Sunday, February 21, 2010

John Meredith's Howell V-Four SN-009

Here's an e-mail I received from John

Hi Allen

I have completed my V4 (no.9) and thought you might like some photos of the finished product.

With any of these little engines one has start up problems. The biggest problem was the exhaust oil.
It was as bad as a 2 cycle glow plug model airplane engine. I had heard about the empty groove in the piston as an oil control means but didn't know the design details so I built the piston per the drawings. I really don't understand how it works. So my solution to the problem was to make new pistons with an oil control ring and that works well.

The next problem, I could not lean the carb. out properly. So, I did the initially runs with a Perry
model airplane carb.  It ran ok but would not operate at all rpms without mixture adjustments. My answer to that problem was to install a Perry type drum throttle and jet with a mixture enriching feature when the throttle is advanced. I also removed the idle jet.

On the distributor I did not see the magnet spacing problem your dad had. I used 45 degrees and statically the mag. switch fired at the 45 degrees. Dynamically, that may not have been the case but the  engine runs fine at all rpms. However, I was not using a Carter type ignition system. I used Mike Neal's CDI system.

It's a cool looking and a great running engine and the use of o-rings sure makes it easy  to work on ( no gaskets to mess with). Other neat design features are the mag. drive on the water pump and the oil pressure relief system.

A neat project!


John Meredith
Livermore CA

Saturday, February 20, 2010

Electric motor sources

I get e-mails from drill plans purchasers wanting to know where to get the electric motors to run the Mini Drill and Micro Drill projects.  It would seem that some of the sources Dad mentioned in the plans are no longer available.  Those of you who found a motor, can you share with us where you got it? (if they are still available) 

I went to Mendelson's in Dayton (one of Dad's favorite places to search for various items) to look for any surplus they might have, and did not find anything matching Dad's specs, as most of the motors they had there are AC or stepper motors.

For Micro-Drill, Dad calls for: 12 volt DC, 1-1/4" long x 7/8" diameter with a 1/8" diameter shaft.  If you can't keep the motor from turning by pressing on the shaft with your index finger and thumb at 6 volts, then it should have enough torque.

For Mini-Drill, Dad calls for: 24-28 volts DC, min 3000 RPM, permanent magnet, ball bearings, 2-1/4" to 2-1/2" diameter and a 1/4" or 5/16" diameter shaft.

Again, if anyone knows of a source for these motors that match these specs, or if you used a motor with different specifications with good results, please reply here, or send me an e-mail to



A builder responds:

"I found a good motor for the mini drill from Zoro on the internet. You can power it with a lap-top type 24v 10 amp supply, but you will need to create a starting device. The resistance before starting is 1.2 Ohms which will draw a 20 Amp surge when starting, looking like a short to the power supply. One way is to put the switch on the ac line side so the power supply and the motor ramp up together. Better to add a 2-3 Ohm 5W resistor shorted out with a relay after a second or two.

Or you can get a big power supply and put it in a box, resulting in something the size of a bread box. Not cool.

The motor I got from Zoro is their # G1958126. 24 V, 6 Amp, which fits nicely."