Results 31 to 45 of 145
-
13th Mar 2020, 11:05 PM #31
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
-
14th Mar 2020, 10:55 PM #32
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
The joy of having a TOS.... ( FNGJ32 mill )
Not surprisingly the worm itself has a bit of corrosion pitting once cleaned up, but will be good enough for now.
Weird, it’s a completely metric machine but the worm is 8tpi.
I happened to have a 24x3 cap screw sitting in the scrap box - should be hard enough to cut a bronze wheel.
3mm is slight bit finer than 8tpi but since there’s only about 4 teeth in mesh I figure it will be close enough.
6 flutes should do it, but I didn’t have any convenient way of indexing it, so welded a flange but on the end to give me something.
Clamp it in one of the tee slots with one of the flats on the nut vertical.
It looks like a fancy setup, but truth is the head was already at 45deg and I couldn’t be bothered changing it!!
The cheap insert shoulder mill raised a lot of burrs, so I did another pass after this photo using a HSS end mill.
The end result with the bronze blank for the wheel.
Steve
-
15th Mar 2020, 04:35 AM #33
Hi Steve Guys,
Based on my recent experience with bronze, is that it is tougher than you think !
Anyway good luck with it.
Edit: Would you believe that I actually have an M24 X 3 HSS steel die in my collection along with an M24 X 3, 2nd tap and a metre of M24 all thread.Best Regards:
Baron J.
-
25th Mar 2020, 02:37 PM #34
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
The joy of having a TOS.... ( FNGJ32 mill )
Slowly been working on making the worm wheel in between other jobs.
Wheel is 36T, and I happened to have a 36T spur gear lying around so decided to use that for indexing. Mounted the gear to a shaft made from an old shoulder bolt, and used the thread and shoulder to hold the blank.
Found a lump of scrap that already had the right size hole in it for the bolt shank/shaft, so gave that a quick skim in the mill to clean it up and then split it in the bandsaw so it would clamp the shaft.
Fitted the shaft and drilled an index hole.
Mounted it in the vice and cut some slots to help the "hob" get a decent bite.
Mounted the blank on a couple of bearings and bolted it to a bit of hot rolled square clamped in a tool holder.
It came out much better than I expected.
Steve
-
25th Mar 2020, 02:56 PM #35
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
I noticed in that photo that there are a couple of slots not lining up with the valleys.
Turns out I have 37 teeth on the wheel instead of 36.
Guess that's what you get when you use 3mm pitch thread instead of 8TPI !!!
Edit: And the grooves aren't centered in the wheel width due to the fact that I eyeballed it roughly from a distance just to do a test run - not expecting it might turn out half decent...
Steve
-
25th Mar 2020, 06:51 PM #36
Hi Steve,
That's a bugger ! When I looked at your pictures, I thought that you were doing so wellit looks like a very nice gear.
Best Regards:
Baron J.
-
25th Mar 2020, 09:32 PM #37
Intermediate Member
- Join Date
- Aug 2009
- Location
- Lara, Vic, Oz
- Posts
- 46
Yeah, nice looking gear, like your approach to hobbing - as it is not particularly timed to anything (36 vs 37T), I'd have though a great job! Good work Steve!
-
25th Mar 2020, 10:32 PM #38
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
I did a quick trial fit of that gear tonight thinking that if it ran nicely I’d just use it to get me going for now. It just didn’t feel quite right - turned ok then got stiff and either freed up or got tighter from there. When I took it apart again I could see where the teeth that were slotted had started to deform - so it’s no go on that one.
The only 8TPI male thread I had around was some all thread. I was pretty sure it wouldn’t be hard enough but gave it a go.
It wasn’t. After a good start for the first couple of gear revolutions, the cutting pressure just rounded the teeth over (blank wasn’t slotted first).
Without getting into single point threading and heat treating an 8TPI hob, my other options are to get a hi-tensile bolt to hack up into a hob, buy a 1” UNC tap or just give the 3mm pitch one another go without slotting the gear first.
Given that going out to buy anything is getting less attractive by the hour, I think I’ll give the 8TPI another go for a start.
Steve
-
25th Mar 2020, 11:22 PM #39
Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,959
Does it have to be a UNC tap, asking as I may have a Whitworth at work? Will check tomorrow.
