140mower
Don
The 3d printed ones will do...... In fact, a help wanted ad might conjour a set out of one of those printer guys that hang around here. .... What say guys? Any takers?
-
Scam Alert. Members are reminded to NOT send money to buy anything. Don't buy things remote and have it shipped - go get it yourself, pay in person, and take your equipment with you. Scammers have burned people on this forum. Urgency, secrecy, excuses, selling for friend, newish members, FUD, are RED FLAGS. A video conference call is not adequate assurance. Face to face interactions are required. Please report suspicions to the forum admins. Stay Safe - anyone can get scammed.
Er40 collet chuck
- Thread starter 140mower
- Start date
I suggest you make a d-bit to do the finish sizing rather than buy a 16 degree reamer. It will involve 3 to five hours to make, harden and hone/polish but it will be good practice.
140mower
Don
It's been a while since I did this, but I think that sounds right. My memory has never been good, and it sure isn't getting any better with age....
It's a dogs breakfast.
Assuming I understand your question, then yes - a 127/100 gear creates a perfect metric conversion. The inches to cm thing is exactly 1" = 2.54 cm. This, was defined as a very deliberate conversion which quite interestingly set the length of a standard inch, not a standard cm.
I digress.
127 is a prime number indivisible by any other whole (integer) number.
A 127 tooth gear is used together with another compound gear (100 in your case) to work with a given piece of equipment. Different numbers of teeth on the compound gear will allow different sets of metric threads. Some compounds use 100, some 50, and some 120. They are all generally multiples of simple numbers like 5, 2, etc.
One cannot have a fractional tooth. There is no such thing as 2.54 teeth. But one can multiply fractional amounts by integer abounts to result in a whole tooth.
The underlying principle is that
25.4 X 5 =127
20 X 5 = 100
So the 100 and 127 gears are related by a common integer factor of 5 and both of those resulting numbers are integers.
Does that help?
Last edited:
It ties in w/ what I've read on the subject. The only issue is, a 127 tooth gear gets sizeable & it may not fit under the guard. Non-issue for me. There are smaller gear combos that are "close enough" and fit under the guard, but I'm a bit OCD about stuff like that. Thx!
Hi Craig, these are the gears I made long time ago to cut metric threads. And the positions in the QCGB.
Attachments
When I made them, I thought I should use the same size/type teeth as the rest. In retrospect, I could have made them smaller, but then I would need a larger idler gear(s) to connect the two. I was going to make the 125 and 140 gear as well, but the 120 gave me all the metric thread pitches I required.
Close enough won't cut it. It MUST BE 127 and some other matching gear. As @thestelster explains, the matching gear can be something else to get the combos you need. But generally 100 will get you the most common metric pitches.
Huge subject Craig. Lots has been written on here. Just search metric threads.
I also posted a thread on how to cut metric threads without leaving the half nut engaged. It can be done. And you do use the thread dial. But it is a different method than used when cutting imperial threads.
I'll see if I can find my thread and post it here (he says to the YYCHM - the master of all thread searching) LOL!
@JustaDB & @YYCHM
Here is the thread I made on the subject of using a thread dial with Metric Threads.
Thread 'Metric Threading on an Imperial Lathe' https://canadianhobbymetalworkers.com/threads/metric-threading-on-an-imperial-lathe.4616/
Here is the thread I made on the subject of using a thread dial with Metric Threads.
Thread 'Metric Threading on an Imperial Lathe' https://canadianhobbymetalworkers.com/threads/metric-threading-on-an-imperial-lathe.4616/
So I got out into the shop to make an ER32 spindle for my indexing jig.
That nice end of 1 3/4" round bar I have is an inch short. No worries, I have this nice 2' bar of...38.1mm diameter. Out of which to get a 40mm socket. Damn it. And MSM is no longer open on weekends.
Ok, stock ordered. I'll go get my mist coolant set up. Or the knee-plus-spindle encoder adder done up. Or even just tidy the place up a bit more.
That nice end of 1 3/4" round bar I have is an inch short. No worries, I have this nice 2' bar of...38.1mm diameter. Out of which to get a 40mm socket. Damn it. And MSM is no longer open on weekends.
Ok, stock ordered. I'll go get my mist coolant set up. Or the knee-plus-spindle encoder adder done up. Or even just tidy the place up a bit more.
140mower
Don
I've been going backwards hard the last two days as well....... I don't feel so lonely now.
It's clear to me that it's time to get the whiskey bottle out. Do not tempt fate...
Does anyone know if they make a female MT3 Finish Reamer? Might be a better way to clean up used MT3 tools purchased on Kijiji.
India stones get boring real fast.
Or is this a bad idea.
DPittman
Ultra Member
If a reamer is needed that seems pretty heavy duty cleanup to me. I think if the tool doesn't clean up with a stoning I'd pass on it myself. I've never heard of a female mt reamer but that ain't saying much.
The typical damage is from a set screw deforming the metal around the locking flat or a groove made by a chip left without proper cleaning of the tapers. It's not usually the whole taper. I agree, I'd pass on something that has been rolling around the bottom of a tool bag.
Right now I have stoned a few of them. But it would be nice to just lightly spin a female Reamer over them. If that turns out to be impractical, difficult, or a waste of time - so be it. I just figured it might be worth a try. Especially given how many I have.
I think one would be better stoning off the offending hill tops & then lapping. A typical tool shank might be pretty hard & put up a fight against any kind of reamer, assuming you could find an internal or female if I understand you. The trick for lapping is finding a internal MT 'tool' form that didn't cost more than the bargoon shank tool found as it will slowly become consumed in lapping, ie. sacrificial if you are doing many. MT sleeves come to mind. I have made a makeshift form tool out of (choose your poison) epoxy dough, polyester Bondo.. cured overtop of a 'good' tool form. Use releasing agent of course. Its not as hard as brass or copper but a whole lot cheaper. Because its softer it will preferentially embed lapping compound. Not a high removal system & a bit hillbilly, but it got me out of a bind because grinding was both impractical & very little material to remove.