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Synergy R/C Synergy N9 > Need help with dial indicating
 
 
EKIM
Veteran
Location: Long Island New York

Like many others I am having trouble getting the fan hub on straight. Without dremeling the top collet, i had a run out of 5 thousands. I dremeled the slot on the top collet and got it to 2.5 thousands but as soon as I tightened it, it went back to 5.5 thousands I've been fighting with this thing for a few hours now and I can't get it straight for the life of me. I looked through some of the posts on here about possible solutions but I didn't find much detail on what to do. Anyone have any pointers/tips? So far I have a fuel tank and a set of landing skids built and I'd like to finish this thing over the weekend.

*******Mike********
09-02-2006 Over year old.
 
 
raptorheli2
Elite Veteran
Location: rip off britain and no changing it

from my previous collet problems

Quote 
after a total of 16 hours the fan is now at 2 thou and start shaft at just over 1 thou. it took a LOT of effort to get it to there. major kudos to AJM on here as he was the one who managed to get it.

before i start i will say i have 2 of everything, 2 set of collets and 2 fan hubs, so i have a good measurement and guage of part consistancy.

here is the important measurements.

OS 91 shz is 7.98mm
both top collets were 8.43mm (the crux of the problem already!)
both bottom collets were same size (can't mind what, the top one is the one that matters here anyway)

the slot in one of my collets isn't even machined and is infact closed, the other one ended up the slot probably 2-3x the original size to get it to clamp properly. this was combined with a 0.13mm shim inside the collet to take the collet to shaft difference up.

this got the fan to about 6 thou, it started at just over 9.

ok, on the gauge, off, on, off etc etc and refitting, turning the fan a million times it was decided to start to mess with the taper of the back collet as the back of the fan was about 5 thou.

so, mark the high spot, take the collet off, sand it with fine wet and dry, try again, mark high spot, sand it, etc etc. after maybe an hour of this the fan was at 2 thou, we called that a victory.

NOW came the start shaft!

it now dialed at about 9 thou. rotate 180 got it to 6.
so, take the start shaft off and san the fan hub where it meets again, again, going slowly (it's easier to take off than put back on). after maybe an hour of this it went to just a tad over 1 thou, we called it a day at that, or by this time a night!

i IMPLORE people to look at their fans, if you haven't gauged them please do yourself a favour and do it. i never dialed a fan that was this difficult before and i've never seen one (or anyone else for that matter) that has needed so much work. i hope they reveiw this collet system in the next batch.


cheers


www.waterfoothelis.com
09-02-2006 Over year old.
HOMEPAGE  
 
 
raptorheli2
Elite Veteran
Location: rip off britain and no changing it

as for pointers or tips.

i would do the following

1. open up the front collet slot to about double what it is just now.

2. get some very thin shim and make a little roll of it to go inside the collet so the difference between the engine and collet is taken up.

3. get it back together and now start at the back of the fan hub with your dial gauge.

4. there is enough of the back collet sitting outside the hub for you to be able to mark where the high spot is, mark it, take the collet off and sand the mark away following the taper of the collet. keep doing this untill you get it down and keep checking the back and front with the indicator.

5. the front collet is a bit more tricky to mark the high spot but it's possible. once you tighten the nut up take it back off being careful not to disturb the hub as it'll still be tightly on, well, tight enough to mark the high spot, again, sand a bit off the collet keeping to the taper. HOWEVER, you might find if you get the back one right you won't need to touch the front one. i didn't.

the start shaft you need to sand the leading edge of the hub on the high side to get it if you need to.

cheers


www.waterfoothelis.com
09-02-2006 Over year old.
HOMEPAGE  
 
 
EKIM
Veteran
Location: Long Island New York

UH OH.......

