For what it's worth, I recall listening to IAMPETH Master Penman discussing speed and accuracy - and how it is not a one-size-fits all situation. It's like riding a bike. If you do not go fast enough, there is wobble on your bike, or wobble in your lettering. So, each person needs to find that balance on their own.
*Everyone* agrees that it is a waste of time to spend hours on practice where the letterforms are way off base. It can be very challenging to help students figure out - or even believe - that they can replicate the shapes on the exemplar. As David mentioned, tracing over the proper shapes can be very helpful. We've all seen the dotted line alphabets that are used to teach kids - but for some reason, it's not a popular way to introduce a new style to adults. Having said that, when I asked around, there was agreement that tracing was the logical solution if a person just can't see the invisible lines, ovals, angles, etc.
I also remember discussions at IAMPETH about the difference between:
1
keeping your hand and wrist in a fixed position
keeping your arm on the desk
moving your arm to do the writing - you will feel the slight friction between the desk and your arm - as your arm is actually moving
and
2
keeping your hand and wrist in a fixed position
keeping your arm on the desk
but the skin does not move, and it is the bone inside the arm that moves
I know this sounds creepy, but if you put your arm on the desk, you can see that you can actually move your hand in the motions for writing
while keeping your skin in contact with the desk and the skin does not move.
I recall people comparing how much *play* they had in that movement - how far they could stretch the bone inside the arm.
When I do it, I can create perfect push pulls that fit comfortably between the lines of narrow ruled notebook paper.
They are much more accurate than sliding the arm, including the skin - up and down.
It is a weird little difference - but once I learned it, it's what comes more naturally to me.
Obviously, you have to slide your arm to the right as you fill up a line.
I do not recall what the IAMPETH people were calling the two different ways to move your arm - but it was an interesting conversation.
When Trazo asks:
"the question is if I can acquire the form without slowing down"
It's entirely up to you to find the balance.
When I start addressing envelopes - the first 15-20 are all warming up. They look fine - but the next 15-20 always look the best to me and they go faster- and then during the next 15-20 - I start losing it - and I take a break. To the client, they all look the same. But to me, I can see a subtle difference.
IMHO - the only way you can create 100% consistency is to put in a a consistent amount of time and keep it up every day.
In ballet, they say: If you skip practice for one day, you can feel it yourself. If you skip practice for two days, your partner will notice. And if you skip practice for 3 days, the audience will notice.
It is hard to quantify how much time every day is optimal. IMHO - penmanship compares to music. It's better to do a half hour a day and not miss a day than to skip 5 days and then think that you can practice for 2.5 hours and catch up. The consistency of your practice sessions will probably have a significant impact on your overall progress. So Trazo's suggestion of an hour a day for 4 years sounds like a good plan. Even a half hour, daily - would probably be fine. But, as I mentioned, some of us need some warm up time - so - if it takes 20 minutes to warm up, you probably want at least 20 minutes where you are in the zone.
Trazo's other question:
My question, to put it in the most simple way, is this: I can write "Onion" 18 times in a minute using my arm (in fact, I think this is something anybody can do with a bit of practice). But will I be ever able to write this word beautifully (like the one in the exemplar) if I keep practicing at this speed?
As you are integrating your skill at making the proper shapes, which speed, slow down enough to achieve accuracy and then speed up, maintaining that accuracy. But, you have to be really honest about how close you are getting to the exemplar. Also -- how close do you want to get?
If your purpose is to have pretty penmanship for your daily life, you don't really need to replicate the exemplar exactly.
It can be fun to have your own personal style sneak in here and there.
Personally, I do not care for the caps on any of the business hands - so, I have my own caps.
Feel free to post samples of your practice here - and get feedback.