29-360 H-268 help please

Hi, while putting together my first 29-360 motor I have a question,
after inserting the grains into the liner agains the foreward seal
assembly that is fitted into the foreward end of the liner, there is a
gap at the aft end of the liner about 1/4 inch wide of exposed liner
before the aft end of the liner where the aft insulator washer is, it
seems to me this space will be exposed the the high temp flame and burn
through and damage the case, is this normal?, Thanks, Le
Reply to
BigRockets
Loading thread data ...
It sounds like you might have the forward seal disc installed backwards. You should have put the thin o-ring around the seal disc, then put the o-ring side of the seal disc into the phenolic liner. The seal disc should be pushed into the liner slightly so that the o-ring portion enters the forward end of the liner, and butt up against the larger diameter portion of the seal disc. Then put the grains into the liner.
David Erbas-White
snipped-for-privacy@gmail.com wrote:
Reply to
David Erbas-White
no, i have it correct, the o-ring end is inside the liner as is stated in my post, if it was backwards it would not be "fitted inside the liner" as the flanged end is the same diamiter as the liner, I assume it is not normal to have the gap then?
Reply to
BigRockets
It's normal to have SOME gap, but 1/4" seems a bit much (but maybe my memory is just playing tricks). Bear in mind that during flight, the grains 'center' themselves from each other. Even if you had no gap whatsoever, the end grain will be burning that insulator -- but it burns so quickly that the insulator does not have time to burn through. Bottom line, I wouldn't worry about it...
David Erbas-White
snipped-for-privacy@gmail.com wrote:
Reply to
David Erbas-White
Thanks Dave, was thinking about how fast it will burnout, the grains were a very tight fit even after unwraping a layer of paper off of them, I had to pretty much force them in with a dowel, no damage was done to them, do you think they will still center out or should i disassemble and sand them some ? Thank you a milliuon times over for your input, Le
Reply to
BigRockets
First, I'm not an expert, but...
I wouldn't worry about it. Even a hairline crack in a grain can allow the flame-front through, so the separate grains (and their faces) will ignite just fine. Even if they don't separate (due to the stiff fit), the total pressure is determined by the total surface area that is burning, and after the first few milliseconds these faces are burning 'away' from each other. So, in essence, there is no real 'need' for them to actually center themselves (I'm sure it makes some minor difference, but I don't think it will keep the motor from working). I'm surprised that the grains were such a tight fit in the phenolic liner, though -- can't say I've had that specific problem with the 29mm motors (I've had problems with certain 38mm motors).
My guess is that the motor might 'chuff' a time or two at launch, as the center core ignites and comes up to pressure with the faces igniting shortly thereafter.
David Erbas-White
snipped-for-privacy@gmail.com wrote:
Reply to
David Erbas-White
I'm glad to hear your surprised, this was my second "fit" problem with the 29mm HP motors (I only assembled 3 so far, having problems with 2 out of 3 was not making me feel good about my choice in AT motors), the first was the 29-240 and the liner just would not go in so I forced it and destroyed it, AT offered me a replacement which was a much smoother fit but it took over a month to get it, I ended up using 24mm LOC tube as the liner, Thanks again :-), Le
Reply to
BigRockets
*And* he used a 24mm LOC tube as the liner which represents a significant modification in parts...
tah
Reply to
hiltyt
No, no, no, a "significant" modification would be something along the lines of using say, LOC 18mm or 29mm or even 38mm tube. That would be significant!
:)
Reply to
Dave Grayvis
Is this place dead or what?
Looks like it's just me and you, Hilty.
'sup?
Went and looked at some chainsaws. Saw man I trust tells me no more parts for my C5 homelite, so I need something to handle the light to medium work so I can save the beastie for the big stuff. Opinions?
Reply to
Tweak
Dead as the proverbial doornail...
You forgot to start the thread up again with OT in the subject...
formatting link
Pick yer poison! Pound for pound, and dollar for dollar, IMHO, Stihl beats anything. Well, maybe except the short-block chainsaw!
My father-in-law bought me this one a couple of years ago:
formatting link