KrynTo grow old is mandatory, growing up is optional.
-
26th Mar 2020, 08:13 AM #40
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
-
26th Mar 2020, 10:20 PM #41
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
Had another go with the 3mm pitch hob tonight, didn’t bother with any slotting.
Came out really well, and seems to run nicely when fitted.
Refitted the pump, motor and belt without connecting the oil lines (gave the worm area a decent squirt with the oil can beforehand) and it runs happily.
The belt is showing its age so I’ll replace that while it’s easily accessible.
Next will be to clean up the mess in the workshop a bit before I attack checking the oil lines are clear and cleaning up the knee.
Here’s a couple of photos of the cam plate on the pump and how it moves the pistons in case anyone is interested.
Steve
-
27th Mar 2020, 08:20 AM #42
Hi Steve,
Great stuff, that is a nice looking gear, what happened to muck it up first time around ?Best Regards:
Baron J.
-
27th Mar 2020, 08:29 AM #43
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
Thanks John.
First time came out nicely except having the 36 slots pre-cut and ending up with 37 teeth from the 3mm hob pitch meant it had slots through the teeth.
I didn’t count the teeth on this one but assume it’s 37.
The hi-tensile bolt/hob held up really well. Still cutting nicely after doing both gears.
Steve
-
28th Mar 2020, 06:46 PM #44
Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,669
The joy of having a TOS.... ( FNGJ32 mill )
Spent about 5 hours over the last couple of days battling to get the oil pump pumping. It wasn't priming so I went through the saga of removing the suction line from the pump and blowing back through it with compressed air to make sure it was clear.
That cleared a little bit of snot, but the pump still wouldn't prime.
The bottom end of the tube is retained in a strainer affair that is bolted to the bottom of the sump. I removed it, blew it out some more, cleaned the strainer while I was at it, but still wouldn't prime while holding it in sump.
To add to that when I tried to refit it I couldn't get the bolts started - I'd stirred up a bit of a cloud in the sump so couldn't see the holes and no luck doing it by feel - so had to drain the oil.
Thankfully that was an easy job with a vacuum pump and a container.
Reattached the strainer/pickup to the bottom of the sump and refilled it with fresh oil
STILL wouldn't prime even after running the pump for 5 mins straight
I was starting to get worried that either the pump had an issue or the suction line was broken inside the knee and pulling air instead of oil....
So I removed the suction line from the pump AGAIN, and sucked the oil up the tube using the vacuum pump.
Refitted it, and finally after running for a couple of minutes it started to pump out the one outlet that is still disconnected from its hose.
Still took about 15mins more of running the pump constantly before all the lines were full and I could see the oil was being delivered to the far side of the knee.
Nearly there with the oiling - just need to replace one length of plastic delivery hose, and get a new belt.
Speaking of which - anyone have experience with timing belts?
This one is 55 tooth, 345mm long (measured by rolling it on its back along the bench), and 12mm wide.
That works out at 6.27mm pitch, which I can't find anything close to online in either metric or imperial.
Any ideas?
Steve
-
28th Mar 2020, 08:10 PM #45
Hi Steve,
Try these people,
https://www.brecoflex.com/products/timing-belts/
I suspect that you have a slightly stretched belt there.Best Regards:
Baron J.
Similar Threads
-
Hercus o mill Vertical mill head lubrication
By china eyes in forum THE HERCUS AREAReplies: 0Last Post: 14th Oct 2018, 06:57 AM -
Selecting a small Mill / Mill/Drill
By Wombat200 in forum METALWORK GENERALReplies: 31Last Post: 15th Mar 2012, 10:58 PM -
Arboga EM825 mill vs Hercus model 0 mill?
By neksmerj in forum METALWORK GENERALReplies: 23Last Post: 14th May 2011, 03:16 PM -
Face Mill V End Mill
By eskimo in forum METALWORK GENERALReplies: 8Last Post: 31st Aug 2010, 03:19 AM -
No. 0 Mill Serial Number and Mill at Work Photos
By Anorak Bob in forum THE HERCUS AREAReplies: 1Last Post: 30th Dec 2008, 03:31 AM