Drill presses and mobile bases.

[David Hostetler]

To steer clear of hijacking another thread, I found the following post (http://www.sawmillcreek.org/showpost.php?p=1519894&postcount=48) in the show your shop made mobile bases thread and wanted to reply...


Do not want to hijack the thread, but I think this still will fit. Does anyone had a mobile base to drill presses, they seems to be more top heavy. I have two old rockwell/delat drill presses and thinking to add the mobile base, but worried they will not be stable enough?

I have been putting off doing this for a while, mostly because my shop is presently a disaster of reorganization and remodeling. HOWEVER, I have seen this done on several occasions. And each time I had seen it done, the mobile base enlarged the footprint of the drill press by several inches at least.

My plan is to build one using a surplus Harbor Freight mobile base set, 20" deep x 24" wide to provide some stability, and use the same footprint as the drill press table. The gap will be filled with 2 layers 3/4" sheathing grade plywood, which will be in turn primed and painted gloss black to match the hardware and foot of the DP. This will be bolted from the bottom to the base hardware, as well as wood screwed to the rails. The drill press itself will be bolted through the plywood sandwich using 1/2"x4" carriage bolts, flat washers, and lock nuts.

There is a small part of me that is considering leaving the HF base out of the equation, and simply mounting up some locking casters, but that idea seems too wiggly to me...

[Gary Herrmann]

Personally, I don't like mobile bases for DPs. They're just so top heavy. I glued 2 2' square pieces of 3/4 MDF together and bolted it to Delta 968. It slides just fine when I need it to.

[Dave Lewis]

I 2nd Gary's comment. Too top heavy and a drill press should be set once in your shop along a wall.

I have a DJ-20 8" jointer on a mobile base and built a wheeled stand for a Delta portable planer though.

[Clint Olver]

[QUOTE=Gary Herrmann;1520424]Personally, I don't like mobile bases for DPs. They're just so top heavy. QUOTE]

Ditto.

C

[David Hostetler]

Weight at the top end is only part of the equation. Unless you are bolting that thing to the floor, you need SOME way of spreading the load across a wider footprint than the factory bases on most drill presses. To be blunt, I am amazed most floor model drill presses don't topple over just standing still! A mobile base built with a large footprint, but without adding too much to the height would go a LONG way to stabilizing it...

[Nino Maini]

Thanks Dave for starting another thread. Seems my concerns are vaild as others have the same worries. I wonder instead of a true mobile can make something that is flat to the floor, but I can jack casters if I need to move it around for whatever reason?

[Van Huskey]

There are two tools I hate (and/or fear) on mobile bases, bandsaws and DPs, DPs are by far the worst of the two. If you need a mobile base make it so there is a big flat base and some sort of jacking casters.

[Kurt Cady]

I have my drill press on a mobile base. HTC mobile base. I did however build a box (maybe 16x20) with 2x6's and will the inside with gravel. I was going to mix up some quickrete, but there was a pile of gravel in my subdivision for 6+ months. Used 1.5 five gallon buckets

[Ben Martin]

I have a mobile base on mine, but it is stationary most of the time. Never had a problem with it being top heavy. When I originally built it, I thought about making the "outriggers" even wider, which is always an option...

http://i424.photobucket.com/albums/pp325/martbj/General%20Workshop%20Pictures/IMG_2580.jpg

[Cary Falk]

I have my DP on a HTC2000 mobile base. I hate the base but it works for the DP. I don't move the DP much. Most of the time it sits against the wall. When I do move it I have never felt it was going to fall over. I have the mobile base the same size as the DP base(I didn't enlarge the footprint) for years without any problems.
http://i139.photobucket.com/albums/q297/caryincamas/DSC_0011.jpg

[David Hostetler]

I understand the concern about top heavy guys... But look at it realistically, from a center of gravity / pivot perspective, If you start with a drill press with a base that is say 10" wide x 16" long (the size of mine), and you fasten it securely to a sub base that is say 24" wide x 20" long, even if you add 2" to the height, you have still greatly added to the stability of the drill press. Much the same way that you see cranes on construction sites with the outriggers deployed, they are widening their footprint for stability. Now mind you, you do need to minimize how much added height you put on there, but a couple of inches isn't going to make things worse as long as you have the base larger...

Mind you, a good mobile base, in my book anyway, will have NO contact between a swivel caster and the ground when it is set and locked in place. And you don't want to just set the drill press on top of the base. EVERYTHING MUST be locked in and secure. You want to eliminate ANY wiggle room in something as top heavy as a drill press...

[J. Greg Jones]

David, FWIW for the last 3 years I had a setup very similar to what you are considering. I had a Delta 17-925 on a 22"x26" HTC base, one of the 3-point models with 2 of their optional side supports to give it 5 points of contact with the floor. The press was mounted to plywood mounted to the base just as you describe above.

I never thought the combination was top heavy. When moving the base around, which I did very infrequently, I wasn't concerned that it would topple over. However, what bothered me was the stability in the fixed position. It just had two much movement for me in use between the flexing of the plywood and the flexing of the base frame. I'm sure it was still stable enough, but I was never happy with the arrangement. I took the press off the base 3 weeks ago and I've not looked back. Hopefully you'll be happier with your setup should you decide to go ahead with the project.

