Shop Holmes

[JohnRobHolmes]

I bet its really tough trying to keep press fit tolerance on 6061, it is hard enough to just keep the tools engaged consistently on that gummy material. You probably spent more time dialing in the feeds to get a good chip than anything else. The worst issue I have had on tolerance is when the feeds weren't pushing the chips right and they were coming back into the cutting zone, that really screws up everything!


The CNC has been working hard the past few weeks, and I've been gathering more intel on how to work my machine efficiently with the temp swings. On monday I installed a temp probe in the coolant tank to keep an eye on the "real" temp of the machine, or at least the best indicator of the system average so far. This week the coolant would drop between 62 and 64f at night, then climb to 72 to 75f by days end depending on how many hours I ran the machine. The biggest jump is on the first few parts when the cutting inserts rise to operating temp and start cutting more efficiently, as much as 0.0004" change from part 1 to 2. I found that banging out parts with no rest is the best method, as even a minute rest between parts makes the final size jump around almost randomly. Because of this we tend to have a few oversized parts at first, better to oversize than undersize! So I'm going to set up the little CNC Taig with a diamond bit to skim off parts that didn't meet specs on this last batch.



Since the Mazak has been running a lot, we are running into a coolant fog problem in that part of the shop. At first I didn't know if it was the coolant or the compressor exhausting oil, and with the new compressor we seemed to get a good break in the haze. But last week it was evident there was still a fog in the shop so this past Monday I rerouted the coolant spray so it wasn't beating against the chuck jaws. It really helped a lot, seemed to have solved it. But after running for 6 hours straight on Thursday it was obvious the fog was back although much better. Maybe some of it is smoke from the steel burning a bit too. So now just one more thing to buy for the shop, a mist collector. There is a whole industry dedicated to this problem. I suppose that 10" jaws beating coolant up at 4000rpm really flings it into a fine mist, and since the mist is hot it literally steams out the top when I open the door.

[JohnRobHolmes]

And yesterday I got a contract for 14 more of these little thruster motors for a UAV company! So now it is time to set up a dedicated serial production and testing line for them. It generally takes about 10 hours for each motor from start to finish, not including machining the parts. There is a lot of quality checks and intensive assembly procedure for them.

[Savagethrash]

Originally Posted by JohnRobHolmes

And yesterday I got a contract for 14 more of these little thruster motors for a UAV company! So now it is time to set up a dedicated serial production and testing line for them. It generally takes about 10 hours for each motor from start to finish, not including machining the parts. There is a lot of quality checks and intensive assembly procedure for them.

That is fantastic!

Very impressed with your setup.

[BigSki]

Would it be worth while to make some sort of localized heating system to keep the working end of the mill nice and warm all night long?

[JohnRobHolmes]

I have a kerosene heater in there that kicks on at the set temp. 62f is affordable, maybe $10 every few weeks in fuel if I keep the doors closed. The machine and compressor will always heat the room until I vent it out ( maybe next spring), and there will always be some jump in tolerance after the first part no matter what temp it starts at. But it does cause more problems when the temp drops too low. As long as I run it often enough to keep the slab temp above 60 the variations are manageable.

I'm +\- 0.0001" nitpicking, first world problems of wanting a bearing slip fit that borders on press fit but not so much that tools are needed. The razors edge of no slop at the race where surface finish is as important as measured size. Specifically, steel driveline parts that ride on bearings, like a spool. If I was making a motor housing where I needed a press it would be cake. Between some lead-in, some taper, and thin enough materials where it matters we can fudge the tolerance .001" if steel or up to 0.002" if stretchy aluminum is involved. Just takes more pressure to mate than a more ideal 0.0005" interference.

[sickcivic95]

Most collection systems are very helpful not only for the obvious but they also help with temperature control. I run 2 smog-hog shn units mounted overhead. They can be run vented or unvented, depending on your needs.

SHN by SMOG-HOG | SHN Parts, SHN Filters

Depending on shop size they have several style units and with minimal maintenance other than cleaning the filters these work unbelievably well for me. With all 6 machines running the 2 units kept my shop mist and odor free.

-Dan

[KJ10]

When I worked in a tight-tolerance gear-making shop, all of our machines were cycled for about 20 minutes before they cut a part each morning. It didn't completely get rid of the thermal drift but, it reduced it to the point that the first few parts were at least within spec. "In spec." being as tight as ±1.5 microns, sometimes.

[JohnRobHolmes]

Lets see if this works. Trying to share a vid that is uploaded on Facebook with public permissions.

Video by Holmes Hobbies.

