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Rebuild old Foredom or buy new one?


#1

Hi all:

I have a Foredom that I got when I bought all the tools and bench
from a jeweler who was teminally ill.? I don’t know the age of the
Foredom, but it has been running great up until the last week or so.?
I replaced the brushes, but haven’t done anything else to it.? It
hangs on one of those poles that I also got in the purchase.? (Got
tools, 2 Meco Midget torches, oxy and propane tanks, wax carving
tools, gravers, jewelers bench, pickle pot,… for less than
$400.)?Anyway, as I was saying, it has been running great until the
last week or so.? Today while cutting jump rings, it started to run
really slow.? I moved the shaft around some and it ran faster for a
couple of minutes, but when I tried to cut some more jump rings it
ran really slow again.? My question is:? do you think I should just
toss the old Foredom and buy a new and improved model, or do you
think it would be worthwhile to try to get the one I have rebuilt??
Provided, of course, that you can have one rebuilt.?

Thanks for the input.? I’ve learned so much from this forum.

Carolyn Vinson


#2

Hi Carolyn,

I’d say send it my way, but I’m most likely in another country to
you, as if I can’t fix it, it probably can’t be fixed anyway!

If you take the flex shaft of does the motor run fine, or is it
rough sounding? If the motor sounds/feels rough (tip with flex shaft
removed turn the motor with your fingers) you will have to replace
the bearings (if this can be done), these may be bearings or
bushings.

This can be a lot of mucking around and may not be worth the
trouble. If you don’t want to do this I might still be interested in
the machine, if only for parts…

Thomas.


#3

Hi Carolyn,

I was having second thoughts about my old Foredom. The brushes were
fine - it turned out to be the footfeed. I replaced it and no more
slow speeds or hesitations. Since it is over 30 years old, I would
not have rebuilt it with the availability of others for sale.

Rose Marie Christison


#4

It’s a good idea when you change the brushes to also need to check
the armature (sp?) for wear and good contact. Often the copper will
need a light refinishing with abrasive paper, to clean it up and
make better contact with the brushes. This sounds like it MIGHT be
your problem here. One other thing I have run into is where the
brushes either do not fit well, are not seated correctly, or the
springs that press the brushes against the armature are not doing
their job (weakened or misshapen).

Good luck.


#5

Carolyn two quick fixes that may or may not help.

1 When was the last time you greased the flex shaft. Just unscrew
the sheath from the motor and slide it down the shaft and use some
foredom shaft grease on it. This should be done every 40 hours of
work or so. Reminds me it is about time to grease all 4 for mine.

  1. Take your fordom motor and blow it out with compressed air.
    Jewelry shops are notoriously dusty and the dust collects inside the
    motor housing ,as well as carbon dust from the brushes, causing it to
    short…

  2. OOPs Just thought of a third thing. Check your foot pedal if it
    is old carbon pile type you might just need to open it up
    (disconnected from the elec. of course) and replace some of the
    carbon wafers, if the wafers are soft and crumbly replace them all, I
    just did this to one I bought that wasn’t working and now it works
    like a charm. Hope either or both of these help.

Frank Goss


#6

Hi Carolyn,

You can send it back to the Foredom Repair Department for a free
estimate to see if it is worth your while to replace it or repair
it. The address is Foredom Repair Dept., 16 Stony Hill Rd., Bethel,
CT 06801. Please include a note with describing the problem and your
daytime phone number. Or you can call us at 800-441-0625 to discuss
the problem.

Mike Zagielski
Foredom Sales Manager


#7

Carolyn

I would try to do a couple of maintenance tasks first. I have a very
old one, that is also ugly, it has not had a nice life, but it still
works as good as a new one.

Have you lubed the flex shaft since you have owned it? This would be
the first thing I would try, low cost and could account for your
problem. Second, the hand piece, see if it turns easily, if not, then
replace it. Lastly it would be the bearings in the motor. Between the
3 items I listed, even if you replaced all, it would set you back
about $90

I believe a new flex shaft and liner would run around $12 to 16, a
new hand piece around $49, and having the bearings replaced may run
as much as $35 depending on where you have it done.

