Hello gents,

Quick question..... Is there any problem using a variable speed
controller on an 110VAC die grinder? The problem I'm having is all mine are
24-30k RPM and I need to run much slower for doing cylinder head porting
with abrasive wheels and discs. I normally use air tools for this but my
compressor makes more noise than air and it's a big drain on the wallet to
run. If this is ok to do can you recommend a suitable unit. A dial or foot
pedal is fine. I just don't want to fry the brushes or unit all together.
Electric stuff is not my forte so I figured I better ask first.

Thanks as usual!

Rob

On Oct 2, 1:02 am, "RDF" wrote:
Hello gents,

Quick question..... Is there any problem using a variable speed
controller on an 110VAC die grinder? A dial or foot
pedal is fine. I just don't want to fry the brushes or unit all together.
Electric stuff is not my forte so I figured I better ask first.

Thanks as usual!

Rob

Well, hi, Rob!

Long time no read, group and groupies!

Sure, you can use a variable speed controller on a 110 VAC die
grinder. I have one made by HF used with their trim router, and that
controller can dim 15 amps. However, it's a crap controller. There is
no "IR compensation" to keep the router speed constant when the
mechanical load changes. You'd need a much more expensive control,
stating a speed/load regulation in percent to determine if you can get
the critical cross hatch hone pattner needed for healthy engine bores.

You'll fry brushes and commutator with such a cheap controller when
you stall the unit with a honing load at low RPM.

My trim router adapts to my Smithy Super Shop's four-way toolpost
using cuts I made into the cubical post body of cast iron. I used a
milling cutter (a 45 degree dovetail cutter) that had the same radius
as the trim router body. IIRC t his was a 2-3/4 diameter. I then used
fence by hand to cut three slots in the post body for hose clamps, so
the router is held by two clamps in radial position and one clamp when
in paraxial position. I like it! I've got the 1/4 inch body center
drill, a selection of 1/4 shank router bits and grinding stones, and a
cutoff wheel and arbor.to work with the trim router's collet.

So, who here can recommend a router speed control with stable
performance and IR compensation at crawling speeds?

Doug Goncz
Replikon Research
Seven Corners, VA 22044-0394

wrote:
On Oct 2, 1:02 am, "RDF" wrote:
Hello gents,

Quick question..... Is there any problem using a variable speed
controller on an 110VAC die grinder? A dial or foot
pedal is fine. I just don't want to fry the brushes or unit all
together. Electric stuff is not my forte so I figured I better ask
first.

Thanks as usual!

Rob

Well, hi, Rob!

Long time no read, group and groupies!

Sure, you can use a variable speed controller on a 110 VAC die
grinder. I have one made by HF used with their trim router, and that
controller can dim 15 amps. However, it's a crap controller. There is
no "IR compensation" to keep the router speed constant when the
mechanical load changes. You'd need a much more expensive control,
stating a speed/load regulation in percent to determine if you can get
the critical cross hatch hone pattner needed for healthy engine bores.

Doug Goncz

Doug , he was talking about porting work on the heads , not cylinder
honing . I used a dremel unit to clean up the ports in a set of motorcycle
heads ... it was slow and underpowered but it worked . A Foredom type unit
with flex cable drive should be just what the doctor ordered , and IIRC they
have a built in speed control . Might cost more than just a controller
though .

--

Snag aka OSG #1
'90 Ultra , "Strider"
The road goes on forever ...
none to one to reply

That's the problem. All porting is done with 1/4" shank bits and mills. I do
indeed use a cabled Dremel for intricate work and I'd be lost without it.
for the big removal it's up to the big-dogs. I prefer my Dewalt# 887 and a
Makita of the same size. When on the compressor, I have six or seven
grinders that I leave chucked up with the bit I'll be needing rather than
swapping tooling. I bought a bunch of the 887's and they have little
vibration and I'm able to feel my work really well but they just spin too
fast. I should have been more clear... Sorry about that.. The heads are
Iron but mostly Aluminum. BTW for the record, my Dremel is about three
years old. I use it about twice a week in what would be easily considered
"above duty cycle" (and then some!) That tool has been abused big-time. I
tear it down regularly and lube the cable and clean it up and it just keeps
working and working.... By rights, that tool should have died a long time
ago. That is how tools SHOULD be made!