We got a batch of sensor boards for my Revolver motors, and not surprisingly the vendor who made the boards substituted a different plug than what was spec'd. This made them not fit into our designed housing at all, so I had to whip up a little Gcode program and throw the faceplates into the mini mill for modification. I haven't fired up the Taig for months, but for small work like this it is really handy. Would have been at least $400 to send them somewhere stateside for modification, took me about two hours to fix all the housings myself. Not a bad rate of work for such a small machine!

[cabron]

what about making these with a 12mm hex instead of the octagon
and making a crawler with four motors, one on each wheel.
what is the size of this motor?

Originally Posted by JohnRobHolmes

And yesterday I got a contract for 14 more of these little thruster motors for a UAV company! So now it is time to set up a dedicated serial production and testing line for them. It generally takes about 10 hours for each motor from start to finish, not including machining the parts. There is a lot of quality checks and intensive assembly procedure for them.

[Crawling Calvin]

a "mist collector" can be VERY helpful. Especially for not getting that nasty "fog" all over your shop or if your like me and the machine has some not so lovely coolant you end up getting a really bad chest cough at the end of a running day... not sure if that is healthy

I do have to say that the mini-machines can have a huge impact on a shop floor for simple mod jobs or even roughing parts out. Just got to be smart in how you use them is all

[JohnRobHolmes]

The mist buster has been absolutely awesome, well worth the investment. Now we just have to deal with temp swings since it is not vented outside.

A short cellphone vid showing a few cuts on soft jaws, it was about half an hour of the same thing over and over. These are being modified for an upcoming drivetrain product that has to be rechucked for backside ops. We are clearancing the jaws so that the vertical drill can tuck in and cross drill without crashing into them. It's really close, about 0.020" clearance during drilling. Really puckering to watch at rapid speeds!

http://youtu.be/4GzawDGKb1w

[JohnRobHolmes]

Speaking of mini machines being useful when used right, we are setting up the taig for being a dedicated engraving machine in coming weeks. I say we because HMC has had a full time employee for a month. I've got 5 employees now and trying to hire another, don't know how the heck I got here! A new startup company is using holmes motion control for manufacturing and we have to mark everything. Instead of tying up the Mazak with slow engraving (due to limited 4,500 rpms on live tooling) we are converting the taig so that it will have a 50,000 spindle speed and can bang out all the etching while the Mazak is doing the big work. It's either that or I buy a laser etcher and have to deal with venting the nasty fumes, but I think the products will look better with a milled etching.

[Duuuuuuuude]

Eek. What kind of soft jaws throw red hot chips?


Still loving that coolant/lube you sent me, and still haven't used up the first batch I mixed up. You weren't kidding when you said a little goes a long ways.

[rob_b]

Where do I get an application? Seriously.

[JohnRobHolmes]

Interrupted cuts don't like coolant with some inserts, they will chip the cutters from the temp swings. Without coolant in the way you can see the steel catching fire and burning as it flies!

[JohnRobHolmes]

Here's a little sneak peek at a part that myself and Don Eidson have codesign together.

Been a whirlwind at the shop between the machine and custom motors. I'm trying to get a new manager into HH to give myself and Jonathan more time for hardware and software design. I think I've got a good enough grasp on motors to focus on in house controller engineering again. Now I can revisit some commutation schemes that other companies won't attempt!

[JohnRobHolmes]

Originally Posted by rob_b

Where do I get an application? Seriously.

A resume is the first step!

[JohnRobHolmes]

Looks like all my old images are broken, the folders on my server moved when we redid the storefront. I'll see about getting them back up or uploaded here directly.


Made 12 feet of armature trays for inventory and manufacturing. I figured it would be plenty, but we filled them up fast so I gotta make 12 more feet! Each tray holds 50, and fits into the oven so we don't have to swap trays now. Too bad my vac chamber only holds 24, or else we would have perfectly matched numbers all around!


It's been nice getting to work on tooling again. I'm really liking my right hand man at holmes motion control. It's almost time to hire a dedicated machine operator to free us up for more equipment improvement.

[rob_b]

So is the output 2pcs or 3? If 3pc I really like the design as far a material efficiency goes

Originally Posted by JohnRobHolmes

A resume is the first step!

Haha. I have never needed one of those things before but just so happen to be working on it...

[JohnRobHolmes]

It's a single piece spool with a sliding lockring. Takes a fraction more time to make, but will reap rewards in strength and keep pressure off the screws for folks running od/ud gears. Material used is a wash vs a regular two peice because we have less part off and facing waste.

New toy for me, 4 channel 50mhz oscilloscope. In this photo I'm lining up hall sensors with zero cross on a motor phase. This one is dead nuts on.