Terry


#8

Call Foredom, they will give you an honest answer. Rebuilding per se
isn’t necessary- just cleaning or maintenance which if you haven’t
kept up with is probably the issue… Of course Foredom, wants you to
buy a new one based on your exact needs, but if you have checked your
connections, greased the shaft regularly, and if it has brushes,
replaced them, ever- then there isn’t a reason to buy a new one, just
the maintenance kit…sounds like maintenance is the answer in your
case as it was working fine…lubrication is essential in the older
models… they ( foredom) will service it for you for about 17 bucks,
but you will be without the tool for a week or so… a new high
torque low speed model TX 300 ( great for stone setting, and most
operations you will probably preform in fabrication) is about 170, 00
from FDJ, or other suppliers ( sometimes it’s more from the
manufacturer- go figure that out- however, if you say to the Foredom
rep, i can get it through x manufacturer for x price, they will
usually match or beat that price direct from blackstone industries -
Foredom’s parent company). By the serial number Foredom can tell you
how old your model is too. There are other equaivalent pendant motors
too, Foredom is not the end all be all of the game. Buffalo dental
offers a high torque, low speed model as do most suppliers with their
names on a pendant motor with flex shaft attachment- so shop around,
sometimes warranties are better. In fact Pfingst flexshafts ( made in
NJ) are outstanding, and a bit heavier duty than some Foredom models.
Don’t misinterpret that Foredom is a great company with great
products, but there are others as well, and if you want the best deal
for your needs and money Pfingst, buffalo dental and some of the
proprietary labels ( grobet, bergeon, etc. ) offer the exact same
features, support, and varying warranties at varying prices,
depending on who has what on special in a given month- or what
products are overstocked at a given supplier’s warehouse- so shop
around if you have limited funds and would rather buy some metals to
use with the machine, than the top of the line machine with features
that are meaningless to you or your needs…do check FDJ for their
monthly specials ( they carry Foredom etc. pendant motors). …all in
all sounds like your machine just needs some maintenance, unless you
have been running it hot and dry without taking care of the equipment
at all…

R. E. Rourke


#9
One other thing I have run into is where the brushes either do not
fit well, are not seated correctly, or the springs that press the
brushes against the armature are not doing 

Another one I forgot about yesterday— There are a couple of good
posts today - look at the foot pedal is one. My first reaction to
this problem is that the commutator is shot or off. It’s not the
armature really. The armature is the bundle of wires and steel plates
that are the bulk of the motor. The commutator is the copper cylinder
that the brushes go up against. The way a motor works is that the
copper on the commutator is divided by insulation - that’s the dark
lines you see. Each of the copper sections is opposite polarity under
power. One of two things can happen - the insulating lines can be
filled will junk, and the brushes won’t be making the proper contact
with the polarity thing happening, or the motor will just plain short
out and one or more of the copper sections will go dead. When one of
those things happens then just what you describe will happen -
intermittent speed problems. If the brush starts on a dead section,
it will struggle, if it starts on a live section, it will run fine -
once it gets going it will just skip over the dead part, though you
won’t have full power if you were to test it. Get some proper tool,
like a small screwdriver or knifeblade, and clean out those dark
lines, and also sand it around, as was suggested. It could also be
some of the other things suggested, too, like lubrication on the
shaft. If it is the commutator, which is a very common problem with
motors and generators, then if cleaning out the insulators doesn’t do
it likely the motor is truly shot, and repair will cost at least as
much as a new one.

http://www.donivanandmaggiora.com


#10

Hi all:

Thanks for all your suggestions about maintenance to my Foredom.? I
bought a repair kit which contained brushes, a new shaft amdn
grease.? I watched the videos on Blackstoneind.com and replaced the
brushes, greased the new shaft and put it on the motor.? It seems to
be running much better.? I didn’t have any compressed air to blow out
the gunk, so I’ll do that tomorrow morning. The only other thing I
haven’t done is to check the foot pedal.? It looks really beat up,
but I don’t know how to take it apart to look at the “innards”.? I’m
going to?tackle that tomorrow.? I figure worse case, it will quit
running and I’ll have to buy a new one (foot pedal).?

