I am looking for the pros and cons of installing stud mounts and or using flat washers that have been epoxied on. Also is there a certian type of epoxy that should be used for this? Does using one or the other effect the sensitivity of the data collected?

I would rather have the stud mounts whenever possible.I have found that the washers we used an epoxy on are good,but we are now seeing in the most hot areas in our plant that these washers are falling off after 3 years of service.The fact that stud mounts that are drilled and tapped sort of become part of the equipment ensures a better signal transfer.There is also a company making an adapter that epoxies onto motors.This unit is a tee shape and is mounted between the fins on electric motors.So rather than babble on I vote for stud mounts that you drill and tap where ever you can. Also we use loctite
330 adhesive which in moderate climates works very well.

We offer an inexpensive stainless steel mounting target for adhesive mounting. Similar in function to a flat washer, but it's stainless and there's not hole so you don't end up with a bump of adhesive in the middle or glue all over your fingers when installing them. They are $60 for a bag of 100.

For permanent accelerometers, we recommend an adhesive mounting stud. It's my experience that gluing a stud down will happen quickly; drilling, tapping and spot facing is always a project for another day! when drilling and tapping there is also the danger of non-perpendicalur holes, bunged up threads and so on that may distort the accelerometer case and cause some problems.

Loctite Depend 330 is an excellent choice, with good long-term properties. Just be certain that it's not past its shelf life - it just won't work after that date.

A helpful hint...."super glue" works great as a short term solution, even in wet areas. If you need to put a mounting target on a pump with a leaking gland, wipe off as much water as posible and stick the target down with super glue. It won't stay on forever, but you'll quickly have mount installed.

Jon
Spintelligent Labs

I agree with Jon about the glob of adhesive that affects flat washers and the wasted work of installing drilled and tapped holes for stud mounting. I have seen flat washer installations that were stuck as-is to an unprepared surface. Flat washers are tempting because they are cheap and readily available. They are not very flat and cad-plating is often not adequate for corosion protection. Save the stud mounting for exceptional measurement requirements and situations.

I prefer magnetic stainless steel disks with aircraft grade corosion coating. Disks are attached with Depend adhesive to a prepared flat surface. High temperature epoxy is available from Loctite, if that is a real issue after doing everything else correctly. About 100,000 disks installed over a 15-year period brings a little experience to this mundane but critical item.

quote:

Originally posted by Walt Strong:
I agree with Jon about the glob of adhesive that affects flat washers and the wasted work of installing drilled and tapped holes for stud mounting. I have seen flat washer installations that were stuck as-is to an unprepared surface. Flat washers are tempting because they are cheap and readily available. They are not very flat and cad-plating is often not adequate for corosion protection. Save the stud mounting for exceptional measurement requirements and situations.

I prefer magnetic stainless steel disks with aircraft grade corosion coating. Disks are attached with Depend adhesive to a prepared flat surface. High temperature epoxy is available from Loctite, if that is a real issue after doing everything else correctly. About 100,000 disks installed over a 15-year period brings a little experience to this mundane but critical item.

Walt - Can you provide some more information (Vendor/Website) on these magnetic stainless steel disks?

Thanks - Steve

Steve,

The disks are proprietary for the services of setting up a monitoring program or permanent installation. They have not been offered for general sales.

Our ecomony mounting pads are shown on our web page here:

http://www.spintelligentlabs.com/p-targets.html

The ecomony pads look like knockouts, but they are magnetic stainless. They hold up well in industrial environments and it's hard to beat the price of $60/bag of 100.

The thicker heavy duty pads are also shown. They can be fitted with a Cap Plug cover, making them nice for harsher enviroments where they might get painted or covered with debris. These are $6 each.

Walt's post did bring up an important point. There is a bit of an art to installing mounting targets, particularly on vertical surfaces. IF you hold the target in position for maybe 15 seconds and let go, resisting all thoughts of "testing" it, it should be ready to use in a couple minutes. If you just can't resist touching it to see if it's ready, you'll usually have to clean all the adhesive off and start over.

Jon
Spintelligent Labs

Sherman,
I have found devcon plastic welder to be a very good epoxy to use. It is not as tempramental as Loctite 330 and seems to have a better shelf life. It is also easier to use and less exspensive. Also, I use a stud/epoxy mount. I take a 1/2 13 jam nut with a 1/2 13 x 3/4 cup point set screw loctited into it. I epoxy this to the equipment and then with a 1/2 13 stud adaptor on my accel, I have a quick stud mount. It has given me very good results. I have also used a 1/4 28 nut and set screw combination to screw the accel directly to the epoxy/stud.

I have had good luck with the economy pads I bought from Jon Chandler (haven't tried the heavy duty pads yet). I have used Loctite Depend adhesive for years with very good success. But it doesn't have much shelf life, so buy the smaller, syringe-type tube -- you'll waste less. I think the surface ought to be clean, but a degree of "texture" is desireable.

If you have a lot of these to mount, I recommend the Dewalt 18V Cordless 4.5" grinder with a knotted-wire brush. If you already have Dewalt 18V tools, you can buy the grinder (or any Dewalt 18V tool) on Ebay for about 1/3 of the cost of a complete unit. They come without case, batteries, or charger, but are usually new, never used tools.

After brushing it off, I clean the surface with a mid-grade contact cleaner... you usually don't need the very best, $20/can cleaner for this application.

If I'm not mounting the pad on 'top' of something, I just hold it in place for 10 secs. or so, and then slap a piece of duct tape over it for insurance.

Another good source for this mounting discs and the motor fin mounts is Connections Technology Center CTC. Their web address is CTCOnline.com or call and ask for Kim at 1 (800)999-5290.
They have the best quality stuff and are willing to be very price competitive.

They have an epoxy call Devcon Plastic Weld that I swear by. I once glue two 1" diameter ball bearings together and challenged anyone to get them apart. It went on for about a month and we have some very ingenious people here that tried several methods. Finally I came into work one morning and there they were apart. Someone had finally done it. They used a band saw to cut them apart. I made no special surface prep except to clean with alcohol.

I echo Walt's warning about the expiration dates. It is near next to useless once it expires.

Rusty,

Thanks for the comments regarding our economy mounting pads. If anybody in the US or Canada would like samples, please send me an e-mail and we'll send you a few to try out.

jon@spintellignetlabs.com

Jon
Spintelligent Labs