Man am I getiing frustrated with this frigin thing! I guess I'll order some more collets But now I have a new problem! The little pin that keeps the piston sleeve from rotating managed to work itself deeper into the hole which now allows my piston sleeve to rotate! I don't see any way to pull it back out. I'll posts some pics of it. Its an Os 91 sz pumped that is brand new. Now I guess I have to send the damn motor in to be repaired. I could have avoided this f@#$%n mess if I could get the stupid hub on straight in the first 400 attempts

here is my motor that tiny black pin in the top of the block is what keeps the sleeve from rotating and now it is flush with the engine block making it useless



*******Mike********
09-03-2006 Over year old.
 
 
raptorheli2
Elite Veteran
Location: rip off britain and no changing it

forget ordering more collets, both sets i had were EXACTLY the same. just fix the ones you have.

one fix a mate found was to try collets for a nova, worked a treat for him.

cheers


www.waterfoothelis.com
09-03-2006 Over year old.
HOMEPAGE  
 
 
EKIM
Veteran
Location: Long Island New York

do you know where I can find these nova collets? I don't want to have to go through this disaster again if I ever need to take the hub off.

*******Mike********
09-03-2006 Over year old.
 
 
R.J.
Senior Heliman
Location: SF bay area, CA USA

Maybe you could try threading a small self tapping screw into the roll pin to pull it out a bit? Sorry about your frustration.

Regards,
Rick
09-03-2006 Over year old.
 
 
TMoore
rrProfessor
Location: Cookeville, TN

Taking the head off to indicate the hub is a no no. It's not necessary. I did the hub for NOLONGERFLYING before he sold the heli and it's a minor aggravation to be sure.

I'm not sure what I can suggest to make this any easier either as experience is the key. The tapered split sleeves that I checked were within .0012-.0015" on the ground crank OD. I would have liked to have seen them a little closer than that. The reason being is that with that amount of runout to start with, it gets multiplied once you start mounting the fan.

I did use some light oil on each tapered split sleeve and the one thing that I might suggest is to position the split tapered sleeve on the crank so that the slot is opposite the woodruff key slot. When you assemble the top sleeve and tighten down the nut, if the runout is excessive try rotating the top sleeve relative to its last position and try again. This is how I got the fan runout under .002" on the fan ID. If you use loctite on the nut you won't be able to take it on and off with any certainty that the loctite will hold, besides loctite isn't necessary to hold the nut on if you tighten it properly. With this assembly, you will need to take it on and off before you get the fan dialed in unless the luck of the Irish is with you.

Once you get the fan hub right you will then have to fight it out with mounting the clutch. I found that the material that the hub is made out of is softer than I would like to see. It's really soft. Be careful when you tighten the button head screws that attach the fan. Use only enough torque to do the job and don't be a gorilla. The start shaft is very soft as well. What I did was to take an X-acto and scrape out the fit of the hub ID so that the clutch can move on the fan hub. Snug the 4mm SHCS's and then you can move the clutch around on the hub. I got the lower surface within .0015" and then tweaked the clutch shaft working my way up the shaft with a box end wrench and the indicator until the entire clutch shaft was running under .0015-.002".

All in all, it was a PIA.

TM
09-03-2006 Over year old.
HOMEPAGE  
 
 
EKIM
Veteran
Location: Long Island New York

Thanks for the replys guys. I was getting too frustrated with it and then the engine thing happened and I was about to blow a gasket. I set everything aside for now and if I can manage to get that pin back out of my engine, I 'll try again tomorow. Its definitely a major pain in the ass if it doesn't want to go on straight. If I do have to send in my engine can I still build the rest of the heli without the motor, clutch system, and shroud and put it in later without major disassembly? I am also concerned that I may have dremeled too much out of the slot in the top collet so I'm going to order a replacement just to be sure. (the gap is now just a little bigger than a thin cutoff wheel for a dremel)

*******Mike********
09-03-2006 Over year old.
 
 
ESWLFSE
Elite Veteran
Location: Bradenton, FL USA

I wouldn't sweat the sleeve pin. As long as its aligned when you tighten the head you're fine. Most engines don't have them.
09-03-2006 Over year old.
 
 
PIGROLL
Senior Heliman
Location: Pig Pen

I had posted three weeks ago that we would hear it soon,The issue of these collets but Synergy is not responding enough to this issue.When you finally achieve a decent runout on the fan,you mess up the run out on the clutch shaft.That is about three hours later.I advise that you take the glow plug out and spin the engine by hand and watch your engine wobble even with the mounting bolts secure you will see a wobble motion in engine.New designed collets are necessary, but where to go?I hate wasting flying time.

