Caster Brackets for my Tables: Multiple Instances of Parts

The flooding in our basement several weekends ago prompted me to raise everything up. I opted to install casters rather than block each desk. The first instances were made of wood and were quite poor. I decided close to 14 Mar 2011 to build a second set out of angle aluminum. The new brackets are much better.

Things I learned since 25 Mar 2011 in building these brackets:

1. Tapping sucks, blind or semi-blind tapping sucks even more. I re-configure my stand-up drill press to hold an MT-2 tapping guide after searching for the straight-shank tapping guide. It eventually turned up on Sat evening. So in addition to re-configing the drill press I have to put a vise assembly together that will allow me to quickly position each part under the center of the tapping guide. Since I have multiple instances I want to have stops on the vise that will position each piece at the same spot. Some clamps and rough square stock will position each piece where I want it. Next the drill press table hold-downs will secure the vise in the correct position. I use the laser sight of the drill press (NTF for the next drill press get better laser cross hairs!) to center the holes of each part under the tap guide. Lots of fiddling for each hole to get them to line up, including re-positioning the table several times. The travel of the quill doesn’t allow me to bring the tap guide down into each hole without then leaving enough room for the tap and T-handle. I need taps with holes in the end to allow me to use a low-profile tap handle. Or a drill press with more quill travel. Blind tapping is a problem if there isn’t enough bottom to allow chips to fall away from the tap. Better to have through-holes if at all possible. Otherwise expect to go slow and clear the chips frequently.

2. The band-saw doesn’t cut all the well. Parts are not cut square even after taking several hours on Fri to try to square the vise. May have to spend more time fixing problems such as the adjustable arm that holds the guide bearings. Lots of deflection in this arm which doesn’t help to cut parts square.

3. Drilling jigs should produce results faster over placing each piece in the milling table, drilling, removing, placing the next piece, etc.

4. Lots of time is spent cleaning up chips after each operation. A small vacuum, operating while cutting, may reduce cleaning time.

5. Tapping fluid works great for steel parts, not very effective for aluminum. Also, the resulting mess isn’t worth it.

6. Certain bits won’t cut drill rod, the titanium-coated bits seem to do the job.

7. Having one movable table to hold raw and semi-machined parts is very beneficial.

8. When limited by front/rear travel of the milling table you can place blocks in the vise to offset the work to bring it into range of the table’s movement.

9. Using the same stop, same side of a work-piece and flipping an L-bracket or other angle stock, take care to subtract the thickness from the front/rear direction when taking readouts from the DRO.

Dev for 10 Feb 2010

Got the lathe secured and leveled tonight, in addition to almost finishing the new four-bolt compound clamp. John Pitkin is a genius! I didn’t do too badly considering the three bolt-holes were circled using the stock ring as a template and then punched and drilled by eye. The compound and clamp fit together like a glove. There’s a small amount of the compound’s boss that protrudes through the bottom which will allow the compound to pivot on the cross-slide same as the old one. I may consider adding graduations but first I need some clamps to get my lathe back up and running.

The mill is showing some vibe problems that were present earlier in Jan 2010. I ended up tightening the vertical gib and the problem went away. There was only wobble when counter-boring. Again tonight, I encountered wobble when counter-boring the clamp. The vertical gib was tightened down pretty good; I tightened it even more to no avail. I’ll try to do some troubleshooting tomorrow night or on Fri and then talk with Busy Bee about what we can do to fix things…

Having a magnetic pick-up tool is handy; in addition to the covers it makes clean-up easy for ferrous chips.

Dev for 09 Feb 2010

The DROs are finished and functioning properly. Ended up using an old piece of painted iron I had laying around from a project for my Jeep a few years ago. Taking a few extra minutes to rummage thru the junk bin really payed off.

On philosophy of building things:

1. Don’t finish a project half-assed. If you’re going to take time to do it, do it right the first time to avoid having to come back and fix mistakes later on. This doesn’t always apply since there can be mitigating circumstances but stick to it under most situations.

2. The man with the most tools isn’t necessarily the one who gets his product to market the quickest. Knowing what to do with the tools you already have has a greater impact on time-to-market.

3. Don’t substitute poor-quality tools for good ones, especially drill bits! I chewed through the concrete floor tonight without any problems thanks to an Irwin bit. Material is another area, especially fasteners. Having one of those cheap Tapcon bolts snap off can be a nightmare. Luckily I had a pair of Vicegrips (the real deal, no imports!!) that did the job of removing the broken bolt but it was SLOW going.

As an aside, I need: bigger Vicegrips, more permanent markers and a muther of a pipe! Trying to man-handle the lathe and milling machine, even just to get them mobile using the stock levers to raise their movable bases is a huge joke. A pipe should give enough leverage to make this task less painful. Plus I’d like a better way to position the machines once they are seated so that the bolt-holes line up to attach them to the floor.

Built another cover for the vice on the milling machine, hopefully it will save time in clean-up. This new cover is form-fitted to the upper portion of the vice to avoid getting swarf in its movable parts.

I’ll hopefully re-start work on the lathe compound mounting plate tomorrow night.

Dev for 08 Feb 2010

Few more things and the y-axis DRO will be finished! Strange behavior once the remote unit is connected; pressing the “zero” button results in “f” or “h,” with “h” holding a value as the scale is moved. “f” on the DRO displays as “ft” on the remote display. May need to call Shars.

It turns out that you need to remove the battery to reset the DRO. Taking the battery out for 30 seconds did the trick.

Remaining activities:

1. Sheath and protect cables.

2. Affix labels to each display to prevent confusion.

3. Clean-up, then start using them!

Dev for 03 Feb 2010

The Y-axis DRO is on! Just a few more hours and both DROs will be fully operational. Lots of tension tonight since most of the operations were by eye. Despite making a few small errors in angle, hole location and thread pitch the system is going to work fine.

Closeout activities:

1. Mill slots for screw holes in transducer bracket to allow some “pivoting” to align the slider with the movable bracket.

2. Connect remote cable to transducer, sheath and protect as required.

3. Re-attach transducer so that cable comes out of bottom.

4. Align y-axis DRO on mounting.

5. Route and protect cables of both DROs behind machine and up to control box.

6. Fabricate a mounting bracket for both remote displays.

7. Affix labels to each display to prevent confusion.

8. Clean-up, then start using them!

Dev for 02 Feb 2010

Happy Groundhog Day. Six more weeks of winter my ass!

I’ll be happier once I get the drill chuck arbors. The stock chuck that came with the mill is not that great. I had to set it up several times before I could get a center-drill to run straight, and even then there were a few times the holes went cak’ayd. Should be close enough for what I need them. Plus it takes forever to clamp the chuck jaws down. The keyless chucks will hopefully work much better.

Y-axis DRO is nearing completion. I’m machining (hopefully) the last bracket; have to put the vice at a funny angle since the side of the milling machine isn’t a true 60 degrees. There will most likely be some trial and error involved; good thing I left some material on the bracket to play with. The mill works great! I’m happy with the slotting saw despite having to hold it in the drill chuck. That and the fact that the end of the arbor comes really really close to hitting the work or vice. But… it does what I need it to do. The vice works great at holding things; I haven’t had any work slip out on me yet. A few taps with the deadblow brings most work to a tight fit with the parallels.

I’m liking the results I’m getting; best of all I’m seeing something tangible for my efforts.

The wheels I’m going to use for the robot are going to be fiddly to install. I’ve been working things over the past day to see what kind of hub I’m going to need. I think the latest iteration will work the best by having a smaller diameter hub mate with a larger diameter plate that attaches to the wheel. At close of yesterday I was going to have to build the hub in two pieces anyway so this doesn’t complicate things more than they already are. Bonus is that the latest design uses one big skinny piece and one little fat piece as opposed to one big fat piece and one little skinny piece. One of my prime considerations is how quickly can I build something and be able to reproduce that thing over and over again?

Lots of new tools on the way as I work through the machining operations for some of the parts!

Dev for 28 Jan 2010

The X axis DRO works great!! Being able to return to the same spot, not to mention being able to travel accurately to a point on the work is amazing. The edge finder is a bit fiddly to work with but it should become easier the more I use it.

I’m taking the same approach for mounting the Y axis angle bracket as I did for X. First I start with an adapter bar for anything that needs to be bolted to the table or base. In the case of Y it is the table and there’s a very small amount of material available to drill and tap for 10-24 screws. I had to eyeball the drilling and tapping which was a bit nerve-wracking. Especially since I’d already drilled the adapter bar and didn’t want to have to re-do it. Thankfully I was accurate enough that the bar fits nearly perfectly to the table. Some additional clearance in the bolt-holes for the angle bracket will allow the DRO to be pivoted as required to keep it parallel with the table.

Twist drill bits, especially the cheap ones are notorious for being off-center at their tips. I center-drilled all of the holes in the bar prior to drilling and this really helped to keep the holes where I wanted.

The idea of building the brackets/bars to attach to the table is so that if I ever need to make any changes I can remove these items and re-do them without affecting the table or base of the mill. Plus I avoid having to remove and install things from the cast iron of the mill an excessive number of times which is good.

Things are really starting to shape up.