range for each # of cutter yes?

EDIT: According to John Stevenson (http://www.metalwebnews.com/howto/gear/gear1.html) , the cutters are correct only for the smallest gear in each range. This means that the reasoning below is allso a bit wrong, the cutter used should have a flank radius of about 4,45mm. This does to some degree explain pointy teeth as a 32t gear in theory should have a flank radius of 5,47mm.

If so, the cutter I used should have a flank radius of something like 5,13 mm if we ignore the involute form, it should at least be somewhere between 4,5 and 5,8mm. There are a lot of assumptions in the reasoning above, but I will try to measure up the cutter. I fear there is something amiss with it. Bugger!

I did not mix up cutters this time, the correct one was on the arbor, there is no wobble on the arbor either.

I guess I will use theese gears anyway, they can allways be replaced.

Regards!

[Bjorn_B]

Flank radius of the cutter used matches a 4,5mm radius gauge best of my set. (0,5mm increments)

Decided to ignore the "peaky teeth" for now....

[Bjorn_B]

bit of a family photo with the spindle, sliding gear and input gear/drive disc.

Sliding gear decouples direct drive and has two backgear ratios. Drive pins to be turned and fitted to sliding gear

[Don1966]

Bjorn, can I ask where you acquired the plans for the Quick Step? Seems that Hemingway doesn't  have the plans on their web site. I am interest in this tool.

Don

[Bjorn_B]

Bjorn, can I ask where you acquired the plans for the Quick Step? Seems that Hemingway doesn't  have the plans on their web site. I am interest in this tool.

Don

Hello Don, it was serialised in Model Engineers Workshop, issues september and october 1998.

[ega]

Bjorn_P:

"I forgot that I had a complet set of adjustable reamers, must find some use for them sometimes."

I have heard of them being used as expanding mandrels to hold work between centres but I have never tried this. I used one to get me out of trouble the other day but always feel more comfortable with a normal helical reamer.

Good luck with the gearcutting!

[Don1966]

Bjorn, can I ask where you acquired the plans for the Quick Step? Seems that Hemingway doesn't  have the plans on their web site. I am interest in this tool.

Don

Hello Don, it was serialised in Model Engineers Workshop, issues september and october 1998.

Thanks Bjorn, by the way I did a no. 1 module in my spreadsheet and the tooth radius was 5.47mm same as Stevenson.

Don

[Bjorn_B]

Bjorn_P:

"I forgot that I had a complet set of adjustable reamers, must find some use for them sometimes."

I have heard of them being used as expanding mandrels to hold work between centres but I have never tried this. I used one to get me out of trouble the other day but always feel more comfortable with a normal helical reamer.

Good luck with the gearcutting!

That is a use I never thought of, I have to look into that!

I prefer fixed reverse helix machine reamers allso, I guess that is why I never bother to get the box out...

[Bjorn_B]

Small step forward today, marked out, drilled and bored the gearbox front end plate. some holes still to be countersunk. Bored holes are for rearmost spindle bearing and countershaft bushing.

Cheers!