Carolyn


#11

Hi Carolyn,

I’m glad to hear that you got your flex shaft up and going. Foredom
has posted in the download area of our website parts price list
which shows blow-up diagrams of our machines and speed controls
(except the CFL). I think that this may help you in your maintenance
tasks. Good luck.

Mike Zagielski
Foredom Sales Manager


#12

Carolyn,

BE SURE YOU UNPLUG THE FOOT PEDAL BEFORE YOU STAT TO
DISASSEMBLE…

if you have the old carbon pile type foot pedal they slide apart…
The bottom plate will slide out of the pedal. Look at the bottom and
see if there is a metal lip on one end and open on the other. You can
usually start it with a flat blade screwdriver, placed in the slot at
the open end, and twist. This motion should start the bottom plate
moving, now just go ahead and slide it free. Inside you will see a
ceramic cylinder that the wires are attached to. It is usually held
in place by a screw at about the center of the cylinder which you
remove. The ceramic is a this point free of the foot pedal housing
but attached by the lead wires at one end and a hinged arm
arrangement at the other. You will see a sort of keyed slot mechanism
that attaches from the foot pedal to a metal strip that contacts a
carbon button on the opposite end of the ceramic from the lead wires
attached to the ceramic cylinder. You detach this by twisting until
the slot lines up and you remove the arm. This frees the ceramic
cylinder from all but the lead wires from the plug. Next flip the
cylinder over and you will see two screws that hold a metal cap on
that end of the ceramic cylinder. This holds the carbon pile in place
and services as one pole for the wires to attach. When you remove
this cap a stack of round flat carbon wafers will be exposed and the
ceramic will be free of the foot pedal housing except for the other
wire lead which removal is optional. Dump out the wafers and at the
very bottom will be the carbon button contact from the other end of
the ceramic cylinder… Now this carbon pile is VERY delicate but if
it crumbles at the touch it is over the hill and will have to be
replaced. You should also replace any broken wafers you come across…
Now replace the carbon button holding the cylinder vertical and then
the wafers. The stack,when full,should reach the top of the ceramic
cylinder with the carbon button fully extended at the bottom. Now
just reverse the disassemble instructions.

BE SURE AND UNPLUG THE FOOT PEDAL BEFORE YOU START.

hope this all helps… Be sure you unplug and I usually get my carbon
wafers from other foot pedals. This should however let you know if
the pile is salvageable or not. I have a few spare wafers if you are
desperate and can’t find any and the pile is just short a few. I
don’t have enough to rebuild the complete pile… Let me know how it
goes. Frank Goss


#13

Carolyn,

Adding to frank goss’s excellent description of how to fix a carbon
pile foot control, I have also used misc. washers or even silver
discs to replace the broken carbon pieces. The over all length of the
stack is what matters most. It won’t quite be the same, but then
again carbon pile foot controllers never were that great. My personal
solution was to graft a linear sliding light dimmer into a foot
pedal. Mine uses an old foot control with a 1/2 length pedal, a
hardware store slide dimmer and a piece of 1.5mm brass wire
connecting them. Very good low speed control and torque. Some extra
creativity might be required with the more recent pedal designs with
longer pedals. (mine is probably using a 25 year old pedal style :slight_smile:

And of course do NOT try this unless you have the needed electrical
skills or a friend who does. Mains electricty is not very forgiving;
minor mistakes hurt and you can end up kicked across the room, major
mistakes you don’t remember ever.

Jeff


#14

Jeff, thanks for the info. I never heard of using silver discs to
replace the carbon pile. Next time I get in a bind I’ll give it a
try. You learn something new every day on Orchid.

Frank Goss


#15

Frank,

Only replace a few of the broken carbon disks with metal, I think
that the maximum I ever did was 1/4". The more you replace the faster
the remaining carbon ones die, fewer disks doing the same work.

Jeff
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand