Super thin titanium rudder blades.

[Terry Keeley]

suggesting using High pressure(500psi) & 30 gallons per minute.

Pressure gets to the tip where you are cutting, gallons/min take the chips and heat away.

dean

lol, that would sure do it! Got a splash guard made up and a smaller nozzle for my coolant pump, hoping that does the trick.

Terry,

There should be some G-Code for setting a starting height, peck retract height and initial peck depth (including a "rapid-to" depth). The controller shouldn't matter, I wouldn't think. G-Code is not really in my wheelhouse, but I've done it. Seems like I remember all kinds of variables that can be used to optimize cycle times.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

Model Machine And Precision LLC

Ya, I thought so too, asked on that Practical Machinist forum but apparently straight G code don't get it:

http://www.practicalmachinist.com/vb/cnc-machining/g83-rapid-out-after-each-peck-cycle-316014/

It ain't so bad, I can do a feedrate override to 280% until I get down to the previous drill, sure beat doing it manually.

 

[Terry Keeley]

More to come, I think I got it!

 

[Terry Keeley]

 

[Terry Keeley]

This is starting to get it:

 

[Andy Brown]

Looking good Terry!

As others mentioned....

In the long run you could get better results by writing your own drill cycle instead of using the canned G83 cycle.

Once it's done you can file it and make modified versions.

The ability to add in a G4 (dwell) once the drill is extracted from the hole would be a big help.

Shoot the coolant down the length of the drill toward the hole. This will flush the flutes and help cool the work.

A little more pressure on the coolant would help, but a long dwell time (5 -10 seconds) could make up for lack of coolant pressure.

 

[Terry Keeley]

Thanks!

My "Hillbilly CNC" is nothing like what you were running but I think it will work.

Agreed, writing the code out would be better, I might do that.

 

[John Beardslee]

Hi Terry,

I know you enjoy a good challange in the winter and it's always good to test skills and equipment but you do know there are other places to get water from not just the rudder.

Thanks John

 

[Terry Keeley]

Hi Terry,

I know you enjoy a good challange in the winter and it's always good to test skills and equipment but you do know there are other places to get water from not just the rudder.

Thanks John

Ya, been there - done that.

The rudder's the most consistent and easily regulated IMHO.

 

[Andy Brown]

Hi Terry,

I know you enjoy a good challange in the winter and it's always good to test skills and equipment but you do know there are other places to get water from not just the rudder.

Thanks John

Ya, been there - done that.

The rudder's the most consistent and easily regulated IMHO.

Me too! I agree Terry. Deep solid water is best.

 

[Andy Brown]

Thanks!

My "Hillbilly CNC" is nothing like what you were running but I think it will work.

Agreed, writing the code out would be better, I might do that.

My propeller programs were mostly long hand G-code with a few canned cycles thrown in. It doesn't take that long to get proficient at G-Code and when utilized with canned cycles can improve the part making success.

 

[Terry Keeley]

Spent quite a bit of time friggin' with my drill grinder, found out it wasn't set up to properly split the point on a parabolic drill, a little hard to see but this is what I came up with, cuts Ti like budda:

Chips are long and stingy tho, any of you toolmaker types know how to break them up? A high pressure mister would clear them for sure but I'm hoping to not havta go that route.

First hole was out about 0.015" in 4", not bad but I think I can do better!

 

[John Beardslee]

Hi Terry,

I know you enjoy a good challange in the winter and it's always good to test skills and equipment but you do know there are other places to get water from not just the rudder.

Thanks John

Ya, been there - done that.

The rudder's the most consistent and easily regulated IMHO.

Hi Terry,

Is this a rudder for only your SAW boats or for heat racing also? I've done some experimenting with a closed loop water system using a perry pump to circulate water in a .21. Only on the test stand at this time but hope to revisit later this year. I agree with Andy on the consistent coolant supply it just that I think there might be some other options, I like the idea of a very thin rudder blade especially for SAW work.