Thanks again,

Rob

Fraser Competition Engines
Chicago, IL.



Doug , he was talking about porting work on the heads , not cylinder
honing . I used a dremel unit to clean up the ports in a set of motorcycle
heads ... it was slow and underpowered but it worked . A Foredom type unit
with flex cable drive should be just what the doctor ordered , and IIRC
they have a built in speed control . Might cost more than just a
controller though .

--

Snag aka OSG #1
'90 Ultra , "Strider"
The road goes on forever ...
none to one to reply

In article ,
"RDF" wrote:

That's the problem. All porting is done with 1/4" shank bits and mills. I do
indeed use a cabled Dremel for intricate work and I'd be lost without it.
for the big removal it's up to the big-dogs.

I'd suggest one of the big (1/3 hp TX, TXH) Foredoms (15,000 RPM top
speed) unless you want lower top speed (5000RPM) with less power (1/12
hp L series).

You could try one of the Foredom heavy-duty speed controls on your
current grinders, I'd guess, as being probably better than harbor
freight, et al, if the current rating for your grinders is less than the
current rating of the Foredom the speed control is made for. But you
might want to just get a set and go, if you're using it that much. They
are good.

--
Cats, coffee, chocolate...vices to live by

Any over the counter Grainger type will work? Very good news. Should I
expect to replace brushes more often as a result? If so, I'll just stock up.
Is there any model in particular you would use if in my shoes?

Thanks again!!

Rob

Fraser Competition Engines
Chicago, IL.


"Ecnerwal" wrote in message
...
In article ,
"RDF" wrote:

That's the problem. All porting is done with 1/4" shank bits and mills. I
do
indeed use a cabled Dremel for intricate work and I'd be lost without it.
for the big removal it's up to the big-dogs.

I'd suggest one of the big (1/3 hp TX, TXH) Foredoms (15,000 RPM top
speed) unless you want lower top speed (5000RPM) with less power (1/12
hp L series).

You could try one of the Foredom heavy-duty speed controls on your
current grinders, I'd guess, as being probably better than harbor
freight, et al, if the current rating for your grinders is less than the
current rating of the Foredom the speed control is made for. But you
might want to just get a set and go, if you're using it that much. They
are good.

--
Cats, coffee, chocolate...vices to live by

You might try to find a dremel foot control, they are great for your
application. I use one with my Makita for porting. Unfortunately I believe
Dremel dropped the foot pedal now that they build the speed control into the
tool. foot pedal controllers.


"RDF" wrote in message
. ..

That's the problem. All porting is done with 1/4" shank bits and mills. I
do
indeed use a cabled Dremel for intricate work and I'd be lost without it.
for the big removal it's up to the big-dogs. I prefer my Dewalt# 887 and a
Makita of the same size. When on the compressor, I have six or seven
grinders that I leave chucked up with the bit I'll be needing rather than
swapping tooling. I bought a bunch of the 887's and they have little
vibration and I'm able to feel my work really well but they just spin too
fast. I should have been more clear... Sorry about that.. The heads are
Iron but mostly Aluminum. BTW for the record, my Dremel is about three
years old. I use it about twice a week in what would be easily considered
"above duty cycle" (and then some!) That tool has been abused big-time. I
tear it down regularly and lube the cable and clean it up and it just
keeps
working and working.... By rights, that tool should have died a long time
ago. That is how tools SHOULD be made!

Thanks again,

Rob

Fraser Competition Engines
Chicago, IL.



Doug , he was talking about porting work on the heads , not cylinder
honing . I used a dremel unit to clean up the ports in a set of
motorcycle
heads ... it was slow and underpowered but it worked . A Foredom type
unit
with flex cable drive should be just what the doctor ordered , and IIRC
they have a built in speed control . Might cost more than just a
controller though .

--

Snag aka OSG #1
'90 Ultra , "Strider"
The road goes on forever ...
none to one to reply