[Rick Potter]

I just use a hand truck (dolly) when I move mine, which is seldom. Works fine. Watch out for that top heavy weight when you lean it back though.

Rick Potter

[Charles Wiggins]

I just bought my DP and it came with the base as you see it. I am not sure what the dimensions of the base are. I have not really had a chance to use it, but I noticed when we took it apart to transport it that we really had to tip it quite a way back to reach the actual tipping point where it would fall. I have rolled it all over the garage and basement while I've been working on finishing the shop space and I've not had anything remotely like a close call. One of the wheels got caught on some debris on the floor and it just stopped moving.

http://www.ncwoodworker.net/pp/data/500/PM_DP.jpg

Cheers

[Alan Schaffter]

David, my Delta drill press has been on a mobile base almost exactly like you described (except I didn't paint it black and make it look pretty :D ) and is similar to Charles' but with a step caster on the front, for over 10 years with no problems, ever! I never thought it was ever close to tipping over. Is it rock steady? No, but because the mobile base is wider that the cast iron base it is as steady as it would have been with no mobile base.

I don't use it for a tackling dummy. Think about how you use a drill press- any pressure is applied downward, and fairly close (16") to the support column. There is no need to push it sideways, ever, during drillling. When I move it, which I DO OFTEN, after stepping on the lift caster which lifts the front edge less than an inch, I push/pull at the table level to move it, not against the headstock or belt housing. I have a relatively level floor, but I wouldn't roll it up or down a ramp. If a scrap of wood gets in the way, it stops a wheel and the base from rolling. If that happens I don't keeping pushing/pulling- I stop and kick the scrap out of the way before continuing to move it- just common sense.

I don't drill huge, long timbers, but if I did, I would do it like I do with any long board- I use a roller stand on each side of the table so there is no tilting force.

I will eventually replace the Delta base and two layers of ply with a steel cross member at the back with wheels mounted to the ends and step caster mounted to a bracket at the front. To keep flex to a minimum the cross member will be short, not much longer than the cast base is wide. An alternative is to shim the sides of the cast base so they are vertical and attach the wheels directly to the cast base. I will use solid front feet, or no feet at all, instead of the rubber ones on the mobile base I'm using now.

Flexing or rocking has absolutely no impact on drilling. The only parts that shouldn't move relative to each other are the headstock/quill/bit and the table, anything else doesn't matter to drilling, and is just a minor annoyance if anything.

The base is just barely visible in this pic:

http://www.ncwoodworker.net/pp/data/500/medium/PB130001.JPG

[J. Greg Jones]

Well I would disagree with that point-flexing and rocking introduces vibration, which absolutely can impact drilling.

[Alan Schaffter]

Well I would disagree with that point-flexing and rocking introduces vibration, which absolutely can impact drilling.

You must have weak a column, poor headstock attachment, poor table mount, or are doing a mighty strange dance when you are drilling to induce vibration from rocking and point flexing, or are putting radial stresses on the column or the quill when they are not designed for that. We are talking about woodworking drill presses not metalworking ones or a Bridgeport mill. You are more likely to be affected by bearing runout in an extended quill, a bad chuck, a poorly seated morse taper and vibration from the motor, pulleys, and belt, than feel or see any effect from rocking induced vibration or point-flexing caused by the mobile base, especially if it is a Delta. If you are drilling metal without first using a center punch you will get bit flex and the tip will wander too. And if your floor is flexing, then it will result in vibration and sway even if the cast iron base is bolted down. I drill metal and wood all the time don't experience any of that.

[J. Greg Jones]

I have none of the above maladies that you describe. What I have is 3 years experience using the press on a mobile base and I know that it created vibration. I have one of those swing-away drill bit trays mounted to the column of the press and every time I would work with 3/4" or larger forstner bits in hardwood, the bits would jingle in the tray from the vibration. I've not experienced that since I removed the mobile base.

[sullivan mcgriff]

Bolted mine to the plywood base, on top of which I store two anvils, one 100lb and one 50lb plus the toolbox containing the wrenches that I use once an eon to repair the tractor, 3inch sockets and the like, it doesn't seem tippy at all to me.

[Alan Schaffter]

I have none of the above maladies that you describe. What I have is 3 years experience using the press on a mobile base and I know that it created vibration. I have one of those swing-away drill bit trays mounted to the column of the press and every time I would work with 3/4" or larger forstner bits in hardwood, the bits would jingle in the tray from the vibration. I've not experienced that since I removed the mobile base.

Sounds like your mobile base did not dampen vibration caused by your Forstner bits (and allowed by your quill and chuck), or belts, pulleys, etc. which is understandable. But the source of the vibration was your bits, etc. not the mobile base. Bolting the base to the floor won't solve the problem, but it will hide or reduce the symptoms.

Now as to your actual symptoms- I suspect you have one of those lightweight plastic trays (see pic) that is supported by a bent, thin, metal arm clamped to the column- it will easily amplify vibrations since the arm can flex. I'm unclear how that type of vibration can be compared to what might cause a problem with the quill/chuck/bit or the the main table or how that affects drilling. It is like a car sun visor vibrating against the clip when it is not snapped in. It bugs the heck out of me but is not an indication there is a vibration problem with the car that needs to be repaired.

http://ep.yimg.com/ca/I/toolsplus_2121_391708253