Engineering Workshop

[jverre]

Nice Job!!! Thanks for the post

[Jimbo86]

Originally Posted by ahahn

What's really great about the mini mills and lathes is now you can make your own $3 parts! And as you continue to make them, the effective cost of those $3 parts will slowly begin to drop from the $200 range to a mere $10-$20!

And don't forget, there are lots of cool accessories too. Sometimes I wonder if buying the accessories is more fun than actually machining something! I hate to think how much I hve tied up in those things! Little Machineshop is a good resource for that.

Actually last weekend I used my min-lathe for my first heli part. I made a brass standoff spacer for the elevator swash ball on flybarless TRex 250! So now I am getting to the effective $5 level per part---ignoring my own labor of course!

Take into account the fact that when you machine your own parts for your aircraft, you select your own material and tolerances. The stuff a skilled machinist makes on his own will put overseas mass production parts to shame every time. So if you look at it from cost per part, your work is actually more valuable because of the higher quality. So that 10-20 dollar part you just made if sold on the market could quite possibly be sold for double just based on quality alone.

I think I just found the endless wormhole of RC Helis that everyone talks about, my wife is going to be pissed

[Gazey]

I've done a few head conversions that need to have the main shaft cut down and drilled.
The problem is for some of us it's hard to drill that Jesus bolt hole through the centre of the shaft.
To make it a bit easier for myself I have made up a simple jig for drilling the hole.
Once you have made the jig you can cut down and drill as many shafts as you need, whenever you need them.
It's easy to make with a minimum of tools.

You will need access to the following tools though.

Drill press.
Scriber.
150mm rule.
Centre punch.
Drills the same as your main shaft diameter.
Drills the same as you Jesus bolt diameter.
You will also need to drill and tap the clamping hole in the block. (I used M4)

You will need to find a suitable size block of steel (I used a piece of scrap I had lying around, a block 46x50x25)
It is important that the block is nice square
My "demo model" was made up to drill the Blade 450 3D main shaft to fit the Align DFC head.

All you will need to do is to substitute the drill sizes to suit your main shaft and Jesus bolt dimensions.

A picture is worth a thousand words so I have added some photos of the jig.
As you can see its very simple and works a treat.


I used used the 150mm rule to mark a line parallel with the edge of the block on three sides.





Centre punch where the lines cross.



Drill a hole through the top of the block the same diameter as the Jesus bolt (2mm for the Blade Jesus bolt)

Flip the block onto its end and drill a pilot hole 0.5mm smaller than the main shaft diameter (4.5mm for the Blade shaft)

Open the hole with a drill the same size as the main shaft diameter (5mm for the blade shaft)

Drill and tap a hole in the side of the block for a clamping screw (M4 in my case)




Now you simply need to insert you new cut down main shaft to the desired depth.
Clamp it with the clamping screw.



Drill through the main shaft with the correct size drill for the Jesus bolt.



I usually drill two or three shafts at a time so I have a few spares ready to go but once you have the jig it only takes a few minutes to set it up and drill a new shaft.

Thought I'd add few tips for drilling main shafts while I was at it.

The material used to make the shafts I have drilled I fairly tough, but it does cut with a HSS hacksaw and it does drill with good quality HSS drill bits.
Surprisingly the toughest shaft I have drilled to date is the Blade 450 one.
I would recommend you go out and purchase new quality HSS drills to make you jig as the size of the holes is important.
When drilling through the shaft use a new drill and don't run it to fast. Always use some cutting oil.
I managed to drill three Blade main shafts before the 2mm drill bit was buggered. There will be nothing worse than breaking the drill in the shaft so take it slow and steady.

I will be drilling a second set of holes in the same block for my 600N shafts.

This is my first attempt at trying to do a "How To Thread" so any comments or criticisms would be appreciated.

Here is the finished product.





Cheers.

[Michaelinpr]

That pretty cool. It's funny that in the next couple of days I planned to be modding a trex 450 shaft to fit an old sjm325. I had no idea how I was going to drill a hole in the center. I will give this a try.

Thank you sir.

[Gazey]

Just keep in mind its only as accurate as your marking out.
It will pay to make sure the two holes are dead in line and drilled dead square.

Also, drill the main shaft hole right through the block so you can use a punch on the end of the shaft to remove it after drilling.

Thanks.

[Mercuriell]

Following a minor prang from loss of tail, due to a set screw in the tail pulley shearing out, I was left with doubts as to whether my tail rotor shaft was straight or not - the glass table rolling test didn't seem conclusive so I mounted it up in the mill with a dial gauge ....



Video - Using a dial gauge and mill to check shaft straightness - wmv 26MB

[Dogdocphil]

Wow! Thanks for that one. Good stuff on runout.

[clough42]

Originally Posted by Gazey

The material used to make the shafts I have drilled I fairly tough, but it does cut with a HSS hacksaw and it does drill with good quality HSS drill bits.
Surprisingly the toughest shaft I have drilled to date is the Blade 450 one.

Okay...I think I need help drilling this stuff.

Inspired by this thread, I made a main shaft drilling jig and set out to drill a Blade 450 shaft for a Tarot DFC head.



The jig worked great, but the drill didn't penetrate the shaft at all. Granted, it's a cheap Harbor Freight bit, but I expected to make some progress at least. Nope. Just a flat shiny spot on the tip. No chips. Nothing.

What kind of bit do I need? I'm thinking about getting some 2.5mm cobalt bits from Grainger. Will these work, or do I need something harder?

http://m.grainger.com/mobile/details/?R=4FXA6

I'm not sure I want to try solid carbide. If I break any of those, it's an expensive shaft.

Maybe I need a friend with an EDM hole popper. Anybody out there with an EDM want to be my friend?

[Gazey]

I have had good results using Cobalt drill bits. The Blade shafts are the hardest to drill for sure. I've used my jig a few times now to drill 450 DFC shafts with good results.
The Align shafts drill a lot easier.

[clough42]

Originally Posted by Gazey

I have had good results using Cobalt drill bits. The Blade shafts are the hardest to drill for sure. I've used my jig a few times now to drill 450 DFC shafts with good results.
The Align shafts drill a lot easier.

What kind of speed and feed pressure are you using?

[clough42]

Originally Posted by clough42

What kind of speed and feed pressure are you using?

I picked up some high-speed-cobalt split-point bits for $1.65 each at a machine shop supplier just up the street from me, and they went through the Blade 450 shaft like it was butter. I figured this was probably among the hardest traditionally-drillable materials, so I used a 15sfpm machining speed, which works out to about 600RPM for a #40 bit. A little oil and just gentle hand pressure on the drill press quill put it right through in about eight seconds.

Here's the shaft with the factory hole and my new 2.5mm (#40) hole, ready to be cut and fitted to the head.

[hopkin]

I've been using silver steel for my home made shafts,v.strong easily drilled (with care) ,comes in metric and imperial sizes with a ground finish ,so accurate diametric sizes comes in 13" lengths

[[X]Outlaw]

Cool! I didn't know this thread existed.

I also have my own home machine shop. My main equipment includes:

Taig CNC Mill with Sherline rotary table as forth axis
Taig manual lathe with power feed
Sherline CNC 17" Lathe

Here are some of the parts I've made over the last year:

Motor mount with universal bolt pattern to convert Miniature Aircraft's Spectra/Stratus to electric. Its designed to fit Scorpion 4035 and similar sized motors. The part has to be remounted three times to get the finished product. Machine the top then flip to machine the bottom, finally its mounted on a jig that holds it on its side so that the frame mounting holes can be drilled then tapped by hand.

It takes about two hours to machine once the program starts. But fixturing takes time as well as final cleanup and polishing by hand before it goes out to the customer.







A holding jig for the above motor mount (This was the very first part I ever machined)



CAM tool paths



A replacement shaft for a food processor I did for a buddy of mine. First time working with 316 Stainless. This was done on my manual lathe. The grove is to fit a plastic retaining ring.