Thanks, John

 

[Terry Keeley]

Hi Terry,

I know you enjoy a good challange in the winter and it's always good to test skills and equipment but you do know there are other places to get water from not just the rudder.

Thanks John

Ya, been there - done that.

The rudder's the most consistent and easily regulated IMHO.

Hi Terry,

Is this a rudder for only your SAW boats or for heat racing also? I've done some experimenting with a closed loop water system using a perry pump to circulate water in a .21. Only on the test stand at this time but hope to revisit later this year. I agree with Andy on the consistent coolant supply it just that I think there might be some other options, I like the idea of a very thin rudder blade especially for SAW work.

Thanks, John

Nope, Ti rudders all around for 2016!

By "closed loop" you mean you carry the water on board?

 

[Hydro Junkie]

That's the definition thereof. The problem with closed loop systems is you need some sort of heat exchanger and thermostat to make it work properly When you look at real world applications of a closed loop, you find on cars a radiator that bleeds off heat into the air while in marine use, it's normally water to water heat transfer. Either way, you still can plan on adding a significant amount of weight to your boat

 

[Brad Christy]

Terry,

.015" run-out at 4" depth is actually pretty good, especially with a parabolic drill with that kind of flute length. I'd be tickled pink with that. The one thing I can think of that will significantly improve your chances of less run-out is to switch to aircraft drills. If you need to make them by cutting off extra-long cobalt drills and regrinding the points, so be it. By the pick of your chips, I'd say about 3/8" flute length would be enough.

You can tell a lot about how a cutting tool is performing by examining the chips. Those chips look pretty good. Nice and consistent, with no jagged edges. Have you put them under a scope or magnifying glass?

Looks like the head of your mill is a bit out of tram.

I am INSANELY picky about this on my mill. Do you know how to check/correct it?

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

Model Machine And Precision LLC

 

[Terry Keeley]

Thanks for the suggestion, thought of that too (more rigid = less wandering) but I couldn't find any aircraft extension drills in cobalt, only HSS. As I'm sure you know HSS is marginal on this stuff.

I checked a few I did in 7075 at different depths and it seemed the run-out was linear, in other words it was out at 4" by four times what it was out at 1". Thinking if if can start the hole straighter it might help. Sooo, First I'm going to re-check my fixture for alignment and make sure it's dead nuts on. Then for the 1st op I'll spot drill and go in with a solid carbide stub drill. Hopefully that'll start things off straight and it will project the 4". I do look at the chips closely with a 5X loup (as well as splitting the 1/16" drill point!) and this is the happiest I've seen things. I have seen jagged, blue chips, they break up better but the drill obviously isn't happy.

Why all this effort? Well, testing with my SAW boat shows rudder drag is huge, cutting just 1/4" off the blade made fair gains. Problem is as you shorten the blade the boats stops wanting to track straight. I've made some 7075 blades that I could get thinner than 6061 but I want to be 1/8" thick with these Ti blades and have them hold up on my 67 SAW 90 oval boats. I'm working on getting the drills to try a 3/64" hole for my 20 and 40!

ps: Trammed as close as I can get, swept the full 24" table. It might be I'm not quite rigid enough with my baby Clausing and face milling Ti. Matter of fact I ended up using an end mill to true up the faces of the actual parts...

 

[mtruex]

Terry you can send me the messed up ones

 

[dwilfong]

Terry the larger the angle of the blade taper is what will create drag not how wide it is from front to back.

a wider front to back will reduce the angle slicing into the water if the thickness is the same that is needed to drill the water hole.

the less angle on the wedge is what will reduce the drag not the over all width front to back.

Just my 2 cents.............................

 

[dwilfong]

Some more food for thought...................

 

[longballlumber]

Terry you can send me the messed up ones

Ha Ha... good call. All of Terry's "messed up" stuff exceeds anything I can do!!! I am not too proud, I will take some of the messed up ones too.

Later,