I use it for brushing out a tree on the ground, and it's also so wonderfully light that I can climb a tree and handle it easily with one hand to prune, or drop storm damaged branches. I use the 12" bar.
My "middle" chainsaw's a Homelite XL. I use a 16", or 18" bar, depending on what I'm cutting. It came with a 20" bar, but IMHO, it really never had enough balls to run that bar and chain combo.
Then, of course, there's the "mother of all chainsaws" a Homelite Model 45 with the 42" bar
You can't go wrong with Stihl tho' -- next time you see a professional tree crew working (Davey, Asplundh, etc.), look at the brand of saw their using. It's usually a Stihl.
tah
Reply to
hiltyt
First place I looked. I replaced all my other yard equipment over the last few years with Stihl (trimmer, weedeater, etc.) and based my decision on the fact that Stihl is what you see on the lawn service trailers. But I try to be open minded about purchases.
Isn't the 009 a little "light" (although I'm sure it's better than a "Wildthing")? I was looking more at their midrange stuff, or maybe even the 260. I don't like equipment that doesn't work, or requires work from me to do work. Same reason I ended buying that Kubota garden tractor and that rack of Stihl yard equipment.
Biggest thing that scares me with those little bitty saws is kickback. The mighty C5 kicks back and moves about an inch, since it weighs about as much as a small block. Little saws take off heads, arms and other appendages.
How old is that XL, and how reliable has it been? Something about that size is what I need.
How do you measure a bar, anyway? Total length? Length from the saw? My C5 is 22" from the body of the saw to the tip.
Reply to
Tweak
A buddy of mine who used to work for a tree service that trimmed for the utility companies swears by Poulan. Although, the company's changed hands a few times. Dunno what the current quality's like, but the "older" ones he has cut just as well as the Stihl's I've used.
Yeah, the 009's really little, but that's why I use it as my small saw. When you're brushing out a 120 foot Maple, even the Homelite XL gets to be pretty damn heavy after awhile. That little 009 is pefect for cutting off all the little stuff in order to get to the logs with the bigger saw.
Interesting. I've never had many issues with kickback. I mean, it's happened a couple of times, but as I'm cutting, I just make myself aware of the fact that it could happen when I'm cutting in a certain situation. I've had more trouble with not properly gauging the torque, or flex on a large branch that I'm cutting. I've gotten much better over the years after being whacked upside of the head, nailed in the shins, and banged in the thighs several times. After those little "incidents" you tend to learn what to look out for extremely quickly...
It's 10 years old this year, and honestly, I've never had a lick of trouble with it. I get "razzed" quite a bit about owning it by many of the other "heavy duty" woodcutting locals, but really, it's been great. It fired up on the second pull last weekend when it was 15 degrees outside, and it had been sitting in the shed all week.
It's essentially the cutting area available on the bar -- so it doesn't count the length of bar inside the powerhead. Generally, you can measure from the tip of the circumference of the end to the bottom of whatever enclosure that contains the sprocket. It does vary, marginally, with the make of the saw.
This is fun!
tah
Reply to
hiltyt
How high does your sprocket go and do you have to be certified? Are you a member of the NCSA? What's your number? Are your papers in order?
SPEAK UP! Vee have vays of making you talk!
Randy
formatting link

Reply to
<randyolb
Motor assy. problems are common. Sometimes you have to peel the liner, or the paper on the grains, or both. Phenolic liners can be sanded. Rattle with some motors is normal. For example, the grains of an H-180 will rattle when correctly assembled. What's important is to make sure the liner is the correct length to seal the O-rings.
If you don't feel resistance when you tighten the rear closure, don't fly it! *BOOM* will be the result.
Reply to
J.A. Michel
tweak, which of the six things I mentioned should I have not mentioned ? and hilty LOC and AT get the tubes from the same suplier, the liner and the loc tube are identicle and even so, modifications are allowed where I fly, but thanks for your input also :-) and Thanks Jerry for reminding them they forgot to mention it was changed to off topic :-) Le
Reply to
BigRockets

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.