Boring bar tool holder out of 6061 AL





This is a motor coupler for a piece of medical equipment. The original is shown below and is made of plastic. What happens over time is the motor shaft round out the plastic and the coupler is unusable. I replicated the part by taking very careful measurements.

This piece takes 8 Hours to machine (cutting at moderate feeds), it starts of as a 1" solid piece of 6061 T6 AL.



Machining on bottom side to fit the motor shaft. Its a slight press fit so I drilled and tapped a 10/32 hole to make removing it easier. Simply screw in a bolt, this pushes on the top of the shaft and the coupler is lifted of.



Original plastic part:



Universal indexing blocks. This allows me to flip and locate a part using dowel pins for those jobs that require machining on both sides.



And here is some automotive stuff I did. These are fender vent finishers. They were later rolled to match the curve of the fender and then powder coated. I don't really care for cosmetic work like this but it payed for a good bit of tooling.

Top:



Bottom:



This is a simple camera mount with pan I did for a buddy of mine (Cletus, he hangs out in the Bergen forum). This was designed by him to use on his Bergen multi-copter. The existing camera mount already had tilt capability. This gave it simple pan capability.

Main plate:



Camera pivot. The camera sits on this part and is secured via a 1/4" bolt from underneath. The hole in the main plate and the center of this part are machined to fit together snugly and is lubricated with tri-flow grease.



Control wheel. This ties the entire assembly together and is linked to the pan servo



How the pivot plate and main plate fit together:



Control wheel installed. This is the fully assembled unit from below:



Fully assembled unit from the top



Hope you guys enjoyed my adventure in machining over the last year

I've almost completed setting up my Sherline CNC lathe. Once I make some parts on it I'll post up some pics. I'm very excited to see it do CNC single point threading. I may make a video of that if you guys want.

[Ranger71d]

Very impressive work.

Sent from my SAMSUNG-SGH-I727 using Tapatalk

[FlyawayClyde]

Yeah, very nice indeed.....

[[X]Outlaw]

Thanks for the kind compliments guys

[Azalin]

I got some machines too. Will post some pictures tonight.

Nice to see people machining for this hobby.

[SCOOBY2013]

I have a lot of machining equipment as well. South Bend heavy 10 lathe (WWII), CNC'd X2 mini mill extended x and y axis, solid column, thompson ballscrews with AC bearings and anti backlash nuts, gecko540 with Ethernet smoothstepper, and more. I've been using Mach3 for years but just recently got Mach4. What do you use to create toolpaths? I use solidworks to model and gibbscam for the toolpaths.

[eKretz]

Originally Posted by clough42

Okay...I think I need help drilling this stuff.

Inspired by this thread, I made a main shaft drilling jig and set out to drill a Blade 450 shaft for a Tarot DFC head.



The jig worked great, but the drill didn't penetrate the shaft at all. Granted, it's a cheap Harbor Freight bit, but I expected to make some progress at least. Nope. Just a flat shiny spot on the tip. No chips. Nothing.

What kind of bit do I need? I'm thinking about getting some 2.5mm cobalt bits from Grainger. Will these work, or do I need something harder?

http://m.grainger.com/mobile/details/?R=4FXA6

I'm not sure I want to try solid carbide. If I break any of those, it's an expensive shaft.

Maybe I need a friend with an EDM hole popper. Anybody out there with an EDM want to be my friend?

Get a real drill. I will never understand why people buy cutting tools from somewhere like Harbor Freight. The drills from places like this are made from garbage steel and are never properly hardened - nor properly ground. I am not remotely surprised that it didn't cut.

I would probably drill at about 40SFM if you have a good cutting oil - closer to the 15SFM posted by the other member if you are just using whatever is available. If you are drilling without cutting oil, you might just as well run the drill on some cement before using it. It will be trashed pretty quick without lubricant when cutting any level of hardened steel.

[Mercuriell]

I had to drill some stainless steel sheet recently and none of my drills would touch it, even tungsten carbide. And yes I do have good engineering HSS bits! - found this ad http://www.ttp-hard-drills.com and yes their drills actually do work slow drilling with lubricant seems important to prevent work hardening the material!