The cheese slipped off my cracker a long time ago
09-03-2006 Over year old.
 
 
Spookyeng
Heliman
Location: Gulf Breeze, FL USA

I am having some trouble with the runout also. The best I can get is .002 on the fan hub face, .006 on the i.d. of the fan hub, and .004 on the o.d. of the fan hub. I have not even done the shaft yet! I am using a little oil on the collet and spinning the fan as I tighten the crank nut. I will keep trying and hopefully it will seat. I have enclosed a couple of pics of the dial indicator set-up and if I can do anything different please let me know. I have ben stuck on the set for about 4 hours now.

09-03-2006 Over year old.
 
 
ehn
Senior Heliman
Location: Fairfax Station, VA

" I have enclosed a couple of pics of the dial indicator set-up and if I can do anything different please let me know. I have ben stuck on the set for about 4 hours now."

It looks to me like you are off 90 degrees with the dial indicator. Unless yours is different from mine, you seem to be measuring in and out along the shaft line, instead of the radial play.

Long Island Eric
09-03-2006 Over year old.
 
 
Spookyeng
Heliman
Location: Gulf Breeze, FL USA

Actually the Starrett gauge has the pointer coming from the back of the case. I have a normal dial indicator but don't have the base for it. I am in the process of rigging up the other gauge and see what happens. Thanks
09-03-2006 Over year old.
 
 
Spookyeng
Heliman
Location: Gulf Breeze, FL USA

I am getting a little confused. I just got the runout to .002 on the o.d. of the fan hub, but the i.d. is now .009 runout. I have been looking for any burrs on the id that would cause such a big difference but have not found any. Maybe machining error between the id and od.. the hub face is got .0035. getting close but no cigar! 1 step forward 2 steps back!
09-03-2006 Over year old.
 
 
TMoore
rrProfessor
Location: Cookeville, TN

This thing is a PIA isn't it? That's what I noticed. If I had not had the experience of doing a couple of hundred Schluters in the old days this would have been torture.

Don't worry about the fan hub ID, just do the OD and then take an X-Acto and scrape out the ID fit so that the clutch can move around in the ID bore. This is the only way you will get this to work right.

TM
09-03-2006 Over year old.
HOMEPAGE  
 
 
Stu.
Veteran
Location: Abrakebabra Kebab shop

I have to admit the collets being a MILE out on the inside diameter is a pain in the proverbial hole.

I spent AGES working on mine, and im still not happy with it. Raptorheli2s collet was just as in bad shape.

PLEASE sort this

Stu
09-03-2006 Over year old.
 
 
Droid
Elite Veteran
Location: Deep down in the Southwest- UK

Do you know what the only problem i haven't had was with collets!
The bottom collet slid on the crank perfectly and the smaller top collet the same, both have gaps with hub tight.

Are these collet issues with certain engines??

I'm running OS91SZ-H.
09-03-2006 Over year old.
 
 
Spookyeng
Heliman
Location: Gulf Breeze, FL USA

Both my collets are a tight fit and have a gap still when tight. but the best I can do is about .002 on the od. .009 on the id. This is my first experience with collets and I must say I do not like it very much. I have owned Raptors in the past so this was a non issue. I am giving up for the day and will try again tomorrow. I have about 8 hours in the fan fit and still not happy. It just seems to not get any better no matter how many times I spin the fan, re-adjust the fan to hub bolts, and trying different collets. I wanted to fly this weekend but that is looking out of the question now! I do think that once done it will be a great machine, I am just stuck on the runout, a real pain for somebody who has never messed with it before.
09-04-2006 Over year old.
 
 
EKIM
Veteran
Location: Long Island New York

I have the same motor Droid. I'm going to try and track down the nova collets mentioned earlier and see if that does the trick. I've put the motor aside for now and continued on with the rest of the build. I've just left all of the motor components out for now. I am currently assembeling the swash plate and have had only a few minor issues that required some minor sanding and grinding. All of my links so far are perfect, but I am just about to put the head together now. So far its been a pretty good build except for the damn collets.

*******Mike********
09-04-2006 Over year old.
 
 
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Synergy R/C Synergy N9 > Need help with dial indicating
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